The FDA has granted Breakthrough Therapy designation to Celator Pharmaceuticals’ Vyxeos (also known as CPX-351). Vyxeos is an investigational product in development as a treatment for acute myeloid leukemia (AML) and other blood cancers.

The Breakthrough Therapy designation is primarily based upon the positive results from the pivotal phase III clinical trial in older patients with previously untreated high-risk (secondary) AML. The designation is for the treatment of adults with therapy-related AML (t-AML) or AML with myelodysplasia-related changes (AML-MRC). This designation includes the patient populations enrolled in the phase III clinical trial.

The phase III trial met its primary endpoint demonstrating a statistically significant improvement in overall survival. Data will be presented at the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting on Saturday, June 4th.

The median overall survival for patients treated with Vyxeos in the study was 9.56 months compared to 5.95 months for patients receiving 7+3, representing a 3.61 month improvement in favor of Vyxeos. The hazard ratio (HR) was 0.69 (p=0.005), which represents a 31% reduction in the risk of death versus 7+3. The percentage of patients alive 12 months after randomization was 41.5% on the Vyxeos arm compared to 27.6% on the 7+3 arm. The percentage of patients alive 24 months after randomization was 31.1% on the Vyxeos arm compared to 12.3% on the 7+3 arm.

Sixty-day all-cause mortality was 13.7% versus 21.2%, in favor of patients treated with Vyxeos.

No substantial difference in Grade 3-5 adverse events was observed between Vyxeos and 7+3. In the intent-to-treat population, Grade 3-5, hematologic adverse events were similar for overall infections, febrile neutropenia, and bleeding events. In the intent-to-treat population, Grade 3-5, non-hematologic adverse events were similar across all organ systems, including cardiac, gastrointestinal, general systems, metabolic disorders, musculoskeletal, nervous system, respiratory, skin and renal.

FDA awards Breakthrough Therapy designation in order to expedite the development and review of new medicines that are intended to treat serious or life-threatening diseases when the therapy has demonstrated substantial improvement over available therapies on at least one clinically significant endpoint or when there is significant unmet medical need.

Celator plans to submit a New Drug Application (NDA) to the FDA by the end of the third quarter of 2016.