Simeprevir and daclatasvir for 12 or 24 weeks in treatment-naïve patients with hepatitis C virus genotype 1b and advanced liver disease.

BACKGROUND & AIMS: We investigated the efficacy and safety of simeprevir plus daclatasvir in treatment-naïve patients with chronic, genotype 1b hepatitis C virus infection and advanced liver disease, excluding patients with pre-defined NS5A resistance-associated substitutions. METHODS: This phase II, open-label, single-arm, multicentre study included patients aged ≥18 years with advanced fibrosis or compensated cirrhosis (METAVIR F3/4). Patients with NS5A-Y93H or L31M/V resistance-associated substitutions at screening were excluded. Simeprevir (150 mg)+daclatasvir (60 mg) once daily was administered for 12 or 24 weeks; treatment could be extended to 24 weeks prior to or at the Week 12 visit. Primary efficacy endpoint was sustained virological response 12 weeks after the end of treatment. RESULTS: A total of 106 patients were treated; 27% patients were aged >65 years, 39% had cirrhosis, 53% had estimated glomerular filtration rate 30-89 mL/min, 14% had diabetes, and 38% had arterial hypertension. Overall, 42/106 received 12 weeks of treatment and 64/106 received 24 weeks of treatment. Ninety-seven (92%) patients achieved a sustained virological response 12 weeks after the end of treatment. The reasons for failure were viral breakthrough (n=7) at weeks 4-16, early treatment discontinuation (n=1) and viral relapse (n=1). Seventy-four (70%) patients had ≥1 adverse event during treatment, including six (6%) patients with ≥1 serious adverse event. Three (3%) patients discontinued treatment owing to adverse events. CONCLUSIONS: Simeprevir+daclatasvir demonstrated strong antiviral activity and was well-tolerated in patients with hepatitis C virus genotype 1b infection, advanced liver disease and a high prevalence of comorbidities. However, viral breakthrough occurred in seven patients, making this regimen unsatisfactory.

Clinical and virological predictors of sustained response with an interferon-based simeprevir regimen for patients with chronic genotype 1 hepatitis C virus infection.

Simeprevir plus peg-interferon/ribavirin (PR) is approved to treat chronic hepatitis C (HCV) genotype 1 (GT1) and GT4 infection. This study aimed to assess baseline and on-treatment the factors predictive of sustained virologic response 12-weeks post-treatment (SVR12) in patients receiving 12 weeks of simeprevir plus PR followed by 12 or 36 weeks of PR. Data from participants in four studies (QUEST-1, QUEST-2, ATTAIN and PROMISE) were pooled to examine the efficacy and safety of simeprevir+PR in HCV GT1 patients. The predictive power of baseline variables for SVR12 was assessed using univariate and multivariate logistic regression models while the relationship between early (Week 4) on-treatment response and SVR12 was analyzed by GT1 subtype and treatment experience. Data for 1160 patients were analyzed (overall SVR12: 71%). Baseline factors predictive of SVR12 were: IL28B CC genotype, GT1a/Q80K-negative, treatment-naïve/prior relapser, no cirrhosis, HCV-RNA ≤2,000,000IU/mL, albumin >42g/L, platelets >200x109 /L. Patients with HCV GT1b (86%), IL28B CC genotype (87%), and treatment-naïve patients (83%) were predicted to achieve the highest SVR12 rates and rates of rapid virologic response. Week 4 early on-treatment response identified treatment-naïve and prior relapse patients likely to achieve SVR12. Patients likely to respond to simeprevir+PR can be identified using baseline factors. Early on-treatment response predicts treatment success.

Low-density lipoprotein and other predictors of response with telaprevir-based therapy in treatment-experienced HCV genotype 1 patients: REALIZE study.

BACKGROUND & AIMS: Predictors of response to treatment with peginterferon plus ribavirin are well established. In these post-hoc analyses of the REALIZE study, we sought to identify predictors of response for telaprevir-based triple therapy. METHODS: Patients from the REALIZE study with baseline data for all predictors evaluated (including baseline disease characteristics and demographics, prior treatment response and baseline laboratory assessments) were included in the post-hoc analyses (n = 465). Univariate and multivariate analyses were used to evaluate factors predicting treatment outcomes. RESULTS: Sustained viral response (SVR) rates were 86% in prior relapsers, 63% in prior partial responders and 32% in prior null-responders. In the final multivariate analysis, baseline factors predicting SVR were prior response to treatment [Odds ratio (OR) = 2.80; 95% confidence interval (CI), 2.13-3.69], low-density lipoprotein (LDL) (≥2.6 mmol/L) (OR = 2.11; 95% CI, 1.52-2.93), HCV genotype (OR = 0.58; 95% CI, 0.36-0.93), and maximum alanine amino transferase and aspartate amino transferase (OR = 0.62; 95% CI, 0.40-0.97). CONCLUSIONS: Prior response to peginterferon plus ribavirin treatment and LDL levels are the main independent predictive markers of response with telaprevir-based triple therapy.

