Antiviral Activity of Oral JNJ-53718678 in Healthy Adult Volunteers Challenged With Respiratory Syncytial Virus: A Placebo-Controlled Study

Antiviral Activity of Oral JNJ-53718678 in Healthy Adult Volunteers Challenged With Respiratory... Abstract Background Respiratory syncytial virus (RSV) disease has no effective treatment. JNJ-53718678 is a fusion inhibitor with selective activity against RSV. Methods After confirmation of RSV infection or 5 days after inoculation with RSV, participants (n = 69) were randomized to JNJ-53718678 75 mg (n = 15), 200 mg (n = 17), 500 mg (n = 18), or placebo (n = 17) orally once daily for 7 days. Antiviral effects were evaluated by assessing RSV RNA viral load (VL) area under the curve (AUC) from baseline (before the first dose) until discharge, time-to-peak VL, duration of viral shedding, clinical symptoms, and quantity of nasal secretions. Results Mean VL AUC was lower for individuals treated with different doses of JNJ-53718678 versus placebo (203.8–253.8 vs 432.8 log10 PFUe.hour/mL). Also, mean peak VL, time to peak VL, duration of viral shedding, mean overall symptom score, and nasal secretion weight were lower in each JNJ-53718678–treated group versus placebo. No clear exposure–response relationship was observed. Three participants discontinued due to treatment-emergent adverse events of grade 2 and 1 electrocardiogram change (JNJ-53718678 75 mg and 200 mg, respectively) and grade 2 urticaria (placebo). Conclusions JNJ-53718678 at all 3 doses substantially reduced VL and clinical disease severity, thus establishing clinical proof of concept and the compound’s potential as a novel RSV treatment. Clinical trials registration ClinicalTrials.gov: NCT02387606; EudraCT number: 2014-005041-41. acute lower respiratory tract infection (ALRTI), challenge, respiratory syncytial virus (RSV), RSV fusion inhibitor Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in children and infants and is responsible for the majority of childhood hospitalizations [1, 2]. Adults are also affected; specifically, the elderly, those who are immunocompromised, and those with comorbid conditions are at higher risk of severe RSV infections [3, 4]. Despite the substantial medical and economic burden, treatment options for RSV-associated bronchiolitis and pneumonia are limited [5, 6] and mainly consist of supportive care. Although vaccination strategies for RSV prevention are being widely investigated, an effective RSV vaccine is not available. Palivizumab, an RSV-specific monoclonal antibody, is approved as a prophylactic for RSV disease but only in a small subgroup of pediatric patients at risk [7]. The lack of available RSV interventions presents an opportunity for investigating small-molecule antivirals. Small-molecule fusion inhibitors are a potent class of compounds that exhibit inhibitory activity against RSV by binding to the viral fusion (F) glycoprotein [8–10]. Several molecules in this class have been studied in clinical trials with limited success, and few are currently under development [11, 12]. We recently discovered JNJ-53718678, a selective and potent RSV F protein inhibitor [13]. Subnanomolar activity has been demonstrated in cellular infection models, and in neonatal lambs, JNJ-53718678 and a close analog have shown substantial inhibition of viral titers and a dramatic reduction of RSV-associated lung pathology after early as well as delayed treatment of animals [13]. In the first-in-human study (53718678RSV1001) conducted in 45 healthy adults with doses ranging up to 1000 mg/day, JNJ-53718678 was well tolerated both at single and multiple oral doses given up to 8 days, with mostly mild and reversible side effects. The pharmacokinetic (PK) study findings of JNJ-53718678 based on median time to peak concentration (Tmax) of 1 hour, half-life (t1/2) of 6.5–10.5 hours, steady state achieving on day 2, and linear PK across all dose ranges support once-daily dosing. The compound is currently in development for the treatment of RSV infection in the pediatric population (NCT02593851). The phase 2a, single-center study reported here was conducted with the primary objective of evaluating the antiviral effect of repeated oral dosing of JNJ-53718678 compared with placebo in healthy adult participants infected through inoculation with RSV-A Memphis 37b virus. The secondary objectives included an assessment of clinical symptoms, safety, and PK of JNJ-53718678. METHODS Study Design This was a phase 2a, randomized, double-blind, placebo-controlled, single-center study with an 8-week screening phase (day −56 to −3), a 2-week quarantine phase (quarantine entry [day −2 or −1] to discharge [day 13]), and a follow-up phase (day 15 [±1] and 28 [±3]) (Figure 1). In cohort 1, participants (n = 35) were randomized (1:1:1) to once-daily placebo, JNJ-53718678 200 mg, or JNJ-53718678 500 mg. Nasal wash samples were collected twice daily, and the antiviral activity was examined by determining RSV nasal viral load (VL) using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) [11, 14]. Safety parameters, PK, clinical symptoms, and mucus weight were also evaluated. Data from cohort 1 were reviewed following completion of day 13, which determined the dose regimens and the timing of treatment start in cohort 2. In cohort 2, participants (n = 32) were randomized (1:2:1:1) to once-daily placebo, JNJ-53718678 75 mg, JNJ-53718678 200 mg, or JNJ-53718678 500 mg orally once daily for 7 days. After completion of day 13 of cohort 2, a similar interim analysis was performed as for cohort 1. A final analysis was performed after the last visit of the last participant. Figure 1. View largeDownload slide Study design and patient disposition. The intent to treat-infected (ITT-I) analysis set (for efficacy analysis) included all participants challenged by virus inoculation with a positive respiratory syncytial virus (RSV) viral load (VL) value (measured with quantitative reverse-transcriptase polymerase chain reaction assay) immediately prior to first dosing or with >2 positive RSV VL values after the first administration of study medication and who received at least 1 dose of JNJ-53718678 or placebo. †Dosing was started 12 hours after a participant tested positive for respiratory syncytial virus (RSV; from day 2 onwards) or at day 6 if not positive. ‡Eleven participants were randomized to placebo in cohort 1 (of which 1 was not dosed), and 6 were randomized to placebo in cohort 2. §Fifteen participants received JNJ-53718678 75 mg in cohort 2. ¶Eleven participants in cohort 1 and 6 in cohort 2 received JNJ-53718678 200 mg. #Thirteen participants in cohort 1 and 5 in cohort 2 received JNJ-53718678 500 mg. Abbreviations: AE, adverse event; ITT-I, intent-to-treat-infected; qd, once daily; RSV, respiratory syncytial virus. Figure 1. View largeDownload slide Study design and patient disposition. The intent to treat-infected (ITT-I) analysis set (for efficacy analysis) included all participants challenged by virus inoculation with a positive respiratory syncytial virus (RSV) viral load (VL) value (measured with quantitative reverse-transcriptase polymerase chain reaction assay) immediately prior to first dosing or with >2 positive RSV VL values after the first administration of study medication and who received at least 1 dose of JNJ-53718678 or placebo. †Dosing was started 12 hours after a participant tested positive for respiratory syncytial virus (RSV; from day 2 onwards) or at day 6 if not positive. ‡Eleven participants were randomized to placebo in cohort 1 (of which 1 was not dosed), and 6 were randomized to placebo in cohort 2. §Fifteen participants received JNJ-53718678 75 mg in cohort 2. ¶Eleven participants in cohort 1 and 6 in cohort 2 received JNJ-53718678 200 mg. #Thirteen participants in cohort 1 and 5 in cohort 2 received JNJ-53718678 500 mg. Abbreviations: AE, adverse event; ITT-I, intent-to-treat-infected; qd, once daily; RSV, respiratory syncytial virus. After screening, eligible participants were admitted to quarantine unit on study day −2 or −1 and were inoculated intranasally with the RSV-A Memphis 37b virus on study day 0. Within 12 hours after confirmation of RSV positivity in nasal wash samples using a qualitative PCR (Simplexa Flu A/B & RSV assay, Focus Diagnostics), or in the morning of study day 6 if remaining RSV-negative, participants were randomized to JNJ-53718678 or placebo and received treatment for 7 days. The study drug was administered as an oral solution within 10 minutes after completing a standardized meal. Participants remained in quarantine until day 13 and were only discharged if virus was not detectable (negative rapid antigen test). If symptoms were present but no virus was detected, participants were discharged at the investigator’s discretion. Study Participants Healthy volunteers were eligible if they were 18–45 years old with a body mass index of >18 kg/m2, serosuitable