MEI Pharma Initiates Phase II Clinical Trial Of Pracinostat In Refractory Myelodysplastic Syndrome

SAN DIEGO, Jan. 14, 2014 /PRNewswire/ -- MEI Pharma, Inc. (Nasdaq: MEIP), an oncology company focused on the clinical development of novel therapies for cancer, announced today that the first patient has been dosed in a Phase II clinical trial of Pracinostat, the Company's investigational oral histone deacetylase (HDAC) inhibitor, in patients with myelodysplastic syndrome (MDS) who either failed to respond or maintain a response to a hypomethylating agent (HMA) alone.

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"We are very excited about getting this study underway," said Robert D. Mass, MD, Chief Medical Officer of MEI Pharma. "This represents the third in a series of Phase II clinical trials we are conducting with Pracinostat in combination with HMAs in an attempt to establish the clinical benefit of selectively combining two epigenetic modifiers. The primary objective in this refractory MDS trial is to determine if the addition of Pracinostat to Vidaza^® or Dacogen^® can improve clinical responses or rescue previous responses achieved with a HMA alone. We look forward to reporting preliminary data from all three Phase II trials of Pracinostat later this year."

This two-stage trial of Pracinostat is expected to enroll up to a total of 76 patients into two groups: 1) patients who have had disease progression or have relapsed following a clinical response to either Vidaza or Dacogen therapy and 2) patients with stable disease who failed to respond to their initial HMA therapy. If at any time two or more responses are observed in the first 29 patients of each group, that group will continue to enroll an additional nine patients in the second stage, for a total of up to 38 evaluable patients per group. Preliminary data from this open-label trial is anticipated by December 2014.

The primary endpoint of the trial is clinical improvement rate, defined as the proportion of patients with complete remission (CR), partial remission (PR) and hematologic improvement (HI). Secondary endpoints include overall response rate, CR rate, HI rate, duration of response, progression-free survival, time to progression and overall survival. Dr. Guillermo Garcia-Manero of the MD Anderson Cancer Center is the study's Principal Investigator. Additional information regarding the trial is available at www.clinicaltrials.gov.

Meanwhile, MEI Pharma remains on track to fully enroll its randomized, placebo-controlled Phase II trial of Pracinostat in combination with Vidaza in patients with previously untreated intermediate-2 or high-risk MDS by June 2014, with topline data expected by December 2014.

In addition, the Company continues to enroll patients in a two-stage Phase II trial of Pracinostat in combination with Vidaza in elderly patients with newly diagnosed acute myeloid leukemia (AML). If at any time three or more responses are observed in the first 27 patients, the trial will continue to enroll an additional 13 patients in the second stage, for a total of up to 40 evaluable patients. Preliminary data from this open-label trial is also anticipated by December 2014.

About Pracinostat

Pracinostat is an orally available HDAC inhibitor that has been tested in a number of Phase I and Phase II clinical trials in advanced hematologic disorders and solid tumor indications. Pracinostat has been generally well tolerated in more than 200 adult and pediatric patients to date, with readily manageable side effects that are often associated with drugs of this class, including fatigue. In a Phase I dose-escalation trial, Pracinostat demonstrated evidence of single-agent activity in elderly AML patients, including two out of 14 (14%) who achieved a CR, with durable responses persisting 206+ and 362 days, respectively. In addition, results from a pilot Phase II study of Pracinostat in combination with Vidaza in patients with advanced MDS showed an overall response rate of 90% (nine out of 10), including eight patients who achieved either a CR or a CR with incomplete blood count recovery (CRi).

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 lead drug candidate is Pracinostat, a potential best-in-class, oral HDAC inhibitor being developed for advanced hematologic diseases, including MDS and AML. Results from a pilot Phase II clinical trial of Pracinostat in combination with Vidaza in patients with advanced MDS showed an overall response rate of 90% (nine out of 10). MEI Pharma is also developing ME-344, a mitochondrial inhibitor that has showed preliminary evidence of single-agent activity in a first-in-human clinical study in patients with refractory solid tumors. In September 2013, the Company further expanded its pipeline of drug candidates with the acquisition of PWT143, a highly selective PI3-kinase delta inhibitor. For more information, go to www.meipharma.com.

Under U.S. law, a new drug cannot be marketed until it has been investigated in clinical trials 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.

SOURCE MEI Pharma, Inc.