Sustained virologic response rates with telaprevir-based therapy in treatment-naive patients evaluated by race or ethnicity.

BACKGROUND: The phase 3 studies of telaprevir (T) in combination with peginterferon α-2a and ribavirin (PR) in treatment-naive genotype 1 chronic hepatitis C virus-infected patients (ADVANCE/ILLUMINATE) were not designed a priori to assess the effect of race and ethnicity on treatment response. However, these factors are important given the lower sustained virologic response (SVR) rates observed in black and Hispanic/Latino patients treated with PR. GOALS: This retrospective pooled analysis evaluated the effect of race or ethnicity on treatment-naive patient response to telaprevir-based therapy and assessed resistant variant profiles. MATERIALS AND METHODS: This analysis comprised patients enrolled in ADVANCE (N=363) and ILLUMINATE (N=540) who received 12 weeks of telaprevir in combination with PR followed by 12 or 36 weeks of PR alone and patients in ADVANCE (N=361) who received 48 weeks of PR alone. Race and ethnicity were self-reported and not mutually exclusive. RESULTS: Higher SVR rates were observed with telaprevir-based therapy compared with PR in blacks [n=99 (62%) vs. n=28 (29%), respectively] and in Hispanics/Latinos [n=89 (72%) vs. n=38 (39%)]. The SVR was lower in telaprevir-treated blacks [n=99 (62%)] compared with nonblacks [n=791 (78%)] and in Hispanic/Latinos compared with non-Hispanics/Latinos [n=89 (72%) vs. n=801 (76%)]. Low discontinuation rates due to adverse events, including rash and anemia, were observed across subgroups. Resistance profiles were similar among the subgroups. CONCLUSIONS: Treatment-naive black and Hispanic/Latino patients with genotype 1 chronic hepatitis C virus infection may benefit from telaprevir-based therapy, an important finding given the lower SVR rates observed in these patients when they are treated with PR alone.

Risk factors predictive of anemia development during telaprevir plus peginterferon/ribavirin therapy in treatment-experienced patients.

BACKGROUND & AIMS: Anemia is a common adverse event associated with telaprevir-based triple therapy of chronic, genotype 1 hepatitis C. Identification of patients at risk of developing anemia could allow evaluation of suitability for therapy, and aid in determining frequency of anemia monitoring and treatment management. METHODS: This post-hoc analysis utilized data from the no lead-in telaprevir, peginterferon and ribavirin arm of the REALIZE study. Anemia was defined as a single occurrence of hemoglobin <10 g/dl at any point during treatment. Pre-treatment factors with potential to act as prognostic indicators of anemia including age, sex, BMI, and baseline hemoglobin were analysed by univariate and multivariate logistic regression analyses. Nomograms (graphical representations of risk factors) were developed to predict the likelihood of developing anemia. RESULTS: Among the 265 patients, 102 (38%) had anemia, with 78/102 (77%) developing anemia on or before week 12. Most patients developed anemia after week 2 and an inverse correlation was found between week 2 hemoglobin and the likelihood of developing anemia. Overall, 60% of patients (60/100) with week 2 hemoglobin <13 g/dl subsequently developed anemia. The multivariate analysis revealed older age (>45 years), lower BMI (≤25 mg/m(2)) and baseline hemoglobin (continuous variable) were significantly associated with the probability of developing anemia during telaprevir treatment. CONCLUSIONS: These analyses indicate the potential of using predictive risk factors such as low baseline and on-treatment hemoglobin to identify patients at risk of developing anemia on telaprevir-based triple therapy, which may increase the potential for treatment success by careful patient monitoring.

Sustained virological response with telaprevir in 1,078 patients with advanced hepatitis C: the international telaprevir access program.

