Poniard Pharmaceuticals, Inc, a biopharmaceutical company focused on innovative oncology therapies, announced updated efficacy and safety data from its randomized, controlled phase-2 clinical trial of picoplatin in patients with metastatic colorectal cancer (CRC). Results continue to suggest that picoplatin, given once every four weeks in combination with 5-fluorouracil and leucovorin (Folpi), is associated with less frequent and less severe neurotoxicity than oxaliplatin given in combination with 5-fluorouracil and leucovorin in the modified Folfox-6 regimen (Folfox). Results also continue to indicate that both regimens have similar anti-tumour activity in first-line metastatic CRC. Net sales in 2007 in the US for Eloxatin (oxaliplatin) were approximately $1.3 billion.
"These new data continue to suggest that picoplatin is an active platinum agent in colorectal cancer, but without the significant neuropathy associated with currently marketed platinums," said Richard Goldberg, associate director of clinical research for the University of North Carolina Comprehensive Center and physician-in-chief of the N C Cancer Hospital. Dr Goldberg also is a member of Poniard's Clinical Advisory Board. "Picoplatin may provide a neuropathy-sparing alternative to oxaliplatin in patients with advanced colorectal cancer. I'm encouraged by the results, which could support additional trials."
Picoplatin, the company's lead product candidate, is a new generation platinum-based chemotherapy agent with the potential to become a platform product addressing multiple indications, combinations and formulations. The picoplatin data will be presented in a poster session Saturday, January 17th at 12:30 pm Pacific Time during the American Society of Clinical Oncology's (ASCO) 2009 Gastrointestinal Cancers Symposium in San Francisco.
The randomized, controlled phase-2 trial is evaluating picoplatin as a neuropathy-sparing alternative to oxaliplatin for the first-line treatment of metastatic CRC in 101 patients who have not received prior chemotherapy. The trial is comparing the safety, including neuropathy, and efficacy of intravenous picoplatin given once every four weeks in combination with bi-weekly 5-fluorouracil and leucovorin (the Folpi regimen) with oxaliplatin given in combination with 5-fluorouracil and leucovorin in the FOLFOX regimen, which is the current standard of care. Severe neuropathy is commonly seen in CRC patients treated with oxaliplatin in combination with 5-fluorouracil and leucovorin as part of the Folfox regimen at cumulative doses above 800 mg/m squared.
The Phase 2 results, scheduled for presentation at the ASCO Symposium, showed that 65 percent of evaluable Folfox-treated patients showed evidence of neurotoxicity compared with 28 percent of patients treated with Folpi. Ten per cent of Folfox-treated patients exhibited severe (Grade 3/4) neuropathy compared with no Folpi-treated patients. Nonhematologic adverse events, including acute gastrointestinal toxicity, were similar between the treatment groups. Thrombocytopenia and neutropenia were more frequent and severe with the Folpi regimen, but manageable.
Anti-tumour activity also was similar in the Folpi and Folfox groups. Of patients in the Folpi arm, 76 percent achieved disease control (complete response, partial response and stable disease), including one patient with a complete response and seven patients with a partial response, as did 76 percent of patients in the Folfox arm, including seven patients with a partial response.
"These interim, proof-of-concept Phase 2 results are very encouraging and continue to suggest the potential of picoplatin as a neuropathy-sparing first-line therapy for metastatic colorectal cancer," said Robert De Jager, chief medical officer of Poniard. "We continue to observe the study participants to obtain progression-free and overall survival data. We expect that those data will support our primary goal of developing picoplatin as a preferred platinum therapy for patients with metastatic colorectal cancer who cannot tolerate the toxicity profile of currently marketed platinums."
Picoplatin is designed to overcome platinum resistance associated with chemotherapy in solid tumours.