Poniard Announces Positive Incremental Efficacy and Safety Data from Phase 2 Picoplatin Trial in Patients With Metastatic Colorectal Cancer
- Updated Preliminary Results Presented at 20th EORTC-NCI-AACR Symposium -
SOUTH SAN FRANCISCO, Calif. and GENEVA, October 22, 2008 /PRNewswire-FirstCall/ -- Poniard Pharmaceuticals, Inc. , a biopharmaceutical company focused on oncology, today announced positive incremental data from its randomized, controlled Phase 2 clinical trial of picoplatin in patients with metastatic colorectal cancer (CRC). The expanded and updated results continue to indicate that picoplatin, given once every four weeks in combination with 5-fluorouracil and leucovorin (FOLPI), is associated with less frequent and severe neurotoxicity than oxaliplatin given in combination with 5-fluorouracil and leucovorin in the modified FOLFOX-6 regimen (FOLFOX). In addition, results continue to suggest that both regimens have similar anti-tumor activity in first-line metastatic CRC.
"Picoplatin appears to be an active platinum in colorectal cancer without the neurotoxicity of the other active platinum agents," said Richard Goldberg, M.D., associate director of clinical research for the Comprehensive Center and physician-in-chief of the N.C. Cancer Hospital. Dr. Goldberg also is a member of Poniard's Clinical Advisory Board. "These early results may support a Phase 3 trial."
The data were presented in a poster session (abstract #210/poster #210) during the 20th EORTC-NCI-AACR Symposium on "Molecular Targets and Cancer" in Geneva, Switzerland. Picoplatin, the Company's lead product candidate, is a new generation platinum chemotherapy agent with the potential to become a platform product addressing multiple indications, combinations and formulations for the treatment of multiple solid tumor indications.
Phase 2 CRC Trial Design and Preliminary Results
The randomized, controlled, Phase 2 study enrolled 101 patients who had not received prior chemotherapy. The trial is comparing the safety 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.
Interim Phase 2 results presented at the Symposium showed that 65 percent of 37 evaluable FOLFOX-treated patients showed evidence of neurotoxicity with 5 percent of these patients exhibiting severe Grade 3 or 4 neurotoxicities. This is in contrast to 18 percent of 34 evaluable patients treated with FOLPI who exhibited resolvable low-grade (Grade 2 or lower) neurotoxicities. In addition, the FOLPI-treated patients did not show any severe Grade 3 or 4 neurotoxicities. Nephrotoxicities and ototoxicities were rare and mild with the FOLPI regimen.
Non-neurologic tolerability was similar between the two treatment groups. Acute gastrointestinal toxicity was similar in the two groups, while thrombocytopenia and neutropenia were more frequent and severe in the FOLPI- treated patients, but considered to be manageable. These findings confirm and extend earlier results presented at the 44th Annual Meeting of the American Society of Clinical Oncology in May.
Anti-tumor activity also was found to be similar in the FOLPI and FOLFOX groups. Of the 35 evaluable patients in the FOLPI arm, 20 achieved disease control (partial response combined with stable disease), including six with partial responses (or 17 percent of evaluable patients). Fifteen patients in the FOLPI arm were not evaluable or too early to evaluate. Of 51 patients in the FOLFOX arm, 23 achieved disease control, including five with partial responses (or 13 percent of evaluable patients). Nine patients in the FOLFOX arm were either not evaluable or too early to evaluate.
"These interim, proof-of-concept Phase 2 colorectal cancer study results are encouraging and continue to suggest the potential of picoplatin as a neuropathy-sparing first-line therapy for metastatic colorectal cancer," said Robert De Jager, M.D., chief medical officer of Poniard. "We are committed to developing picoplatin as a preferred platinum therapy for patients with metastatic colorectal cancer who cannot tolerate the toxicity profile of currently marketed platinums, and we are optimistic that the additional data from this trial support that strategy. We are continuing to observe the study population in order to obtain progression-free and overall survival data, potentially supporting the future development of picoplatin."
Picoplatin has an improved safety profile relative to existing platinum-based cancer therapies and is designed to overcome platinum resistance associated with chemotherapy in solid tumors. It is being studied in multiple cancer indications, combinations and formulations. Picoplatin has been evaluated in more than 750 patients and has demonstrated anti-tumor activity in multiple indications with less severe kidney toxicity (nephrotoxicity) and nerve toxicity (neurotoxicity) than is commonly observed with other platinum chemotherapy drugs.
In addition to the Phase 2 clinical trial in CRC, Poniard is evaluating intravenous picoplatin in an ongoing pivotal Phase 3 trial, known as SPEAR (Study of Picoplatin Efficacy After Relapse), in small cell lung cancer. This registration trial currently is being conducted under a Special Protocol Assessment (SPA) from the U.S. Food and Drug Administration and is evaluating overall survival as the primary endpoint. Picoplatin is also being evaluated in an ongoing Phase 2 clinical trial in patients with metastatic hormone-refractory prostate cancer. Oral picoplatin is being evaluated in a Phase 1 clinical trial in solid tumors. The oral formulation of picoplatin has the same active pharmaceutical ingredient as the intravenous formulation. Picoplatin has not been approved by any regulatory authority for use in humans.
Posted: October 2008