Immunologic Effects of HCV Therapy With HARVONI in HCV Genotype 1 Chronically Mono-infected Active and Former IDUs

This group of multidisciplinary investigators has discovered increased levels of immune
activation among HIV-1-uninfected active injection drug users (IDUs) when compared to non-IDU
controls . The vast majority (80%) are also infected with HCV.

Active injectors have high levels of immune activation as measured by sCD14, CD8
co-expression of CD38 and HLA-DR, as well as Type 1 cytokines.

Within months of ceasing injecting, there are observable decreases in some parameters however
in general they remain elevated when compared to non-injecting healthy volunteers.

As approximately 80% of these subjects are HCV infected and viremic, these results are
confounded as to the cause of the observed increased levels of markers of immune activation-
active injection or chronic Hepatitis C. Until recently HCV treatment required the use of IFN
which has immunomodulatory activity which would cause perturbations in the markers of immune
activation. However the development of direct acting agents (DAA) to treat HCV has
revolutionized therapy. In this trial the investigators will employ the once daily FDC
formulation of sofosbuvir and ledipasvir to assess changes in markers of immune activation
during therapy.

There have been multiple clinical trials of FDC LDV-SOF in patients with Genotype 1 HCV. When
taken once daily for 12 weeks, sustained virologic response rates have been very high with
response rates nearing 99% in most studies with a 12-week course of therapy.

Common adverse events associated with FDC LDV-SOF in ION-1 include fatigue (21%), headache
(25%), nausea (11%), insomnia (8%), asthenia (7%), diarrhea (11%), rash (7%), irritibility
(7%), cough (3%), and pruritis (5%).

Ledipasvir undergoes minimal metabolism and expectations are that this medication will have
few clinically significant drug-drug interactions. In general, sofosbuvir is considered to
have relatively few clinically significant drug-drug interactions, but coadministration of
sofosbuvir with the following medications is not recommended because these medications may
significantly lower sofosbuvir levels:

Anticonvulsants: carbamazepine, oxycarbazepine, phenobarbital, and phenytoin
Antimycobacterials: rifabutin, rifampin, rifapentine Herbal Supplements: St. John's wort HIV
Protease Inhibitors: tipranavir-ritonavir Antiarrhythmic Drugs : amiodarone (Cordarone®,
Nexterone®, Pacerone®)

Participants will be provided with a 12-week course of FDC LDV-SOF which will provide a near
99% likelihood of a SVR in participants who are adherent to therapy with low likelihood of
significant adverse events and drug-drug interactions.

In treating HCV effectively the investigators will measure changes in immune activation and
gene expression that accompany HCV treatment.

Inclusion Criteria:

1. Ability to give written informed consent in English

2. Age≥18 and ≤55

3. HCV antibody positive

4. HCV RNA >1,000 copies/mL plasma

5. HCV treatment naive

6. HCV genotype 1a or 1b or mixed type 1

7. AST, ALT <10x ULN

8. Direct bilirubin <3.0

9. Platelet count >50,000

10. Creatinine clearance >30mL/min as estimated by Cockroft Gault

11. Hemoglobin >10 if female, >11 if male

12. Albumin > 2.8

13. INR<2.0

14. If Group A: urine dip for opiates + and active injection drug use of heroin defined as
injecting at least 3 times per week.

15. If Group B then no IDU for at least 4 months and a negative urine for opiates at
screening.

16. Venous access for phlebotomy

17. Willingness to agree to effective contraception during the course of the study.

18. If Group C: - negative urine for opiates at screening

- no recreational drug use for at least 2 years (excluding marijuana)

- HIV, HCV and HBV uninfected

Exclusion Criteria:

1. HIV infection

2. Chronic infection with Hepatitis B

3. Uncompensated cirrhosis

4. Required use of:

Anticonvulsants: carbamazepine, oxycarbazepine, phenobarbital, and phenytoin

Antimycobacterials: rifabutin, rifampin, rifapentine

Herbal Supplements: St. John's wort

HIV Protease Inhibitors: tipranavir-ritonavir

Antiarrhythmic Drugs: amiodarone (Cordarone, Nexterone, Pacerone)

5. Any medical condition that in the opinion of the investigator would interfere with
study participation and medical adherence

6. Pregnancy/breast feeding