PARP inhibitors prevent cancer cells from repairing themselves after experiencing DNA damage (for example from chemotherapy or radiation). Research has previously shown that veliparib is effective in combination with chemotherapy, but little data was available to indicate whether veliparib was effective as a single agent. Results of this multicenter trial suggest that it is.
"One criticism of the PARP drugs is they are not active in patients who have developed resistance to other therapies, but we found veliparib appears to be effective in some platinum-resistant patients with recurrent or persistent disease," said Robert L. Coleman, MD, lead author of the study and professor and vice chair of clinical research at the University of Texas MD Anderson Cancer Center, Houston. "Most of these patients have run out of treatment options, and it is very hopeful to potentially have another therapy to offer them."
In the study, 50 patients with BRCA gene mutations treated at one of 18 centers took veliparib by mouth twice a day. The median number of monthly treatment cycles was six (ranging from one to 22). Overall, 13 patients (26 percent) responded positively to the therapy, meaning the tumors shrank in size, including two patients in whom the tumors disappeared completely. In addition, disease was stabilized for more than four months in nearly half of the women (24).
"Patient recruitment can be a problem for many clinical trials, however, this one filled up very quickly, which reflects that women and their doctors understand that PARP inhibitors hold real promise," said Dr. Coleman.