Merck & Co and RNA-interference specialist Alnylam Pharmaceuticals have agreed to end their development partnership and some observers believe that the termination of the deal is not as amicable as may seem on the surface.

The firms have been partners since 2003 and amended their agreement in July 2006 in a move which would have seen Merck agreed to pay Alnylam up to $120 million in milestone payments for the successful development of three drugs based on its RNAi technology. However, Alnylam has now rescinded all grants of its intellectual property related to past, present and future Merck development programmes, with chief executive John Maraganore saying that the termination is “fundamentally in our best interests”.

The problems seem to have arisen when Merck decided to acquire Sirna Therapeutics, another developer of RNAi treatments, at the end of 2006 for a hefty $1.1 billion in cash, just months after expanding their pact. The New Jersey-based drugs giant’s decision to buy a direct competitor would appear to have spoilt the firm’s relationship beyond repair.

Barry Greene, Alnylam's chief operating officer, told Reuters that the Sirna purchase led the firm to initiate the termination of the agreement. He said that "Merck has chosen to be a competitor and is challenging our patents in Europe, so to protect our intellectual property and the breakthrough discoveries that we're making, we have chosen to distance ourselves from them and deny them access to our IP and know-how”.

The announcement did no harm to Alnylam’s shares, in fact quite the opposite as the stock hit an all-time high before closing at $32.40, up 4.1%. The firm is not short of suitors and Swiss major Roche recently

obtained a non-exclusive licence to technology platform for developing RNAi therapeutics covering oncology, as well as respiratory, metabolic and liver diseases and could have to pay up to more than $1 billion for the privilege. Alnylam also has deals in place with Novartis, Biogen Idec and Medtronic.

Ending the deal with Merck will allow Alnylam to look for more partners and there should be plenty of takers. RNAi is a naturally-occurring mechanism within cells and potentially forms the basis for a new class of therapeutics that can selectively silence genes within the cell. Since many diseases are caused by the inappropriate activity of specific genes, the ability to regulate them selectively through RNAi has led to great excitement in the scientific community.

Osteoporosis drug odanacatib set for Phase III

Back to Merck and the firm is awash with clinical news. Most striking was positive Phase IIb data presented at the American Society for Bone and Mineral Research meeting in Hawaii which showed that the firm's experimental once-weekly osteoporosis drug odanacatib increased bone mineral density at key fracture sites and reduced bone turnover in postmenopausal women with low BMD, compared with placebo.

399 postmenopausal women with low BMD were randomised to receive one of four doses (3, 10, 25 or 50 mg) of the drug, a cathepsin K inhibitor, or placebo for 12 months. The findings showed that patients who received the highest dose experienced a 3.4% increase from baseline in BMD at the lumbar spine and 1.9% gain in the hip, compared to decreases of 0.1% and 0.6% respectively, for patients who received placebo. Patients who took the three highest doses of the treatment also experienced reductions in bone turnover from baseline, compared with placebo. Phase III trials of odanacatib are being initiated.

Gardasil may protect against added strains

Over in Chicago and Merck presented data at the Interscience Conference on Antimicrobial Agents and Chemotherapy on its human papillomavirus vaccine Gardasil. The jab protects against cervical cancer caused by HPV strains 6, 11, 16 and 18, and also against genital warts, and the latest analysis proffered by the company reduces the risk of developing pre-cancerous cervical lesions caused by ten other types of HPV.

The findings showed that the combined efficacy for preventing precancerous lesions caused by all 10 types of HPV was about 38, rising to 62% for HPV strains 45 and 31.