Allos Therapeutics Announces FOLOTYN® Data Presentation at the 35th ESMO Congress

Allos Therapeutics, Inc. (Nasdaq: ALTH) today announced that results from the Phase 2b investigational trial of FOLOTYN^® (pralatrexate injection) versus erlotinib in patients with Stage IIIB/IV (advanced) non-small cell lung cancer (NSCLC) will be presented at the 35^th European Society of Medical Oncology (ESMO) Congress — Milan, Italy from October 8-12, 2010.

"This is the first time that Allos will have an opportunity to present the results from the Phase 2b trial of FOLOTYN in patients with advanced non-small cell lung cancer,” said Charles Morris, MB ChB, MRCP, chief medical officer at Allos Therapeutics. "We believe these are important results for the cancer community – generating data on the efficacy and safety profile for FOLOTYN in this treatment setting where there remains a high unmet need – and are pleased that the ESMO Congress has accepted these data as a late-breaking abstract to be highlighted in an oral presentation.”

The randomized, open-label, international, multi-center Phase 2b study comparing FOLOTYN versus erlotinib, marketed as TARCEVA®, enrolled 201 current or former smokers with Stage IIIB/IV (advanced) NSCLC who had received one or two previous treatments including at least one prior platinum-based chemotherapy regimen. The objective of the trial was to estimate the efficacy of FOLOTYN compared to that of erlotinib as assessed by overall survival. The primary endpoint of the trial was overall survival. Secondary endpoints included progression-free survival and response rate, both compared to erlotinib, and the safety and tolerability of FOLOTYN.

Presentation details are as follows:

Presentation Date/Time: Monday, October 11, 13:15 – 14:30 CEST
Poster Title: "Randomized Phase 2b Study of Pralatrexate vs Erlotinib in Patients with Stage IIIB/IV Non-small Cell Lung Cancer (NSCLC) after Failure of Prior Platinum-Based Therapy”
First Author: K. Kelly, University of Kansas, Kansas City/US
Abstract Number: LBA17
Location: Chest tumors II, Gold Hall

About Lung Cancer

More people die each year from lung cancer than any other type of cancer – including breast, prostate, and colorectal cancers combined. In 2010, it is estimated that there will be more than 200,000 new cases of lung cancer diagnosed in the United States and over 150,000 deaths. There are primarily two types of lung cancer: NSCLC and small cell lung cancer (SCLC). NSCLC accounts for the majority of lung cancers (about 87 percent) and develops slowly – often causing few or no symptoms until very late stages. The most common subtypes of NSCLC are squamous cell carcinoma, adenocarcinoma, and large-cell undifferentiated carcinoma; squamous cell carcinomas account for 25-30 percent of all lung cancers while adenocarcinoma and large-cell undifferentiated carcinoma account for 40 percent and 10-15 percent of lung cancers, respectively. The majority of people are diagnosed with advanced stage disease and only one to five percent of people with advanced stage (IIIB/IV) NSCLC survive to five years. The most widely used therapies to date remain surgery, chemotherapy, and radiation therapy.

About Allos Therapeutics

Allos Therapeutics, Inc. (Nasdaq: ALTH) is a biopharmaceutical company committed to the development and commercialization of innovative anti-cancer therapeutics. Allos is currently focused on the development and commercialization of FOLOTYN^® (pralatrexate injection), a folate analogue metabolic inhibitor. FOLOTYN is the first and only drug approved in the U.S. for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma. Allos is also developing FOLOTYN in other hematologic malignancies and solid tumors. Allos retains exclusive worldwide rights to FOLOTYN for all indications. Allos is headquartered in Westminster, CO. For additional information, please visit www.allos.com.

IMPORTANT SAFETY INFORMATION

Warnings and Precautions:

FOLOTYN may suppress bone marrow function, manifested by thrombocytopenia, neutropenia, and anemia. Monitor blood counts and omit or modify dose for hematologic toxicities.

Mucositis may occur. If = Grade 2 mucositis is observed, omit or modify dose.

Patients should be instructed to take folic acid and receive vitamin B12 to potentially reduce treatment-related hematological toxicity and mucositis.

FOLOTYN can cause fetal harm. Women should avoid becoming pregnant while being treated with FOLOTYN, and pregnant women should be informed of the potential harm to the fetus.

Use caution and monitor patients when administering FOLOTYN to patients with moderate to severe renal function impairment.

Elevated liver function test abnormalities may occur and require monitoring. If liver function test abnormalities are = Grade 3, omit or modify dose.

Dermatologic reactions may occur. Patients with dermatologic reactions should be monitored closely.

Adverse Reactions:

The most common adverse reactions observed were mucositis (70%), thrombocytopenia (41%), nausea (40%), and fatigue (36%). The most common serious adverse events were pyrexia, mucositis, sepsis, febrile neutropenia, dehydration, dyspnea and thrombocytopenia.

Use in Specific Patient Population:

Nursing mothers should be advised to discontinue nursing or the drug, taking into consideration the importance of the drug to the mother.

Drug Interactions:

Co-administration of drugs subject to renal clearance (e.g., probenecid, NSAIDs, and trimethoprim/sulfamethaxazole) may result in delayed renal clearance.

For additional important safety information, please see the full prescribing information for FOLOTYN 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 safety and efficacy of FOLOTYN for the treatment of patients with advanced non-small cell lung cancer, the potential development of FOLOTYN for the treatment of advanced non-small cell lung cancer; 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 data from preclinical studies and clinical trials may not necessarily be indicative of future clinical trial results; that the safety and/or efficacy profile for FOLOTYN may not support further clinical development in advanced non-small cell lung cancer; and the risk that the Company may lack the financial resources and access to capital to fund future clinical trials for FOLOTYN. 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 Quarterly Report on Form 10-Q for the quarter ended June 30, 2010, 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 and FOLOTYN name are trademarks of Allos Therapeutics, Inc.