Bictegravir Matches Dolutegravir in HIV Control and Safety

April 4, 2017

Combined with tenofovir alafenamide/emtricitabine (TAF/FTC, Descovy), the investigational HIV integrase inhibitor bictegravir matched the licensed integrase inhibitor dolutegravir (Tivicay, DTG) in viral suppression and safety in a double-blind phase 2 trial. Phase 3 trials of bictegravir are underway.

Three integrase inhibitors -- raltegravir (Isentress), dolutegravir and cobicistat (Tybost)-boosted elvitegravir (Vitekta) -- rank as recommended components of first-line antiretroviral regimens. Bictegravir is a potent once-daily integrase inhibitor that does not require boosting. In vitro it maintains activity against virus resistant to the licensed integrase inhibitors. Researchers at 22 U.S. outpatient clinics conducted this double-blind, placebo-controlled, phase 2 comparison of bictegravir and dolutegravir, both with TAF/FTC, in previously untreated people.

The study included antiretroviral-naive adults with a viral load above 1000 copies/mL and HIV sensitive to TAF and FTC. Participants could not have hepatitis B or C infection or an AIDS-defining condition within 30 days of screening. Researchers randomized them 2:1 to 75 mg of bictegravir once daily or 50 mg of dolutegravir once daily plus coformulated TAF/FTC.

Related: Bictegravir versus Dolutegravir: Phase-2 Results of New Integrase Inhibitor

The 65 participants randomized to bictegravir had a median age of 30 years, compared with 36 years for the 33 people randomized to dolutegravir. Overall, 57% were white and 37% black. Median pretreatment viral load stood at 4.45 log10 copies/mL (about 28,000 copies/mL), and 12% had a viral load above 100,000 copies/mL. Median pretreatment CD4 count measured 444 cells/mm3, with no significant difference between groups.

After 24 weeks, 63 of 65 people randomized to bictegravir (97%) and 31 of 33 randomized to dolutegravir (94%) had a viral load below 50 copies/mL by the FDA snapshot algorithm, the primary endpoint (weighted difference 2.9%, 95% confidence interval -8.5 to 14.2, P = .50). After 48 weeks, 97% assigned to bictegravir and 91% assigned to dolutegravir had a viral load below 50 copies/mL (P = .17). Median adherence at week 48 was 97% in the bictegravir group and 96% in the dolutegravir group, and no one stopped treatment because of loss of efficacy. No resistance mutations arose in the bictegravir group; a transient T97A integrase mutation arose in the dolutegravir group. Mean CD4 count rose by an average 258 cells/mm3 with bictegravir and 192 cells/mm3 with dolutegravir (P = .16).

Through 48 weeks, 85% in the bictegravir arm and 67% in the dolutegravir arm had a treatment-emergent adverse event, usually diarrhea (12% and 12%) or nausea (8% and 12%). One person taking bictegravir with a history of atopic dermatitis stopped study drugs after 24 weeks because of urticaria. There were no treatment-related serious adverse events in either group.

Rates of grade 2 to 4 lab abnormalities were similar in the two groups. Through 48 weeks, creatinine clearance fell 7.0 mL/min with bictegravir and 11.3 mL/min with dolutegravir. Grade 2 to 4 aminotransferase elevations were more frequent with bictegravir than dolutegravir (9% versus 3%); all resolved or improved on treatment, except in one bictegravir participant with acute hepatitis C infection and ongoing alcohol abuse.

Two double-blind phase 3 trials are comparing single-pill bictegravir/TAF/FTC with dolutegravir plus TAF/FTC or with single-pill dolutegravir/abacavir/lamivudine (Triumeq) in antiretroviral-naive people. These trials are no longer recruiting participants.

Mark Mascolini writes about HIV infection.

Related Stories

Bictegravir versus Dolutegravir: Phase 2 Results of New Integrase Inhibitor
Bictegravir -- An Emerging Integrase Inhibitor
Top HIV Researcher Hails a Resurgent Antiretroviral Pipeline

This article was provided by TheBodyPRO.

No comments have been made.

Add Your Comment:
(Please note: Your name and comment will be public, and may even show up in
Internet search results. Be careful when providing personal information! Before
adding your comment, please read's Comment Policy.)

Your Name:

Your Location:

(ex: San Francisco, CA)

Your Comment:

Characters remaining:


The content on this page is free of advertiser influence and was produced by our editorial team. See our content and advertising policies.