Double-Pronged Attack on Ovarian Cancer

Ovarian cancer responded to standard chemotherapy following targeted therapy

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Sometimes cancer needs more than one kind of treatment to shrink or disappear. That’s why treatment often includes a mixture of surgery, radiation and/or chemotherapy. In a recent study, ovarian cancer responded to a double-pronged attack.

The study found that after a new targeted therapy stopped working, standard plantinum-based chemotherapy extended the lives of ovarian cancer patients with certain genetic mutations.

The researchers concluded that the double-pronged attack of a specific class of medications plus chemotherapy may be an appropriate approach for some ovarian cancer patients.

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Professor Stan Kaye, BSc, MD, head of the Drug Development Unit at Cancer Research UK, professor of Medical Oncology at The Institute of Cancer Research, and Consultant at the Royal Marsden NHS Foundation Trust, and colleagues conducted this study.

This research team evaluated follow-up data from patients who had previously participated in clinical trials sponsored by pharmaceutical company AstraZeneca.

This study involved women with BRCA gene mutations, which are linked to an increased risk of breast and ovarian cancer. Mutations in the BRCA genes also increase the likelihood of ovarian cancer returning after treatment.

Study members included 89 women who had been treated with and became resistant to a medication called olaparib — an investigational medication currently under development. Olaparib is a member of a class of drugs called PARP (poly-ADP ribose polymerase) inhibitors.

PARP inhibitors have been shown to be less toxic and have fewer side effects than conventional chemotherapy.

Clinical trials around the world are testing the effectiveness of PARP inhibitors in treating primarily BRCA-mutated cancers.

The women in this study had received chemotherapy before receiving olaparib.

After olaparib stopped working and the cancer progressed, the women then received conventional forms of chemotherapy.

The researchers were measuring how the tumors responded following the post-olaparib chemotherapy.

Two methods of evaluating the response were used: Response Evaluation Criteria in Solid Tumors (RECIST) and Gynecologic Cancer InterGroup (GCIG).

The objective response rate of women receiving platinum-based chemotherapy following olaparib was 40 percent by RECIST and 49 percent by GCIG, compared to an overall (among women taking different types of chemotherapy) objective response rate of 36 percent (RECIST) and 45 percent (GCIG).

Median progression-free survival (period during which the cancer does not get worse) was 22 weeks for women taking platinum-based chemotherapy, and median overall survival was 45 weeks in this group, the researchers found.

In comparison, the overall median progression-free survival was 17 weeks, and median overall survival was 34 weeks for the non-platinum-based chemotherapy group.

“Our study finds that for many women with ovarian cancer, it is not a case of either/or chemotherapy or PARP inhibitors — there is a good chance that they may respond to both,” Dr. Kaye said in a prepared statement.

This study appeared in the October issue of the journal Clinical Cancer Research.

The research was supported by grants from the Experimental Cancer Medicine Centre and a range of institutions including Cancer Research UK, the National Institute for Health Research and the Wellcome Trust.

Several of the authors disclosed financial relationships with AstraZeneca, the developer of olaparib.

Review Date: 
October 14, 2013
Last Updated:
January 2, 2014