Efficacy and safety of peg-IFN alfa-2a with ribavirin for the treatment of HCV/HIV coinfected patients who failed previous IFN based therapy

2.1. Patient selection 

Adult patients (>21 years old) with chronic hepatitis C defined as, detectable plasma HCV RNA and stable HIV infection were enrolled in this study. Patients had to have a liver biopsy (unless contraindicated), within 6 months of enrollment consistent with chronic HCV infection. Cirrhotic patients were restricted to no more than 20% of enrolled patients. Patients had to have plasma HIV RNA<25,000copies/mL, CD4+ cell counts >200cells/μL, and be in stable antiretroviral therapy for at least 4 weeks prior to enrollment. Patients with CD4 count≤200cells/μL but >100cells/μL could participate if they had HIV RNA<5000copies/mL. All patients were non-responders to prior therapy with IFN or IFN plus RBV for a minimum period of 24 weeks, defined as showing no virological response (HCV RNA) at end of treatment, nor at any other point during treatment. (No relapsers or breakthrough relapsers were enrolled in the study.)

Patients were excluded from participation if they had active opportunistic diseases, other causes of chronic liver disease, absolute neutrophil count<1250/μL, platelet count<65,000/μL, Hgb<10mg/dL, serum albumin<3.0gm/dL, bilirubin>2.5g/dL, prolongation of prothrombin time greater than 4s ULN, or uncontrolled thyroid disease. Other exclusion criteria included decompensated liver disease, defined as Child-Pugh other than Grade A; severe pulmonary, cardiac, psychiatric, or ophthalmic disease; history of transplantation; or active history of drug or alcohol abuse. Patients with incomplete or complete cirrhosis of the liver were excluded if their serum alpha-fetoprotein (AFP) levels were >200ng/mL. For inclusion, cirrhotic patients with AFP>50μg/mL were required to have a CT scan, MRI or sonogram negative for hepatocellular carcinoma.

All patients gave written informed consent, and were required to use effective contraception throughout the study period. The Institutional Review Board of the Medical Sciences Campus, University of Puerto Rico, approved the study.

2.2. Study design 

Patients received subcutaneous weekly injections of 180μg peg-IFNα-2a plus RBV (800mg/day) for 24 weeks. Patients who had virological response, defined as undetectable HCV RNA (<600copies/mL) or a decrease of at least 2-log from baseline at week 24, were treated with peg-IFNα-2a (180μg/week) plus RBV (800mg/day) for an additional 24 weeks. Patients who did not achieve viral response at week 24 were discontinued from treatment.

2.3. Assessment of efficacy 

The primary end point of the study was sustained viral response (SVR), defined as undetectable HCV RNA titer (<600copies/mL, the Roche Amplicor HCV Monitor test v 2.0) at study week 72. Changes in HCV RNA were also assessed during the course of treatment at weeks 12, 24, and 48.

2.4. Assessment of liver histology 

Histology activity indexes (HAI) was obtained using Ishak score necroinflamation, grade (0–18) and fibrosis stage (0–6) by a single experienced pathologist (AF). To be acceptable for interpretation, biopsies had to be ≥25mm long and have no less than 15 portal spaces. Fibrosis progression rate (FPR) was calculated by the ratio of Ishak fibrosis stage score at baseline and the estimated duration of HCV infection in years and reported as IshakF/years. Post-treatment FPR was calculated by subtracting the Ishak fibrosis stage score at week 72 (post-treatment) biopsy from baseline (pre-treatment) and dividing between the interval of time (years) between biopsies. Ishak necroinflamation grade, fibrosis stage and FPR mean scores were determined at baseline and week 72. The percentage (%) of patients with Ishak stage score changes ≥2 points between baseline and week 72 was also obtained.

2.5. Assessment of safety 

Laboratory measurements during the 48 weeks of treatment and 24 weeks of follow up, included hematology, blood chemistry, thyroid function, CD4+ cell counts, and HIV and HCV RNA viral loads. Post-treatment liver biopsies at or after week 72 were obtained from all patients who agreed to this procedure. All adverse events (AEs), concomitant medications, alterations in antiretroviral treatment, concomitant illnesses or opportunistic diseases, vital signs, and physical examination were assessed at each study visit. All AEs were graded for severity using World Health Organization (WHO) parameters. The total number of AEs, AEs requiring dose reductions, withdrawals, lost-to-follow, and discontinuations were obtained.

