West Coast Editor

The finishing touches on their rolling new drug application for the fast-track prostate cancer drug satraplatin boosted Spectrum Pharmaceuticals Inc. and partner GPC Biotech AG, and strong Phase III data suggested the FDA will grant a priority, six-month review.

Irvine, Calif.-based Spectrum's stock (NASDAQ:SPPI) closed Friday at $6.56, up 20 cents, and GPC's shares (NASDAQ:GPCB) ended the day at $32.81, up $1.86.

Spectrum stands to get a $4 million milestone payment if the agency accepts the NDA, which will be known within 60 days, and GPC's European marketing partner Pharmion Corp., of Boulder, Colo., plans to file for approval overseas in the first half of this year.

GPC handed over the third and final part of the NDA. That consists of clinical data from the Phase III SPARC (Satraplatin and Prednisone Against Refractory Cancer) trial, which enrolled 950 patients and yielded strong results in progression-free survival with the platinum-based compound, the only oral drug in its class. Patients took the drug once daily for five days, stopped for 30 days and then resumed.

Details of the SPARC data will be offered during a prostate cancer symposium sponsored by the American Society of Clinical Oncology later this week. Laurie Doyle, director of investor relations and corporate communications for GPC, said the firm could provide no details about the data until then. ASCO maintains famously tight embargoes on its presentations.

Spectrum also gets milestone payments and royalties in the potential $22 million deal with GPC signed more than four years ago, and retains co-promotion rights in the U.S. if GPC markets the drug here. (See BioWorld Today, Oct. 2, 2002.)

Satraplatin came originally from Johnson Matthey, a London-based precious metals firm that "had a relationship with [Bristol-Myers Squibb Co.], which had done quite a bit of clinical work on it," Doyle said. Members of the GPC team were familiar with New York-based BMS' work on satraplatin.

"We were in a somewhat unique situation and were able to do the deal relatively quickly," she said. If cleared for marketing worldwide, the drug's sales could reach about $500 million annually.

As with other platinum-based drugs, which are given intravenously, the dose-limiting toxicity with satraplatin is myelosuppression, but "you're not seeing the significant renal toxicity you get with other platinums," Doyle said.

"They tend to get lumped together, but they're actually quite different," she added.

Paris-based Sanofi-Aventis Group's Eloxatin (oxaliplatin), for example, works well against colorectal cancer but not in other tumors.

"There's a lot going on with satraplatin," she said, noting that GPC has the compound in a Phase II trial for non-small-cell lung cancer in combination with Taxol (paclitaxel, Bristol-Myers Squibb Co.), and another that adds satraplatin to Tarceva (erlotinib, Genentech Inc. and OSI Pharmaceuticals Inc.) as therapy for elderly NSCLC patients. Doyle allowed that GPC won favorable terms in the satraplatin deal, but said the drug's success would be a "win-win" for all involved.

The licensing arrangement hasn't gone entirely smoothly, though. In December, Spectrum filed a demand for arbitration and statement of claim with the American Arbitration Association to resolve a dispute.

Spectrum claims it is entitled to a payment of €9 million (US$11.8 million) in connection with a reimbursement for past development expenses, and alleges that GPC has not used "commercially reasonable efforts" to gain regulatory approval of the drug and to promote satraplatin in Japan. GPC said Spectrum's claims were "made in bad faith," and lack merit. Doyle said the arbitration is ongoing.

Behind satraplatin, GPC has ID09C3, a monoclonal antibody aimed at treating relapsed or refractory B-cell lymphomas, such as non-Hodgkin's lymphoma and chronic lymphocytic leukemia. "We're hoping to complete the Phase I later this year," Doyle said, and the Phase II program could start around the end of the year.

Mark Monane, analyst with Needham & Co. in New York, called GPC a "very favorable investment opportunity." In his January research report, Monane set a $27 price target, but GPC spiked earlier, and the Martinsried, Germany-based firm raised €33.6 million (US$43.7 million) that month to support the satraplatin effort. (See BioWorld Today, Jan. 25, 2007.)

Spectrum's shares have been a different story. Positive news last year failed to push the stock upward, but the firm ended the year debt-free with $45 million in cash, and 2007 could bring more value. Not only is satraplatin, the company's main driver, likely to win approval late in the year, but also the Phase III push with EOquin (apaziquone for intravesical instillation) in noninvasive bladder cancer, is expected to start in the second quarter.

Earlier this month, Spectrum finished patient accrual in a pilot safety study with EOquin, and the Phase III work would be carried out under a special protocol assessment.

Phase IIb data are due this summer with ozarelix, Spectrum's fourth-generation luteinizing hormone-releasing hormone antagonist for benign prostate hypertrophy. The first patient was dosed in late January.