'Combo therapy against ovarian, breast cancer can overcome drug resistance'

Submitted by alvin on Mon, 2016-09-26 10:29 Kolkata: Bolstering the knowhow behind targeted cancer treatment, Indian scientists have offered a new rationale for combination drug therapy for ovarian and breast cancer, which they say can counter drug resistance and reduce side-effects. The insight into molecular mechanisms of how the drug combination works to selectively hunt down cancer cells with minimum effect on healthy cells is "highly relevant" for ongoing clinical trials, the researchers say. "Cancer specific-cell killing" is the most exciting change in the treatment strategy since the advent of the recent personalised chemotherapy, contends senior scientist Benu Brata Das of the Indian Association for the Cultivation of Science here. In that arena, Das and his team worked on the two classes of drugs, PARP inhibitors and Top1 inhibitors, which exploit the cell's own DNA repair machinery to kill cancer cells. The US FDA recently approved Olaparib, a PARP inhibitor for ovarian cancer. "PARP inhibitors (Poly ADP-ribose polymerase) have triggered immense interest in clinical trials as a single agent for the treatment of breast and ovarian cancer or in combination with DNA topoisomerase1 (Top1) inhibitors. However, some of these patients develop resistance," Das said. To overcome such chemotherapeutic limitations, combination therapy (PARP Top1 inhibitors) is the "effective" strategy, Das asserted. Further, the overarching idea of combination therapy is to reduce side-effects in patients. "Combination therapy generates synergy at low drug concentrations for selective killing of the cancer cells," said Das, Assistant Professor