for RSV within 57 days before inoculation (cut-off RSV antibody level < 1403), and adhered to contraceptive measures. Participants with previous experimental inoculation with a Paramyxoviridae were excluded. Participants symptomatic with an acute respiratory infection at admission (Study day −1 or −2) were also excluded. The study was conducted under the ethical principles that have their origin in the Declaration of Helsinki, the International Conference on Harmonization Good Clinical Practices, and applicable regulatory requirements. All participants provided written informed consent to participate in the study. Endpoints The primary efficacy endpoint was the area under the curve (AUC) for RSV VL in nasal washes determined by qRT-PCR from baseline (last value before the first dosing) until discharge (day 13). The secondary endpoints included nasal wash RSV VL as determined by plaque (culture) assay, RSV VL over time, peak RSV VL, time-to-peak RSV VL, and duration of viral shedding measured using qRT-PCR assay; the effect of JNJ-53718678 on clinical symptoms reported as the total clinical symptom score, time-to-peak VL, and duration of peak symptom score; total weight of mucus produced and number of tissues used; and safety and tolerability. Assessments Viral load was measured from nasal washes, twice daily, approximately 12 hours apart from the first day after inoculation until dosing day 7, and once in the morning on days 13, 15, and 28. Nasal wash samples were collected for qRT-PCR and plaque assays within 30 minutes prior to dosing of study drug or at approximately the same dosing time if a participant was not dosed. In the qRT-PCR assay, the viral RNA was extracted from the nasal wash, complementary DNA was generated, and qRT-PCR of the N gene of the RSV strain was performed to evaluate the presence of the RSV in the nasal wash [11, 14]. The results of the qRT-PCR were expressed in log10 plaque-forming unit (PFU) equivalents (PFUe) per milliliter. For the plaque assay, serial dilutions of the nasal wash samples were produced and then added to tissue culture plates containing Hep-2 cell monolayers. Plates were then incubated at 37°C for 6 days. After incubation, the log10 PFU per milliliter of the sample was calculated [15]. Clinical symptoms of RSV infection were assessed based on self-evaluation of 10 symptoms (runny nose, stuffed nose, sneezing, sore throat, earache, malaise, cough, shortness of breath, headache, and joint/muscle ache) on a score of 0 (“I have no symptoms”) to 3 (“It’s quite bothersome most or all of the time and it stops me from participating in activities”) on a Symptom Diary Card filled in thrice daily from admission to quarantine until end of dosing (day 8) and at discharge (day 13) [16, 17]. Mucus (nasal secretion) collected on nasal tissues was weighed, and the number of tissues used was counted from admission to quarantine, before viral inoculation, and from day 1 through to discharge. Venous blood samples were collected at specific timepoints on days 1, 3, 5, 6, and 7, on dosing day 1 (before dosing and 0.5, 1, 2, 4, 8, and 24 hours after dosing), on dosing days 3, 5, and 6 (before dosing), and on dosing day 7 (before dosing and 0.5, 1, 1.5, 2, 4, 8, 12, and 24 hours after dosing). Concentrations of JNJ-53718678 were measured using a validated, specific, and sensitive liquid chromatography–tandem mass spectrometry/mass spectrometry (LC-MS/MS) method with a lower limit of quantification of 5.00 (plasma and whole blood). The following individual JNJ-53718678 PK parameters were calculated using actual sampling times and applying linear-linear trapezoidal summation: on day 1 and day 7, Cmax (maximum observed analyte concentration), Tmax (actual sampling time to reach the maximum observed analyte concentration), and AUC24h (area under the time concentration curve in 24-h period) were derived, and additionally on day 7, Cmin (minimum observed analyte concentration) was reported. Safety assessments included the recording of treatment-emergent adverse events (TEAEs), clinical laboratory tests, electrocardiograms (ECGs), and vital sign assessments. Events of interest included the coagulation system (prothrombin and activated partial thromboplastin time) as well as hepatobiliary toxicities (alanine aminotransferase, aspartate aminotransferase, bilirubin). Grading of laboratory abnormalities was done according to the Division of Microbiology and Infectious Diseases toxicity grading list [18]. Statistical Analyses Efficacy analyses were performed in the intent-to-treat-infected (ITT-I) population, defined as all participants with virus inoculation and with a positive qRT-PCR VL value either immediately before first dosing or with >2 positive VL values after the first administration of study medication, and who received at least 1 dose of study drug. Viral load over time was individually evaluated and summarized using descriptive statistics. The least-squares (LS) mean RSV VL AUC for each treatment group was estimated with a general linear mixed model, including treatment as fixed effect and controlling for baseline RSV VL. A 95% confidence interval (CI) was constructed around the difference between the LS mean of each dose level and placebo. Secondary efficacy endpoints were analyzed using descriptive statistics; mean difference and CIs were calculated where appropriate. Kaplan–Meier curves were produced to describe the time-to-event data graphically. The total symptom score was determined per time point as a composite (sum) of 10 self-reported symptoms on the Symptom Diary Card. Descriptive statistics were calculated for the plasma concentrations of JNJ-53718678 and the derived PK parameters, as applicable. The demographic, baseline characteristics and safety analyses were performed in the intent-to-treat (ITT) population, defined as all participants with virus inoculation receiving at least 1 dose of study drug. Safety parameters were summarized using descriptive statistics and frequency tabulations. RESULTS Of the 113 healthy volunteers screened, 69 were challenged with the RSV-A Memphis 37b virus. Two participants discontinued before randomization to active drug due to adverse events (AEs) that occurred after viral inoculation. Of 67 randomized, one participant in the placebo group discontinued due to an AE before dosing; hence this participant was not included in the ITT population (Figure 1). The ITT population included 66 participants randomized and dosed with once-daily JNJ-53718678 75 mg (n = 15), JNJ-53718678 200 mg (n = 17), JNJ-53718678 500 mg (n = 18), or placebo (n = 16). The ITT-I population included 45 participants who received JNJ-53718678 75 mg (n = 9), JNJ-53718678 200 mg (n = 12), JNJ-53718678 500 mg (n = 12), or placebo (n = 12). The demographic and baseline characteristics were similar in the ITT and ITT-I populations (Supplementary Table 1). Efficacy The mean RSV VL AUC from baseline until discharge in the JNJ-53718678 75-mg, JNJ-53718678 200-mg, and JNJ-53718678 500-mg dose groups was reduced by 44%, 53%, and 41%, respectively, relative to placebo, with a significant reduction only in the 200-mg group (P = .02) (Table 1). Considerable variability was observed in all groups, and no clear dose–response relationship was found. Similar results were observed using the plaque assay data (Table 1). The mean RSV VL AUC over the 7 dosing days was also lower in the JNJ-53718678 groups compared with placebo (Supplementary Tables 2 and 3). Table 1. Respiratory Syncytial Virus Viral Load Area Under the Curve From Baseline Until Discharge (Intent-to-Treat-Infected Analysis Set)   Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …    Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …  Abbreviations: AUC, area under the curve; CI, confidence interval; PFU, plaque-forming unit; PFUe, plaque-forming unit equivalent; qd, once daily; VL, viral load. aMeans and confidence intervals for means based on least squares estimates. bUsing quantitative reverse-transcriptase polymerase chain reaction. cUsing plaque assay. VL, viral load; AUC, area under the curve View Large Table 1. Respiratory Syncytial Virus Viral Load Area Under the Curve From Baseline Until Discharge (Intent-to-Treat-Infected Analysis Set)   Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …    Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …  Abbreviations: AUC, area under the curve; CI, confidence interval; PFU, plaque-forming unit; PFUe, plaque-forming unit equivalent; qd, once daily; VL, viral load. aMeans and confidence intervals for means based on least squares estimates. bUsing quantitative reverse-transcriptase polymerase chain reaction. cUsing plaque assay. VL, viral load; AUC, area under the curve View Large After treatment start, mean RSV VL increased during the first 24 hours, followed by a decline in the active treatment groups on day 2 and more gradual decline