BACKGROUND & AIMS: There is little information regarding the extent to which difficult to cure patients with advanced liver fibrosis, due to hepatitis C virus genotype-1 (HCV-1) can successfully and safely be treated with triple therapy with telaprevir (TVR), pegylated interferon alpha (P) and ribavirin (R). In the TVR early access program HEP3002 we aimed to explore treatment safety and efficacy, and identify predictors of sustained virological response at week 24 (SVR24). METHODS: 1078 patients with bridging fibrosis (n=552) or cirrhosis (n=526) diagnosed by either liver biopsy or non-invasive markers, with compensated bone marrow (neutrophils >1500/mm(3), Hb >12/13 g/dl) and liver function (Albumin >3.3g/dl, Platelets >90,000/ml) received TVR PR for 12 weeks, followed by a PR tail according to label. RESULTS: Overall, 614 (57%) achieved SVR24 by intention-to-treat analysis. The SVR24 rate was 68% in 221 treatment naïve patients (62.8% F4), 72% in 356 prior relapsers (64.4% F4), 55% in 139 partial responders (53.2% F4), and 34% in 294 null responders (28.6% F4). The SVR24 rate to response-guided therapy (24 weeks treatment duration if undetectable viremia at weeks 4 and 12) was 84% in 222 naïve/relapser F3 patients. Independent predictors of response were: (A) F3 (odds ratio (OR)=1.51, 95% CI 1.31-2.00, p=0.005), (B) subtype 1b (OR=1.63, 95% CI 1.18-2.24, p=0.0029), (C) alpha-fetoprotein <10 ng/ml (OR=2.50, 95% CI 1.87-3.36, p<0.0001) and (D) any prior response other than null (OR=3.29, 95% CI 2.40-4.52, p<0.0001). SVR24 rose for patients who had more of these predictive factors: 6/32 (19%) for none, 38/139 (27%) for 1, 129/260 (50%) for 2, 202/329 (61%) for 3, and 194/235 (83%) for 4 factors. Grade 2-4 treatment-related adverse events (AE) were experienced by 719 (67%) patients; 169 (16%) discontinued therapy for AE and 7 (0.6%) died during the PR tail. CONCLUSIONS: Naïve and experienced patients with advanced fibrosis or cirrhosis due to HCV-1 who have compensated bone marrow and liver function, can effectively and safely be treated by TVR triple therapy. Baseline predictors of outcome have been identified to optimize pre-treatment counselling.

Homeostasis model assessment of insulin resistance does not seem to predict response to telaprevir in chronic hepatitis C in the REALIZE trial.

UNLABELLED: Baseline homeostasis model assessment-estimated insulin resistance (HOMA-IR), a marker for insulin resistance, has been associated with poor virologic response to peginterferon alpha/ribavirin (PR) in chronic hepatitis C. We evaluated the association between baseline HOMA-IR and pretreatment factors on sustained virologic response (SVR) to telaprevir (TVR) in genotype 1 patients with hepatitis C and prior peginterferon/ribavirin (PR) treatment failure. Patients were randomized to 12 weeks of TVR (750 mg q8h) plus peginterferon (180 µg/week) and ribavirin (1,000-1,200 mg/day) (with or without a 4-week lead-in) followed by PR, or PR alone (PR48), for 48 weeks. Univariate and multiple logistic regression analyses explored the prognostic significance of baseline HOMA-IR alone and adjusted for other pretreatment factors and SVR. The TVR arms were pooled for the purposes of this analysis. In all, 662 patients were randomized; 578 had baseline HOMA-IR and other prognostic data and were included in this analysis. Median baseline HOMA-IR was 2.6 (interquartile range [IQR] 1.7-4.3); 207 (36%), 206 (36%), and 165 (29%) patients had baseline HOMA-IR <2, 2 to <4, and ≥ 4, respectively. Male gender, higher body mass index, triglycerides, gamma-glutamyl transpeptidase, maximum alanine aminotransferase/aspartate aminotransferase, and fibrosis stage were associated with higher baseline HOMA-IR. Baseline HOMA-IR was associated with SVR in univariate analysis, but not after adjustment for other baseline prognostic factors (TVR: OR = 0.95, 95% confidence interval [CI]: 0.71,1.29; PR48: 0.60; 95% CI: 0.25,1.43). CONCLUSION: In patients with prior PR treatment failure, baseline HOMA-IR correlated with SVR in univariate but not multivariate analyses, suggesting other factors have a more direct causal relationship with virologic response to TVR-based therapy than HOMA-IR.

Insulin resistance and response to telaprevir plus peginterferon α and ribavirin in treatment-naive patients infected with HCV genotype 1.

