A phase 2 clinical trial promises an alternative to chemotherapy, in pill form. Researchers found that combining the two drugs olaparib and cediranib can offer similar cancer cell-killing effects as chemotherapy in recurrent ovarian cancer patients. Patients who took the two drugs had 18 months of progression-free survival (PFS) — the amount of time during and after treatment of the disease that a patient has the disease without it worsening — when compared to nine months PFS for those who took only olaparib.
Researchers say that four out of five women with severe ovarian cancer experience relapses. When the cancer comes back, it's likely to spread to other parts of the body, making it more difficult to treat with chemotherapy. According to the Centers for Disease Control and Prevention (CDC), ovarian cancer is the eighth most common cancer, affecting three percent of women with cancer. When it's detected early, treatment tends to be successful.
Olaparib inhibits the enzyme Poly ADP-Ribose polymerase (PARP), which repairs DNA damage in cells, and thus helps to kill cancer cells. The second drug, cediranib, hinders the growth of blood vessels in a tumor. As a result, the cancer loses the nutrients and oxygen it needs to survive.
The trial involved 90 women with aggressive ovarian cancer that had returned after they underwent chemotherapy. Women were selected randomly to take the olaparib alone or as a combination with cediranib, according to a press release. The results showed that tumors shrank 80 percent more in participants who used the combination treatment, compared to 48 percent in participants who only received olaparib. Five of the patients using the combination of drugs experienced total remission, compared to two patients who used only olaparib.
Women who wish to avoid some of the side effects of chemo therapy may soon be able to use the new form of treatment instead. Since the two drugs are taken together, there is a higher risk of side effects, such as diarrhea, high blood pressure, and fatigue, but the researchers said that the likliness of experiencing these can be minimized depending on the dosage a patient takes.
Researchers are still trying to understand how combining the drugs produced such significant results, but they're excited. "We're entering an era where we are identifying unique pathways for cancer, and therapies that attack the unique biology of cancer will be much more effective than we've had in the past," Dr. David Fishman, a professor at Mount Sinai's Icahn School of Medicine in New York City who was involved with the trial, told HealthDay.
Source: Fishman D, Liu J, et al. At The Annual Meeting Of The American Society of Clinical Oncology. 2014.