John Fry

Hepatitis B virus genotypes and virologic response in 694 patients in phase III studies of adefovir dipivoxil

Abstract Background & aims: Hepatitis B virus (HBV) genotype may influence disease progression and antiviral response. We therefore analyzed the frequency and distribution of genotypes in patients from 2 multinational phase III studies of adefovir dipivoxil. Antiviral efficacy of adefovir dipivoxil 10-mg therapy was examined with respect to HBV genotype, hepatitis B e antigen (HBeAg) serostatus, and race. Methods: HBV genotypes were assigned by phylogenetic analyses of DNA sequences amplified from baseline serum samples (n = 694). Results: Patients from Asia/Oceania were infected predominantly with genotypes B and C, whereas patients from Western European countries were infected predominantly with genotypes A and D. In Mediterranean countries, genotype D was dominant. The most common genotype in North America was C, followed by A, B, and D. Regardless of location, Asian patients were infected predominantly with genotypes B or C, whereas Caucasian patients were infected predominantly with A or D. There were significant differences in the baseline serum HBV-DNA levels of patients infected with different HBV genotypes regardless of HBeAg serostatus. Forty-eight weeks of adefovir dipivoxil 10-mg therapy resulted in potent reductions in serum HBV DNA with no significant differences based on genotype, HBeAg status, or race; similarly, there was no statistical difference in HBeAg seroconversion rates between genotypes in these patients. Conclusions: HBV genotypes were distributed asymmetrically with respect to race, geography, and HBeAg status. Forty-eight weeks of adefovir dipivoxil therapy resulted in significant decreases in serum HBV-DNA levels in patients regardless of HBV genotype, HBeAg status, or race.

A Randomized, Double-Blind Trial of Valaciclovir Prophylaxis for Cytomegalovirus Disease in Patients with Advanced Human Immunodeficiency Virus Infection

Cytomegalovirus (CMV) disease is a common complication of advanced human immunodeficiency virus (HIV) infection. Administration of oral valaciclovir, a valine ester of acyclovir, achieves sufficient plasma acyclovir levels to inhibit many clinical isolates. Acyclovir has been associated with enhanced survival in AIDS but not with CMV disease prevention. CMV-seropositive patients (1227) with CD4 cell counts <100/mm3 were enrolled in a randomized, double-blind trial. Valaciclovir, 8 g/day, was compared with acyclovir, 3.2 or 0.8 g/day, for CMV prevention; all three arms were compared for survival. The confirmed CMV disease rate was 11.7% among valaciclovir recipients and 17.5% in the pooled acyclovir arms, a 33% reduction in risk. Time to confirmed CMV disease was significantly longer for the valaciclovir group (P = .03). A trend toward earlier mortality for valaciclovir recipients was seen (P = .06). Toxicity and earlier medication discontinuation were more common in this group. Valaciclovir significantly reduces the risk of CMV disease. Further exploration of a better-tolerated dose is warranted.

Activity of Oral ALS-008176 in a Respiratory Syncytial Virus Challenge Study

BACKGROUND Respiratory syncytial virus (RSV) infection is a cause of substantial morbidity and mortality. There is no known effective therapy. METHODS We conducted a randomized, double-blind, clinical trial in healthy adults inoculated with RSV. Participants received the oral nucleoside analogue ALS-008176 or placebo 12 hours after confirmation of RSV infection or 6 days after inoculation. Treatment was administered every 12 hours for 5 days. Viral load, disease severity, resistance, and safety were measured throughout the 28-day study period, with measurement beginning before inoculation. The primary end point was the area under the curve (AUC) for viral load, which was assessed immediately before administration of the first dose through the 12th day after inoculation in participants infected with RSV. RESULTS A total of 62 participants received placebo or one of three ALS-008176 dosing regimens: 1 loading dose of 750 mg followed by 9 maintenance doses of 500 mg (group 1), 1 loading dose of 750 mg followed by 9 maintenance doses of 150 mg (group 2), or 10 doses of 375 mg (group 3). In the 35 infected participants (23 of whom were treated with ALS-008176), the AUCs for viral load for groups 1, 2, and 3 and the placebo group were 59.9, 73.7, 133.4, and 500.9 log10 plaque-forming-unit equivalents × hours per milliliter, respectively (P≤0.001). The time to nondetectability on polymerase-chain-reaction assay (P<0.001), the peak viral load (P≤0.001), the AUC for symptom score (P<0.05), and the AUC for mucus weight were lower in all groups receiving ALS-008176 than in the placebo group. Antiviral activity was greatest in the two groups that received a loading dose--viral clearance was accelerated (P≤0.05), and the AUC for viral load decreased by 85 to 88% as compared with the placebo group. Within this small trial, no viral rebound or resistance was identified. There were no serious adverse events, and there was no need for premature discontinuation of the study drug. CONCLUSIONS In this RSV challenge study, more rapid RSV clearance and a greater reduction of viral load, with accompanying improvements in the severity of clinical disease, were observed in the groups treated with ALS-008176 than in the placebo group. (Funded by Alios BioPharma; ClinicalTrials.gov number, NCT02094365.).

