New regimen delivers "one-two punch" to treatment-resistant colorectal cancer
A new drug regimen for persons with metastatic colorectal cancer was shown to be clinically beneficial and well tolerated in a study involving patients who had already undergone all standard therapies.
The treatment combines temozolomide with a poly(ADP-ribose) polymerase (PARP) inhibitor. According to the study's lead author, Michael Pishvaian, MD, PhD, this represents “a classic one-two punch”: After temozolomide chemotherapy damages the DNA of a cancer cell, the PARP inhibitor—in this case, ABT-888—interferes with the cell's ability to repair the damage.
Pishvaian, of Georgetown University Medical Center's Georgetown Lombardi Comprehensive Cancer Center in Washington, DC, and his team evaluated 47 people (median age 54 years) with metastatic, unresectable colorectal cancer who underwent temozolomide/ABT-888 therapy. The patients had undergone an average of 4 prior therapies, none of which stopped their disease from progressing.http://abstract.asco.org/AbstView_102_80618.html
In the temozolomide/ABT-888 regimen, the median time to progression was 11 weeks overall, but 23 weeks in patients who had disease control. Only five grade 3 adverse events occurred, all related to myelosuppression and all resolving with a 1-week treatment delay.
“To have a period of 6 months with no tumor growth, but also no significant side effects, was really meaningful for the patients,” remarked Pishvaian, whose will present the study results on June 4 at the annual meeting of the American Society of Clinical Oncology in Chicago, Illinois (http://abstract.asco.org/AbstView_102_80618.html).