2.6. Statistical analysis 

The data was analyzed using Stata version 7.0 (Stata Corporation, College Station, TX, USA). The Mann–Whitney test was used for analysis of continuous variables and χ2 (Fisher's exact test) for comparison of group frequencies. Wilcoxon signed-rank test was used to compare values at baseline and week 72 for sustained viral responders (SVR) and non-responders. p-Values less than or equal to 0.05 were considered significant.

3.1. Baseline characteristics 

Baseline characteristics of the population at baseline are shown in Table 1. Initially this study was designed as a randomized pilot trial of peg-IFN alfa-2a monotherapy versus peg-IFN alfa-2a plus RBV combination. The reason for the inclusion of a monotherapy arm was concerns about drug interactions of HAART and RBV, and mitochondrial toxicity. As soon it was demonstrated that monotherapy was suboptimal to achieve SVR, and that HIV/HCV coinfected patients could safely be treated with RBV, the study was modified to open label combination treatment. Of the 76 patients enrolled in this study, 41 were assigned to combination treatment with peg-IFNα-2a and 800mg RBV daily and 35 patients were randomized to peg-IFN alfa 2a monotherapy and excluded from this analysis. In the combination cohort, most of the patients were males, risk factor for HCV infection was IDU, with mean age 47 years and mean HCV duration of infection of 21 years. Mean log10 HCV RNA was 5.89 and HCV genotypes in the majority were types 1 and 4 (80.4%). Patients had HIV disease under control, with a mean log10 HIV RNA of 2.82, and mean CD4+ counts was 555cells/μL. The distribution of non-responders was 60% to IFN monotherapy and 40% to IFN plus RBV. Patients had mean Ishak necroinflamation grade 7.00 (S.D. 3.64) and fibrosis stage 3.49 (S.D. 1.70) scores at baseline. Mean FPR was 0.44IshF/years (S.D. 0.45) and 14.6% of the patients were cirrhotic. At baseline, 34 patients or 82.9%, were in antiretroviral treatment (ART), with only seven (17%) without treatment because high CD4 levels or long-term non-progression. The majority of the patients were using highly active antiretroviral therapy (HAART) combinations (28% or 82%) versus (6% or 18%) only in nucleoside transcriptase inhibitors (NTI) combinations of zidovudine/stavudine with lamiduvine. The protease inhibitors used were nelfinavir 21/75%, indinavir 5/17.8%, and ritonavir and saquinavir 1% or 3.6% each. Almost all patients were receiving zidovudine/stavudine plus lamiduvine in the HAART combination.

Table 1. Baseline characteristics (intent-to-treat population)

	Characteristic	N=41
	Sex
	Males, n (%)	35 (85%)
	Females, n (%)	6 (15%)
	Age (years), mean (S.D.)	47.0 (8.7)
	HCV duration (years), mean (S.D.)	21.0 (10)
	logHCV RNA (copies/mL), mean (S.D.)	5.89 (0.75)
	logHIV (copies/mL), mean (S.D.)	2.82 (0.58)
	CD4+ (cell count/μL), mean (S.D.)	555 (324)
	ALT (IU/L) (S.D.)	98 (62.2)
	Risk of infection
	IVDU, n (%)	25 (61%)
	Non-IVDU, n (%)	16 (39%)
	HCV genotype
	1 and 4, n (%)	33 (80.4%)
	2 and 3, n (%)	4 (9.8%)
	Not known, n (%)	4 (9.8%)
	Prior treatment
	IFN monotherapy, n (%)	24 (58%)
	IFN/RBV combination, n (%)	17 (42%)

3.2. Efficacy results 

Intention-to-treat (ITT) analysis showed SVR at week 72 of 21.9% (Fig. 1). In patients who completed at least 24 weeks of treatment, SVR was 25.7%. Eight patients were genotype 1 and one patient was genotype 2. Five were previous non-responders to IFN monotherapy and four to prior combination treatment.

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Fig. 1. Virological response rates at different weeks after initiation of treatment. At week 12, the virological response was determined by a 2-log HCV RNA decrease from baseline. For weeks 24, 48, and 72 the virological response was assigned to patients with undetectable plasma HCV RNA. SVR is sustained viral response and ITT is intention to treat where discontinuation equals failure.

