Valacyclovir Decreases Plasma HIV-1 RNA in HSV-2 Seronegative Individuals: A Randomized Placebo-Controlled Crossover Trial.

BACKGROUND: Acyclovir (ACV), a highly specific anti-herpetic drug, acts as a DNA chain terminator for several human herpesviruses (HHVs), including HHV-2 (HSV-2), a common human immunodeficiency virus (HIV)-1 co-pathogen. Several trials demonstrated that HSV-2 suppressive therapy using ACV or its prodrug valacyclovir (valACV) reduced plasma HIV-1 viral load (VL) in HIV-1/HSV-2 coinfected persons, and this was proposed to be due to a decrease in generalized immune activation. Recently, however, we found that ACV directly suppresses HIV-1 ex vivo in tissues free of HSV-2 but endogenously coinfected with other HHVs. Here, we asked whether valACV suppresses VL in HIV-1 infected HSV-2-seronegative persons. METHODS: Eighteen HIV-1 infected HSV-2-seronegative individuals were randomly assigned in a double blind placebo-controlled, crossover trial. Eligible participants had CD4 cell counts of ≥500 cells/µL and were not taking antiretroviral therapy. Subjects in group A received 12 weeks of valACV 500 mg given twice daily by mouth followed by 2 weeks of a no treatment washout and then 12 weeks of placebo; subjects in group B received 12 weeks of placebo followed by 2 weeks of no treatment washout and then 12 weeks of valACV 500 mg twice daily. RESULTS: HIV-1 VL in plasma of patients treated with valACV 500 mg twice daily for 12 weeks was reduced on average by 0.37 log10 copies/mL. CONCLUSIONS: These data indicate that the effects of valACV on HIV-1 replication are not related to the suppression of HSV-2-mediated inflammation and are consistent with a direct effect of ACV on HIV-1 replication.

Response-guided telaprevir combination treatment for hepatitis C virus infection.

BACKGROUND: Patients with chronic infection with hepatitis C virus (HCV) genotype 1 often need 48 weeks of peginterferon-ribavirin treatment for a sustained virologic response. We designed a noninferiority trial (noninferiority margin, -10.5%) to compare rates of sustained virologic response among patients receiving two treatment durations. METHODS: We enrolled patients with chronic infection with HCV genotype 1 who had not previously received treatment. All patients received telaprevir at a dose of 750 mg every 8 hours, peginterferon alfa-2a at a dose of 180 µg per week, and ribavirin at a dose of 1000 to 1200 mg per day, for 12 weeks (T12PR12), followed by peginterferon-ribavirin. Patients who had an extended rapid virologic response (undetectable HCV RNA levels at weeks 4 and 12) were randomly assigned after week 20 to receive the dual therapy for 4 more weeks (T12PR24) or 28 more weeks (T12PR48). Patients without an extended rapid virologic response were assigned to T12PR48. RESULTS: Of the 540 patients, a total of 352 (65%) had an extended rapid virologic response. The overall rate of sustained virologic response was 72%. Among the 322 patients with an extended rapid virologic response who were randomly assigned to a study group, 149 (92%) in the T12PR24 group and 140 (88%) in the T12PR48 group had a sustained virologic response (absolute difference, 4 percentage points; 95% confidence interval, -2 to 11), establishing noninferiority. Adverse events included rash (in 37% of patients, severe in 5%) and anemia (in 39%, severe in 6%). Discontinuation of all the study drugs was based on adverse events in 18% of patients overall, as well as in 1% of patients (all of whom were randomly assigned) in the T12PR24 group and 12% of the patients randomly assigned to the T12PR48 group (P<0.001). CONCLUSIONS: In this study, among patients with chronic HCV infection who had not received treatment previously, a regimen of peginterferon-ribavirin for 24 weeks, with telaprevir for the first 12 weeks, was noninferior to the same regimen for 48 weeks in patients with undetectable HCV RNA at weeks 4 and 12, with an extended rapid virologic response achieved in nearly two thirds of patients. (Funded by Vertex Pharmaceuticals and Tibotec; ILLUMINATE ClinicalTrials.gov number, NCT00758043.).

