This is an open-label, single arm, multicenter, pilot-study to compare the efficacy and safety of LDV/SOF fixed dose combination (FDC) in subjects with acute genotype 1 HCV infection. A total of 20 subjects will be assigned to receive LDV/SOF FDC tablet (LDV 90 mg/SOF 400 mg/) once daily for 6 weeks.Patients will be followed up for 24 weeks.

Inclusion Criteria:

1. Willing and able to provide written informed consent

2. Male or female, age ≥ 18 years

3. HCV RNA ≥ 103 IU/mL at Screening

4. Confirmation of acute genotype 1 HCV infection documented by either:

   documented seroconversion to HCV antibody positivity within the 4 months preceding screening or known or suspected exposure to HCV within the 4 months preceding screening with 10 times elevated serum ALT Level at screening or 4 weeks preceding screening without evidence of confounding liver disorders

5. If the patient visits a physician due to symptoms of acute HCV, no greater than a 12 week interval may have elapsed between the time of the visit and screening

6. Non-cirrhotic. Absence of cirrhosis will be determined based on clinical parameters or ultrasound

7. Body mass index (BMI) ≥ 18 kg/m2

8. Screening ECG without clinically significant abnormalities

9. Subjects must have the following laboratory parameters at screening:

   1. Hemoglobin ≥ 10 g/dL
   2. Platelets ≥ 90,000/µL
   3. INR ≤1.5 x ULN unless subject has known hemophilia or is stable on an anticoagulant regimen affecting INR
   4. Albumin ≥ 3 g/dL
   5. HbA1c ≤ 10%
   6. Creatinine clearance (CLcr) ≥ 60 mL/min, as calculated by the Cockcroft- Gault equation

10. Subject has not been treated with any investigational drug or device within 42 days of the Screening visit

11. A negative serum pregnancy test is required for female subjects (unless surgically sterile or women ≥ 54 years of age with cessation for 24 ≥ months of previously occurring menses).

    Complete abstinence from intercourse. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) is not permitted.

    Or

    Consistent and correct use of 1 of the following methods of birth control listed below, in addition to a male partner who correctly uses a condom, from the date of Screening until 30 days after last dose of study drug:

    • intrauterine device (IUD) with a failure rate of < 1% per year
    • female barrier method: cervical cap or diaphragm with spermicidal agent
    • tubal sterilization
    • vasectomy in male partner
    • hormone-containing contraceptive:
    • implants of levonorgestrel
    • injectable progesterone
    • oral contraceptives (either combined or progesterone only)
    • contraceptive vaginal ring
    • transdermal contraceptive patch

12. Male subjects must agree to refrain from sperm donation from the day of screening and for at least 90 days after the last dose of study drug.

13. Subject must be of generally good health as determined by the Investigator.

14. Subject must be able to comply with the dosing instructions for study drug administration and be able to complete the study schedule of assessments.

Exclusion Criteria:

1. Clinically-significant illness (other than HCV) or any other major medical disorder that, in the opinion of the investigator, may interfere with subject treatment, assessment or compliance with the protocol; subjects currently under evaluation for a potentially clinically-significant illness (other than HCV) are also excluded.
2. Gastrointestinal disorder or post operative condition that could interfere with the absorption of the study drug (for example, gastric bypass or severe ulcerative colitis).
3. Difficulty with blood collection and/or poor venous access for the purposes of phlebotomy.
4. Clinical hepatic decompensation (i.e., clinical ascites, encephalopathy or variceal hemorrhage).
5. Solid organ transplantation.
6. Significant pulmonary disease or significant cardiac disease.
7. Psychiatric hospitalization, suicide attempt, and/or a period of disability as a result of their psychiatric illness within the last 2 years. Subjects with psychiatric illness that is well-controlled on a stable treatment regimen for at least 12 months prior to screening or has not required medication in the last 12 months may be included.
8. Malignancy within 5 years prior to screening, with the exception of specific cancers that are entirely cured by surgical resection (basal cell skin cancer, etc). Subjects under evaluation for possible malignancy are not eligible.
9. Significant drug allergy (such as anaphylaxis or hepatotoxicity).
10. Any prior treatment for HCV infection including prior exposure to any inhibitor of the NS5B and NS5A.
11. Pregnant or nursing female or male with pregnant female partner
12. Chronic liver disease of a non-HCV etiology (e.g., hemochromatosis, autoimmune hepatitis, alcoholic liver disease, Wilson's disease, α1 antitrypsin deficiency, cholangitis)
13. Infection with hepatitis B virus (HBV; defined as HBsAg-positive) or human immunodeficiency virus (HIV)
14. Chronic use of systemically administered immunosuppressive agents (e.g., prednisone equivalent > 10 mg/day)
15. Clinically-relevant drug or alcohol abuse within 12 months of screening including any uncontrolled drug use within 6 months of screening. A positive drug screen will exclude subjects unless it can be explained by a prescribed medication; the diagnosis and prescription must be approved by the investigator. Uncontrolled users of intravenous drugs will not be permitted to enroll in the study.
16. Donation or loss of more than 400 ml blood within 2 months prior to Baseline/Day 1
17. Use of any prohibited concomitant medications within 21 days of the Baseline/Day 1 visit, this washout period does not apply to proton pump inhibitors, which can be taken up to 7 days before Day 1.
18. Known hypersensitivity to LDV, SOF or formulation excipients