Early virological response (EVR), defined as undetectable or ≥2log10HCV RNA decline at week 12, was obtained in 22 patients (53.6%). Of those who achieved EVR, eight patients achieved SVR at week 72. Thus, the positive predictive value of EVR for achieving SVR was 8/22 or 36.6%. Of the 19 patients who did not achieve EVR, only one (5.2%) achieved SVR. Thus, the overall negative predictive value of EVR for achieving SVR was 18/19 or 95.2%. The percent of relapsers was 40% (6/15). All relapsers were documented at week 72.

3.3. Histological response 

We obtained liver biopsies from 41/41 (100%) patients at baseline. At week 72, 22/41 or 54% of the patients agreed to have post-treatment liver biopsy. There was a statistical significance decrease in mean grade, and FPR between baseline and follow-up biopsies (Ishak grade score: −1.86, p=0.01 and FPR: −1.46, p=0.0005). When patients were classified according to virological response (i.e. those with SVR versus non-responder), we found that both groups of patients showed improvement in histological parameters at the end of follow-up (Fig. 2). However, patients who achieved SVR showed significantly greater improvements in mean grade (−3.3, p=0.02), stage score (−1.2, p=0.02), and FPR (−2.3, p=0.03) compared to baseline values. Non-responders also shown statistically significant improvements in grade (−1.3, p=0.09) and FPR (−1.2, p=0.01) from baseline.

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Fig. 2. Effect of treatment on liver histology according to virological response at using the Ishak grade (white area), Ishak stage (gray area), and fibrosis progression rate (FPR) calculated as the ratio of Ishak stage between the estimated duration of HCV infection and is defined as Ishak/years.

3.4. Safety 

There were a total of 165 adverse events with the majority of AE's those commonly associated with IFN-based treatment (Table 2). There were 24 serious AE's in 17 patients, all previously reported complications of IFN-RBV treatment as bone marrow toxicity, neuropathy, lipoatrophy and skin diseases aggravation.

Table 2. Most frequently reported adverse events

	Adverse event	N=41
	Myalgias/artralgias	31
	Flu symptoms	30
	Mygraine/headache	17
	Weight loss
	>5%	14 (34%)
	>10%	8 (19%)
	>15%	2 (5%)
	Anemia	15 (37%)
	Neutropenia	16 (39%)
	Depression	7 (17%)
	Thrombocytopenia	2
	Gastrointestinal	6
	Sinusitis/infections/bronchitis/pneumonia	2
	Bloody oral secretions/oral herpes/dental	1
	Swelling left leg/arm/ankle	1
	Hepatic decompensation (increased bilirubin)	2
	Psoriasis/herpes zoster/pruritus	2
	Neuropathy/facial palsy	1
	Lipodystrophy worsening	1
	Hypothyroidism	1
	Hypertension	0
	Hematuria/urinary symptoms	1
	Fracture right leg	0
	Diabetes (uncontrolled)	2
	Decreased compliance	1
	Lipidemia	2
	Total	165

Table 3 shows all discontinuations and drug modifications. Anemia and neutropenia was documented frequently, and required dose modifications, and in some patients, the concomitant use of growth factors. In total, 26/41 or 63% required dose modifications due to laboratory abnormalities. Six patients were treated with epoetin alfa, three with filgastrim and one with both drugs. Most of the drug dose modifications occurred during the first 24 weeks of treatment. The PI used her criteriae to use growth factors, when patient had 2 weeks dose of study drugs reduced or withhold, or unable to re-challenge full dose of RBV. In some cases availability of growth factors precluded its use. Although 6/41 or 14.6% were cirrhotic no patient experienced hepatic decompensation or lactic acidosis. There were no deaths in study, and all adverse events resolved with medical intervention, or after study drugs were discontinued.

Table 3. Discontinuations, dose modifications and reasons

		N=41
	Discontinuations
	Lost to follow up	4
	Adverse events uncompliance	1
	Total	5
	Dose modifications
	Adverse events	0
	Lab. abnormalities (26)
	Neutropenia	10
	Thrombocytopenia	2
	Anemia	13
	Other	1
	Total	26