depletion of clot-forming platelet cells (thrombocytopenia); while other common side effects were rash, muscle pain, abdominal pain, and dry skin. Out of the 403 enrolled patients, there were five serious cases each (1.2 percent incidence) of diarrhea, anemia, fever associated with white-blood cell depletion (febrile neutropenia), and fever.
Unlike most cancer drugs, which tend to have their greatest effect early in treatment and decline over time, the Ariad product appears to get more effective with time.
Patients on the Ariad drug were only followed up for a median time of 57 days, so the results on effectiveness are still quite preliminary. Ariad plans to continue following patients, and should have at least a median of six months follow-up data by the time it’s ready to file its new drug application to the FDA in mid-2012, Berger says. The patients in the study were quite sick, as 94 percent had their disease worsen after getting two or more drugs in the class, and 57 percent had worsened after getting three or more of the other drugs.
That said, the Ariad drug’s effectiveness rate looks consistent with the prior trial at the same point in time, with about two months of patient follow-up, Berger says. At this snapshot with a median of 57 days of follow-up, 38 out of 83 patents with the chronic phase of chronic myeloid leukemia (46 percent) had reached the primary goal, defined as a major cytogenetic response. For those of you who want to dig into the data cohort by cohort, you can check this copy of the study abstract and a slide from Ariad.
