Gilead Sciences announces 96 week results from to Phase III trials evaluating daily Vemlidy (tenofovir alafenamide, TAF 25mg) as a treatment for Hepatitis B.

Gilead Sciences, Inc. announced 96-week results from two ongoing Phase III studies evaluating the safety and efficacy of daily Vemlidy (tenofovir alafenamide, TAF 25mg) in immune active patients and in patients switching from Gilead�s Viread (tenofovir disoproxil fumarate, TDF 300mg). In addition, Gilead presented data from preclinical studies of investigational compounds being studied for their potential role in HBV cure strategies. Data were presented this week at The International Liver Congress 2017 in Amsterdam.

TAF is a novel, targeted prodrug of tenofovir that has demonstrated antiviral efficacy that is noninferior to that of TDF at Week 48 in patients with chronic HBV. TAF treatment at the same time point also demonstrated a beneficial impact on renal and bone laboratory safety parameters compared to TDF (#PS-042, #FRI-153). Analyses now conducted at Week 96 of treatment demonstrate continued benefits of TAF including high rates of viral suppression, with no evidence of resistance, and less impact on renal and bone safety parameters as compared to TDF. Additionally, patients switching from TDF to TAF after Week 96 demonstrated maintenance of viral suppression, improvement in ALT normalization rates, and improvement in bone and renal parameters 24 weeks after switching to TAF (#PS-041: �Hepatitis B and D: emerging treatment options�).

The two randomized, double-blinded Phase III studies (Studies 108 and 110) from which the data are presented evaluated the use of TAF given once-daily versus Gilead�s TDF given once-daily in treatment-na�ve and treatment-experienced adults with HBeAg-negative and HBeAg-positive chronic HBV infection. Results demonstrate continued advantages of treatment with TAF over TDF between Week 48 and Week 96. Virologic response rates at Week 96 were 90 percent (n=257/285) and 91 percent (n=127/140) in HBeAg-negative patients (Study 108) receiving TAF and TDF, respectively. In HBeAg-positive patients (Study 110), virologic response rates at Week 96 were 73 percent (n=423/581) and 75 percent (n=218/292) in the TAF and TDF groups, respectively. In both studies, a greater percentage of patients taking TAF achieved normalization of serum alanine aminotransferase (ALT) levels relative to patients taking TDF as measured by both central laboratory criteria, and by the American Association for the Study of Liver Diseases (AASLD) criteria. Patients receiving TAF also demonstrated ongoing benefits at Week 96 in bone and renal safety parameters, including smaller declines from baseline in hip and spine bone mineral density (BMD) and smaller declines from baseline in estimated creatinine clearance compared with patients taking TDF in both studies. Similar rates of adverse events and low and similar rates of adverse events leading to discontinuation were observed in both treatment arms. Viral resistance analyses showed no resistance to TAF or TDF at Week 96.