Big Pharma Companies Team Up to Develop Once-Daily, Triple-Combination HIV Drug

Gilead Sciences Inc. (Foster City, CA, www.gilead.com) and Bristol-Myers Squibb Company (New York, NY, www.bms.com) have joined forces to bring a three-drug, once-daily treatment regimen for HIV to market. If approved, the treatment would be the first highly active antiretroviral therapy (HAART) for HIV that joins several drugs in a one-a-day tablet. Though HIV is a chronic, long-term treatable disease, pill burden and convenience have been a major challenge. Many HIV treatments require several pills to be taken several times per day, often resulting in missed doses. Says Norbert W. Bischofberger, PhD, executive vice-president of research and development at Gilead Sciences, "To come up with one pill that is essentially a triple-combination regimen is a big plus for patients. It makes the treatment much more convenient."

The new drug will combine Bristol-Myers Squibb's "Sustiva" (efavirenz) and Gilead's "Truvada" (emtricitabine and tenofovir disoproxil fumarate). Because all three drugs are on the market and proven safe for use, the main challenges will be formulation-related such as ensuring bioequivalence and stability for each component and also limiting interactions between the active ingredients.

A key concern for formulators is to develop a tablet that is small enough to swallow. If formulators simply combined the three existing formulations into a trilayer tablet, the drug would be 2.2 g. "You cannot make a pill more than 1.8 g. That's about the biggest size you can go so that people can still swallow it," explains Bischofberger. Limiting the volume and how many excipients are used in the formulations to use could be one way to create a single tablet that is less than 1.8 g.