New drug improves survival in advanced ovarian cancer

CANCER DIGEST – June 24, 2023 – Nearly half of women with advanced ovarian cancer that is resistant to standard chemotherapy survived more than 13 months when treated with a newer drug, interim results of an ongoing trial show.

The results of the international trial, named MIRASOL, were presented by lead investigators Merry Jennifer Markham, MD, FACP, of the University of Florida, and Julie Gralow, MD of the American Society of Clinical Oncology (ASCO) at the recent ASCO annual meeting held in Chicago May 31 - June 4, 2023.

The drug called Mirvetuximab soravtansine-gynx or simply Mirvetuximab (mir ve tux i mab) is being tested in a clinical trial involving 453 women with ovarian cancer, cancers of the peritoneal lining covering the internal organs, or cancer of the fallopian tubes.

Over 70 percent of women annually diagnosed with ovarian cancer are diagnosed at this advanced stage, where the cancer spreads to distant sites, as is the case with women in this trial. Only 30 percent survive five years.

The women treated had advanced cancers that were resistant to platinum-based chemotherapy. Of the 453 women, 281 had been previously treated with bevacizumab (Avastin®) and 172 had only received standard chemotherapy.

Among the 281 women in the bevacizumab group 13 months after treatment began with Mirvetuximab 36 percent more patients survived without their cancers progressing, compared to those not treated with bevacizumab alone. Also 26 percent more of the women treated with Mirvetuximab were surviving overall compared the bevacizumab alone group over that time.

Among the 172 women who had been treated with standard chemotherapy alone and had not received bevacizumab, 34 percent more women who received Mirvetuximab survived 13 months progression-free compared to the standard chemo alone group. In addition 49 percent more of the women treated with Mirvetuximab survived overall compared to those treated with chemo alone.

“Mirvetuximab soravtansine has fewer serious side effects, especially those that can lead to stopping treatment, compared to standard chemotherapies for patients with platinum-resistant ovarian cancer,” said Merry Jennifer Markham, MD, FACP, FASCO in a press release. "This, coupled with the overall survival advantage, demonstrates progress and offers hope for these patients."

In 2023, there will be an estimated 19,710 new cases of ovarian cancer and 13,270 deaths in the U.S.

Sources: ASCO press release.