afterward. Mean RSV VL increased for 4 days following treatment initiation in the placebo group and decreased later (Figure 2A). The peak RSV VLs in the JNJ-53718678 groups were lower than in the placebo group (Supplementary Table 2 and 3). Figure 2. View largeDownload slide View largeDownload slide A, Mean (SE) viral load over time estimated using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) assay (intent-to-treat-infected (ITT-I) population). B, Time to peak viral load using qRT-PCR assay (ITT-I population). C, Overall total symptom score (ITT-I population). D, Time to peak symptom score (ITT-I population). Abbreviation: qd, once daily. Figure 2. View largeDownload slide View largeDownload slide A, Mean (SE) viral load over time estimated using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) assay (intent-to-treat-infected (ITT-I) population). B, Time to peak viral load using qRT-PCR assay (ITT-I population). C, Overall total symptom score (ITT-I population). D, Time to peak symptom score (ITT-I population). Abbreviation: qd, once daily. The time to peak VL, as measured from the last value before the first dose and the duration of viral shedding, was shorter in the JNJ-53718678 groups versus the placebo group, both for qRT-PCR (Figure 2B) and the plaque assay results (Supplementary Figure 1A and B). The proportion of participants with detectable virus as measured by qRT-PCR increased in all treatment groups up to 24 hours after baseline; thereafter, a decrease was observed in all treatment groups with a faster decline in active treatment groups versus placebo group. At day 6, 12.5%, 8.3%, and 9.1% of the participants had detectable virus in the JNJ-53718678 75-mg, JNJ-53718678 200-mg, and JNJ-53718678 500-mg groups, respectively, versus 41.7% in the placebo group. The severity of RSV infection was lower in the active treatment groups than in the placebo group as suggested by the mean overall total symptom score (sum of all total scores from day 1 to day 13) over time (JNJ-53718678 75 mg: 6.4 [95% CI, −12.3 to 25.2]; JNJ-53718678 200 mg: 23.1 [95% CI, 6.9–39.3]; JNJ-53718678 500 mg: 14.8 [95% CI, −1.4 to 31.1]; placebo: 36.6 [95% CI, 20.4–52.8]) (Figure 2C), and the peak total symptom score (maximum of the total symptom score values for 1 participant from baseline up to discharge). The time to peak symptom score tended to be shorter in the JNJ-53718678 treatment groups than in the placebo group (Figure 2D). The duration of symptoms was shorter in the JNJ-53718678 75-mg and JNJ-53718678 200-mg groups, but not in the 500-mg group, versus placebo. The overall mucus weight (Supplementary Figure 2A) and overall number of tissues used (Supplementary Figure 2B) during the treatment phase were lower in the JNJ-53718678 treatment groups compared with the placebo group. Pharmacokinetics The key plasma exposure measures are reported in Table 2. Pharmacokinetics parameters were consistent with previous observations [19]. On day 7, mean Cmax and AUC24h of JNJ-53718678 increased roughly proportionally with increasing doses. No meaningful accumulation was observed. Table 2. Pharmacokinetic Observations After Oral Administration of JNJ-53718678 75 mg (Cohort 1), 200 mg, and 500 mg (Cohort 1 + 2) Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Data are mean + SD, except for Tmax, which is median (range). Abbreviations: AUC24h, area under the time concentration curve in 24-hour period; Cmax, maximum observed analyte concentration; Cmin, minimum observed analyte concentration; qd, once daily; Tmax, actual sampling time to reach the maximum observed analyte concentration. an = 15 for Cmax, Tmax, and AUC24h on day 1 bn = 16 for all pharmacokinetic parameters on day 7. cn = 17 for all pharmacokinetic parameters of day 7. View Large Table 2. Pharmacokinetic Observations After Oral Administration of JNJ-53718678 75 mg (Cohort 1), 200 mg, and 500 mg (Cohort 1 + 2) Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Data are mean + SD, except for Tmax, which is median (range). Abbreviations: AUC24h, area under the time concentration curve in 24-hour period; Cmax, maximum observed analyte concentration; Cmin, minimum observed analyte concentration; qd, once daily; Tmax, actual sampling time to reach the maximum observed analyte concentration. an = 15 for Cmax, Tmax, and AUC24h on day 1 bn = 16 for all pharmacokinetic parameters on day 7. cn = 17 for all pharmacokinetic parameters of day 7. View Large No clear dose (or exposure)–response relationship between plasma parameters (AUC and Ctrough) and AUC RSV VL was observed for the different JNJ-53718678 doses (Supplementary Figures 3 and 4). Safety The most frequently reported TEAEs (>2 participants in any treatment group) were diarrhea, increased blood cholesterol, increased low-density lipoprotein (LDL), and epistaxis (Table 3 and Supplementary Table 4). Three participants discontinued the study due to TEAE: 1 in the 75-mg JNJ 53718678 group due to grade 2 ECG change, 1 in the 200-mg group due to grade 1 ECG change, and 1 in the placebo group due to grade 2 TEAE urticaria. The grade 2 ECG change (change in morphology [from incomplete right bundle branch block]) was noted approximately 22 hours after administration of JNJ-53718678 75 mg on day 2, whereas the grade 1 AE (nonspecific ECG change) was observed about 1 hour after the intake of JNJ-53718678 200 mg on day 3. The grade 2 urticaria was reported on day 3 of dosing (placebo). Table 3. Treatment-Emergent Adverse Events (≥2 Participants in Any Treatment Group) in the Intent-to-Treat Analysis Set System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  Data are provided as n (%). The intent-to-treat set for safety analysis included all participants challenged by virus inoculation and having received at least 1 dose of JNJ-53718678 or placebo. Abbreviation: qd, once daily. View Large Table 3. Treatment-Emergent Adverse Events (≥2 Participants in Any Treatment Group) in the Intent-to-Treat Analysis Set System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  Data are provided as n (%). The intent-to-treat set for safety analysis included all participants challenged by virus inoculation and having received at least 1 dose of JNJ-53718678 or placebo. Abbreviation: qd, once daily. View Large An ECG abnormality of grade 1 abnormally high PR duration was reported in 1 participant receiving placebo. Abnormally high QRS duration was reported in 2 (13.3%) participants in the JNJ-53718678 75-mg group (one each grade 1 and grade 2). A Grade 2 standing diastolic blood pressure was reported in 1 (6.3%) placebo participant. No other vital signs abnormalities of grade 2 or higher were reported. Laboratory abnormalities were grade 1 or 2 and included neutrophil count and blood fibrinogen below the lower limit of normal, prolonged activated partial thromboplastin time, and values above the upper limit of normal for alanine aminotransferase, bilirubin conjugated, cholesterol, LDL cholesterol, creatinine, and C-reactive protein. The only grade 3 AE was increased lipase during the follow-up phase in the placebo group (n = 1; 6.3%). No grade 4 (severe) or serious AEs and deaths were reported during the study. DISCUSSION JNJ-53718678 reduced RSV VL AUC, peak VL, and the duration of viral shedding, and these findings correlated with relatively lower clinical symptom scores and mucus production. Considerable variability was observed within JNJ-53718678 and placebo groups. A greater sample size may have provided a better opportunity to evaluate treatment differences and potential dose–response relationship. No safety concerns were noted; however, larger studies are needed before any firm conclusions about safety can be drawn. Although ECG abnormalities led to discontinuation of study medication in 2 participants, subsequent cardiologist consultation for these 2 participants, including review of their study-collected ECGs, indicated that the observed ECG findings represented normal variability in otherwise healthy individuals (data not shown). The severity of the AEs was at most grade 2 (moderate), and the only reported AE of higher grading was grade 3 increased lipase in a placebo-treated participant during the follow-up phase. Epistaxis has been observed in other challenge studies [11, 17] and has been related to the inoculation and subsequent infection, as well as to the numerous nasal washes. The other most frequently reported AEs (increased blood cholesterol, increased LDL) were associated with the objective testing of laboratory parameters and tend to vary in the populations studied in phase 1 trials. Diarrhea was also observed in the placebo group and considered related to the increasing amount of hydroxylpropyl-β-cyclodextrin in the formulation, a known osmotic agent [20]. The plasma PK in this study were in line with that of the earlier study [19]. No exposure–response relationship was observed. Comparison of in