The Phase 1/2 trial of PX-866 in combination with docetaxel mentioned above has advanced to the Phase 2 portion, which is an open-label, randomized evaluation of the antitumor activity and safety of PX-866 administered at the recommended daily dose in combination with docetaxel, versus docetaxel alone, in two groups of patients. Group 1 is enrolling patients with non-small cell lung cancer (NSCLC) receiving second or third line treatment. Group 2 is enrolling patients with locally advanced, recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN) after failure of prior therapy. The two groups will be randomized and evaluated independently. Enrollment of a planned 88 patients in the NSCLC group is currently expected to be completed this month. Additional centers are being added to the SCCHN arm of the trial, with a goal to complete enrollment of 82 patients in the first half of 2013.
Oncothyreon has also advanced to the Phase 2 portion of a Phase 1/2 trial of PX-866 in combination with the chimeric monoclonal antibody cetuximab (Erbitux®), which is an open-label, randomized evaluation of the antitumor activity and safety of PX-866 administered at the recommended daily dose in combination with cetuximab, versus cetuximab alone, in two groups of patients . Group 1 is enrolling patients with metastatic colorectal cancer (CRC) who have a history of progression or recurrence following prior treatment with irinotecan and oxaliplatin containing regimens or who are intolerant of irinotecan. Over 50 of a planned 80 patients are currently enrolled in this arm of the trial, with enrollment currently expected to be completed in the fourth quarter of 2012. Group 2 is currently enrolling patients with incurable progressive, recurrent or metastatic SCCHN. The two groups will be randomized and evaluated independently.
Oncothyreon also recently announced the initiation of a Phase 1/2 trial of PX-866 in combination with vemurafenib (Zelboraf®). The Phase 1 portion of this trial will evaluate the safety and tolerability of PX-866 in combination with twice daily oral administration of vemurafenib in up to 36 patients with any BRAF-mutant cancer. The Phase 2 portion of the trial will compare the anti-tumor activity and safety of PX-866 and vemurafenib at the doses recommended from Phase 1 with vemurafenib alone administered at the approved dose. This randomized Phase 2 trial is expected to enroll 110 patients with advanced BRAF-mutant melanoma and has a primary endpoint of progression-free survival. This Phase 1/2 trial is being conducted in collaboration with the Melanoma Research Foundation Breakthrough Consortium (MRFBC).