Allos Therapeutics Reports Interim Response and Safety Data from Pivotal Phase 2 PROPEL Trial

  
    
  
  
    
      Allos Therapeutics, Inc. (Nasdaq:ALTH) today reported interim response 
      and safety data from the Company's pivotal Phase 2 PROPEL trial of PDX 
      (pralatrexate) in patients with relapsed or refractory peripheral T-cell 
      lymphoma (PTCL). The Company will host a conference call at 9:00 a.m. 
      Eastern, today, May 15, 2008, to review the data.
    
    
      Twenty-nine percent (n=19) of the first 65 evaluable patients enrolled 
      in the trial experienced either a complete or partial response, as 
      assessed by central independent oncology review. Forty-five percent 
      (n=29) of the first 65 evaluable patients experienced either a complete 
      or partial response, as assessed by the PROPEL investigators. Patients 
      are considered evaluable if they received at least one dose of PDX and 
      their diagnosis of PTCL has been confirmed by independent review. The 
      median duration of response for these patients cannot be estimated at 
      this time due to the current length of follow up. The most common drug 
      related grade 3/4 adverse events were mucositis and thrombocytopenia, 
      which were observed in 14% and 23% of patients, respectively. Patients 
      received a median of three prior treatment regimens.
    
    
      “We are pleased to share these interim data as 
      we continue to evaluate the clinical utility of PDX in patients with 
      relapsed or refractory peripheral T-cell lymphoma,” 
      said Pablo J. Cagnoni, M.D., Chief Medical Officer of Allos. “We 
      believe PDX, a unique antifolate rationally designed for improved cancer 
      cell uptake and retention, has the potential to offer a new treatment 
      option for patients with this challenging disease. We look forward to 
      reporting top line results of the trial by the end of this year.”
    
    
      “The PROPEL trial is the largest prospectively 
      designed single-agent trial conducted to date focused on patients with 
      relapsed or refractory peripheral T-cell lymphoma,” 
      said Owen O’Connor, M.D. Ph.D., Director 
      Lymphoid Development and Malignancy Program and Chief of the Lymphoma 
      Service at the Irving Comprehensive Cancer Center at Columbia University 
      Medical Center, and Principal Investigator of the PROPEL trial. “PDX’s 
      pre-clinical and clinical profile to date suggest that it has the 
      potential to provide therapeutic benefit to patients with this 
      challenging disease for which there are currently no approved treatments.”
    
    
      The Company completed patient enrollment in the PROPEL trial in April 
      2008 and expects to report top line results of the trial by the end of 
      2008. Following its review of the trial results, the Company intends to 
      submit a New Drug Application for PDX as a treatment for patients with 
      relapsed or refractory PTCL as expeditiously as possible.
    
    
      PROPEL (Pralatrexate in patients with Relapsed Or refractory PEripheral 
      T-cell Lymphoma) is a pivotal Phase 2, international, multi-center, 
      open-label, single-arm trial that enrolled more than 100 evaluable 
      patients with relapsed or refractory PTCL who progressed after at least 
      one prior treatment. Patients receive 30 mg/m2 
      of PDX once every week for six weeks followed by one week of rest per 
      cycle of treatment. The treatment regimen also includes vitamin B12 
      and folic acid supplementation. The primary endpoint of the trial is 
      objective response rate (complete and partial response), which will be 
      assessed by central independent oncology review. Duration of response is 
      the key secondary endpoint. All patients enrolled in the trial will 
      continue to be followed for long-term survival.
    
    
      The PROPEL trial was initiated in August 2006. In accordance with the 
      PROPEL trial protocol, three pre-planned interim analyses of safety data 
      and one pre-planned interim analysis of response data were previously 
      conducted. In January, September and December 2007, the Company 
      announced that an independent data monitoring committee (DMC) completed 
      interim analyses of safety data from the first 10, 35 and 65 evaluable 
      patients who completed at least one cycle of treatment with PDX, 
      respectively, and recommended that the trial continue per the protocol 
      at each analysis. No major safety concerns were identified by the DMC. 
      In September 2007, the Company announced that the results of the interim 
      analysis of patient response data exceeded the pre-specified threshold 
      for continuation of the trial, which required a minimum of four 
      responses (complete or partial) out of the first 35 evaluable patients, 
      as determined by independent oncology review.
    
    
      The PROPEL trial is being conducted under an agreement reached with the 
      United States Food and Drug Administration (FDA) under its Special 
      Protocol Assessment (SPA) process. The SPA process allows for FDA 
      evaluation of a clinical trial protocol intended to form the primary 
      basis of an efficacy claim in support of a new drug application (NDA), 
      and provides an agreement that the trial design, including trial size, 
      clinical endpoints and/or data analyses are acceptable to the FDA. The 
      response rate, duration of response and safety profile required to 
      support FDA approval are not specified in the PROPEL trial protocol and 
      will be subject to FDA review.
    
    
      The FDA granted orphan drug designation and fast track designation to 
      PDX for the treatment of patients with T-cell lymphoma in July 2006 and 
      September 2006, respectively. In April 2007, the Commission of the 
      European Communities, with a favorable opinion of the Committee for 
      Orphan Medicinal Products of the European Medicines Agency, or EMEA, 
      granted orphan medicinal product designation to PDX for the treatment of 
      patients with PTCL.
    
    
      Conference Call
    
    
      The Company will host a conference call to review the PROPEL 65-patient 
      interim data on Thursday, May 15, 2008, at 9:00 a.m. ET. The dial in 
      number for U.S. residents to participate is 800-762-8973. International 
      callers should dial 480-629-9041. Participants should reference the 
      Allos Therapeutics conference call.
    
