Credit: Bill Branson
The US Food and Drug Administration (FDA) has granted full approval of omacetaxine mepesuccinate (Synribo) for the treatment of chronic myeloid leukemia (CML).
The drug received accelerated approval in October 2012 to treat adults with chronic phase (CP) or accelerated phase (AP) CML who were resistant to or could not tolerate 2 or more tyrosine kinase inhibitors (TKIs).
But additional clinical trial data were required before the FDA could grant the drug full approval.
Now, the agency has granted that approval based on the final analysis of two phase 2 trials.
The original approval of omacetaxine mepesuccinate was based on an analysis of combined data subsets from these trials. The pooled analysis included patients who had received 2 or more approved TKIs and, at a minimum, had evidence of resistance or intolerance to dasatinib and/or nilotinib.
Forty-seven percent of patients with CP CML and 63% of patients with AP CML had failed treatment with 3 TKIs—imatinib, dasatinib, and nilotinib. The majority of patients had also received other treatments, including hydroxyurea, interferon, and cytarabine.
Among CP patients, 18% (14/76) achieved a major cytogenetic response (MCyR). The mean time to MCyR onset was 3.5 months, and the median duration of MCyR was 12.5 months.
Among AP Patients, 14% (5/35) achieved a major hematologic response (MaHR). The mean time to MaHR onset was 2.3 months, and the median duration of MaHR was 4.7 months.
The most common adverse events for AP and CP patients (occurring in 20% or more) were thrombocytopenia, anemia, neutropenia, diarrhea, nausea, fatigue, asthenia, injection site reaction, pyrexia, infection, and lymphopenia.
Omacetaxine mepesuccinate is the first protein synthesis inhibitor for CML. Although the drug’s mechanism of action is not fully understood, it is known to prevent the production of Bcr-Abl and Mcl-1, which help drive CML.
For more details on omacetaxine mepesuccinate, see the full prescribing information.
