ATLANTA, Oct. 4 /PRNewswire-FirstCall/ -- Allos Therapeutics, Inc. (Nasdaq: ALTH - News) announced the presentation of new findings from its Phase 3 clinical trial of the investigational radiation sensitizer EFAPROXYN(TM) (efaproxiral) in patients with brain metastases. A retrospective analysis of the results from the study led to the identification of the strongest prognostic factors for survival in patients with brain metastases. John H. Suh, M.D., Clinical Director, Radiation Oncology, Brain Tumor Institute at the Cleveland Clinic Foundation and the study's lead investigator presented the findings in an oral presentation today at the 46th Annual Meeting of the American Society for Therapeutic Radiation Oncology. Preliminary data from the Phase 3 study, called REACH, were first announced in April 2003.

In abstract #60, titled "Prognostic Factors for Survival in Patients with Brain Metastases Enrolled on a Worldwide Phase 3 Randomized Trial of 538 Patients," Dr. Suh and colleagues evaluated certain factors influencing long-term survival of brain metastases patients, including Karnofsky Performance Status (KPS), site of primary, age, presence of extra cranial metastases, control of primary, gender, presence of liver metastases, timing of brain metastases diagnosis, prior brain tumor resection and number of brain metastases. Results of the analysis indicated that KPS, prior brain tumor resection, the presence of extra cranial metastases and gender were the strongest variables in predicting outcome. Moreover, the analysis affirmed the effectiveness of the study drug, EFAPROXYN, in improving survival time across a heterogeneous patient population.

"This study has significant implications for the design of future randomized trials in brain metastases patients," said Dr. Suh. "Our findings confirm the impact of certain variables in determining survival outcome for brain metastases patients. Moreover, the results demonstrated an improvement in survival for patients with brain metastases who received EFAPROXYN and whole brain radiation therapy (WBRT) with supplemental oxygen over those who received WBRT with supplemental oxygen only."

Results from Dr. Suh's retrospective analysis were incorporated into the study design of Allos' Phase 3, randomized, open-label, multi-center trial, called ENRICH (ENhancing Whole Brain Radiation Therapy In Patients with Breast Cancer and Hypoxic Brain Metastases), designed to compare the effect of whole brain radiation therapy (WBRT) with supplemental oxygen with or without EFAPROXYN in women with brain metastases from breast cancer. The trial, which was initiated in February 2004, incorporated certain identified prognostic factors into the stratification and design, including KPS and presence of liver metastases.

Study Design

The REACH study was a randomized, open label Phase 3 clinical trial designed to demonstrate the safety and efficacy of EFAPROXYN in treating patients with brain metastases and good performance status. Patients with SCLC, germ cell tumors or lymphoma were excluded. Prior brain tumor resection was allowed as long as measurable lesion(s) remained. The study enrolled 538 patients and compared the safety and efficacy of EFAPROXYN plus WBRT and supplemental oxygen (271 patients) versus WBRT and supplemental oxygen (267 patients) in patients with brain metastases. The primary endpoint of the trial was survival.

About EFAPROXYN

EFAPROXYN is the first synthetic small molecule designed to "sensitize" hypoxic (oxygen-deprived) areas of tumors during radiation therapy by facilitating the release of oxygen from hemoglobin, the oxygen-carrying protein contained within red blood cells, and increasing the level of oxygen in tumors. The presence of oxygen in tumors is an essential element for the effectiveness of radiation therapy in the treatment of cancer. By increasing tumor oxygenation at the time of treatment, EFAPROXYN has the potential to enhance the efficacy of standard radiation therapy. Unlike chemotherapeutics or other radiation sensitizers, EFAPROXYN does not have to cross the blood brain barrier or enter the tumor to be effective.

About Allos Therapeutics, Inc.

Allos Therapeutics, Inc. is a biopharmaceutical company focused on developing and commercializing innovative drugs for improving cancer treatments. The company's lead clinical candidate, EFAPROXYN, is a synthetic small molecule that has the potential to sensitize hypoxic (oxygen deprived) tumor tissues and enhance the efficacy of standard radiation therapy. In addition, Allos is developing PDX (pralatrexate), a novel small molecule cytoxic injectable antifolate (DHFR inhibitor) intended to treat non-small cell lung cancer, mesothelioma and non-Hodgkin's lymphoma. For more information, please visit the company's web site at: www.allos.com.

Safe Harbor Statement

This announcement contains forward-looking statements that involve risks and uncertainties. Future events may differ materially from those discussed herein due to a number of factors, including, but not limited to, risks and uncertainties related to the Company's ability to adequately demonstrate the safety and efficacy of EFAPROXYN for use as an adjunct to WBRT for the treatment of patients with brain metastases from breast cancer or any other solid tumor, and to obtain regulatory approval to market EFAPROXYN for this or any other indication, as well other risks and uncertainties detailed from time to time in the Company's SEC filings, including its Annual Report on Form 10-K, as amended, for the year ended December 31, 2003. [The company's product candidates are in various stages of development and may never be fully developed in a manner suitable for commercialization. If the company does not develop commercially successful products, its ability to generate revenue will be limited. If the company is unable to raise additional capital when required or on acceptable terms, it may have to significantly delay, scale back or discontinue one or more of its drug development programs. Delays in clinical trials, whether caused by adverse events, patient enrollment rates, regulatory issues or other factors, could adversely affect the company's financial position and prospects. Results from earlier clinical trials are not necessarily predictive of future clinical results. If the company is unable to generate meaningful amounts of revenue or cannot otherwise raise the necessary funds to support operations, it may not be able to continue as a going concern.] 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 assumes no responsibility to update such statements.