FDA approves fixed dose raltegravir/3TC formulation: Merck holds back from marketing in US
Simon Collins, HIV i-Base
On 6 February 2015, the FDA approved a dual formulation of 300 mg raltegravir with 150 mg lamivudine (3TC). 
The indication is for use in combination with other antiretroviral drugs to treat HIV-1 in adults or children older than six years. Approval was based on pharmacokinetic equivalence in an open-label, single dose, randomised, two-period, crossover study in HIV negative people (n=108).
The new formulation uses a lower dose of raltegravir that has better bioavailability compared to the current 400 mg twice-daily formulation.
Raltegravir is an integrase inhibitor and 3TC is an NRTI that is now off-patent.
The joint formulation is manufactured by Merck and has the brand name Dutrebis.
Merck does not plan to make this new formulation commercially available immediately post-approval.
Merck announced submission of this formulation in June 2014. 
Approval in the EU is expected within two months, following a positive recommendation by the Committee for Human Medicinal Products (CHMP) on 22 January 2015. In Europe, a pharmacovigilance plan will be implemented as part of the marketing authorisation. 
Although Merck are not planning to market this in the US, the company are still looking at whether there may be a greater role for the formulation in the UK and Europe.
- FDA listserve. Dutrebis approved, though not commercially marketed in US at this time. (9 February 2015).
- Merck press statement. FDA accepts Merck’s NDA for fixed-dose combination of raltegravir plus lamivudine. (24 June 2014).
- Committee for Medicinal Products for Human Use (CHMP) Summary of opinion (initial authorisation): Dutrebis lamivudine/raltegravir. EMA/CHMP/38006/2015 CHMP. (22 January 2015).