21st International AIDS Conference (AIDS 2016)


Once-Daily Raltegravir at Last Available: Week 48 Results From ONCEMRK Study

August 6, 2016

After many years of research, Merck now have a once-daily formulation of raltegravir -- though it requires two tablets with a higher milligram dose.

In addition to developing the new formulation, non-inferiority needed to be shown in a randomised, double-blind placebo controlled phase 3 study, rather than relying on pharmacokinetic bioequivalence studies.

The original raltegravir 400 mg twice-daily version was compared to the new 2 x 600 mg once-daily formulation, with background NRTIs tenofovir DF + FTC for all participants. Results of this study were presented as a late-breaker oral abstract at AIDS 2016 by Pedro Cahn from Fundación Huesped, Buenos Aires.

Of the 802 participants randomised 2:1 to the once- vs twice-daily formulations, 797 received study drug and 732 (92%) completed follow-up to week 48.

Baseline characteristics overall included a study population that was 85% male, 59% white and mean age 36. Mean CD4 and viral load were 415 cell/mm3 and 4.6 log copies/mL respectively, with 28% having viral load >100,000 copies/mL.

At the primary endpoint at week 48, viral suppression to <40 copies/mL was reported by 88% of each arm with no significant differences related to efficacy or tolerability between arms. The once-daily formulation has slightly fewer serious side effects (5.8% vs 9.4%; difference -3.6% [95%CI -8.0 to +0.2]) and discontinuations due to side effects (0.8% vs 2.3%; difference -1.5 [95%CI -4.1 to + 0.1]), though neither difference was statistically significant.

Viral failure during the study (defined as non-suppression by week 24 or more than one consecutive blip >40 copies/mL) was reported in 7% of each group. Of these, approximately half resuppressed by week 48 without changing treatment: 20/26 vs 8/18 in the once-vs twice-daily arms groups respectively.

Of the 5/14 with drug resistance in the once-daily arm, 4/5 (0.9%) had resistance to raltegravir. Of the 3 people tested in the twice-daily arm, 2/3 had no resistance and 1/3 failed testing.

The study will continue until week 96 for secondary endpoint analyses.


  1. Cahn P et al. Raltegravir (RAL) 1200 mg once daily (QD) is non-inferior to RAL 400 mg twice daily (BID), in combination with tenofovir/emtricitabine, in treatment-naive HIV-1-infected subjects: week 48 results. AIDS 2016, 18-22 July 2016, Durban. Oral late breaker abstract FRAB0103LB. (Abstract) (Slides online thanks to

Related Stories

Really Rapid Review -- AIDS 2016, Durban
This Week in HIV Research: Vaginal Ring Prevents SHIV in Monkeys; Mortality Risk After Hospital Admission for Heart Attack or Stroke

This article was provided by HIV i-Base. It is a part of the publication HIV Treatment Bulletin. Visit HIV i-Base's website to find out more about their activities, publications and services.

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:

Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.


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