Telaprevir for previously untreated chronic hepatitis C virus infection.

BACKGROUND: In phase 2 trials, telaprevir, a hepatitis C virus (HCV) genotype 1 protease inhibitor, in combination with peginterferon-ribavirin, as compared with peginterferon-ribavirin alone, has shown improved efficacy, with potential for shortening the duration of treatment in a majority of patients. METHODS: In this international, phase 3, randomized, double-blind, placebo-controlled trial, we assigned 1088 patients with HCV genotype 1 infection who had not received previous treatment for the infection to one of three groups: a group receiving telaprevir combined with peginterferon alfa-2a and ribavirin for 12 weeks (T12PR group), followed by peginterferon-ribavirin alone for 12 weeks if HCV RNA was undetectable at weeks 4 and 12 or for 36 weeks if HCV RNA was detectable at either time point; a group receiving telaprevir with peginterferon-ribavirin for 8 weeks and placebo with peginterferon-ribavirin for 4 weeks (T8PR group), followed by 12 or 36 weeks of peginterferon-ribavirin on the basis of the same HCV RNA criteria; or a group receiving placebo with peginterferon-ribavirin for 12 weeks, followed by 36 weeks of peginterferon-ribavirin (PR group). The primary end point was the proportion of patients who had undetectable plasma HCV RNA 24 weeks after the last planned dose of study treatment (sustained virologic response). RESULTS: Significantly more patients in the T12PR or T8PR group than in the PR group had a sustained virologic response (75% and 69%, respectively, vs. 44%; P<0.001 for the comparison of the T12PR or T8PR group with the PR group). A total of 58% of the patients treated with telaprevir were eligible to receive 24 weeks of total treatment. Anemia, gastrointestinal side effects, and skin rashes occurred at a higher incidence among patients receiving telaprevir than among those receiving peginterferon-ribavirin alone. The overall rate of discontinuation of the treatment regimen owing to adverse events was 10% in the T12PR and T8PR groups and 7% in the PR group. CONCLUSIONS: Telaprevir with peginterferon-ribavirin, as compared with peginterferon-ribavirin alone, was associated with significantly improved rates of sustained virologic response in patients with HCV genotype 1 infection who had not received previous treatment, with only 24 weeks of therapy administered in the majority of patients. (Funded by Vertex Pharmaceuticals and Tibotec; ADVANCE ClinicalTrials.gov number, NCT00627926.).

Telaprevir for previously treated chronic HCV infection.

BACKGROUND: Patients with genotype 1 hepatitis C virus (HCV) who do not have a sustained response to therapy with peginterferon alfa and ribavirin have a low likelihood of success with retreatment. METHODS: We randomly assigned patients with HCV genotype 1 who had not had a sustained virologic response after peginterferon alfa-ribavirin therapy to one of four treatment groups: 115 patients to the T12PR24 group, receiving telaprevir (1125-mg loading dose, then 750 mg every 8 hours) for 12 weeks and peginterferon alfa-2a (180 microg per week) and ribavirin (1000 or 1200 mg per day, according to body weight) for 24 weeks; 113 patients to the T24PR48 group, receiving telaprevir for 24 weeks and peginterferon alfa-2a and ribavirin for 48 weeks (at the same doses as in the T12PR24 group); 111 patients to the T24P24 group, receiving telaprevir and peginterferon alfa-2a for 24 weeks (at the same doses as in the T12PR24 group); and 114 patients to the PR48 (or control) group, receiving peginterferon alfa-2a and ribavirin for 48 weeks (at the same doses as in the T12PR24 group). The primary end point was sustained virologic response (undetectable HCV RNA levels 24 weeks after the last dose of study drugs). RESULTS: The rates of sustained virologic response in the three telaprevir groups--51% in the T12PR24 group, 53% in the T24PR48 group, and 24% in the T24P24 group--were significantly higher than the rate in the control group (14%; P<0.001, P<0.001, and P=0.02, respectively). Response rates were higher among patients who had previously had relapses than among nonresponders. One of the most common adverse events in the telaprevir groups was rash (overall, occurring in 51% of patients, with severe rash in 5%). Discontinuation of study drugs because of adverse events was more frequent in the telaprevir groups than in the control group (15% vs. 4%). CONCLUSIONS: In HCV-infected patients in whom initial peginterferon alfa and ribavirin treatment failed, retreatment with telaprevir in combination with peginterferon alfa-2a and ribavirin was more effective than retreatment with peginterferon alfa-2a and ribavirin alone. (ClinicalTrials.gov number, NCT00420784.)