Activity of adefovir dipivoxil against all patterns of lamivudine‐resistant hepatitis B viruses in patients

Summary.  One hundred and thirty‐one post‐liver transplantation patients with chronic hepatitis B and failing lamivudine therapy with detectable serum hepatitis B virus (HBV) deoxyribonucleic acid by hybridization assays or ≥1 × 106 copies/mL by polymerase chain reaction, and elevated alanine transaminase levels despite continuous lamivudine, were enrolled in an open‐label study of adefovir dipivoxil. The B and C domains of HBV polymerase were sequenced for baseline samples to determine the presence of lamivudine resistance mutations. The results showed that 98% of the samples had tyrosine‐methionine‐aspartate‐aspartate (YMDD) mutations, indicating a strong correlation between the above clinical definition of lamivudine treatment failure and the presence of YMDD mutations. In addition to the rtM204V/I and the rtL180M mutations, the mutation rtV173L was identified in 19% of patients. Four major patterns of lamivudine‐resistant HBV were identified: rtL180M + rtM204V (60%), rtV173L + rtL180M + rtM204V (19%), rtM204I (9%) and rtL180M + rtM204I (9%). Treatment with adefovir dipivoxil showed similar antiviral efficacy in patients with lamivudine‐resistant virus from all four patterns.

ALS-008176 for respiratory syncytial virus infection

The authors reply: A family history of cancer is a key component in identifying an underlying cancer-predisposition syndrome. Bardai et al. raise concern regarding the conclusion that family history should not be used as the sole indication to guide genetic referrals for children with cancer. We, too, recognize the importance of collecting and analyzing family-history information.1,2 Nonetheless, identifying a family history that is positive for cancer can be challenging. It is perhaps because of this that emerging research suggests that children with certain tumor types (e.g., retinoblastoma or adrenocortical carcinoma) be referred for genetic counseling regardless of whether a family history has been documented, since a substantial proportion of these tumors are caused by an underlying susceptibility and established interventions exist to reduce syndromeassociated morbidity and mortality. Indeed, this approach has been endorsed by the American Society of Clinical Oncology.3 In addition, some children with cancer harbor de novo predisposing mutations, whereas others inherit mutations that exert incomplete penetrance. In such cases, the family history is likely to be negative. We do not dispute the importance of a family history of cancer in guiding genetics referral and oncology clinical practice. However, providers must recognize the limitations of family-history information and not overlook the possibility of an underlying syndrome when the family history is negative. Jinghui Zhang, Ph.D. Kim E. Nichols, M.D. James R. Downing, M.D.

Antiviral Activity, Safety, and Pharmacokinetics of AL-794, a Novel Oral Influenza Endonuclease Inhibitor: Results of an Influenza Human Challenge Study

Background AL-794 is an orally active prodrug of ALS-033719, which selectively inhibits the endonuclease domain of influenza virus A and B polymerase. Methods In a phase 1, double-blinded, randomized, placebo-controlled study, healthy subjects were inoculated intranasally with influenza virus (A/Perth/16/2009 H3N2) after confirmation of infection or on day 4. Subjects received 50 mg of AL-794, 150 mg of AL-794, or placebo twice daily for 5 days. Viral load, influenza symptoms, pharmacokinetics, and safety were evaluated. Results A total of 61 subjects were inoculated. In 42 infected subjects, the mean peak viral load for 50-mg AL-794 recipients, 150-mg AL-794 recipients, and placebo recipients was 3.54, 2.77, and 3.72 log10 50% tissue culture infectious doses (TCID50)/mL, respectively. The mean influenza viral load area under the curve in the corresponding treatment groups was 137, 87.5, and 142 log10 TCID50/mL·h, respectively, and the median time to virus nondetection was 117, 75.3, and 108 hours, respectively. AL-794 was well tolerated, and no viral resistance to ALS-033719 was identified. Conclusion Following oral administration of AL-794, significant dose-dependent antiviral activity was noted, with a greater decrease in viral load, symptoms, and mucus weight at the 150-mg dose, compared with the 50-mg dose, and no safety concerns for either dose or placebo. Clinical Trials Registration NCT02588521.

Pharmacokinetics, safety, and tolerability of the 2‐ and 3‐direct‐acting antiviral combination of AL‐335, odalasvir, and simeprevir in healthy subjects