vivo trough levels obtained in the human challenge study to that of in vitro 90% effective concentration (EC90) levels of 26 ng/mL suggest that current median trough levels at day 7 are approximately 2-, 2.5-, and 10-fold higher for 75 mg, 200 mg and 50- mg once-daily regimens, respectively, which could imply that maximal effect is already achieved at the lowest dose. As compared with the human challenge study, naturally infected adults had similar VLs [21, 22], but infants demonstrated higher peak VLs, slower viral clearance, and greater viral AUC [23–26]. The severity of RSV disease, whether assessed by hospital admission, prolonged hospitalization, admission to the intensive care unit, or respiratory failure, is strongly correlated with greater RSV load, and a quick decrease in VL may determine the time to disease resolution [27]. However, even though a correlation has been shown between VL and symptom scores, the symptom severity in challenged participants seldom leads to hospital admission. In addition to small sample size, there are some limitations in this human challenge study that need to be considered. The participants enrolled were mostly men and were white, which is common for phase 1 studies in healthy volunteers. This may also be due to the criterion for women to be of nonchildbearing potential and also to the study location (United Kingdom). Apart from these, the start of treatment 12 hours after the established RSV infection as in this study is difficult to replicate in clinical practice because patients do not present to their healthcare provider at the very onset of symptoms. Consequently, in patients who are naturally infected, the course of infection at the time of initiation of the antiviral will likely be more advanced. In infants, inflammatory processes do not appear to be major contributors to disease severity at the time of severe lung disease [28, 29]. However, it is likely that virus-driven inflammatory responses may be contributing factor at later time points during infection. Therefore, the present findings cannot directly be extrapolated to a clinical setting. Translating the clinical findings from healthy challenged adults to a natural -infected pediatric population also remains a challenge, especially because this model assessed nasal RSV VL. It is not clear yet how this may correlate with VL in the lower airways and lungs of adult and pediatric patients presenting with lower respiratory tract infection, although recent data obtained in neonatal lambs suggest that treating patients relatively late after their onset of symptoms may have a clinical benefit [13]. In that recent study, oral treatment of animals with JNJ-53718678 or a very close analog efficiently inhibited viral replication as well as RSV-associated lung damage, even when treatment was delayed until day 3 after an acute lower respiratory tract infection was established and prominent external signs of RSV illness had developed. In conclusion, JNJ-53718678 has demonstrated an effective inhibition of viral replication and reduction in clinical disease severity in infected healthy adults. Clinical trials, including formal dose range-finding studies evaluating the effectiveness and safety of JNJ-53718678 in larger naturally infected populations, are needed to fully evaluate clinical outcomes and therapeutic value. Supplementary Data Supplementary materials are available at The Journal of Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author. Notes Author contribution. S. R., D. H., N. L., K. M., M. S., and R. V. participated in the study design, participated in study governance, and supervised study recruitment, monitoring of data quality, data analysis, and interpretation of results. D. R. and A. K. were involved in study design. A. B. and J. F. S. were involved in project management, sample and inoculum virus management, screening and intent-to-dose assays, and generating the viral load data in cell-based (plaque) assays. J. D. participated in the study design and viral load data generation quantitative PCR. Y. K. directed antiviral resistance detection and assays. L. H. and E. A. M. managed and generated the quantitative virological assessments. In addition, all authors contributed to the interpretation of study results. All authors meet ICMJE criteria and all those who fulfilled those criteria are listed as authors. All authors had access to the study data, provided direction and comments on the manuscript, made the final decision about where to publish these data, and approved submission to this journal. Finally, the authors confirm that they have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. Acknowledgements. The authors thank Shivangi Gupta, PhD, and Ramji Narayanan, M Pharm, ISMPP CMPP (SIRO Clinpharm Pvt. Ltd., Thane, India), for writing assistance and Bradford Challis, PhD (Janssen Research & Development, LLC, New Jersey), for additional editorial assistance. Financial support. This work was funded by Janssen Sciences, Ireland. Potential conflicts of interest. S. R., D. H., N. L., K. M., B. R., D. R., A. K., M. S., and R. V. are employees of Janssen Research & Development and may hold company stock. A. B. and J. F. S. are employees of hVIVO services. All other authors report no conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. Presented in part: IDWeek 2016, 26–30 October 2016, New Orleans, Louisiana. Abstract 650, poster 266. 10th International Respiratory Syncytial Virus Symposium, 28 September–1 October 2016, Patagonia, Argentina. Poster 262. References 1. Shi T, McAllister DA, O’Brien KLet al.   Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study. Lancet  2017; 390: 946– 58. Google Scholar CrossRef Search ADS PubMed  2. Nair H, Nokes DJ, Gessner BDet al.   Global burden of acute lower respiratory infections due to respiratory syncytial virus in young children: a systematic review and meta-analysis. Lancet  2010; 375: 1545– 55. Google Scholar CrossRef Search ADS PubMed  3. Falsey AR, Hennessey PA, Formica MA, Cox C, Walsh EE. Respiratory syncytial virus infection in elderly and high-risk adults. N Engl J Med  2005; 352: 1749– 59. Google Scholar CrossRef Search ADS PubMed  4. Chemaly RF, Shah DP, Boeckh MJ. Management of respiratory viral infections in hematopoietic cell transplant recipients and patients with hematologic malignancies. Clin Infect Dis  2014; 59( suppl 5): S344– 51. Google Scholar CrossRef Search ADS PubMed  5. Empey KM, Peebles RSJr, Kolls JK. Pharmacologic advances in the treatment and prevention of respiratory syncytial virus. Clin Infect Dis  2010; 50: 1258– 67. Google Scholar CrossRef Search ADS PubMed  6. Roymans D, Koul A. Respiratory syncytial virus: a prioritized or neglected target? Future Med Chem  2010; 2: 1523– 7. Google Scholar CrossRef Search ADS PubMed  7. Turner TL, Kopp BT, Paul G, Landgrave LC, Hayes DJr, Thompson R. Respiratory syncytial virus: current and emerging treatment options. Clinicoecon Outcomes Res  2014; 6: 217– 25. Google Scholar CrossRef Search ADS PubMed  8. Costello HM, Ray WC, Chaiwatpongsakorn S, Peeples ME. Targeting RSV with vaccines and small molecule drugs. Infect Disord Drug Targets  2012; 12: 110– 28. 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Roymans D, Alnajjar SS, Battles MBet al.   Therapeutic efficacy of a respiratory syncytial virus fusion inhibitor. Nat Commun  2017; 8: 167. Google Scholar CrossRef Search ADS PubMed  14. Perkins SM, Webb DL, Torrance SAet al.   Comparison of a real-time reverse transcriptase PCR assay and a culture technique for quantitative assessment of viral load in children naturally infected with respiratory syncytial virus. J Clin Microbiol  2005; 43: 2356– 62. Google Scholar CrossRef Search ADS PubMed  15. Devincenzo JP. Natural infection of infants with respiratory syncytial virus subgroups A and B: a study of frequency, disease severity, and viral load. Pediatr Res  2004; 56: 914– 7. Google Scholar CrossRef Search ADS PubMed  16. DeVincenzo J, Lambkin-Williams R, Wilkinson Tet al.   A randomized, double-blind, placebo-controlled study of an RNAi-based therapy directed against respiratory syncytial virus. Proc Natl Acad Sci U S A  2010; 107: 8800– 5. 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Food Chem Toxicol  2005; 43: 1451– 9. Google Scholar CrossRef Search ADS PubMed  21. Duncan CB, Walsh EE, Peterson DR, Lee FE, Falsey AR. Risk factors for respiratory failure associated with respiratory syncytial virus infection in adults. J Infect Dis  2009; 200: 1242– 6. Google Scholar CrossRef Search ADS PubMed  22. Walsh EE, Peterson DR, Kalkanoglu AE, Lee FE, Falsey AR. Viral shedding and immune responses to respiratory syncytial virus infection in older adults. J Infect Dis  2013; 207: 1424– 32. Google Scholar CrossRef Search ADS PubMed  23. Buckingham SC, Bush AJ, Devincenzo JP. Nasal quantity of respiratory syncytical virus correlates with disease severity in hospitalized infants. Pediatr Infect Dis J  2000; 19: 113– 7. Google Scholar CrossRef Search ADS PubMed  24. DeVincenzo JP, El Saleeby CM, Bush AJ. Respiratory syncytial virus load predicts disease severity in previously healthy infants. J Infect Dis  2005; 191: 1861– 8. Google Scholar CrossRef Search ADS PubMed  25. 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A new direction in understanding the pathogenesis of respiratory syncytial virus bronchiolitis: how real infants suffer. J Infect Dis  2007; 195: 1084– 6. Google Scholar CrossRef Search ADS PubMed  © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Infectious Diseases Oxford University Press