    
      Webcast
    
    
      The Company will hold a live webcast of the conference call. The webcast 
      will be available from the homepage and the investors/media section of 
      the Company's web site at www.allos.com 
      and will be archived for 30 days.
    
    
      Conference Call Replay
    
    
      An audio replay of the conference call will be available from 
      approximately two hours after completion of the call through Friday, May 
      30, 2008. To access the replay, please dial 800-406-7325 (domestic) or 
      303-590-3030 (international). The replay pass code is 3878869#.
    
    
      About Peripheral T-cell Lymphoma
    
    
      Peripheral T-cell lymphomas, or PTCLs, are a biologically diverse group 
      of blood cancers that account for approximately 10% to 15% of all cases 
      of non-Hodgkin's lymphoma (NHL) in the United States. According to the 
      American Cancer Society, approximately 63,000 patients are expected to 
      be diagnosed with NHL in the United States in 2008. The Company 
      estimates the current annual prevalence of PTCL at approximately 9,500 
      patients. There are currently no pharmaceutical agents approved for use 
      in the treatment of either first-line or relapsed or refractory PTCL. 
      PTCL patients are often treated with multi-agent chemotherapy regimens, 
      for which first-line treatment response rates range from 50%-70%. In 
      addition to the 30-50% of PTCL patients that do not respond to 
      first-line treatment, a significant number of first-line multi-agent 
      chemotherapy responders relapse or become refractory after treatment. A 
      study that included patients with aggressive PTCL found that the average 
      five-year survival for those patients was approximately 25%.
    
    
      About PDX (pralatrexate)
    
    
      PDX is a novel, small molecule chemotherapeutic agent that inhibits 
      dihydrofolate reductase, or DHFR, a folic acid (folate)-dependent enzyme 
      involved in the building of nucleic acid, or DNA, and other processes. 
      PDX was rationally designed for efficient transport into tumor cells via 
      the reduced folate carrier, or RFC-1, and effective intracellular drug 
      retention. The Company believes these biochemical features, together 
      with preclinical and clinical data in a variety of tumors, suggest that 
      PDX may have a favorable safety and efficacy profile relative to 
      methotrexate and other related DHFR inhibitors.
    
    
      About Allos Therapeutics, Inc.
    
    
      Allos Therapeutics is a biopharmaceutical company focused on developing 
      and commercializing innovative small molecule drugs for the treatment of 
      cancer. The Company's lead product candidate, PDX (pralatrexate), is a 
      novel antifolate currently under evaluation in a pivotal Phase 2 
      (PROPEL) trial in patients with relapsed or refractory peripheral T-cell 
      lymphoma. The PROPEL trial is being conducted under an agreement reached 
      with the U.S. Food and Drug Administration under its special protocol 
      assessment, or SPA process. The Company is also investigating PDX in 
      patients with non-small cell lung cancer and a range of lymphoma 
      sub-types. The Company's other product candidate is RH1, a targeted 
      chemotherapeutic agent currently under evaluation in a Phase 1 trial in 
      patients with advanced solid tumors or non-Hodgkin’s 
      Lymphoma (NHL). For additional information, please visit the Company’s 
      website at www.allos.com.
    
    
      Safe Harbor Statement
    
    
      This press release contains forward-looking statements that are made 
      pursuant to the safe harbor provisions of the Private Securities 
      Litigation Reform Act of 1995. Such forward-looking statements include 
      statements regarding the potential for PDX to offer a new treatment 
      option for patients with relapsed or refractory PTCL, the Company’s 
      projected timeline for reporting top line results from the PROPEL trial, 
      the Company’s intent to submit a New Drug 
      Application for PDX as a treatment for patients with relapsed or 
      refractor PTCL following its review of the trial results, the potential 
      safety and efficacy profile of PDX relative to methotrexate and other 
      related DHFR inhibitors; and other statements that are other than 
      statements of historical facts. In some cases, you can identify 
      forward-looking statements by terminology such as “may,” 
      “will,” “should,” 
      “expects,” “intends,” 
      “plans,” “anticipates,” 
      “believes,” “estimates,” 
      “predicts,” “projects,” 
      “potential,” “continue,” 
      and other similar terminology or the negative of these terms, but their 
      absence does not mean that a particular statement is not 
      forward-looking. Such forward-looking statements are not guarantees of 
      future performance and are subject to risks and uncertainties that may 
      cause actual results to differ materially from those anticipated by the 
      forward-looking statements. These risks and uncertainties include, among 
      others: that the Company may experience delays in the completion of the 
      PROPEL trial, whether caused by adverse events, regulatory issues or 
      other factors; that the PROPEL trial may not demonstrate that PDX is 
      both safe and effective for the treatment of patients with relapsed or 
      refractory PTCL; that the results of the PROPEL trial may not support an 
      application for marketing approval in the United States or any other 
      country; that an application for marketing approval may not be accepted 
      for priority review or at all by the FDA or any other regulatory 
      authority; and that the Company may lack the financial resources and 
      access to capital to fund future clinical trials for PDX or any of its 
      other product candidates. Additional information concerning these and 
      other factors that may cause actual results to differ materially from 
      those anticipated in the forward-looking statements is contained in the 
      "Risk Factors" section of the Company's Annual Report on Form 10-K for 
      the year ended December 31, 2007 and in the Company's other periodic 
      reports and filings with the Securities and Exchange Commission. The 
      Company cautions investors not to place undue reliance on the 
      forward-looking statements contained in this press release. All 
      forward-looking statements are based on information currently available 
      to the Company on the date hereof, and the Company undertakes no 
      obligation to revise or update these forward-looking statements to 
      reflect events or circumstances after the date of this presentation, 
      except as required by law.
    
    
      Note: The Allos logo is a trademark of Allos Therapeutics, Inc.