OBJECTIVE: Insulin resistance is a predictor of poor response to peginterferon/ribavirin in patients infected with the chronic hepatitis C virus (HCV). There are no data on direct-acting antivirals. This exploratory analysis assessed the effect of metabolic factors and insulin resistance, measured by homoeostatic model assessment (HOMA), on virological response to telaprevir in Study C208. DESIGN: Overall, 161 HCV genotype 1-infected, treatment-naïve patients received 12 weeks of telaprevir plus peginterferon/ribavirin, then 12/36 weeks of peginterferon/ribavirin depending on on-treatment response criteria. The prognostic significance of several factors, including HOMA-insulin resistance (HOMA-IR), on virological response at weeks 4 and 12, end of treatment and 24 weeks after treatment was explored by multiple regression analysis. RESULTS: Baseline HOMA-IR data were available for 147 patients; baseline characteristics were consistent with the overall population. Baseline HOMA-IR <2, 2-4 and >4 was seen in 54%, 30% and 16% of patients, respectively. Neither response rates (any time point) nor week 4 viral load decline were significantly influenced by baseline HOMA-IR. In multivariate analyses, fibrosis stage and low-density lipoprotein cholesterol level were predictive of sustained virological response (OR 0.47 and 1.02, respectively). After the end of treatment, HOMA-IR was significantly lower in patients with sustained virological response than in those without (0.61 vs 1.34 for relapsers and 1.15 for non-responders; p<0.05). CONCLUSION: In this study, baseline HOMA-IR was not predictive of virological response to telaprevir in HCV genotype 1-infected, treatment-naïve patients, while sustained virological response was associated with improved HOMA-IR. These results suggest that metabolic factors and insulin resistance do not have a significant effect on telaprevir-based treatment efficacy.

Evaluating Diversity in Randomized Clinical Trials of Dolutegravir-Based Antiretroviral Therapy Regimens: Pooled 48-Week Analyses by Race, Sex, and Regional Subgroups.

Background: In HIV clinical trials, proportions of Black and female participants achieving virologic suppression (VS) are often lower compared with White and male participants. As the antiretroviral therapy (ART) landscape continues to evolve, addressing existing challenges in clinical trial diversity will be critical to effectively translate results into clinical practice. Here, we pooled data to evaluate the efficacy and safety of dolutegravir (DTG)-containing regimens by race, sex, and regional subgroups. Methods: Three pooled analyses were conducted using 48-week results from phase 3/3b trials: DTG 3-drug vs non-DTG-containing 3- or 4-drug regimens in ART-naive participants (ARIA, FLAMINGO, SINGLE, SPRING-2), DTG-containing 2-drug vs 3-drug regimens in ART-naive participants (GEMINI-1, GEMINI-2), and DTG 3-drug vs non-DTG-containing 3- or 4-drug regimens in ART-experienced participants (SAILING, DAWNING). Proportions of participants with VS, safety, and change from baseline in CD4+ cell count were analyzed. Results: Proportions of participants achieving VS were high among those receiving DTG vs comparator regimens. Proportions of participants achieving VS were generally lower in Black (vs non-Black), female (vs male), and US (vs non-US) subgroups. No new safety signals emerged from any subgroup in pooled analyses. Conclusions: These analyses confirm that, across subgroups, DTG has robust efficacy and a good safety profile at week 48 relative to comparator regimens. Achieving VS may vary by participant characteristics, highlighting the urgent need for enrollment to reflect the demographics of global HIV populations more accurately. Future studies should strive to support participants throughout the trial to ensure optimal representation, inclusion, and retention.

Effect of baseline characteristics on the efficacy and safety of once-daily darunavir/ ritonavir in HIV-1-infected, treatment-naïve ARTEMIS patients at week 96.

OBJECTIVES: ARTEMIS demonstrated significantly greater efficacy of once-daily darunavir/ritonavir (DRV/r) 800/100 mg versus lopinavir/ritonavir 800/200 mg (total daily dose) in treatment-naïve, HIV-1-infected patients at week 96. The influence of baseline characteristics on efficacy and safety was analyzed in DRV/r patients. METHODS: Patients received once-daily DRV/r plus fixed-dose tenofovir/emtricitabine. Week 96 efficacy and safety data were analyzed by gender (males, n=239; females, n=104), age (≤30, n=115; 31-45, n=175; >45, n=53), race (Asian, n=44; Black, n=80; Caucasian/White, n=137; Hispanic, n=77), and hepatitis B and/or C virus coinfection (n=43). RESULTS: Week 96 virologic response rates (HIV-1 RNA<50 copies/mL) were as follows: gender: 79% for both males and females; age: 72% (≤30), 81% (31-45), and 89% (>45); race: 96% (Asian), 71% (Black), 77% (Caucasian/White), and 79% (Hispanic); coinfection status: 72% (coinfected) and 80% (non-coinfected). The incidence of treatment-related adverse drug reactions (ADRs) and laboratory abnormalities were comparable across gender, age, and race subgroups. Coinfected patients had a higher incidence of liver-related ADRs than non-coinfected patients. CONCLUSIONS: DRV/r 800/100 mg qd is an effective, well-tolerated treatment option for treatment-naïve patients of different gender, age, race, or coinfection status.