Telaprevir with peginterferon and ribavirin for chronic HCV genotype 1 infection.

BACKGROUND: Current therapy for chronic hepatitis C virus (HCV) infection is effective in less than 50% of patients infected with HCV genotype 1. Telaprevir, a protease inhibitor specific to the HCV nonstructural 3/4A serine protease, rapidly reduced HCV RNA levels in early studies. METHODS: We randomly assigned patients infected with HCV genotype 1 to one of three telaprevir groups or to the control group. The control group (called the PR48 group) received peginterferon alfa-2a (180 microg per week) and ribavirin (1000 or 1200 mg per day, according to body weight) for 48 weeks, plus telaprevir-matched placebo for the first 12 weeks (75 patients). The telaprevir groups received telaprevir (1250 mg on day 1 and 750 mg every 8 hours thereafter) for 12 weeks, as well as peginterferon alfa-2a and ribavirin (at the same doses as in the PR48 group) for the same 12 weeks (the T12PR12 group, 17 patients) or for a total of 24 weeks (the T12PR24 group, 79 patients) or 48 weeks (the T12PR48 group, 79 patients). The primary outcome was a sustained virologic response (an undetectable HCV RNA level 24 weeks after the end of therapy). RESULTS: The rate of sustained virologic response was 41% (31 of 75 patients) in the PR48 group, as compared with 61% (48 of 79 patients) in the T12PR24 group (P=0.02), 67% (53 of 79 patients) in the T12PR48 group (P=0.002), and 35% (6 of 17 patients) in the T12PR12 group (this group was exploratory and not compared with the control group). Viral breakthrough occurred in 7% of patients receiving telaprevir. The rate of discontinuation because of adverse events was higher in the three telaprevir-based groups (21%, vs. 11% in the PR48 group), with rash the most common reason for discontinuation. CONCLUSIONS: Treatment with a telaprevir-based regimen significantly improved sustained virologic response rates in patients with genotype 1 HCV, albeit with higher rates of discontinuation because of adverse events. (ClinicalTrials.gov number, NCT00336479.)

Telaprevir and peginterferon with or without ribavirin for chronic HCV infection.

