Merck-Serono today announced that it will be collaborating with US firm Ambrx on the development and commercialisation of long-acting growth hormone products. Having recently entered Phase I/II clinical trials, early hopes are that the new product could drastically reduce dosing requirements from the once-daily dose of current therapies, right down to once weekly or possibly even less frequently. This could prove a major boost to Merck-Serono's portfolio, which already boasts growth hormone products Saizen (somatropin) and Serostim (somatropin) which together account for over 10 per cent of the company's product sales, contributing $282m (€210.4m) in 2006. Despite Merck-Serono's efforts to introduce new, user-friendly injection devices to promote its products, the company's hGH business has suffered a little due to generic version that have recently hit the US market. This new product, therefore, could help galvanise the firm's position before generic competition erodes too much of its market share. The new product, currently known as ARX201, has benefited from the application of a patented technology developed by biotech firm Ambrx, which improves the products pharmacological properties and allows for less frequent administration than currently available growth hormones. Ambrx's protein engineering platform, ReCODE, enhances hGH performance by allowing precise positioning of the site of a polyethylene glycol (PEG) polymer through biosynthetically incorporating a chemically unique amino acid. Through the application of this platform technology, Ambrx claims that it can introduce a single, selective attachment point at any site on a protein's surface, thus enabling protein engineering in a manner not previously possible. According to the firm, the ReCODE system confers enhanced potency, reduced dosing frequency, improved product homogeneity and facilitated manufacturing as well as providing strong intellectual property positions. The company has already demonstrated the scalability of the manufacturing process in a GMP environment at 1,500L. ARX201 is the company's first clinical candidate and the leading light in its pipeline, with Ambrx hoping to take advantage of the growing hGH market currently worth several billion dollars. Through the Merck-Serono deal, Ambrx will receive an undisclosed initial payment and is eligible to receive further milestone payments based on successful development and commercialisation, as well as undisclosed royalties on net sales of the products. In addition to this, Ambrx retains the rights to co-promote products in the US which would involve both companies sharing commercialisation expenses and profits. With protein therapeutics representing one of the most rapidly expanding classes of treatment, and the human growth hormone market offering such a healthy revenue stream to tap in to, Ambrx' technology could well be one to watch should the current clinical trials progress well. Beyond growth hormone, the company also sees applications for the technology in other areas such as cytokines, peptides, and antibodies, and across multiple therapeutic areas including cancer, endocrine disorders, inflammation and infectious disease.