FDA Approves Teva's CML Drug

US regulators have approved Teva Pharmaceuticals' chronic myelogenous leukemia (CML) drug, Synribo (omacetaxine mepesuccinate), the second approval for a CML drug by FDA in as many months.

As with Pfizer's CML drug, Bosulif (bosutinib), Synribo was approved with an orphan drug designation. Approximately 5,400 patients are expected to be diagnosed with CML, a cancer affecting the body's production of white blood cells, each year, FDA said.

Drugs that treat conditions affecting fewer than 200,000 people are considered orphan drugs, and the conditions they treat are collectively referred to as rare diseases.

Synribo was also given an accelerated review by FDA, allowing it to show proof of efficacy based on surrogate endpoints, which showed the drug to be useful in treating the condition. The US Food and Drug Administration (FDA) said 14 of 76 patients enrolled in the company's clinical studies (18.4%) experienced a reduction in the development of cancer cells in just 3.5 months, with the median length of the reduction lasting 12.5 months.

For patients with accelerated phase CML, 14.3% of patients in a 40-person study experienced a major hematologic response (normalization of white blood cells or no evidence of CML) within 2.3 months, which lasted for an average of 4.7 months.

Richard Pazdur, director of FDA's office of Hematology and Oncology Products (OHOP), said the drug is a step forward for patients who are unable to tolerate or do not respond to other FDA-approved CML drugs.