MEI Pharma Highlights New Data from Phase II Clinical Studies of Pracinostat in Acute Myeloid Leukemia and Myelodysplastic Syndrome

American Society of Hematology Annual Meeting Abstracts Now Available

Nov 5, 2015

SAN DIEGO, Nov. 5, 2015 /PRNewswire/ -- MEI Pharma, Inc. (Nasdaq: MEIP), an oncology company focused on the clinical development of novel therapies for cancer, today announced the publication of new data from the Company's Phase II clinical studies of the investigational drug Pracinostat in patients with previously untreated myelodysplastic syndrome (MDS) and elderly patients with acute myeloid leukemia (AML). Results from these studies were recently selected for oral presentation at the upcoming American Society of Hematology (ASH) Annual Meeting in Orlando on December 7, 2015. The abstracts are now available on the ASH website at

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"The data contained within the abstracts released this morning point to certain trends worth highlighting," said Daniel P. Gold, Ph.D., President and Chief Executive Officer of MEI Pharma. "Since the unblinding of our randomized study in front-line MDS, we have learned that the combination of Pracinostat and azacitidine resulted in a high rate of discontinuations due to adverse events compared to azacitidine alone. These discontinuations occurred predominantly within the first two cycles of treatment and often before a response assessment could be performed, leading to a higher complete response (CR) rate overall with azacitidine alone. However, exploratory sensitivity analyses among patients who were able to tolerate treatment for at least four cycles (n=54) suggest that patients treated with Pracinostat plus azacitidine appear to derive benefit compared to azacitidine alone, with hazard ratios for progression-free survival (0.37), event-free survival (0.33) and overall survival (0.59) all favoring the Pracinostat plus azacitidine arm.

"The data from our open-label study in elderly patients with newly diagnosed AML," continued Dr. Gold, "demonstrate that many patients are achieving responses within the first two cycles and continue to improve with ongoing therapy, with fewer discontinuations due to adverse events than in our MDS study. Overall, 54% of patients (27 of 50) have achieved a clinical response with 42% (21 of 50) achieving a CR. The 60-day mortality rate in the study is 10% (5 of 50) and the one-year survival rate is estimated at 60%. All of these data points compare favorably to a recent study of azacitidine alone in this population1. Median overall survival, the most important measure in determining the development path forward for this combination, still has not been reached. We will continue to follow these patients and look forward to the presentation of updated overall survival data at ASH next month."

The data contained within the abstracts listed below are as of the ASH submission deadline on August 4, 2015. In accordance with ASH policies, information that goes beyond that which is contained within these abstracts is embargoed until their presentation on December 7, 2015.

Title: Final Results from a Phase 2 Study of Pracinostat in Combination with Azacitidine in Elderly Patients with Acute Myeloid Leukemia (Abstract #453)
Session Name: 613. Acute Myeloid Leukemia: Clinical Studies: Advances in Therapy
Session Date: Monday, December 7, 2015
Session Time: 7:00 AM - 8:30 AM
Presentation Time: 7:30 AM

Title: A Randomized, Placebo-Controlled, Phase II Study of Pracinostat in Combination with Azacitidine in Patients with Previously Untreated Myelodysplastic Syndrome (Abstract #911)
Session Name: 637. Myelodysplastic Syndromes – Clinical Studies I
Session Date: Monday, December 7, 2015
Session Time: 6:15 PM - 7:45 PM
Presentation Time: 7:15 PM

About Pracinostat

Pracinostat is an orally available inhibitor of a group of enzymes called histone deacetylases, or HDACs. HDACs belong to a larger set of proteins collectively known as epigenetic regulators that can alter gene expression by chemically modifying DNA or its associated chromosomal proteins. Abnormal activity of these regulators is believed to play an important role in cancer and other diseases. Pracinostat has been tested in multiple Phase I and Phase II clinical studies in advanced hematologic diseases and solid tumor indications. The results of these studies suggest that Pracinostat has potential best-in-class pharmacokinetic properties when compared to other oral HDAC inhibitors, with side effects often associated with drugs of this class, including fatigue and myelofibrosis. Pracinostat has not been approved for commercial distribution in the U.S.

MEI Pharma owns exclusive worldwide rights to Pracinostat.

About MEI Pharma

MEI Pharma, Inc. (Nasdaq: MEIP) is a San Diego-based oncology company focused on the clinical development of novel therapies for cancer. The Company's portfolio of drug candidates includes Pracinostat, a potential best-in-class, oral HDAC inhibitor currently in Phase II studies for advanced hematologic diseases. The Company is also developing ME-344, a novel mitochondrial inhibitor that has shown evidence of clinical activity in refractory solid tumors. In addition, the Company has completed a first-in-human study of PWT143, a highly selective, oral PI3K delta inhibitor. For more information, please visit

Under U.S. law, a new drug cannot be marketed until it has been investigated in clinical studies and approved by the FDA as being safe and effective for the intended use. Statements included in this press release that are not historical in nature are "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. You should be aware that our actual results could differ materially from those contained in the forward-looking statements, which are based on management's current expectations and are subject to a number of risks and uncertainties, including, but not limited to, our failure to successfully commercialize our product candidates; costs and delays in the development and/or FDA approval, or the failure to obtain such approval, of our product candidates; uncertainties or differences in interpretation in clinical trial results; our inability to maintain or enter into, and the risks resulting from our dependence upon, collaboration or contractual arrangements necessary for the development, manufacture, commercialization, marketing, sales and distribution of any products; competitive factors; our inability to protect our patents or proprietary rights and obtain necessary rights to third party patents and intellectual property to operate our business; our inability to operate our business without infringing the patents and proprietary rights of others; general economic conditions; the failure of any products to gain market acceptance; our inability to obtain any additional required financing; technological changes; government regulation; changes in industry practice; and one-time events. We do not intend to update any of these factors or to publicly announce the results of any revisions to these forward-looking statements.

1 Dombret H et al. International phase 3 study of azacitidine vs conventional care regimens in older patients with newly diagnosed AML with >30% blasts. Blood. 2015 May 18.


SOURCE MEI Pharma, Inc.

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