Suboptimal adherence to darunavir/ritonavir has minimal effect on efficacy compared with lopinavir/ritonavir in treatment-naive, HIV-infected patients: 96 week ARTEMIS data.

OBJECTIVES: To examine how treatment adherence differences in ARTEMIS (96 week analysis) affected clinical outcome, and to assess factors impacting adherence. PATIENTS AND METHODS: ARTEMIS is a Phase III trial, in HIV-1-infected treatment-naive patients, comparing efficacy and safety of once-daily darunavir/ritonavir (800/100 mg) versus lopinavir/ritonavir (800/200 mg total daily dose), each with a fixed-dose background tenofovir and emtricitabine regimen. Self-reported treatment adherence was assessed using the Modified Medication Adherence Self-Report Inventory (M-MASRI). In post-hoc analyses, mean adherence from weeks 4-96 was used to assess overall adherence for each patient, and transformed into a binary variable (>95% , adherent; < or = 95% , suboptimally adherent). RESULTS: Overall adherence was high: 83% of darunavir/ritonavir-treated patients and 78% of lopinavir/ritonavir-treated patients were >95% adherent. The difference in virological response rate for adherent versus suboptimally adherent patients was smaller for darunavir/ritonavir (6% difference: 82% versus 76%, P = 0.3312) than for lopinavir/ritonavir (25% difference: 78% versus 53%, P < 0.0001). In suboptimally adherent patients, a higher virological response rate was seen with darunavir/ritonavir (76%) versus lopinavir/ritonavir (53%) (P < 0.01). Suboptimally adherent patients (both treatment groups) reported more adverse events (AEs), including gastrointestinal AEs, than adherent patients. Darunavir/ritonavir had a lower rate of AEs, including gastrointestinal AEs, than lopinavir/ritonavir, in adherent and suboptimally adherent patients. CONCLUSIONS: Suboptimal adherence had no significant effect on the virological response rate with once-daily darunavir/ritonavir treatment. In contrast, the lopinavir/ritonavir response rate was significantly reduced in suboptimally adherent patients compared with adherent patients. Once-daily darunavir/ritonavir resulted in a higher virological response rate in suboptimally adherent patients compared with lopinavir/ritonavir.

Adherence to enfuvirtide and its impact on treatment efficacy.

High adherence rates to antiretroviral (ARV) therapy are associated with increased durability of viral suppression and decreased rates of drug resistance. The requirement of twice-daily subcutaneous self-administration of enfuvirtide (ENF) has raised concerns about adherence. This study assesses adherence to ENF and an optimized background (OB) of ARVs and its impact on virological and immunological responses during the TORO trials. Eighty-eight percent of patients in the OB arm reported > or = 85% adherence versus 87% of patients in the ENF + OB arm. Higher overall adherence was associated with improved virological and immunological response in both treatment arms at 48 weeks. In patients with > or = 85% adherence, 33% of patients in the ENF + OB arm achieved HIV-1 RNA < 400 copies/ml, versus 13% in the OB arm (p < 0.0001). Similarly, patients with > or = 85% adherence in the ENF + OB arm achieved a mean increase in CD4 cell count of 104 cells/mm(3) compared with 58 cells/mm(3) for patients in the OB arm (p < 0.001). None of the demographic factors explored (age, gender, race) or baseline characteristics (CD4 count, viral load, or baseline sensitivity score) was significant in predicting adherence to ENF when analyzed by multiple regression. Importantly, a history of intravenous drug use (IDU) was not associated with a significant decrease in adherence (mean adherence for IDU 96% versus mean adherence for non-IDU 96%; p = 0.825). Adherence was high in patients receiving the self-injectable ARV enfuvirtide. In addition, the inclusion of ENF did not negatively impact adherence to the ARV regimen as a whole.