BACKGROUND: In patients with chronic infection with hepatitis C virus (HCV) genotype 1, treatment with peginterferon alfa and ribavirin for 48 weeks results in rates of sustained virologic response of 40 to 50%. Telaprevir is a specific inhibitor of the HCV serine protease and could be of value in HCV treatment. METHODS: A total of 334 patients who had chronic infection with HCV genotype 1 and had not been treated previously were randomly assigned to receive one of four treatments involving various combinations of telaprevir (1250 mg on day 1, then 750 mg every 8 hours), peginterferon alfa-2a (180 microg weekly), and ribavirin (dose according to body weight). The T12PR24 group (81 patients) received telaprevir, peginterferon alfa-2a, and ribavirin for 12 weeks, followed by peginterferon alfa-2a and ribavirin for 12 more weeks. The T12PR12 group (82 patients) received telaprevir, peginterferon alfa-2a, and ribavirin for 12 weeks. The T12P12 group (78 patients) received telaprevir and peginterferon alfa-2a without ribavirin for 12 weeks. The PR48 (control) group (82 patients) received peginterferon alfa-2a and ribavirin for 48 weeks. The primary end point, a sustained virologic response (an undetectable HCV RNA level 24 weeks after the end of therapy), was compared between the control group and the combined T12P12 and T12PR12 groups. RESULTS: The rate of sustained virologic response for the T12PR12 and T12P12 groups combined was 48% (77 of 160 patients), as compared with 46% (38 of 82) in the PR48 (control) group (P=0.89). The rate was 60% (49 of 82 patients) in the T12PR12 group (P=0.12 for the comparison with the PR48 group), as compared with 36% (28 of 78 patients) in the T12P12 group (P=0.003; P=0.20 for the comparison with the PR48 group). The rate was significantly higher in the T12PR24 group (69% [56 of 81 patients]) than in the PR48 group (P=0.004). The adverse events with increased frequency in the telaprevir-based groups were pruritus, rash, and anemia. CONCLUSIONS: In this phase 2 study of patients infected with HCV genotype 1 who had not been treated previously, one of the three telaprevir groups had a significantly higher rate of sustained virologic response than that with standard therapy. Response rates were lowest with the regimen that did not include ribavirin. (ClinicalTrials.gov number, NCT00372385.)

Retreatment with telaprevir combination therapy in hepatitis C patients with well-characterized prior treatment response.

UNLABELLED: Retreatment with peginterferon alpha and ribavirin (PR) offers a limited chance of sustained virologic response (SVR) in patients who did not achieve SVR with prior PR treatment. This study evaluated the safety and efficacy of telaprevir-based treatment in combination with PR in well-characterized patients who did not achieve SVR in the control arms of three Phase II clinical trials. Patients eligible to enroll in this open-label nonrandomized study either met on-treatment criteria for nonresponse or relapsed after 48 weeks of treatment in the control arm of the three Phase II PROVE studies. The initial protocol was a 24-week regimen: 12 weeks of telaprevir and PR followed by an additional 12 weeks of PR. During the study the protocol was amended to extend PR to 48 weeks for patients with previous null response. All other patients with undetectable hepatitis C virus (HCV) RNA at weeks 4 and 12 received 24 weeks of therapy. Those with detectable HCV RNA at weeks 4 or 12 received a total of 48 weeks of therapy. The overall SVR rate was 59% (69/117). SVR rates with T12PR were 37% (19/51) in prior null responders, 55% (16/29) in prior partial responders, 75% (6/8) in prior breakthroughs, and 97% (28/29) in prior relapsers. The overall relapse rate was 16% (13/83). Adverse events were similar to those in previous trials with telaprevir, with 9% of patients discontinuing due to an adverse event (most commonly rash and anemia). CONCLUSION: This study demonstrated the benefit of retreatment with a telaprevir-based regimen for patients with well-characterized nonresponse (null and partial) or relapse to a prior course of PR treatment.

Merimepodib, pegylated interferon, and ribavirin in genotype 1 chronic hepatitis C pegylated interferon and ribavirin nonresponders.