Antiviral Activity of Oral JNJ-53718678 in Healthy Adult Volunteers Challenged With Respiratory Syncytial Virus: A Placebo-Controlled Study

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Oxford University Press
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© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
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0022-1899
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10.1093/infdis/jiy227
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Abstract

Abstract Background Respiratory syncytial virus (RSV) disease has no effective treatment. JNJ-53718678 is a fusion inhibitor with selective activity against RSV. Methods After confirmation of RSV infection or 5 days after inoculation with RSV, participants (n = 69) were randomized to JNJ-53718678 75 mg (n = 15), 200 mg (n = 17), 500 mg (n = 18), or placebo (n = 17) orally once daily for 7 days. Antiviral effects were evaluated by assessing RSV RNA viral load (VL) area under the curve (AUC) from baseline (before the first dose) until discharge, time-to-peak VL, duration of viral shedding, clinical symptoms, and quantity of nasal secretions. Results Mean VL AUC was lower for individuals treated with different doses of JNJ-53718678 versus placebo (203.8–253.8 vs 432.8 log10 PFUe.hour/mL). Also, mean peak VL, time to peak VL, duration of viral shedding, mean overall symptom score, and nasal secretion weight were lower in each JNJ-53718678–treated group versus placebo. No clear exposure–response relationship was observed. Three participants discontinued due to treatment-emergent adverse events of grade 2 and 1 electrocardiogram change (JNJ-53718678 75 mg and 200 mg, respectively) and grade 2 urticaria (placebo). Conclusions JNJ-53718678 at all 3 doses substantially reduced VL and clinical disease severity, thus establishing clinical proof of concept and the compound’s potential as a novel RSV treatment. Clinical trials registration ClinicalTrials.gov: NCT02387606; EudraCT number: 2014-005041-41. acute lower respiratory tract infection (ALRTI), challenge, respiratory syncytial virus (RSV), RSV fusion inhibitor Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in children and infants and is responsible for the majority of childhood hospitalizations [1, 2]. Adults are also affected; specifically, the elderly, those who are immunocompromised, and those with comorbid conditions are at higher risk of severe RSV infections [3, 4]. Despite the substantial medical and economic burden, treatment options for RSV-associated bronchiolitis and pneumonia are limited [5, 6] and mainly consist of supportive care. Although vaccination strategies for RSV prevention are being widely investigated, an effective RSV vaccine is not available. Palivizumab, an RSV-specific monoclonal antibody, is approved as a prophylactic for RSV disease but only in a small subgroup of pediatric patients at risk [7]. The lack of available RSV interventions presents an opportunity for investigating small-molecule antivirals. Small-molecule fusion inhibitors are a potent class of compounds that exhibit inhibitory activity against RSV by binding to the viral fusion (F) glycoprotein [8–10]. Several molecules in this class have been studied in clinical trials with limited success, and few are currently under development [11, 12]. We recently discovered JNJ-53718678, a selective and potent RSV F protein inhibitor [13]. Subnanomolar activity has been demonstrated in cellular infection models, and in neonatal lambs, JNJ-53718678 and a close analog have shown substantial inhibition of viral titers and a dramatic reduction of RSV-associated lung pathology after early as well as delayed treatment of animals [13]. In the first-in-human study (53718678RSV1001) conducted in 45 healthy adults with doses ranging up to 1000 mg/day, JNJ-53718678 was well tolerated both at single and multiple oral doses given up to 8 days, with mostly mild and reversible side effects. The pharmacokinetic (PK) study findings of JNJ-53718678 based on median time to peak concentration (Tmax) of 1 hour, half-life (t1/2) of 6.5–10.5 hours, steady state achieving on day 2, and linear PK across all dose ranges support once-daily dosing. The compound is currently in development for the treatment of RSV infection in the pediatric population (NCT02593851). The phase 2a, single-center study reported here was conducted with the primary objective of evaluating the antiviral effect of repeated oral dosing of JNJ-53718678 compared with placebo in healthy adult participants infected through inoculation with RSV-A Memphis 37b virus. The secondary objectives included an assessment of clinical symptoms, safety, and PK of JNJ-53718678. METHODS Study Design This was a phase 2a, randomized, double-blind, placebo-controlled, single-center study with an 8-week screening phase (day −56 to −3), a 2-week quarantine phase (quarantine entry [day −2 or −1] to discharge [day 13]), and a follow-up phase (day 15 [±1] and 28 [±3]) (Figure 1). In cohort 1, participants (n = 35) were randomized (1:1:1) to once-daily placebo, JNJ-53718678 200 mg, or JNJ-53718678 500 mg. Nasal wash samples were collected twice daily, and the antiviral activity was examined by determining RSV nasal viral load (VL) using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) [11, 14]. Safety parameters, PK, clinical symptoms, and mucus weight were also evaluated. Data from cohort 1 were reviewed following completion of day 13, which determined the dose regimens and the timing of treatment start in cohort 2. In cohort 2, participants (n = 32) were randomized (1:2:1:1) to once-daily placebo, JNJ-53718678 75 mg, JNJ-53718678 200 mg, or JNJ-53718678 500 mg orally once daily for 7 days. After completion of day 13 of cohort 2, a similar interim analysis was performed as for cohort 1. A final analysis was performed after the last visit of the last participant. Figure 1. View largeDownload slide Study design and patient disposition. The intent to treat-infected (ITT-I) analysis set (for efficacy analysis) included all participants challenged by virus inoculation with a positive respiratory syncytial virus (RSV) viral load (VL) value (measured with quantitative reverse-transcriptase polymerase chain reaction assay) immediately prior to first dosing or with >2 positive RSV VL values after the first administration of study medication and who received at least 1 dose of JNJ-53718678 or placebo. †Dosing was started 12 hours after a participant tested positive for respiratory syncytial virus (RSV; from day 2 onwards) or at day 6 if not positive. ‡Eleven participants were randomized to placebo in cohort 1 (of which 1 was not dosed), and 6 were randomized to placebo in cohort 2. §Fifteen participants received JNJ-53718678 75 mg in cohort 2. ¶Eleven participants in cohort 1 and 6 in cohort 2 received JNJ-53718678 200 mg. #Thirteen participants in cohort 1 and 5 in cohort 2 received JNJ-53718678 500 mg. Abbreviations: AE, adverse event; ITT-I, intent-to-treat-infected; qd, once daily; RSV, respiratory syncytial virus. Figure 1. View largeDownload slide Study design and patient disposition. The intent to treat-infected (ITT-I) analysis set (for efficacy analysis) included all participants challenged by virus inoculation with a positive respiratory syncytial virus (RSV) viral load (VL) value (measured with quantitative reverse-transcriptase polymerase chain reaction assay) immediately prior to first dosing or with >2 positive RSV VL values after the first administration of study medication and who received at least 1 dose of JNJ-53718678 or placebo. †Dosing was started 12 hours after a participant tested positive for respiratory syncytial virus (RSV; from day 2 onwards) or at day 6 if not positive. ‡Eleven participants were randomized to placebo in cohort 1 (of which 1 was not dosed), and 6 were randomized to placebo in cohort 2. §Fifteen participants received JNJ-53718678 75 mg in cohort 2. ¶Eleven participants in cohort 1 and 6 in cohort 2 received JNJ-53718678 200 mg. #Thirteen participants in cohort 1 and 5 in cohort 2 received JNJ-53718678 500 mg. Abbreviations: AE, adverse event; ITT-I, intent-to-treat-infected; qd, once daily; RSV, respiratory syncytial