Efficacy and safety of 48 weeks of enfuvirtide 180 mg once-daily dosing versus 90 mg twice-daily dosing in HIV-infected patients.

PURPOSE: To evaluate the safety and antiviral activity of once-daily (qd) enfuvirtide (ENF) compared with twice daily (bid) ENF. METHOD: T20-401 was a phase 2, open-label, randomized, 48-week pilot study comparing ENF 180 mg qd versus ENF 90 mg bid, added to an optimized background (OB) regimen. Patients were randomized 1:1 to receive ENF 180 mg qd given as two 90-mg injections (n = 30) or one 90-mg injection bid (n = 31), plus OB. The primary efficacy endpoint was the proportion of patients achieving a HIV-1 RNA viral load <400 copies/mL. Adherence, pharmacokinetics, safety, and tolerability parameters, including injection site reactions (ISRs), were compared between treatment arms. RESULTS: At Week 48, 23.3% of patients on once daily versus 22.6% on twice daily (p = .969) reached <400 copies/mL and 13.3% and 22.6% (p = .323), respectively, reached <50 copies/mL. The proportion reporting 1 adverse event or ISRs was comparable between arms, despite an increased incidence of grade 4 erythema (13% vs. 0%), induration (33% vs. 12%), and ecchymosis (7% vs. 0%) on twice daily versus once daily. ENF adherence (95% of prescribed doses) was higher on once daily (80.0%) versus twice daily (58.1%). CONCLUSION: The antiviral efficacy, safety, and tolerability of 180 mg ENF qd appeared comparable with that of 90 mg ENF bid at Week 48, although the study was not powered to demonstrate the noninferiority of once daily versus twice daily.

Efficacy of enfuvirtide in patients infected with drug-resistant HIV-1 in Europe and Australia.

BACKGROUND: The T-20 vs. Optimized Regimen Only Study 2 (TORO 2) compared the efficacy and safety of 24 weeks of treatment with the fusion inhibitor enfuvirtide in combination with an optimized background antiretroviral regimen with the efficacy and safety of the optimized background regimen alone. METHODS: The patients had previous treatment with each of the three classes of antiretroviral drugs, documented resistance to each class, or both and a plasma level of human immunodeficiency virus type 1 (HIV-1) RNA of at least 5000 copies per milliliter. They were randomly assigned in a 2:1 ratio to receive either enfuvirtide (90 mg twice daily) plus a background regimen optimized with the aid of resistance testing (enfuvirtide group) or the background regimen alone (control group). RESULTS: Of the 512 patients who underwent randomization, 335 in the enfuvirtide group and 169 in the control group received at least one dose of study medication and had at least one follow-up measurement of plasma HIV-1 RNA. The median base-line plasma HIV-1 RNA level was 5.1 log10 copies per milliliter in both groups. The median CD4+ cell count was 98.0 cells per cubic millimeter in the enfuvirtide group and 101.5 cells per cubic millimeter in the control group. Patients had a median of seven years of previous treatment and had received a median of 12 antiretroviral drugs. The background regimen comprised a mean of four antiretroviral drugs in both groups. At 24 weeks, the least-squares mean change from base line in the plasma viral load (intention-to-treat, last observation carried forward) was a decrease of 1.429 log10 copies per milliliter in the enfuvirtide group and a decrease of 0.648 log10 copies per milliliter in the control group, a difference of 0.781 log10 copies per milliliter (P<0.001). The mean increase in the CD4+ cell count was greater in the enfuvirtide group (65.5 cells per cubic millimeter) than in the control group (38.0 cells per cubic millimeter, P=0.02). CONCLUSIONS: The addition of enfuvirtide to an optimized background regimen provided significant viral suppression and immunologic benefit over a 24-week period in HIV-1-infected patients who had previously received multiple antiretroviral drugs.

Enfuvirtide, an HIV-1 fusion inhibitor, for drug-resistant HIV infection in North and South America.

