H. Thomas Watkins, Human Genome Sciences President and CEO.

Albumin fusion is being touted as a useful tool to extend the half-life of certain small peptides, so it's no surprise that the field has seen a bloom of activity lately. In May, Bagsvaerd, Denmark–based Novozymes licensed its albumin fusion technology, Albufuse, to Dyax, in Cambridge, Massachusetts, for use in a research collaboration around the development of Kunitz-domain proteins, disulfide-bonded domains forming a loop structure. “It could give us a way of targeting a wider range of chronic diseases with that scaffold,” says Dyax's executive vice president, discovery research, Clive Wood. The most advanced clinical candidate using albumin fusion technology is Human Genome Sciences' closely watched Albuferon (albinterferon alfa-2b) for the treatment of hepatitis C. In January 2008, the company reduced the maximum dose of Albuferon in its phase 3 trials to 900 μg from 1200 μg, based on recommendations made by the studies' independent Data Monitoring Committee. President and CEO H. Thomas Watkins said, “For some time we have viewed the 900-μg dose administered every two weeks as the most likely marketed dose of Albuferon.” But the Rockville, Maryland, biotech nonetheless saw its stock price cut in half on the news. A day after the Albuferon dosing change was announced, Jerusalem-based Teva Pharmaceutical, a generics company, announced the purchase of CoGenesys, also in Rockville, which Human Genome Sciences had owned and spun out into an independent company in 2006, during the development of Albuferon. Teva has identified biopharmaceuticals—primarily copies of biologicals—as a key, long-term growth opportunity. “With this acquisition, Teva is taking a significant step towards advancing its strategic goals, demonstrating its commitment to becoming a leading player in the biogenerics market, as that market evolves,” it stated. CoGenesys is already developing long-acting versions of granulocyte colony-stimulating factor and interferon-beta; Teva already sells versions of both as well as a biogeneric human growth hormone. Albumin is an additional active ingredient, so it is difficult to call albumin fusion a technology for making follow-on biologics. But the traditional definition of therapeutic equivalence “isn't relevant to most products in this field,” says Joseph Schwartz, an analyst at Leerink Swann in Boston, adding “the distinction is becoming blurred. If you have to do clinical trials anyway, which is looking like the way it will shape up to be in the biogenerics field, to show that their drugs work, it doesn't matter if you're therapeutically equivalent or not.”