virus. After screening, eligible participants were admitted to quarantine unit on study day −2 or −1 and were inoculated intranasally with the RSV-A Memphis 37b virus on study day 0. Within 12 hours after confirmation of RSV positivity in nasal wash samples using a qualitative PCR (Simplexa Flu A/B & RSV assay, Focus Diagnostics), or in the morning of study day 6 if remaining RSV-negative, participants were randomized to JNJ-53718678 or placebo and received treatment for 7 days. The study drug was administered as an oral solution within 10 minutes after completing a standardized meal. Participants remained in quarantine until day 13 and were only discharged if virus was not detectable (negative rapid antigen test). If symptoms were present but no virus was detected, participants were discharged at the investigator’s discretion. Study Participants Healthy volunteers were eligible if they were 18–45 years old with a body mass index of >18 kg/m2, serosuitable for RSV within 57 days before inoculation (cut-off RSV antibody level < 1403), and adhered to contraceptive measures. Participants with previous experimental inoculation with a Paramyxoviridae were excluded. Participants symptomatic with an acute respiratory infection at admission (Study day −1 or −2) were also excluded. The study was conducted under the ethical principles that have their origin in the Declaration of Helsinki, the International Conference on Harmonization Good Clinical Practices, and applicable regulatory requirements. All participants provided written informed consent to participate in the study. Endpoints The primary efficacy endpoint was the area under the curve (AUC) for RSV VL in nasal washes determined by qRT-PCR from baseline (last value before the first dosing) until discharge (day 13). The secondary endpoints included nasal wash RSV VL as determined by plaque (culture) assay, RSV VL over time, peak RSV VL, time-to-peak RSV VL, and duration of viral shedding measured using qRT-PCR assay; the effect of JNJ-53718678 on clinical symptoms reported as the total clinical symptom score, time-to-peak VL, and duration of peak symptom score; total weight of mucus produced and number of tissues used; and safety and tolerability. Assessments Viral load was measured from nasal washes, twice daily, approximately 12 hours apart from the first day after inoculation until dosing day 7, and once in the morning on days 13, 15, and 28. Nasal wash samples were collected for qRT-PCR and plaque assays within 30 minutes prior to dosing of study drug or at approximately the same dosing time if a participant was not dosed. In the qRT-PCR assay, the viral RNA was extracted from the nasal wash, complementary DNA was generated, and qRT-PCR of the N gene of the RSV strain was performed to evaluate the presence of the RSV in the nasal wash [11, 14]. The results of the qRT-PCR were expressed in log10 plaque-forming unit (PFU) equivalents (PFUe) per milliliter. For the plaque assay, serial dilutions of the nasal wash samples were produced and then added to tissue culture plates containing Hep-2 cell monolayers. Plates were then incubated at 37°C for 6 days. After incubation, the log10 PFU per milliliter of the sample was calculated [15]. Clinical symptoms of RSV infection were assessed based on self-evaluation of 10 symptoms (runny nose, stuffed nose, sneezing, sore throat, earache, malaise, cough, shortness of breath, headache, and joint/muscle ache) on a score of 0 (“I have no symptoms”) to 3 (“It’s quite bothersome most or all of the time and it stops me from participating in activities”) on a Symptom Diary Card filled in thrice daily from admission to quarantine until end of dosing (day 8) and at discharge (day 13) [16, 17]. Mucus (nasal secretion) collected on nasal tissues was weighed, and the number of tissues used was counted from admission to quarantine, before viral inoculation, and from day 1 through to discharge. Venous blood samples were collected at specific timepoints on days 1, 3, 5, 6, and 7, on dosing day 1 (before dosing and 0.5, 1, 2, 4, 8, and 24 hours after dosing), on dosing days 3, 5, and 6 (before dosing), and on dosing day 7 (before dosing and 0.5, 1, 1.5, 2, 4, 8, 12, and 24 hours after dosing). Concentrations of JNJ-53718678 were measured using a validated, specific, and sensitive liquid chromatography–tandem mass spectrometry/mass spectrometry (LC-MS/MS) method with a lower limit of quantification of 5.00 (plasma and whole blood). The following individual JNJ-53718678 PK parameters were calculated using actual sampling times and applying linear-linear trapezoidal summation: on day 1 and day 7, Cmax (maximum observed analyte concentration), Tmax (actual sampling time to reach the maximum observed analyte concentration), and AUC24h (area under the time concentration curve in 24-h period) were derived, and additionally on day 7, Cmin (minimum observed analyte concentration) was reported. Safety assessments included the recording of treatment-emergent adverse events (TEAEs), clinical laboratory tests, electrocardiograms (ECGs), and vital sign assessments. Events of interest included the coagulation system (prothrombin and activated partial thromboplastin time) as well as hepatobiliary toxicities (alanine aminotransferase, aspartate aminotransferase, bilirubin). Grading of laboratory abnormalities was done according to the Division of Microbiology and Infectious Diseases toxicity grading list [18]. Statistical Analyses Efficacy analyses were performed in the intent-to-treat-infected (ITT-I) population, defined as all participants with virus inoculation and with a positive qRT-PCR VL value either immediately before first dosing or with >2 positive VL values after the first administration of study medication, and who received at least 1 dose of study drug. Viral load over time was individually evaluated and summarized using descriptive statistics. The least-squares (LS) mean RSV VL AUC for each treatment group was estimated with a general linear mixed model, including treatment as fixed effect and controlling for baseline RSV VL. A 95% confidence interval (CI) was constructed around the difference between the LS mean of each dose level and placebo. Secondary efficacy endpoints were analyzed using descriptive statistics; mean difference and CIs were calculated where appropriate. Kaplan–Meier curves were produced to describe the time-to-event data graphically. The total symptom score was determined per time point as a composite (sum) of 10 self-reported symptoms on the Symptom Diary Card. Descriptive statistics were calculated for the plasma concentrations of JNJ-53718678 and the derived PK parameters, as applicable. The demographic, baseline characteristics and safety analyses were performed in the intent-to-treat (ITT) population, defined as all participants with virus inoculation receiving at least 1 dose of study drug. Safety parameters were summarized using descriptive statistics and frequency tabulations. RESULTS Of the 113 healthy volunteers screened, 69 were challenged with the RSV-A Memphis 37b virus. Two participants discontinued before randomization to active drug due to adverse events (AEs) that occurred after viral inoculation. Of 67 randomized, one participant in the placebo group discontinued due to an AE before dosing; hence this participant was not included in the ITT population (Figure 1). The ITT population included 66 participants randomized and dosed with once-daily JNJ-53718678 75 mg (n = 15), JNJ-53718678 200 mg (n = 17), JNJ-53718678 500 mg (n = 18), or placebo (n = 16). The ITT-I population included 45 participants who received JNJ-53718678 75 mg (n = 9), JNJ-53718678 200 mg (n = 12), JNJ-53718678 500 mg (n = 12), or placebo (n = 12). The demographic and baseline characteristics were similar in the ITT and ITT-I populations (Supplementary Table 1). Efficacy The mean RSV VL AUC from baseline until discharge in the JNJ-53718678 75-mg, JNJ-53718678 200-mg, and JNJ-53718678 500-mg dose groups was reduced by 44%, 53%, and 41%, respectively, relative to placebo, with a significant reduction only in the 200-mg group (P = .02) (Table 1). Considerable variability was observed in all groups, and no clear dose–response relationship was found. Similar results were observed using the plaque assay data (Table 1). The mean RSV VL AUC over the 7 dosing days was also lower in the JNJ-53718678 groups compared with placebo (Supplementary Tables 2 and 3). Table 1. Respiratory Syncytial Virus Viral Load Area Under the Curve From Baseline Until Discharge (Intent-to-Treat-Infected Analysis Set)   Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …    Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …  Abbreviations: AUC, area under the curve; CI, confidence interval; PFU, plaque-forming unit; PFUe, plaque-forming unit equivalent; qd, once daily; VL, viral load. aMeans and confidence intervals for means based on least squares estimates. bUsing quantitative reverse-transcriptase polymerase chain reaction. cUsing plaque assay. VL, viral load; AUC, area under the curve View Large Table 1. Respiratory Syncytial Virus Viral Load Area Under the Curve From Baseline Until Discharge (Intent-to-Treat-Infected Analysis Set)   Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …    Difference JNJ53718678–Placebo    No.  