A fixed dose combination of three branded antiretrovirals could be on the market within 18 months if manufacturers can solve co-formulation problems, following an announcement yesterday by Gilead Sciences (manufacturers of tenofovir [Viread] and FTC [Emtriva]) and Merck & Co. and Bristol-Myers Squibb (manufacturers of efavirenz [Sustiva / Stocrin]).
Both Merck and Bristol-Myers Squibb are involved in the deal because both companies hold licenses for the drug. Whilst Bristol-Myers Squibb markets efavirenz as Sustiva in North America and five European Union countries, Merck markets efavirenz as Stocrin in the rest of the world.
In a statement yesterday, the companies said they are discussing how to put the drugs together in one tablet and are also looking at `co-blistering` - packaging the products together in blister packs that will make clear to patients when the medications must be taken.
The three-drug combination would be the first collaboration between patent holders in the antiretroviral market. Although Dr Jeff Sturchio of Merck would not comment to aidsmap on the timescale for submission, a coformulation is still dependent on addressing manufacturing issues, carrying out required studies and clearing the hurdle of securing approval for a fixed dose combination of tenofovir and FTC – which is likely to be approved before the end of 2004.
All these factors suggest that a co-formulated product is unlikely to be approved before the end of 2005. A co-blistered product could be available sooner, depending only on the consideration of packaging stability studies by the FDA.
Fixed-dose products containing generic versions of nevirapine have already been developed by several Indian companies and have been recommended for first-line treatment in resource-limited settings by the World Health Organisation.
However, fixed-dose products containing efavirenz have not been developed, partly because of the volume of drug that must be incorporated into one tablet and partly because efavirenz is a more difficult and expensive drug to manufacture than nevirapine.
Current WHO treatment guidelines recommend that efavirenz should be used with nucleoside analogue fixed-dose combinations - either stavudine/lamivudine or zidovudine/lamivudine.
Meanwhile GlaxoSmithKline (GSK) and Boehringer Ingelheim (BI) announced that they plan to investigate the co-blistering of their products. “Both GSK and BI are committed to working to find solutions for easier dosing of HIV medicines, and believe co-packaging could be a useful option in treating the millions of individuals living with HIV in the developing world,” said Jean-Pierre Garnier, GSK’s Chief Executive yesterday.
The most likely combination of the companies’ products will be zidovudine (AZT or Retrovir), lamivudine (3TC, Epivir) manufactured by GlaxoSmithKline and nevirapine (Viramune), manufactured by Boehringer Ingelheim.
In a related announcement, the US Health Secretary Tommy Thompson said the US Food and Drug Administration would adopt new procedures for approving fixed-dose combinations, and that some products could be approved within two to six weeks of submitting applications under the new regulations.
The US appears to have adopted international guidelines agreed at the end of March at an international conference in Botswana. The guidelines will permit fixed-dose combinations to be reviewed rapidly and will also permit generic manufacturers to submit antiretroviral products for US approval so that they can be purchased by the US government.