BACKGROUND: The T-20 vs. Optimized Regimen Only Study 1 (TORO 1) was a randomized, open-label, phase 3 study of enfuvirtide (T-20), a human immunodeficiency virus type 1 (HIV-1) fusion inhibitor. METHODS: Patients from 48 sites in the United States, Canada, Mexico, and Brazil with at least six months of previous treatment with agents in three classes of antiretroviral drugs, resistance to drugs in these classes, or both, and with at least 5000 copies of HIV-1 RNA per milliliter of plasma were randomly assigned in a 2:1 ratio to receive enfuvirtide plus an optimized background regimen of three to five antiretroviral drugs or such a regimen alone (control group). The primary efficacy end point was the change in the plasma HIV-1 RNA level from base line to week 24. RESULTS: A total of 501 patients underwent randomization, and 491 received at least one dose of study drug and had at least one measurement of plasma HIV-1 RNA after treatment began. The two groups were balanced in terms of the median base-line HIV-1 RNA level (5.2 log10 copies per milliliter in both groups), median CD4+ cell count (75.5 cells per cubic millimeter in the enfuvirtide group, and 87.0 cells per cubic millimeter in the control group), demographic characteristics, and previous antiretroviral therapy. At 24 weeks, the least-squares mean change from base line in the viral load (intention-to-treat, last observation carried forward) was a decrease of 1.696 log10 copies per milliliter in the enfuvirtide group, and a decrease of 0.764 log10 copies per milliliter in the control group (P<0.001). The mean increases in CD4+ cell count were 76 cells per cubic millimeter and 32 cells per cubic millimeter, respectively (P<0.001). Reactions at the site of the injections were reported by 98 percent of patients receiving enfuvirtide. There were more cases of pneumonia in the enfuvirtide group than in the control group. CONCLUSIONS: The addition of enfuvirtide to an optimized antiretroviral regimen provided significant antiretroviral and immunologic benefit through 24 weeks in patients who had previously received multiple antiretroviral drugs and had multidrug-resistant HIV-1 infection.

TORO: ninety-six-week virologic and immunologic response and safety evaluation of enfuvirtide with an optimized background of antiretrovirals.

The additional 48-week optional treatment extension of the T-20 versus Optimized Regimen Only (TORO) studies evaluated long-term safety and efficacy of enfuvirtide (ENF) through week 96 in patients receiving ENF plus optimized background (OB) and patients switching to ENF plus OB from OB alone. Patient randomization was 2:1 to ENF plus OB (n = 663) and OB (n = 334), of which 89.7% and 89.8% were male, 89.3% and 88.6% were Caucasian, and median age was 41 and 42 years, respectively. HIV risk factors were comparable between the ENF plus OB and OB groups with the major factors being 65.2% versus 66.2% homosexual contact, 17.8% versus 19.8% heterosexual contact, 4.1% versus 4.8% bisexual contact, respectively, and 6.9% injection drug use in both groups. OB patients were allowed to switch to ENF plus OB at virologic failure before week 48 and required to switch at week 48 to continue in the study (n = 230). Efficacy and safety assessments were conducted for each group. At week 96, 55% of ENF plus OB subjects completed the study and 26.5% achieved a viral load of less than 400 copies per milliliter (17.5% achieved less than 50 copies per milliliter). Viral load and CD4 mean change from baseline was -2.1 and -1.1 log(10) HIV-1-RNA copies per milliliter and +166 and +116 CD4 cells/mm(3) for ENF plus OB and switch patients, respectively. No new ENF-related safety issues emerged in weeks 48-96. Injection site reactions led to discontinuation in 7% and 10% of ENF plus OB and switch patients, respectively. In conclusion, these data demonstrate durable efficacy and safety of ENF over 96 weeks and that early use of ENF in combination with other agents for the treatment of antiretroviral-experienced HIV-infected subjects is beneficial.

Enfuvirtide: the first therapy to inhibit the entry of HIV-1 into host CD4 lymphocytes.

Highly active antiretroviral therapy (HAART) based on combinations of drugs that target key enzymes in the life-cycle of human immunodeficiency virus (HIV) has considerably reduced morbidity and mortality from HIV infection since its introduction in the mid-1990s. However, the growing problem of the emergence of HIV strains that are resistant not only to individual drugs, but to whole drug classes, means that agents with new mechanisms of action are needed. Here, we describe the discovery and development of enfuvirtide (Fuzeon), the first drug to inhibit the entry of HIV-1 into host cells.

Cost-efficacy comparison among three antiretroviral regimens in HIV-1 infected, treatment-experienced patients.

