–– Significantly Improved Depression Scores in 142-Patient Study Testing Novel Mechanism of Action for Once-Daily, Oral Medication ––
–– Company Plans to Initiate Pivotal Development Program ––
–– Data to be Presented at NCDEU Conference in May ––

DUBLIN, Ireland I April 17, 2013 I Alkermes plc (ALKS) today announced positive preliminary topline results from a phase 2 study of ALKS 5461, its novel drug compound for major depressive disorder (MDD) in patients who have an inadequate response to standard therapies for clinical depression. ALKS 5461 reflects a new approach to the treatment of MDD based on modulation of opioid receptors in the brain and is designed as a non-addictive, oral, once-daily medicine. Data from the study showed that ALKS 5461 significantly reduced depressive symptoms across a range of standard measures including the study’s primary outcome measure, the Hamilton Depression Rating Scale (HAM-D17) (p=0.026), the Montgomery–Åsberg Depression Rating Scale (MADRS) (p=0.004) and the Clinical Global Impression – Severity Scale (CGI-S) (p=0.035). ALKS 5461 was generally well tolerated. Based on these results, as well as the positive phase 1/2 results previously reported, Alkermes plans to request a meeting with the U.S. Food and Drug Administration (FDA) and advance ALKS 5461 into a pivotal development program. Data from this phase 2 study will be presented at the 53rd Annual New Clinical Drug Evaluation Unit (NCDEU) Meeting in Hollywood, Fla., May 28-31, 2013.

“The improvements in depressive symptoms observed in patients treated with ALKS 5461 in this study were clinically meaningful and among the most robust I have seen in a phase 2 study for depression in the past two decades. This promising candidate could provide a valuable new treatment approach for this serious and chronic disease,” stated Maurizio Fava, M.D., Director of the Depression Clinical and Research Program at Massachusetts General Hospital and Slater Family Professor of Psychiatry at Harvard Medical School. “There is significant unmet medical need for novel treatments with new mechanisms of action for depression, as many patients do not adequately respond to existing pharmacological therapies.”

The phase 2, randomized, double-blind, multicenter, placebo-controlled study assessed the efficacy and safety of two doses of ALKS 5461 when administered once daily for four weeks as adjunctive treatment in 142 patients with MDD who had an inadequate response to a stable dose of either a selective serotonin reuptake inhibitor (SSRI) or a serotonin-norepinephrine reuptake inhibitor (SNRI). Patients received one of two dosing regimens of oral ALKS 5461 or placebo for a treatment period of four weeks. The study utilized a sequential parallel comparison design, a design developed ten years ago by Drs. Fava and Schoenfeld at Massachusetts General Hospital and now widely utilized in clinical trials. The primary endpoint of the study was the change from baseline in depressive symptoms over a four-week treatment period, as measured by the HAM-D17. Secondary endpoints included additional analyses of patient responses based on HAM-D17, MADRS and CGI-S scores.

“ALKS 5461 has the potential to be a novel therapy with a unique mechanism of action for depression and validates our expertise with opioid modulators,” stated Elliot Ehrich, M.D., Chief Medical Officer of Alkermes. “Based on the strength of these data, as well as the positive results seen in the prior clinical study, we will move forward rapidly to meet with the FDA and initiate a pivotal development program with a goal of bringing this important new medication to patients with MDD.”

About ALKS 5461

ALKS 5461 is the combination of ALKS 33 and buprenorphine and is designed to be a non-addictive opioid modulator. ALKS 33 is an oral opioid modulator that builds on Alkermes’ scientific expertise in opioid biology and pharmacology, as well as the company’s clinical and commercial knowledge in the field of addiction and central nervous system disorders.

About MDD

According to the DSM-IV-TR® (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision), major depressive disorder (MDD) is a condition in which patients exhibit depressive symptoms, such as a depressed mood or a loss of interest or pleasure in daily activities consistently for at least a two-week period, and demonstrate impaired social, occupational, educational or other important functioning. An estimated 16.1 million people in the U.S. suffer from MDD in a given year,1,2 the majority of whom may not adequately respond to initial antidepressant therapy.3

About Alkermes plc

Alkermes plc is a fully integrated, global biopharmaceutical company that applies its scientific expertise and proprietary technologies to develop innovative medicines that improve patient outcomes. The company has a diversified portfolio of more than 20 commercial drug products and a substantial clinical pipeline of product candidates that address central nervous system (CNS) disorders such as addiction, schizophrenia and depression. Headquartered in Dublin, Ireland, Alkermes plc has an R&D center in Waltham, Massachusetts; a research and manufacturing facility in Athlone, Ireland; and manufacturing facilities in Gainesville, Georgia and Wilmington, Ohio. For more information, please visit Alkermes’ website at www.alkermes.com.

SOURCE: Alkermes