Japanese drugmaker Astellas has licensed exclusive rights to a series of anaemia drugs from FibroGen, in a deal that could eventually bring in up to $2 billion to the US firm in the coming years.

Astellas had previously licensed Japanese rights to the drugs, known as hypoxia-inducible factor prolyl hydroxylase inhibitors, but in the latest agreement has extended its rights to include Europe, the Commonwealth of Independent States, the Middle East and South Africa.

The deal includes FG-2216 and FG-4592, which are currently in human clinical trials, with FibroGen retaining rights to compounds in the rest of the world.

Under the terms of the agreement, Astellas will pay a licensing fee of $300 million upon signing, milestones totaling $465 million and share in the costs of a transatlantic development programme and patent support. If all forecast sales targets are achieved, FibroGen could receive in excess of $2 billion during the 10 to 15 years after 2010. In addition, Astellas will purchase $50 million worth of shares in the US biotechnology firm.

The oral compounds inhibit the enzyme that degrades erythropoietin, and could be a more patient-friendly therapy option for anaemia, which is currently treated with injectable recombinant forms of EPO such as Amgen’s Epogen (epoetin alfa) and Aranesp (darbepoetin alfa), as well as Roche’s NeoRecormon (epoetin beta).

Together these drugs account for a multibillion dollar market worldwide. For example, in Europe, sales of EPO products for anaemia of chronic kidney disease and chemotherapy-induced anaemia total approximately $3 billion a year.

Astellas noted that oral treatments to stimulate red blood cell production could address larger, multi-million patient market opportunities currently not penetrated by EPO products, including chronic kidney disease in patients not yet on dialysis and anaemias caused by cancer, congestive heart failure, advancing age and chronic disease.

Sales potential

Astellas said it plans to start marketing the agents in 2011-2012, and predicts that the drugs have an annual sales potential in Europe of around 50 billion yen (roughly $450 million), which could double at peak. A launch in Japan should occur a little later, and Astellas said the market potential there is in the region of 30-50 billion yen.