UNLABELLED: Merimepodib (MMPD) is an orally administered, inosine monophosphate dehydrogenase inhibitor that has shown antiviral activity in nonresponders with chronic hepatitis C (CHC) when combined with pegylated interferon alfa 2a (Peg-IFN-alfa-2a) and ribavirin (RBV). We conducted a randomized, double-blind, multicenter, phase 2b study to evaluate the antiviral activity, safety, and tolerability of MMPD in combination with Peg-IFN-alfa-2a and RBV in patients with genotype 1 CHC who were nonresponders to prior therapy with Peg-IFN and RBV. Patients received 50 mg MMPD, 100 mg MMPD, or placebo every 12 hours, in addition to Peg-IFN-alfa-2a and RBV, for 24 weeks. Patients with a 2-log or more decrease from baseline or undetectable hepatitis C virus (HCV) RNA levels at week 24 were then eligible to continue Peg-IFN-alfa-2a and RBV for a further 24 weeks, followed by 24 weeks of follow-up. The primary efficacy endpoint was sustained virological response (SVR) rate at week 72 in all randomized patients who received at least one dose of study drug and had a history of nonresponse to standard therapy. A total of 354 patients were randomized to treatment (117 to placebo; 119 to 50 mg MMPD; 118 to 100 mg MMPD), and 286 completed the core study. The proportion of patients who achieved SVR was similar among the treatment groups: 6% (6/107) for 50 mg MMPD, 4% (5/112) for 100 mg MMPD, and 5% (5/104) for placebo (P = 0.8431). Adverse-event profiles for the MMPD combination groups were similar to that for Peg-IFN-alfa and RBV alone. Nausea, arthralgia, cough, dyspnea, neutropenia, and anemia were more common in patients taking MMPD. CONCLUSION: The addition of MMPD to Peg-IFN-alfa-2a and RBV combination therapy did not increase the proportion of nonresponder patients with genotype 1 CHC achieving an SVR.

VX-222, a non-nucleoside NS5B polymerase inhibitor, in telaprevir-based regimens for genotype 1 hepatitis C virus infection.

OBJECTIVE: To investigate in this phase 2a study (ZENITH) the safety, tolerability, and antiviral activity of VX-222, a selective, non-nucleoside inhibitor of hepatitis C virus (HCV) NS5B polymerase, combined with various telaprevir-based regimens for treatment of genotype 1 HCV. METHODS: In total, 152 treatment-naive patients received VX-222+telaprevir ('DUAL' regimen; n=47), with ribavirin ('TRIPLE' regimen; n=46), or with peginterferon+ribavirin ('QUAD' regimen; n=59) for 12 weeks. Patients with detectable HCV RNA at weeks 2 and/or 8 received peginterferon+ribavirin for 24 (DUAL and TRIPLE) or 12 (QUAD) additional weeks. RESULTS: VX-222 (100 or 400 mg twice daily) was well tolerated, with an increased rate of gastrointestinal adverse events observed with the higher dose. Across VX-222 400-mg twice-daily regimens, the QUAD was associated with the highest frequency of grade 3/4 adverse events. The DUAL was discontinued because of high viral breakthrough before week 12. Sustained virologic response (SVR) 24 weeks after end of treatment (SVR24), including patients treated with 12 or 24 additional weeks of peginterferon+ribavirin, was 67% for TRIPLE (VX-222 400 mg twice daily) and 79 and 90% for QUAD (VX-222 100 and 400 mg twice daily, respectively). CONCLUSION: These results provide valuable information regarding the safety, tolerability, and efficacy of telaprevir combined with a non-nucleoside polymerase inhibitor, as dual therapy or with ribavirin without or with peginterferon. Telaprevir and VX-222, alone or with ribavirin without or with peginterferon, were generally well tolerated, with improved tolerability without peginterferon. SVR24 rates achieved with TRIPLE and QUAD regimens containing telaprevir and VX-222 were comparable to those observed with telaprevir-based therapy.

Telaprevir: pharmacokinetics and drug interactions.

Telaprevir is an inhibitor of the HCV NS3/4A protease. When used in combination with pegylated interferon and ribavirin, telaprevir has demonstrated a substantial increase in sustained virological response compared with pegylated interferon and ribavirin used alone. Telaprevir has good oral bioavailability, which is enhanced when administered with food. Telaprevir is extensively metabolized and primarily eliminated via faeces. No dose adjustment of telaprevir is needed in patients with mild to severe renal impairment or mild liver impairment. Telaprevir is a substrate and inhibitor of cytochrome P450 3A and P-glycoprotein and, thus, might interact with coadministered drugs that affect or are affected by these metabolic/transport pathways. This article reviews the pharmacokinetic and drug interaction profile of telaprevir.

