GPC Biotech of Germany says that its partner Pharmion Corp has submitted a marketing authorisation application to the European Medicines Agency for its cancer treatment satraplatin in combination with prednisone.

Satraplatin is being filed for the treatment of patients with metastatic hormone refractory prostate cancer who have failed prior chemotherapy and is based on data from the SPARC Phase III trial which involved 950 patients and showed highly statistically-significant results for prolonging progression-free survival. GPC’s chief executive Bernd Seizinger noted that more than 60,000 people are expected to die from prostate cancer in the European Union this year, so “there is an urgent need for new therapies”.

As a result of the EU filing, GPC will receive an $8 million milestone payment from Pharmion and under a separate deal, it will have to fork out $3.2 million to Spectrum Pharmaceuticals of the USA. The agreement with Pharmion, signed in December 2005, covers Europe, Turkey, the Middle East, Australia and New Zealand and its total value could be in excess of $300 million.

The German firm licensed satraplatin from Spectrum in 2002, though the latter company filed a demand for arbitration against GPC in December last year, charging that the company has not used "commercially reasonable efforts" to gain regulatory approval of the product in Japan, and asked to be reimbursed for nine million euros spent on development in the past.

Satraplatin deal signed with Japan’s Yakult Honsha

At the time, GPC said that Spectrum’s claim was without merit and it would seem to have a case, given that the firm has also announced a licence agreement with Yakult Honsha Co for satraplatin in Japan.

Under the terms of the deal, Yakult gains exclusive commercialisation rights to satraplatin at home and will take the lead in developing the drug in Japan. Yakult is to provide an upfront payment of 1.2 billion yen (around $10 million) to GPC as reimbursement for past satraplatin clinical expenses and the Martinsried-based group will also get additional payments based on the achievement of certain regulatory filing and approval milestones. GPC will also receive a minimum of 21% royalties on sales of satraplatin in Japan.

Satraplatin is a member of the platinum family of compounds and are used to treat a wide variety of cancers but all those that are currently on the market require intravenous administration, unlike GPC’s drug. It has yet to be approved anywhere but analysts think that peak sales in the USA could be in the region of $500 million. The US Food and Drug Administration is scheduled to review the firm’s New Drug Application for satraplatin on July 24.