Meana  Median  95% CIa  Meana  95% CIa  P value  VL AUC from baseline until discharge (log10 PFUe.hour/mL)b  JNJ-53718678 75 mg qd  9  240.3  101.0  (42.3–438.4)  −192.5  (−429.6 to 44.7)  .11  JNJ-53718678 200 mg qd  12  203.8  114.2  (96.7–310.8)  −229.0  (−411.8 to −46.2)  .02  JNJ-53718678 500 mg qd  12  253.8  225.4  (135.4–372.2)  −179.0  (−368.6 to 10.6)  .06  Placebo  12  432.8  484.4  (272.4–593.2)  …  …  …  VL AUC from baseline until discharge (log10 PFU.hour/mL)c  JNJ-53718678 75 mg qd  9  206.6  122.7  (92.4–320.7)  −75.5  (−226.5 to 75.5)  …  JNJ-53718678 200 mg qd  12  150.6  100.6  (51.7–249.5)  −131.5  (−271.3 to 8.3)  …  JNJ-53718678 500 mg qd  12  256.0  239.4  (157.1–354.9)  −26.1  (−165.9 to 113.8)  …  Placebo  12  282.1  297.8  (183.2–380.9)  …  …  …  Abbreviations: AUC, area under the curve; CI, confidence interval; PFU, plaque-forming unit; PFUe, plaque-forming unit equivalent; qd, once daily; VL, viral load. aMeans and confidence intervals for means based on least squares estimates. bUsing quantitative reverse-transcriptase polymerase chain reaction. cUsing plaque assay. VL, viral load; AUC, area under the curve View Large After treatment start, mean RSV VL increased during the first 24 hours, followed by a decline in the active treatment groups on day 2 and more gradual decline afterward. Mean RSV VL increased for 4 days following treatment initiation in the placebo group and decreased later (Figure 2A). The peak RSV VLs in the JNJ-53718678 groups were lower than in the placebo group (Supplementary Table 2 and 3). Figure 2. View largeDownload slide View largeDownload slide A, Mean (SE) viral load over time estimated using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) assay (intent-to-treat-infected (ITT-I) population). B, Time to peak viral load using qRT-PCR assay (ITT-I population). C, Overall total symptom score (ITT-I population). D, Time to peak symptom score (ITT-I population). Abbreviation: qd, once daily. Figure 2. View largeDownload slide View largeDownload slide A, Mean (SE) viral load over time estimated using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) assay (intent-to-treat-infected (ITT-I) population). B, Time to peak viral load using qRT-PCR assay (ITT-I population). C, Overall total symptom score (ITT-I population). D, Time to peak symptom score (ITT-I population). Abbreviation: qd, once daily. The time to peak VL, as measured from the last value before the first dose and the duration of viral shedding, was shorter in the JNJ-53718678 groups versus the placebo group, both for qRT-PCR (Figure 2B) and the plaque assay results (Supplementary Figure 1A and B). The proportion of participants with detectable virus as measured by qRT-PCR increased in all treatment groups up to 24 hours after baseline; thereafter, a decrease was observed in all treatment groups with a faster decline in active treatment groups versus placebo group. At day 6, 12.5%, 8.3%, and 9.1% of the participants had detectable virus in the JNJ-53718678 75-mg, JNJ-53718678 200-mg, and JNJ-53718678 500-mg groups, respectively, versus 41.7% in the placebo group. The severity of RSV infection was lower in the active treatment groups than in the placebo group as suggested by the mean overall total symptom score (sum of all total scores from day 1 to day 13) over time (JNJ-53718678 75 mg: 6.4 [95% CI, −12.3 to 25.2]; JNJ-53718678 200 mg: 23.1 [95% CI, 6.9–39.3]; JNJ-53718678 500 mg: 14.8 [95% CI, −1.4 to 31.1]; placebo: 36.6 [95% CI, 20.4–52.8]) (Figure 2C), and the peak total symptom score (maximum of the total symptom score values for 1 participant from baseline up to discharge). The time to peak symptom score tended to be shorter in the JNJ-53718678 treatment groups than in the placebo group (Figure 2D). The duration of symptoms was shorter in the JNJ-53718678 75-mg and JNJ-53718678 200-mg groups, but not in the 500-mg group, versus placebo. The overall mucus weight (Supplementary Figure 2A) and overall number of tissues used (Supplementary Figure 2B) during the treatment phase were lower in the JNJ-53718678 treatment groups compared with the placebo group. Pharmacokinetics The key plasma exposure measures are reported in Table 2. Pharmacokinetics parameters were consistent with previous observations [19]. On day 7, mean Cmax and AUC24h of JNJ-53718678 increased roughly proportionally with increasing doses. No meaningful accumulation was observed. Table 2. Pharmacokinetic Observations After Oral Administration of JNJ-53718678 75 mg (Cohort 1), 200 mg, and 500 mg (Cohort 1 + 2) Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Data are mean + SD, except for Tmax, which is median (range). Abbreviations: AUC24h, area under the time concentration curve in 24-hour period; Cmax, maximum observed analyte concentration; Cmin, minimum observed analyte concentration; qd, once daily; Tmax, actual sampling time to reach the maximum observed analyte concentration. an = 15 for Cmax, Tmax, and AUC24h on day 1 bn = 16 for all pharmacokinetic parameters on day 7. cn = 17 for all pharmacokinetic parameters of day 7. View Large Table 2. Pharmacokinetic Observations After Oral Administration of JNJ-53718678 75 mg (Cohort 1), 200 mg, and 500 mg (Cohort 1 + 2) Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Pharmacokinetic parameter  JNJ-53718678  75 mg qd (cohort 2) (n = 13)a  200 mg qd (cohort 1 + 2) (n = 17)b  500 mg qd (cohort 1 + 2) (n = 18)c  Day 1   Cmax, ng/mL  276 ± 69.7  733 ± 182  2029 ± 543   Tmax, h  4.00 (1.00–7.97)  4.00 (0.47–4.02)  4.00 (1.95–4.08)   AUC24h, ng.h/mL  3147 ± 599  8341 ± 1462  26 752 ± 7252  Day 7   Cmin, ng/mL  44.3 ± 16.2  77.1 ± 45.5  307 ± 192   Cmax, ng/mL  355 ± 91.1  827 ± 203  2184 ± 604   Tmax, h  2.00 (0.50–4.02)  2.00 (0.98–4.00)  3.98 (1.08–4.00)   AUC24h, ng.h/mL  3874 ± 831  8362 ± 1920  26 520 ± 7520  Data are mean + SD, except for Tmax, which is median (range). Abbreviations: AUC24h, area under the time concentration curve in 24-hour period; Cmax, maximum observed analyte concentration; Cmin, minimum observed analyte concentration; qd, once daily; Tmax, actual sampling time to reach the maximum observed analyte concentration. an = 15 for Cmax, Tmax, and AUC24h on day 1 bn = 16 for all pharmacokinetic parameters on day 7. cn = 17 for all pharmacokinetic parameters of day 7. View Large No clear dose (or exposure)–response relationship between plasma parameters (AUC and Ctrough) and AUC RSV VL was observed for the different JNJ-53718678 doses (Supplementary Figures 3 and 4). Safety The most frequently reported TEAEs (>2 participants in any treatment group) were diarrhea, increased blood cholesterol, increased low-density lipoprotein (LDL), and epistaxis (Table 3 and Supplementary Table 4). Three participants discontinued the study due to TEAE: 1 in the 75-mg JNJ 53718678 group due to grade 2 ECG change, 1 in the 200-mg group due to grade 1 ECG change, and 1 in the placebo group due to grade 2 TEAE urticaria. The grade 2 ECG change (change in morphology [from incomplete right bundle branch block]) was noted approximately 22 hours after administration of JNJ-53718678 75 mg on day 2, whereas the grade 1 AE (nonspecific ECG change) was observed about 1 hour after the intake of JNJ-53718678 200 mg on day 3. The grade 2 urticaria was reported on day 3 of dosing (placebo). Table 3. Treatment-Emergent Adverse Events (≥2 Participants in Any Treatment Group) in the Intent-to-Treat Analysis Set System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  Data are provided as n (%). The intent-to-treat set for safety analysis included all participants challenged by virus inoculation and having received at least 1 dose of JNJ-53718678 or placebo. Abbreviation: qd, once daily. View Large Table 3. Treatment-Emergent Adverse Events (≥2 Participants in Any Treatment Group) in the Intent-to-Treat Analysis Set System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  System organ class/preferred term  Placebo (n = 16)  JNJ-53718678  75 mg qd (n = 15)  200 mg qd (n = 17)  500 mg qd (n = 18)  Gastrointestinal disorders  5 (31.3)  0  4 (23.5)  9 (50.0)  Diarrhea  4 (25.0)  0  3 (17.6)  9 (50.0)  Investigations  5 (31.3)  6 (40.0)  2 (11.8)  3 (16.7)  Activated partial thromboplastin time prolonged  2 (12.5)  2 (13.3)  1 (5.9)  0  Blood cholesterol increased  0  4 (26.7)  0  1 (5.6)  Low-density lipoprotein  0  3 (20.0)  0  0  Musculoskeletal and connective tissue disorders  0  0  1 (5.9)  2 (11.1)  Respiratory, thoracic, and mediastinal disorders  0  2 (13.3)  6 (35.3)  1 (5.6)  Epistaxis  0  2 (13.3)  6 (35.3)  1 (5.6)  Skin and subcutaneous tissue disorders  1 (6.3)  0  5 (29.4)  0  Erythema  0  0  2 (11.8)  0  Data are provided as n (%). The intent-to-treat set for safety analysis included all participants challenged by virus inoculation and having received at least 1 dose of JNJ-53718678 or placebo. Abbreviation: qd, once daily. View Large An ECG abnormality of grade 1 abnormally high PR duration was reported in 1 participant receiving placebo. Abnormally high QRS duration was reported in 2 (13.3%) participants in the JNJ-53718678 75-mg group (one each grade 1 and grade 2). A Grade 2 standing diastolic blood pressure was reported in 1 (6.3%) placebo participant. No other vital signs abnormalities of grade 2 or higher were reported. Laboratory abnormalities were grade 1 or 2 and included neutrophil count and blood fibrinogen below the lower limit of normal, prolonged activated partial thromboplastin time, and values above the upper limit of normal for alanine aminotransferase, bilirubin conjugated, cholesterol, LDL cholesterol, creatinine, and C-reactive protein. The only grade 3 AE was increased lipase during the follow-up phase in the placebo group (n = 1; 6.3%). No grade 4 (severe) or serious AEs and deaths were reported during the study. DISCUSSION JNJ-53718678 reduced RSV VL AUC, peak VL, and the duration of viral shedding, and these findings correlated with relatively lower clinical symptom scores and mucus production. Considerable variability was observed within JNJ-53718678 and placebo groups. A greater sample size may have provided a better opportunity to evaluate treatment differences and potential dose–response relationship. No safety concerns were noted; however, larger studies are needed before any firm conclusions about safety can be drawn. Although ECG abnormalities led to discontinuation of study medication in 2 participants, subsequent cardiologist consultation for these 2 participants, including review of their study-collected ECGs, indicated that the observed ECG findings represented normal variability in otherwise healthy individuals (data not shown). The severity of the AEs was at most grade 2 (moderate), and the only reported AE of higher grading was grade 3 increased lipase in a placebo-treated participant during the follow-up phase. Epistaxis has been observed in other challenge studies [11, 17] and has been related to the inoculation and subsequent infection, as well as to the numerous nasal washes. The other most frequently reported AEs (increased blood cholesterol, increased LDL) were associated with the objective testing of laboratory parameters and tend to vary in the populations studied in phase 1 trials. Diarrhea was also observed in the placebo group and considered related to the increasing amount of hydroxylpropyl-β-cyclodextrin in the formulation, a known osmotic agent [20]. The plasma PK in this study were in line with that of the earlier study [19]. No exposure–response relationship was observed. Comparison of in vivo trough levels obtained in the human challenge study to that of in vitro 90% effective concentration (EC90) levels of 26 ng/mL suggest that current median trough levels at day 7 are approximately 2-, 2.5-, and 10-fold higher for 75 mg, 200 mg and 50- mg once-daily regimens, respectively, which could imply that maximal effect is already achieved at the lowest dose. As compared with the human challenge study, naturally infected adults had similar VLs [21, 22], but infants demonstrated higher peak VLs, slower viral clearance, and greater viral AUC [23–26]. The severity of RSV disease, whether assessed by hospital admission, prolonged hospitalization, admission to the intensive care unit, or respiratory failure, is strongly correlated with greater RSV load, and a quick decrease in VL may determine the time to disease resolution [27]. However, even though a correlation has been shown between VL and symptom scores, the symptom severity in challenged participants seldom leads to hospital admission. In addition to small sample size, there are some limitations in this human challenge study that need to be considered. The participants enrolled were mostly men and were white, which is common for phase 1 studies in healthy volunteers. This may also be due to the criterion for women to be of nonchildbearing potential and also to the study location (United Kingdom). Apart from these, the start of treatment 12 hours after the established RSV infection as in this study is difficult to replicate in clinical practice because patients do not present to their healthcare provider at the very onset of symptoms. Consequently, in patients who are naturally infected, the course of infection at the time of initiation of the antiviral will likely be more advanced. In infants, inflammatory processes do not appear to be major contributors to disease severity at the time of severe lung disease [28, 29]. However, it is likely that virus-driven inflammatory responses may be contributing factor at later time points during infection. Therefore, the present findings cannot directly be extrapolated to a clinical setting. Translating the clinical findings from healthy challenged adults to a natural -infected pediatric population also remains a challenge, especially because this model assessed nasal RSV VL. It is not clear yet how this may correlate with VL in the lower airways and lungs of adult and pediatric patients presenting with lower respiratory tract infection, although recent data obtained in neonatal lambs suggest that treating patients relatively late after their onset of symptoms may have a clinical benefit [13]. In that recent study, oral treatment of animals with JNJ-53718678 or a very close analog efficiently inhibited viral replication as well as RSV-associated lung damage, even when treatment was delayed until day 3 after an acute lower respiratory tract infection was established and prominent external signs of RSV illness had developed. In conclusion, JNJ-53718678 has demonstrated an effective inhibition of viral replication and reduction in clinical disease severity in infected healthy adults. Clinical trials, including formal dose range-finding studies evaluating the effectiveness and safety of JNJ-53718678 in larger naturally infected populations, are needed to fully evaluate clinical outcomes and therapeutic value. Supplementary Data Supplementary materials are available at The Journal of Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author. Notes Author contribution. S. R., D. H., N. L., K. M., M. S., and R. V. participated in the study design, participated in study governance, and supervised study recruitment, monitoring of data quality, data analysis, and interpretation of results. D. R. and A. K. were involved in study design. A. B. and J. F. S. were involved in project management, sample and inoculum virus management, screening and intent-to-dose assays, and generating the viral load data in cell-based (plaque) assays. J. D. participated in the study design and viral load data generation quantitative PCR. Y. K. directed antiviral resistance detection and assays. L. H. and E. A. M. managed and generated the quantitative virological assessments. In addition, all authors contributed to the interpretation of study results. All authors meet ICMJE criteria and all those who fulfilled those criteria are listed as authors. All authors had access to the study data, provided direction and comments on the manuscript, made the final decision about where to publish these data, and approved submission to this journal. Finally, the authors confirm that they have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. Acknowledgements. The authors thank Shivangi Gupta, PhD, and Ramji Narayanan, M Pharm, ISMPP CMPP (SIRO Clinpharm Pvt. Ltd., Thane, India), for writing assistance and Bradford Challis, PhD (Janssen Research & Development, LLC, New Jersey), for additional editorial assistance. Financial support. This work was funded by Janssen Sciences, Ireland. Potential conflicts of interest. S. R., D. H., N. L., K. M., B. R., D. R., A. K., M. S., and R. V. are employees of Janssen Research & Development and may hold company stock. A. B. and J. F. S. are employees of hVIVO services. All other authors report no conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. Presented in part: IDWeek 2016, 26–30 October 2016, New Orleans, Louisiana. 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A new direction in understanding the pathogenesis of respiratory syncytial virus bronchiolitis: how real infants suffer. J Infect Dis  2007; 195: 1084– 6. Google Scholar CrossRef Search ADS PubMed  © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)

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The Journal of Infectious DiseasesOxford University Press

Published: Apr 19, 2018

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