Hepatitis C viral evolution in genotype 1 treatment-naïve and treatment-experienced patients receiving telaprevir-based therapy in clinical trials.

BACKGROUND: In patients with genotype 1 chronic hepatitis C infection, telaprevir (TVR) in combination with peginterferon and ribavirin (PR) significantly increased sustained virologic response (SVR) rates compared with PR alone. However, genotypic changes could be observed in TVR-treated patients who did not achieve an SVR. METHODS: Population sequence analysis of the NS3•4A region was performed in patients who did not achieve SVR with TVR-based treatment. RESULTS: Resistant variants were observed after treatment with a telaprevir-based regimen in 12% of treatment-naïve patients (ADVANCE; T12PR arm), 6% of prior relapsers, 24% of prior partial responders, and 51% of prior null responder patients (REALIZE, T12PR48 arms). NS3 protease variants V36M, R155K, and V36M+R155K emerged frequently in patients with genotype 1a and V36A, T54A, and A156S/T in patients with genotype 1b. Lower-level resistance to telaprevir was conferred by V36A/M, T54A/S, R155K/T, and A156S variants; and higher-level resistance to telaprevir was conferred by A156T and V36M+R155K variants. Virologic failure during telaprevir treatment was more common in patients with genotype 1a and in prior PR nonresponder patients and was associated with higher-level telaprevir-resistant variants. Relapse was usually associated with wild-type or lower-level resistant variants. After treatment, viral populations were wild-type with a median time of 10 months for genotype 1a and 3 weeks for genotype 1b patients. CONCLUSIONS: A consistent, subtype-dependent resistance profile was observed in patients who did not achieve an SVR with telaprevir-based treatment. The primary role of TVR is to inhibit wild-type virus and variants with lower-levels of resistance to telaprevir. The complementary role of PR is to clear any remaining telaprevir-resistant variants, especially higher-level telaprevir-resistant variants. Resistant variants are detectable in most patients who fail to achieve SVR, but their levels decline over time after treatment.

Discovery and development of telaprevir: an NS3-4A protease inhibitor for treating genotype 1 chronic hepatitis C virus.

Infection with hepatitis C virus (HCV) is a major medical problem with over 170 million people infected worldwide. Substantial morbidity and mortality are associated with hepatic manifestations (cirrhosis and hepatocellular carcinoma), which develop with increasing frequency in people infected with HCV for more than 20 years. Less well known is the burden of HCV disease associated with extrahepatic manifestations (diabetes, B-cell proliferative disorders, depression, cognitive disorders, arthritis and Sjögren's syndrome). For patients infected with genotype 1 HCV, treatment with polyethylene glycol decorated interferon (peginterferon) α and ribavirin (PR) is associated with a low (40-50%) success rate, substantial treatment-limiting side effects and a long (48-week) duration of treatment. In the past 15 years, major scientific advances have enabled the development of new classes of HCV therapy, the direct-acting antiviral agents, also known as specifically targeted antiviral therapy for hepatitis C (STAT-C). In combination with PR, the HCV NS3-4A protease inhibitor telaprevir has recently been approved for treatment of genotype 1 chronic HCV in the United States, Canada, European Union and Japan. Compared with PR, telaprevir combination therapy offers significantly improved viral cure rates and the possibility of shortened treatment duration for diverse patient populations. Developers of innovative drugs have to blaze a new path with few validated sign posts to guide the way. Indeed, telaprevir's development was once put on hold because of its performance in a standard IC(50) assay. Data from new hypotheses and novel experiments were required to justify further investment and reduce risk that the drug might fail in the clinic. In addition, the poor drug-like properties of telaprevir were a formidable hurdle, which the manufacturing and formulation teams had to overcome to make the drug. Finally, novel clinical trial designs were developed to improve efficacy and shorten treatment in parallel instead of sequentially. Lessons learned from the development of telaprevir suggest that makers of innovative medicines cannot rely solely on traditional drug discovery metrics, but must develop innovative, scientifically guided pathways for success.