Experimental cancer drug responses rise

SAN DIEGO - Reuters

AFP photo

Early results from a pivotal trial of an experimental leukemia drug ponatinib show it is effective in nearly half of patients who had stopped responding to currently available drugs.

An interim look at the study, presented at a meeting of the American Society of Hematology, shows that 47 percent of chronic myeloid leukemia (CML) patients with chronic-phase disease had a major response to ponatinib, meaning that at least two-thirds of their bone marrow was normal.

Thirty-nine percent of those patients achieved complete remission of their leukemia, a cancer of the bone marrow.

The trial involves 449 patients, the interim results are from 392 subjects, who had stopped responding to treatment with other drugs. Both of these older drugs, respectively known generically as dasatinib and nilotinib, are members of a class called tyrosine kinase inhibitors.

New drug is designed to target an abnormal tyrosine kinase that is closely associated with CML and Philadelphia chromosome positive acute lymphoblastic leukemia.

Side effects seen in the trial included rash (in 32 percent of patients), thrombocytopenia (31 percent), dry skin (24 percent), abdominal pain (19 percent), and headache (17 percent).
Researchers said the deaths of four patients, all of whom had advanced leukemia and other serious medical conditions, may have been related to treatment with ponatinib.