New Analysis from Phase 2b Study (ALTH)

Allos Therapeutics, Inc. ALTH today announced the presentation of further data from the Company's randomized, international Phase 2b investigational study of FOLOTYN® (pralatrexate injection) relative to erlotinib in patients with Stage IIIB/IV (advanced) non-small cell lung cancer (NSCLC) at the 2010 Chicago Multidisciplinary Symposium in Thoracic Oncology. The presentation, which includes additional results from several pre-specified analyses, reinforces the favorable survival data observed with FOLOTYN in patients with advanced NSCLC—including outcomes observed in patients with non-squamous and squamous histologies, as well as results from an analysis adjusting for important baseline factors and potential imbalances in the number of patients between cohorts. “The results presented at this important lung cancer conference further demonstrate the activity of FOLOTYN relative to erlotinib, an active comparator, in advanced non-small cell lung cancer – where nearly all patients progress through initial treatment and more treatment options are needed,” said Karen Kelly, M.D., presenter and an investigator of the study, The University of Kansas Medical Center. “Based on these results, I believe further studies are warranted to fully understand the potential role of FOLOTYN in the treatment of advanced non-small cell lung cancer in patients with both squamous and non-squamous histologies.” The objective of this randomized, international, multi-center Phase 2b study (PDX-012) was to estimate the efficacy of FOLOTYN relative to that of erlotinib as assessed by overall survival, the primary endpoint of the trial. As previously reported, patients receiving FOLOTYN had a 16 percent reduction in the risk of death compared to erlotinib in the overall (intent-to-treat) population (n=201; hazard ratio (HR)=0.84) and a 13 percent reduction in the risk of death in the primary efficacy analysis population (n=166; HR=0.87). Secondary endpoints included progression-free survival (PFS) (HR=0.91; median PFS=3.4 months and 2.8 months for FOLOTYN and erlotinib, respectively). Review of the predefined patient cohorts indicated that the majority of cohorts responded favorably to FOLOTYN relative to erlotinib. The largest benefit was observed in patients with non-squamous cell carcinoma, while comparable survival was observed across both treatments in patients with squamous cell carcinoma. The additional data presented at the Chicago symposium were based on analyses of the overall population (n=201) and showed that when adjusting for potential imbalances in several important baseline factors, the hazard ratio for overall survival, which favored FOLOTYN, was 0.73. These baseline factors included gender, race, histology, ECOG performance status, smoking history, response to prior therapy, prior treatment with pemetrexed, number of prior regimens, stage of disease at enrollment, weight loss prior to study and age at study entry. The presentation also included additional data from patients with non-squamous cell carcinoma (n=107) and squamous cell carcinoma (n=76). As previously presented, in patients with non-squamous cell carcinoma, overall survival and progression-free survival favored FOLOTYN with hazard ratios of 0.65 and 0.58, respectively; in patients with squamous cell carcinoma, a hazard ratio of 1.06 for overall survival was observed. Further details presented at the Chicago symposium showed that of those patients with non-squamous cell carcinoma who received FOLOTYN (n=61), 25 percent (n=15) had received prior treatment with pemetrexed. Additionally, in patients with squamous cell carcinoma, a hazard ratio of 1.06 was observed for progression-free survival, which reinforces the potential activity of FOLOTYN, given that erlotinib has historically shown a benefit in both overall and progression-free survival relative to placebo in patients with squamous cell carcinoma. Of those patients treated with FOLOTYN (n=97) in the trial, 32 patients (33%) discontinued treatment due to adverse events, including 13 patients who discontinued within the first cycle of treatment or within 30 days. Of those patients treated with erlotinib (n=101), 10 patients (10%) discontinued treatment due to adverse events, including two patients who discontinued within the first 30 days. The rate of discontinuation for progression of disease was comparable between the two arms during the first cycle of treatment. To better understand the impact of discontinuation on the overall study results, an exploratory landmark analysis was conducted to assess the activity of FOLOTYN relative to erlotinib in patients who remained on treatment at 30 days (n=145). These data showed a hazard ratio of 0.61, which suggests that maintaining patients on FOLOTYN therapy may be important for efficacy. The safety profile of FOLOTYN was consistent with that observed and reported in previous FOLOTYN solid tumor studies. The most common Grade 3-4 adverse event observed in patients treated with FOLOTYN was mucositis (23 percent). Other Grade 3-4 adverse events occurring in more than five percent (but less than 10 percent) of patients were fatigue (9 percent), dyspnea (6 percent), neutropenia (6 percent), thrombocytopenia (5 percent) and anemia (5 percent) in patients treated with FOLOTYN, and rash (8 percent), dyspnea (8 percent), anemia (8 percent) and fatigue (5 percent) in patients treated with erlotinib. “We are pleased with these results that demonstrated the clinical activity of FOLOTYN in patients with advanced non-small cell lung cancer, an area of high unmet need,” said Charles Morris, MB ChB, MRCP, chief medical officer at Allos Therapeutics. The 2010 Chicago Multidisciplinary Symposium in Thoracic Oncology (December 9-11) is co-sponsored by the American Society of Clinical Oncology (ASCO), American Society for Radiation Oncology (ASTRO), International Association for the Study of Lung Cancer (IASLC), and the University of Chicago. The Company had previously announced the top-line results from this trial in July and presented the results for the first time at the European Society of Medical Oncology in October 2010.