Early identification of acute HCV infection is essential to prevent chronic infections and the long-term liver disease complications that may occur. Early identification and treatment of HCV during the acute phase can result in significantly higher response rates with shorter durations of therapy.

Pegylated-interferon alfa (PEG-IFN) was the typical treatment for HCV infection. Participants subcutaneously inject PEG-IFN where the average duration of treatment was approximately 20 weeks. With the advancement of direct-acting antivirals (DAAs), it was possible to see if a new DAA might be non-inferior compared to (PEG-IFN).

The study was designed to see if a fixed-dose combination tablet can replace the old HCV treatments by being more effective, safer and better tolerated in HIV-infected participants with new HCV infection. The study was a Phase I, open-label, two cohort clinical trial, in which 44 acutely HCV-infected HIV-1 positive participants were enrolled. Participants in each cohort were evaluated in two steps: on treatment (Step 1) and follow-up after discontinuing study treatment (Step 2). The cohorts were enrolled sequentially. Participants in Cohort 1 were enrolled and administered oral Sofosbuvir (SOF) in combination with weight-based ribavirin (RBV). Participants in Cohort 2 were enrolled and administered an oral fixed dose combination of Ledipasvir/Sofosbuvir (LDV/SOF).

The first cohort opened with SOF/RBV treatment for 12 weeks and accrued 17 participants. All participants under Cohort 1 were to visit the clinical site at weeks 0, 1, 2, 4, 8, and 12 when on treatment (Step 1), then visit the clinical site again at 2, 4, 8, 12 and 24 weeks during follow-up after discontinuing study treatment (Step 2).

The second cohort opened for an 8-week treatment of LDV/SOF and included at least 27 subjects. All participants under Cohort 2 were to visit the clinical site at weeks 0, 1, 2, 4, and 8 when on treatment (Step 1), then visit the clinical site again at 2, 4, 8, 12 and 24 weeks during follow-up after discontinuing study treatment (Step 2).

Both cohorts were monitored for safety and HCV viral load response while the participants were on treatment.

The primary objective did not compare the cohorts together; instead, each study cohort was formally assessed for efficacy with sustained virologic response 12 weeks after treatment based on non-inferiority criteria compared to a historical SVR rate of 60% separately.

A5327 Eligibility Criteria (Cohort 1 and Cohort 2)

Step 1 inclusion criteria for both cohorts (Cohort 1 and Cohort 2)

• HIV-1 infection, documented by any licensed rapid HIV test or HIV enzyme or chemiluminescence immunoassay (E/CIA) test kit at any time prior to study entry and confirmed by a licensed Western blot or a second antibody test by a method other than the initial rapid HIV and/or E/CIA, or by HIV-1 p24 antigen, or plasma HIV-1 RNA viral load. [NOTE: The term "licensed" refers to a FDA-approved kit, which is required for all IND studies.] WHO (World Health Organization) and CDC (Centers for Disease Control and Prevention) guidelines mandate that confirmation of the initial test result must use a test that is different from the one used for the initial assessment. A reactive initial rapid test should be confirmed by either another type of rapid assay or an E/CIA that is based on a different antigen preparation and/or different test principle (e.g., indirect versus competitive), or a Western blot or a plasma HIV-1 RNA viral load.

• A documented confirmation of acute HCV infection within 6 months prior to A5327 entry or HCV reinfection as described below:

  1. Acute HCV infection was defined as meeting one of the following criteria and exclusion of other causes of acute hepatitis:

     • New (<24 weeks prior to initial A5327 entry) ALT elevation to ≥5X upper limit of normal (ULN) OR >250 U/L in patients with documented normal ALT in the preceding 12 months or ≥10X ULN OR >500 U/L in patients with abnormal or no measured ALT baseline in the preceding 12 months with detectable HCV RNA excluding those with any prior positive anti-HCV. OR
     • Detectable HCV RNA with prior negative anti-HCV Ab or undetectable HCV RNA within the preceding 6 months.

  2. Acute HCV reinfection was defined by documentation of clearance of prior infection (as evidenced by positive anti-HCV Ab) either spontaneously or after treatment with two negative HCV RNA a minimum of 6 months apart AND meeting one of the following criteria in addition to exclusion of other causes of acute hepatitis:

     • New (<24 weeks prior to initial A5327 entry) ALT elevation to ≥5X ULN OR >250 U/L in patients with documented normal ALT in the preceding 12 months or ≥10X ULN OR >500 U/L in patients with abnormal or no measured ALT baseline in the preceding 12 months with detectable HCV RNA. OR
     • Positive HCV RNA with prior negative HCV RNA within the preceding 6 months.