This Phase I, open‐label, two‐group, fixed‐sequence study evaluated the pharmacokinetics and safety of AL‐335, odalasvir, and simeprevir in healthy subjects. Group 1 (n = 16) received AL‐335 800 mg once daily (QD) (days 1‐3, 11‐13, and 21‐23), simeprevir 150 mg QD (days 4‐23), and odalasvir 150 mg (day 14) followed by 50 mg QD (days 15‐23). Group 2 (n = 16) received the same AL‐335 regimen as in Group 1 plus odalasvir 150 mg (day 4) followed by 50 mg QD (days 5‐23) and simeprevir 150 mg QD (days 14‐23). Blood samples were collected to determine plasma concentrations of AL‐335 (prodrug) and its metabolites, ALS‐022399 (monophosphate precursor) and ALS‐022227 (parent nucleoside), odalasvir, and simeprevir. Thirty‐two subjects were enrolled. Odalasvir and simeprevir given alone, or in combination, increased AL‐335 area under plasma concentration‐time curve over 24 hours (AUC0‐24 h) 3‐, 4‐, and 7‐ to 8‐fold, respectively; ALS‐022399 AUC0‐24 h increased 2‐, 2‐, and 3‐fold, respectively. Simeprevir had no effect on ALS‐022227 AUC0‐24 h, whereas odalasvir with/without simeprevir increased ALS‐022227 AUC0‐24 h 1.5‐fold. AL‐335 had no effect on odalasvir or simeprevir pharmacokinetics. Odalasvir and simeprevir AUC0‐24 h increased 1.5‐ to 2‐fold for both drugs when coadministered irrespective of AL‐335 coadministration. Study medications were well tolerated with no serious adverse events. One subject prematurely discontinued study drugs (unrelated event). This study defined the preliminary pharmacokinetic and safety profiles of the combination of AL‐335, odalasvir, and simeprevir in healthy subjects. These data support the further evaluation of this combination for the treatment of chronic hepatitis C virus infection.

Safety, tolerability, and pharmacokinetics of AL-335 in healthy volunteers and hepatitis C virus-infected subjects

Background The nucleotide analog AL-335 is a pangenotypic hepatitis C virus (HCV) nonstructural protein (NS)5B inhibitor being evaluated as treatment for chronic HCV infection. Methods This three-part randomized, double-blind study evaluated the safety and pharmacokinetics of single and multiple ascending oral doses of AL-335. Healthy volunteers (HVs) received single doses of AL-335 (100–1,200 mg) or placebo in a fasted or fed (400 mg) state. Non-cirrhotic subjects (HCV genotype [GT]1−4) and GT1-infected subjects with Child Pugh A cirrhosis received multiple doses of AL-335 (400, 800, 1,200 mg) or placebo once daily (QD) for 7 days. Results Forty-eight HVs and 64 subjects with HCV GT1−4 were randomized and received treatment. AL-335 was well tolerated in HVs and HCV-infected subjects with/without cirrhosis. AL-335 was rapidly absorbed and converted to the metabolites ALS-022399 and ALS-022227. ALS-022227 exposure increased less than dose-proportionally and was unaffected by food, while AL-335 and ALS-022399 exposure increased with food by 85% and 50%, respectively, in HVs. Rapid and dose-dependent reductions in HCV-RNA were observed in GT1-infected subjects. In non-cirrhotic, GT1−4-infected subjects receiving AL-335 800 mg QD, potent antiviral activity was observed, regardless of genotype (mean maximum reductions in HCV-RNA of 4.0−4.8 log10 IU/mL). The same dose in GT1-infected cirrhotic subjects resulted in a 3.5 log10 IU/mL mean maximum reduction in HCV-RNA. Conclusions AL-335 was well tolerated when administered as single and multiple doses, with an acceptable pharmacokinetic profile. The drug also demonstrated potent antiviral activity in HCV GT1–4-infected subjects, including GT1-infected subjects with cirrhosis.

Short Duration AL‐335, Odalasvir, With/Without Simeprevir, in Patients With HCV GT1 or 3 Infection Without Cirrhosis

This open‐label, phase IIa study assessed the safety, pharmacokinetics, and efficacy of direct‐acting antiviral agent (DAA) regimens in patients with chronic hepatitis C virus (HCV) infection. Multiple 6‐12‐week oral regimens of 400‐800 mg once daily (QD) AL‐335 + 50 mg QD/every other day odalasvir ± 75‐150 mg QD simeprevir were evaluated in treatment‐naïve, HCV genotype (GT)1/3‐infected patients without cirrhosis. Safety/pharmacokinetic parameters, HCV‐RNA, and sequencing data were assessed. Treatment regimens for later study cohorts were adjusted based on emerging data. In total, 112 patients were enrolled. Three serious treatment‐emergent adverse events occurred, one of which (a Mobitz type 1 second‐degree atrioventricular block [Wenckebach]) was possibly related to high odalasvir exposure and resulted in premature discontinuation of study drugs. No other clinically significant safety findings were identified. GT1‐infected patients receiving 3‐DAA for 6‐8 weeks achieved 100% sustained virologic response 12 weeks and 24 weeks after the end of treatment (sustained virologic response [SVR12/24]). GT1‐infected patients receiving 2‐DAA or GT3‐infected patients receiving 3‐DAA had SVR12/24 less than 90%, whether treated for 8 weeks or 12 weeks. Virologic failure was associated with the emergence of generally persistent NS5A and/or transient NS5B resistance‐associated substitutions in most patients. Pharmacokinetic characteristics of the three drugs were also elucidated. Conclusions: In treatment‐naïve subjects without cirrhosis, AL‐335 + odalasvir + simeprevir for 6‐8 weeks was generally safe and highly efficacious against HCV GT1. However, inadequate efficacy was observed for the 2‐DAA regimen in GT1‐infected subjects and the 3‐DAA regimen in GT3‐infected subjects.