Days after handing to the FDA the first parts of a rolling new drug application for satraplatin, GPC Biotech AG found an ex-U.S. marketing partner for the oral platinum-based compound, which is in development to treat hormone-refractory prostate cancer.

In a deal potentially worth $269.8 million, Pharmion Corp. will take on all commercial responsibility for satraplatin in Europe, Turkey, the Middle East, Australia and New Zealand, while Martinsried, Germany-based GPC retains rights to the North American market and all other territories.

The deal translates into a $37.1 million up-front payment to GPC, which also could receive $232.7 million in development, regulatory and sales milestone payments, as well as royalties of 26 percent to 30 percent on annual sales of up to $500 million, and 34 percent on annual sales over that amount.

The attractive terms not only offer GPC a hefty initial payment, downstream money and a high royalty rate, but the company is able to hold onto its plans to promote or co-promote satraplatin for the U.S. market, or as a third option, to use another company's sales force.

While GPC took on the financial responsibility and clinical risk for developing satraplatin, after in-licensing the product from Irvine, Calif.-based Spectrum Pharmaceuticals Inc. in the fall of 2002, the strategy seems to have paid off if the deal with Pharmion is any measure of success.

"Clearly, the deal terms are very favorable," said Laurie Doyle, GPC's associate director of investor relations and corporate communications. "We are very excited, and it is, to our knowledge, one of the largest oncology product deals signed for Europe, so that excites us, as well."

Part of the up-front payment to GPC - $18 million - is for reimbursement for past satraplatin clinical development costs. The other $19.1 million will fund ongoing and future clinical development to be conducted jointly by Pharmion and GPC. The companies plan to develop satraplatin in a variety of tumor types, sharing global costs, for which Pharmion has committed another $22.2 million on top of the up-front payment.

Pharmion also will pay GPC $30.5 million for achieving regulatory filing and approval milestones, and up to $75 million for a maximum of five subsequent European approvals for additional indications. GPC is entitled to sales milestones totaling up to $105 million.

While the deal looks good on paper, there are certain hurdles ahead - namely, approvals in the U.S. and overseas. GPC anticipates completing the rolling NDA submission in the second half of 2006. And Boulder, Colo.-based Pharmion plans to file a marketing authorization application in Europe in 2007.

Satraplatin, which has fast-track designation in the U.S. for hormone-refractory prostate cancer, is the only oral platinum-based compound in advanced clinical development. In a randomized study of first-line treatment of patients with hormone-refractory prostate cancer, it has demonstrated a significant improvement in progression-free survival.

The drug currently is in an ongoing Phase III registration trial, called SPARC (Satraplatin and Prednisone Against Refractory Cancer), as a second-line chemotherapy treatment for patients with hormone-refractory prostate cancer. GPC achieved its target enrollment of 912 patients earlier this month, and it began to submit the rolling NDA last week. (See BioWorld Today, Dec. 16, 2005.)

Data from the study will support the MAA and NDA filings in Europe and the U.S. If approved, Satraplatin would become the first orally bioavailable platinum drug on the market, which last year generated more than $2.2 billion in worldwide sales. All other platinum therapies are intravenously administered. With satraplatin, patients could take the capsules home with them, which is a key advantage.

Satraplatin is in several other trials, including a Phase I/II study combining it with radiation therapy in non-small-cell lung cancer, as well as a Phase II trial in metastatic breast cancer. Another Phase II study is evaluating satraplatin in combination with Taxol (paclitaxel) in non-small-cell lung cancer. In addition, GPC started a Phase I trial over the summer of satraplatin in combination with Taxotere (docetaxel) in advanced solid tumors.

"If those data are promising, the expectation is that we would do some additional work looking at satraplatin plus Taxotere in hormone-refractory prostate cancer," Doyle said.

But the company's main focus for now is on completing the registration Phase III trial and getting satraplatin approved.

"We see satraplatin as having potential in a variety of oncology areas," Doyle told BioWorld Today. "To really do that well, it's nice to now have a partner that's going to help us with that, but also, at the same time, believes in the potential of satraplatin like we do and also shares our development goals and vision."

Founded in 1997, GPC first listed its shares on the Frankfurt Stock Exchange in 2000, then listed on Nasdaq last year. The company has a presence in Waltham, Mass., and Princeton, N.J.

It has one other product in clinical development, 1D09C3, a monoclonal antibody with activity against a variety of lymphoid tumors, which is in a Phase I trial. Other earlier-stage programs are focused on kinase inhibitors.

GPC's stock (NASDAQ:GPCB) rose $1.04 Tuesday to close at $12.60, while Pharmion's stock (NASDAQ:PHRM) climbed 18 cents to close at $18.45.