• HCV RNA confirmed to be detectable >12 weeks after first laboratory evidence of acute HCV and still within the <24 week from first laboratory evidence of acute HCV infection window. First laboratory evidence of infection was defined as date of first elevated liver enzymes or date of first serologic evidence of HCV seroconversion and/or viremia (whichever occurs first). [NOTE: If the screening visit occurred less than 12 weeks from the first laboratory evidence of infection, then the participant was required a pre-entry study visit to confirm detectable HCV RNA at least 12 weeks from the first laboratory evidence of infection had passed. It was optimal for this pre-entry visit to occur as close as possible to 12 weeks from first laboratory evidence to ensure timely treatment. Potential participants who entered screening but who had an undetectable HCV RNA (<LLOQ TND) at the pre-entry visit (when required) exhibited evidence of possible spontaneous clearance and will not meet the entry criteria.]

• Body mass index (BMI) ≥ 18 kg/m^2

• Screening electrocardiogram (ECG) without clinically significant abnormalities as determined by the investigator.

• Willing and able to provide written informed consent.

• Men and women age ≥ 18 years.

• All participants agreed not to participate in a conception process (eg, active attempt to become pregnant or to impregnate, sperm donation, in vitro fertilization). [NOTE: Female candidates who were pregnant or breastfeeding were not eligible. A male candidate who had a pregnant female partner was not eligible for the study.]

• When participating in sexual activity that could lead to pregnancy, all participants must agree to use at least two reliable forms of contraceptive simultaneously while receiving protocol-specified medications, and for 6 months after stopping the medications. Such methods included:

  • Condoms (male or female) with or without a spermicidal agent
  • Diaphragm or cervical cap with spermicide
  • Intrauterine device (IUD)
  • Tubal ligation
  • Hormone-based contraceptive (except those containing drospirenone)

[NOTE: Providers and participants were advised that not all contraceptive choices listed above can prevent HIV transmission and that some may actually increase the risk of HIV acquisition. Study participants who were sexually active with HIV-1 negative or unknown HIV-1 serostatus partners were advised that they needed to consider effective strategies for reducing the risk of HIV transmission, as well as meeting the requirement for effective contraception during their participation in the study. Study participants discussed contraceptive choices and HIV risk reduction methods with their health care provider.]

• Participants who were not of reproductive potential (women who had been post-menopausal for at least 24 consecutive months or had undergone hysterectomy and/or bilateral oophorectomy or salpingectomy or men who had documented azoospermia or undergone vasectomy) were eligible without requiring the use of contraceptives. Acceptable documentation of sterilization and menopause was specified below.

  • Written or oral documentation communicated by clinician or clinician's staff of one of the following:
  • Physician report/letter
  • Operative report or other source documentation in the patient record (a laboratory report of azoospermia was required to document successful vasectomy)
  • Discharge summary
  • Follicle stimulating hormone-release factor (FSH) measurement elevated into the menopausal range as established by the reporting laboratory.

• Intention to comply with the dosing instructions for study drug administration and able to complete the study schedule of assessments.

Step 1 inclusion criteria for Cohort 1 only

• HIV-1 ARV therapy fell into one of the following criteria:

  1. ARV untreated, for example due to (1) lack of indication per provider (CD4 T-cell count >500 cells/mm3) or (2) decision by provider and participant to defer ARV therapy during the study drug dosing period (8 or 12 weeks), or (3) elite controller (CD4+ >200 cells/mm3). OR
  2. On a stable, protocol-approved (didanosine (ddI), stavudine (d4T), zidovudine (ZDV) excluded), ARV regimen for >8 weeks prior to screening with a CD4 T-cell count >200 cells/mm3 and a documented plasma HIV-1 RNA level <50 copies/mL or < lower limit of quantification (LLOQ) of local assay if LLOQ is >50 copies/mL by any laboratory that has a Clinical Laboratory Improvement Amendments (CLIA) certification or its equivalent ≥ 8 weeks preceding the A5327 screening visit. HIV-1 RNA levels should be within 1 year of the screening visit. Screening HIV-1 RNA must be < 50 copies/mL as measured by any local laboratory using an FDA-approved assay.

• Candidates must have had the following laboratory parameters within 10-42 days prior to study entry:

  1. Hemoglobin ≥ 12 g/dL for male, ≥11 g/dL for female participants
  2. International normalized ratio (INR) ≤1.5 x ULN unless participant was known hemophilia or was stable on an anticoagulant regimen affecting INR
  3. Albumin ≥ 3 g/dL
  4. Creatinine clearance (CrCl) ≥ 60 mL/min, as calculated by the Cockcroft-Gault equation (refer to section 6.3.5 for calculator utility link)

• Female participants of reproductive potential (defined as women who have not been post-menopausal for at least 24 consecutive months, ie, who have had menses within the preceding 24 months, or women who had not undergone surgical sterilization, specifically hysterectomy and/or bilateral oophorectomy or bilateral salpingectomy) must had a negative serum pregnancy test with a sensitivity of at least 25 mIU/mL performed during screening, within 48 hours prior to study entry.

Step 1 inclusion criteria for Cohort 2 only

• HCV genotype 1a, 1b, or 4 infection with source documentation from a CLIA-approved laboratory (or its equivalent). [NOTE: Those with mixed 1a/b genotype were classified as 1a.]

