Pivotal PROPEL trial data of FOLOTYN in patients with refractory PTCL reported at ASH Annual Meeting

Dec 6 2010

Allos Therapeutics, Inc. (NASDAQ: ALTH) today reported new analyses of data from the Company's pivotal PROPEL trial of FOLOTYN^® (pralatrexate injection) in patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) at the 52^nd American Society of Hematology (ASH) Annual Meeting held in Orlando, Florida.

“These analyses demonstrate the ability of FOLOTYN to achieve responses in patients in the second-line treatment setting immediately following treatment with CHOP, and indicate that FOLOTYN may be an effective treatment option in patients who have progressed after aggressive chemotherapy regimens such as ICE”

Results from three new retrospective analyses of single-agent FOLOTYN showed:

• Of the patients who received prior 'ICE' or similar aggressive combinations (primarily used for salvage treatment of PTCL)>
• Of the patients whose disease progressed following treatment with first-line 'CHOP' therapy>
• Of the patients who received three or more systemic therapies prior to enrolling in the PROPEL trial>

"These analyses demonstrate the ability of FOLOTYN to achieve responses in patients in the second-line treatment setting immediately following treatment with CHOP, and indicate that FOLOTYN may be an effective treatment option in patients who have progressed after aggressive chemotherapy regimens such as ICE," said Owen A. O'Connor, M.D., Ph.D., principal investigator in the PROPEL study; deputy director for Clinical Research and Cancer Treatment, NYU Cancer Institute; chief, Division of Hematologic Malignancies and Medical Oncology; professor of Medicine and Pharmacology at the NYU Langone Medical Center. "These analyses also suggest that FOLOTYN may reverse the pattern of progressive resistance in patients with drug-resistant peripheral T-cell lymphoma."

"Allos is pleased that PROPEL has and continues to provide important insights into the role of FOLOTYN to treat patients with relapsed or refractory peripheral T-cell lymphoma - which is a devastating disease," said Charles Morris, MB ChB, MRCP, chief medical officer at Allos Therapeutics.

Below is a summary of conclusions and key findings from the new analyses of data from the pivotal PROPEL trial - which enrolled 115 patients, 109 of whom were considered evaluable for efficacy according to the trial protocol. Study endpoints included overall response rate (ORR) - defined as complete response, unconfirmed complete response, and partial response - as well as duration of response (DoR), progression-free survival (PFS), and overall survival (OS). ORR, DoR and PFS were evaluated by independent central review using International Workshop Criteria (IWC).

Poster #1753: Pralatrexate is Effective in Patients with Relapsed/Refractory Peripheral T-cell Lymphoma (PTCL) After Progression Following Prior Ifosfamide, Carboplatin, and Etoposide (ICE)-based Regimens

A poster presentation by Dr. Andre Goy of The John Theurer Cancer Center at Hackensack University Medical Center assessed the efficacy of FOLOTYN in patients with PTCL whose disease progressed following prior treatment with an ICE-based regimen>

Prior to enrolling in PROPEL, response to ICE-based therapy was observed in five of 20 patients (25%). Of those patients whose disease progressed following prior ICE-based chemotherapy, objective responses with FOLOTYN were observed in eight of 20 patients (40%), including several patients who did not respond to ICE-based therapy; these results were consistent across independent central review and local investigator review. Three of the 20 patients (15%), based on independent central review, and five of the 20 patients (25%), based on local investigator review, experienced complete response; two patients went on to receive a stem cell transplant, which may result in long-term remissions in some patients. The median duration of response to FOLOTYN was 13.1 months per independent central review and 16.2 per local investigator review. The safety profile observed in these patients was consistent with that observed in the overall PROPEL study. The most common non-hematologic Grade 3-4 adverse event observed in these patients was mucositis (30%); the most common hematologic Grade 3-4 adverse events were anemia (45%) and thrombocytopenia (40%).

Abstract #4882: Pralatrexate is Effective as Second-line Treatment Following Cyclophosphamide/Doxorubicin/Vincristine/Prednisone (CHOP) Failure in Patients with Relapsed or Refractory Peripheral T-cell Lymphoma (PTCL)

This analysis by Dr. Andrei Shustov of Seattle Cancer Care assessed the efficacy of FOLOTYN as a second-line treatment in patients with PTCL whose disease progressed following first-line treatment with CHOP. Although CHOP is the most common therapy for first-line treatment of PTCL, most patients progress within 6 to 12 months and there is no standard of care for second-line treatment. Results of this analysis indicate activity of FOLOTYN in the second-line treatment setting following CHOP for patients with relapsed or refractory PTCL.

Of the 15 evaluable patients in the PROPEL study whose disease progressed following first-line treatment with CHOP, objective responses with FOLOTYN were observed in seven patients (47%) as assessed by independent central review and in six patients (40%) as assessed by local investigators. Three of the 15 patients (20%), based on independent central review, and four of the 15 patients (27%), based on local investigator review, experienced a complete response; two of these patients went on to receive a stem cell transplant and sustain complete responses for 20.1 and 21.7 months. The median duration of response to FOLOTYN was 12.5 months per local investigator review; by independent central review, the median duration of response had not yet been reached.

Abstract #4881: Pralatrexate Reverses the Trend to Progressive Resistance to Successive Systemic Treatment Regimens in Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma (PTCL)

This analysis by Dr. Owen O'Connor of the NYU Langone Medical Center was conducted to determine whether a trend of progressive resistance is observed in patients with relapsed or refractory PTCL, as well as to assess the potential ability of FOLOTYN to overcome drug resistance. Progressive resistance - characterized by a continual decrease of responses and progression-free survival in patients in the second-line treatment setting and then with each subsequent therapy - is often observed in hematologic malignancies and solid tumors. Results of this analysis demonstrated, for the first time, that patients with PTCL exhibit the same pattern of progressive drug resistance observed in other tumor types. This analysis also showed that following treatment with FOLOTYN, response rates and progression-free survival increased relative to the immediate prior line of therapy, thus reversing the trend of progressive resistance.

Of the 57 patients who received three lines of therapy or more prior to enrolling in the PROPEL trial, objective responses and progression-free survival decreased with each line of treatment - with response rates decreasing from 56 percent (32 of 57 patients) to 30 percent (17 of 57 patients) and progression-free survival decreasing from 213 days to 95 days. Following treatment with FOLOTYN, response rates and progression-free survival increased to 40 percent (23 of 57 patients) and 134 days, respectively.