FDA Approves CML Drug Synribo (Omacetaxine Mepesuccinate) for Home Administration
Subcutaneous injections help TKI nonresponders
The FDA has approved Synribo (omacetaxine mepesuccinate, Teva Pharmaceutical Industries) for injection, for subcutaneous use, to include home administration, and has also approved a related medication guide and instructions for use.
With these approvals, physicians who treat adults with chronic or accelerated-phase chronic myeloid leukemia (CML) who are no longer responding to, or who could not tolerate, two or more tyrosine kinase inhibitors (TKIs) will have the option to allow their patients to administer Synribo at home.
CML is one of four main types of leukemia and is a cancer of the blood and bone marrow. In CML, part of the DNA from one chromosome (chromosome 9) breaks off and trades places with another chromosome (chromosome 22) in a “translocation.” This forms the Philadelphia chromosome, an abnormal chromosome 22 that contains the BCR-ABL hybrid gene. This gene leads to over-production of the enzyme tyrosine kinase in the bone marrow, which causes too many stem cells to develop into white blood cells (granulocytes or blasts).
The American Cancer Society estimates that, in 2014, 5,980 new cases of CML will be diagnosed in the U.S. and 810 deaths from the disease will occur.
Synribo (omacetaxine mepesuccinate) for injection, for subcutaneous use, is indicated for the treatment of adult patients with chronic or accelerated-phase CML with resistance and/or intolerance to two or more TKIs. It is the first protein synthesis inhibitor and was granted accelerated approval by the FDA in October 2012. In February 2014, the agency granted full approval based on the submission of a 24-month update to the safety and efficacy data.
Although the mechanism of action of Synribo is not fully understood, the drug has been shown to prevent the production of specific proteins in laboratory studies. The proteins affected by Synribo are Bcr-Abl and Mcl-1. These proteins are produced at increased levels by cancerous CML cells and help drive the disease. As a protein synthesis inhibitor, the way Synribo is believed to work does not directly depend on Bcr–Abl binding.