• HIV-1 ARV therapy fell into one of the following criteria:

  1. ARV untreated, for example due to (1) lack of indication per provider (CD4 T-cell count >500 cells/mm3) or (2) decision by provider and participant to defer ARV therapy during the study drug dosing period (8 or 12 weeks), or (3) elite controller (CD4+ >200 cells/mm3). OR
  2. On a stable, protocol-approved ARV regimen (the following ARVs are not allowed: ddI, d4T, and TPV/r) for >8 weeks prior to screening with a CD4 T-cell count >200 cells/mm3 and a documented plasma HIV-1 RNA level <50 copies/mL or <LLOQ of local assay if LLOQ is >50 copies/mL by any laboratory that had a Clinical Laboratory Improvement Amendments (CLIA) certification or its equivalent ≥ 8 weeks preceding the A5327 screening visit. HIV-1 RNA levels should be within 1 year of the screening visit. Screening HIV-1 RNA must be <50 copies/mL as measured by any local laboratory using an FDA-approved assay.

• Candidates must have had the following laboratory parameters within 10-42 days prior to study entry:

  1. Hemoglobin ≥9 g/dL for male and female participants
  2. International normalized ratio (INR) ≤1.5 x ULN unless participant had known hemophilia or wass stable on an anticoagulant regimen affecting INR
  3. Albumin ≥3 g/dL
  4. Creatinine clearance (CrCl) ≥60 mL/min, as calculated by the Cockcroft-Gault equation (refer to section 6.3.5 for calculator utility link)

• Female participants of reproductive potential (defined as women who had not been post-menopausal for at least 24 consecutive months, ie, who had menses within the preceding 24 months, or women who had not undergone surgical sterilization, specifically hysterectomy and/or bilateral oophorectomy or bilateral salpingectomy) must had a negative serum or urine pregnancy test within 48 hours prior to study entry by any laboratory or clinic that had a CLIA certificate or its equivalent, or was using a point-of-care (POC)/CLIA-waived test. The serum, urine or POC pregnancy test must had a sensitivity of at least 25 mIU/mL.

Step 1 exclusion criteria for both cohorts (Cohort 1 and Cohort 2)

• Received investigational drug or device within 60 days prior to study entry.
• Chronic liver disease of a non-HCV etiology (eg, hemochromatosis, Wilson's disease, α1 antitrypsin deficiency, primary sclerosing cholangitis).
• Presence of active or acute AIDS-defining opportunistic infections within 30 days prior to study entry. [NOTE: A list of AIDS-defining opportunistic infections as defined by the CDC, can be found in Appendix B of the following document: http://www.cdc.gov/mmwr/preview/mmwrhtml/00018871.htm\]
• Active, serious infection (other than HIV-1 or HCV) requiring parenteral antibiotics, antivirals, or antifungals within 30 days prior to study entry.
• Infection with hepatitis B virus (HBV) defined as HBsAg positive.
• Evidence of acute hepatitis A infection defined as HAV IGM positive.
• Chronic use of systemically administered immunosuppressive agents (eg, prednisone equivalent > 10 mg/day).
• History of solid organ transplantation.
• Current or prior history of clinical hepatic decompensation (eg, ascites, encephalopathy or variceal hemorrhage).
• History of a gastrointestinal disorder (or post operative condition) that could interfere with the absorption of the study drug.
• History of significant or symptomatic pulmonary disease, cardiac disease, or porphyria.
• History of difficulty with blood collection and/or poor venous access for the purposes of phlebotomy.
• History of clinically significant illness or any other major medical disorder that may interfere with participant treatment, assessment, or compliance with study requirements, which may included active drug or alcohol use or dependence.
• Use of any prohibited concomitant medications within 30 days prior to study entry.
• Acute HIV infection defined as the phase immediately following infection during which anti-HIV antibodies are undetectable. [NOTE: Participants with early infection, defined as within the first 6 months of infection and with a positive HIV antibody, should be discussed with the A5327 protocol core team. These participants may be considered for inclusion in the study on a case by case basis with the specific documented approval of the protocol chairs.]

Step 1 exclusion criteria for Cohort 1 only

• Prior exposure to a direct-acting antiviral (DAA) targeting the HCV NS5B polymerase. [NOTE: DAAs include but are not limited to: mericitabine, ABT-333, ABT-072, BI-207127, BMS-791325, VX-222, tegobuvir, IDX719, setrobuvir, GS-9669, VX-135.]
• History of clinically significant hemoglobinopathy (eg, sickle cell disease, thalassemia).
• Known hypersensitivity to RBV, SOF, its metabolites, or formulation excipients or any other contraindication to the use of RBV or SOF.
• Currently receiving ZDV, ddI, or d4T.

Step 1 Exclusion criteria for Cohort 2 only

• Any preceding attempt at HCV treatment during this acute HCV infection episode, ie, 24 weeks prior to entry.
• Known hypersensitivity to SOF or LDV, the metabolites, or formulation excipients or any other contraindication to the use of SOF or LDV.
• Currently receiving TPV/r, ddI, d4T or amiodarone.
• Pregnancy or Breastfeeding.