BACKGROUND AND OBJECTIVE: In the face of increasing antiretroviral (ARV) treatment options and costs, payers are progressively challenged with prioritising resources. The cost effectiveness of the ARV agent enfuvirtide has been shown to be comparable to that of other available HIV treatment strategies, based on Markov modeling. However, an evaluation of enfuvirtide treatment costs that considers the impact of virological and immunological responses to therapy may provide a more clinically meaningful perspective for primary HIV healthcare providers. The aim of this study was to assess the cost per unit change in efficacy (HIV RNA decreases and CD4 count increases) of three different ARV regimens for triple class-experienced HIV-1 infected patients using actual drug costs and data from randomised, controlled clinical trials. STUDY DESIGN: The analysis included three steps. First, re-analysis of 48-week clinical trial data (T-20 vs Optimized Regimen Only [TORO]) to allow for a more direct comparison of enfuvirtide versus other commonly used ARV agents. All patients included in the re-analysis received a common optimised background (COB) regimen of three drugs: two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) and a ritonavir-boosted protease inhibitor (PI), lopinavir. HIV RNA levels and CD4 count changes were determined for three patient groups according to the treatment received - group 1: COB + enfuvirtide; group 2: COB + PI; group 3: COB + NRTI + PI. The second step of the analysis involved calculating the annualised regimen costs ($US wholesaler acquisition cost) for each patient group. In the third step, cost-efficacy ratios were calculated and compared between groups: (a) the annualised regimen cost ($US)/change in viral load from baseline, and (b) the annualised regimen cost ($US)/change in CD4+ cell count from baseline. RESULTS: One hundred and fifty-seven patients were included in this previously unplanned secondary analysis (group 1: 79 patients; group 2: 42 patients; group 3: 36 patients). HIV RNA and CD4 count changes from baseline to week 48 were -1.80, -0.89 and -0.61 log(10) copies/mL (p < 0.001 for enfuvirtide vs each non-enfuvirtide group) and +102, +57 and +52 cells/mm(3) (p < 0.05 for enfuvirtide versus each non-enfuvirtide subgroup) for groups 1, 2 and 3, respectively. The annualised costs of the combination therapies were $US 35,624, $US 27,549 and $US 30,624; and the costs per 0.50 log(10) copies/mL HIV RNA decrease were $US 9,872, $US 15,542 and $US 24,907 (p < 0.05 for enfuvirtide vs each non-enfuvirtide subgroup) for groups 1, 2 and 3, respectively. The costs per 25 cells/mm(3) CD4 count increase were $US 8,722, $US 12,127 and $US 14,636 for subgroups 1, 2 and 3, respectively. Similar patterns in regimen cost per unit change were achieved after adjusting for baseline prognostic variables. The incremental cost-efficacy ratios for group 1 versus the combination of groups 2 and 3 were $US 3,124 for HIV RNA reduction and $US 3,239 for CD4 count increase. CONCLUSION: Enfuvirtide-containing regimens are associated with higher cost as well as improved virological and immunological outcomes when compared with alternative four- and five-drug regimens. When costs and outcomes are considered jointly, an enfuvirtide-based regimen is more cost efficacious than alternative regimens in this patient population.

Chronic Hepatitis C Treatment in Patients with Drug Injection History: Findings of the INTEGRATE Prospective, Observational Study.

INTRODUCTION: People who inject drugs represent an under-treated chronic hepatitis C virus (HCV)-infected patient population. METHODS: INTEGRATE was a prospective, observational study investigating the effectiveness, safety, and adherence in routine clinical practice to telaprevir in combination with peg-interferon and ribavirin (Peg-IFN/RBV) in patients with history of injecting drug use chronically infected with genotype 1 HCV. RESULTS: A total of 46 patients were enrolled and included in the intent-to-treat (ITT) population. Among heroin and/or cocaine users (n = 37; 80%), 22% reported use in the past month; 74% (34/46) of patients were on opioid substitution therapy in the pre-treatment phase, and 43% (20/46) discontinued HCV treatment prematurely. Sustained virologic response rate was 54% (25/46) in the ITT population and 74% (25/34) in the per protocol (evaluable-for-effectiveness) population. The main reason for failure in the ITT analysis was loss to follow-up (n = 8; 17%). Adverse events occurred in 91% (42/46) of patients. Mean patient-reported adherence to study drugs was >89% at Week 4, Week 12 and end of treatment. CONCLUSION: Despite a high rate of treatment discontinuation (including loss to follow-up), self-reported adherence to treatment was good and virologic cure rates were similar to those reported in large real-world cohorts. Our findings suggest that people with a history of injecting drug use should be considered for treatment of chronic HCV infection, and highlight the need for improvements in patient support to boost retention in care and, in turn, help to prevent reinfection and transmission. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier, NCT01980290. FUNDING: Janssen Pharmaceuticals.