Delaloge S. Ann Oncol . April 23, 2014 .Trabectedin demonstrated safety and efficacy among women with metastatic breast cancer who harbored BRCA1 or BRCA2 germline mutations, according to phase 2 study results.
The analysis included 40 women with pretreated breast cancer, all of whom carried BRCA1 or BRCA2 germline mutations. All patients received 1.3 mg/m2 trabectedin (Yondelis; PharmaMar and Johnson & Johnson) in 3-hour IV infusions every 3 weeks.
Among the 35 evaluable women, six achieved a partial response, equating to an overall response rate of 17% (95% CI, 7%-34%). The responses endured from 1.4 months to 6.8 months, and median PFS was 3.9 months (95% CI, 1.6-5.5).
Researchers observed changes in tumor volume among eight patients (21%). Fourteen patients (40%) demonstrated clinical benefit from trabectedin.
The most common adverse events associated with treatment were fatigue, nausea, constipation and anorexia, although the researchers noted these were generally mild or moderate.
Severe laboratory abnormalities resulting in dose reductions — including neutropenia and transaminase increases — were transient and noncumulative.
“With the caveat of the limited patient number, trabectedin monotherapy showed activity and was well tolerated in heavily pretreated metastatic breast cancer patients selected for germline BRCA mutation,” the researchers wrote.
“These results prompt further evaluation of trabectedin alone or combined with other specific drugs in this indication.”