Cell Therapeutics' STELLAR 2 and 4 Pivotal Trials Miss Primary Endpoint

Cell Therapeutics announced the results of its Phase III clinical studies of Xyotax in non-small cell lung cancer (NSCLC), known as STELLAR 2 and 4. The studies were designed to determine if Xyotax could increase the overall survival of patients while reducing serious side effects associated with the treatment of first-line or second-line NSCLC. Both trials demonstrated equivalent survival with significant reductions in serious side effects when compared to either docetaxel or gemcitabine/vinorelbine; although they missed their primary endpoints of superior overall survival. Xyotax was administered in a convenient 10-minute infusion without the requirement for steroids and other premedications.

STELLAR 4, a Phase III clinical trial of Xyotax versus either gemcitabine or vinorelbine for the first-line treatment of poor performance status (PS2) patients with NSCLC, resulted in a median survival of 7.3 months and 2 year survival of 15 percent for patients on the Xyotax arm compared to 6.6 months and 10 percent for the control arm. Significantly more patients completed full six courses of therapy on the Xyotax arm compared to the control arm. Side effects were comparable on both arms, except for a significant reduction in all cardiac toxicities, gastrointestinal side effects, nausea, and vomiting. Xyotax patients also had a significant reduction in severe hematologic toxicities including anemia, neutropenia, and thrombocytopenia. Hair loss was uncommon on both arms. Grade 3/4 neuropathy was observed more frequently on the Xyotax arm (4 percent versus 0 percent).

STELLAR 2, a Phase III clinical trial of Xyotax versus docetaxel for the second-line treatment of NSCLC patients, resulted in a 6.9 month median survival for both arms. Patients treated with Xyotax had significantly fewer hematologic side effects than patients on the docetaxel arm, including grade 3/4 infections, severe neutropenia, and febrile neutropenia. Xyotax therapy also resulted in a significant reduction in hair loss, fatigue, asthenia, breathing problems, severe hypoxia, mucositis and ocular toxicity. As expected, severe neuropathy on Xyotax at a dose of 210 mg/m2 was higher than on the docetaxel arm.