Gilead Sciences, Inc. (NASDAQ:GILD) announced that four Phase 3 studies evaluating a fixed-dose combination of bictegravir (50mg) (BIC), a novel investigational integrase strand transfer inhibitor (INSTI), and emtricitabine/tenofovir alafenamide (200/25mg) (FTC/TAF) for the treatment of HIV-1 infection met their primary objectives of non-inferiority. Three of the ongoing studies are designed to explore the efficacy and safety of BIC/FTC/TAF compared to regimens containing dolutegravir (50mg) (DTG) among treatment-naïve patients (Studies 1489 and 1490), and among virologically suppressed patients switching from an existing antiretroviral regimen (Study 1844). A fourth ongoing study in virologically suppressed patients compares switching to BIC/FTC/TAF versus remaining on a suppressive regimen of two nucleoside/nucleotide reverse transcriptase inhibitors and a boosted protease inhibitor (Study 1878).

“Since the approval of Viread 16 years ago, Gilead has continually worked to develop and improve treatments for people living with HIV. This investigational single tablet regimen brings together the potency of an integrase inhibitor, bictegravir, with the demonstrated efficacy and safety profile of the FTC/TAF backbone,” said Norbert Bischofberger, PhD, Executive Vice President, Research and Development and Chief Scientific Officer, Gilead Sciences. “Based on the results from these Phase 3 studies, the combination of bictegravir and FTC/TAF could represent an important advance in triple-therapy treatment for a broad range of HIV patients, and we look forward to submitting regulatory applications in the U.S. and EU this year.”

Studies 1489 and 1490 are double-blind studies in which treatment-naïve patients (n=600 in each study) were randomized 1:1 to receive BIC/FTC/TAF and abacavir/dolutegravir/lamivudine (600/50/300mg) (ABC/DTG/3TC) (Study 1489) or DTG+FTC/TAF (Study 1490). The primary endpoint is proportion of patients with HIV-1 RNA levels <50 copies/mL at Week 48, and the lower bound of the 95 percent CI for non-inferiority is 12 percent. The studies remain blinded through 144 weeks.

In study 1844, patients (n=520) who were virologically suppressed (HIV-1 RNA levels <50 copies/mL) on a regimen of ABC/DTG/3TC or DTG+ABC/3TC were randomized 1:1 to stay on their existing regimen or switch to BIC/FTC/TAF in a blinded manner. Study 1878 is an open-label study in which patients (n=520) who were virologically suppressed on a boosted protease inhibitor of darunavir (800mg) or atazanavir (300mg) plus a nucleoside/nucleotide backbone of ABC/3TC or emtricitabine/tenofovir disoproxil fumarate (200/300mg) were randomized 1:1 to either maintain their current regimen or switch to BIC/FTC/TAF. The primary endpoint in these studies is the proportion of patients with HIV RNA ≥50 copies/mL at Week 48, and the lower bound of the 95 percent CI for non-inferiority is 4 percent. Both studies were randomized through 48 weeks, after which point patients continuing in the studies enter an open-label extension receiving BIC/FTC/TAF.

BIC/FTC/TAF met the definition of non-inferiority in all four studies, with comparable proportions of patients having HIV-1 RNA <50 copies/mL (Studies 1489 and 1490) and HIV-1 RNA ≥50 copies/mL (Studies 1844 and 1878). In all studies BIC/FTC/TAF was well tolerated and no patients discontinued study medication due to renal events. No patients randomized to the bictegravir or dolutegravir arms developed treatment-emergent resistance. One patient randomized to the protease inhibitor arm in Study 1878 developed an abacavir resistance mutation (L74V).

Gilead plans to submit data from these Phase 3 studies for presentations at scientific conferences in 2017.

Bictegravir in combination with FTC/TAF as a single tablet regimen is an investigational treatment that has not been determined to be safe or efficacious.

Shares of Gilead are trading at $64.71, up $0.21 or 0.33% in pre-market trading Tuesday. GILD has a 1-year high of $88.85 and a 1-year low of $63.88. The stock’s 50-day moving average is $66.38 and its 200-day moving average is $70.15.

On the ratings front, GILD stock has been the subject of a number of recent research reports. In a report issued on May 9, Jefferies analyst Brian Abrahams reiterated a Buy rating on GILD, with a price target of $82, which represents a potential upside of 27% from where the stock is currently trading. Separately, on May 3, Maxim’s Gabrielle Zhou reiterated a Hold rating on the stock.

According to TipRanks.com, which ranks over 7,500 financial analysts and bloggers to gauge the performance of their past recommendations, Brian Abrahams and Gabrielle Zhou have a yearly average return of 2.0% and a loss of 16.2% respectively. Abrahams has a success rate of 46% and is ranked #1645 out of 4571 analysts, while Zhou has a success rate of 28% and is ranked #4432.

Overall, 4 research analysts have assigned a Hold rating and 9 research analysts have given a Buy rating to the stock. When considering if perhaps the stock is under or overvalued, the average price target is $79.00 which is 22.5% above where the stock closed last Friday.

Gilead Sciences, Inc. is a biopharmaceutical company, which discovers, develops and commercializes therapeutics for unmet medical need. It focuses on human immunodeficiency virus and liver diseases, such as chronic hepatitis C virus infection & chronic hepatitis B virus infection, hematology & oncology, and cardiovascular & inflammation as well as respiratory diseases. The company’s products include Descovy, Odefsey, Genvoya, Stribild, Complera, Atripla, Truvada, Viread, Emtriva, Tybost, Vitekta, Vemlidy, Epclusa, Harvoni, Sovaldi, Viread, Hepsera, Zydelig, Letairis, Ranexa, Lexiscan, Cayston, Tamiflu, AmBisome and Macugen.