As a result, the FORWARD I trial (NCT02631876) will continue as planned after an independent data monitoring committee recommended no changes.
The trial has already completed patient recruitment, two months ahead of schedule. ImmunoGen now plans to release top-line data during the first half of 2019.
“Ovarian cancer is the leading cause of death from gynecological cancers, and patients diagnosed with this life-threatening disease have limited treatment options, especially once they develop platinum-resistant disease,” Anna Berkenblit, MD, vice president and chief medical officer of ImmunoGen, said in a press release. “We are encouraged that the IDMC recommended FORWARD I proceed as planned and are pleased that the trial has reached full enrollment earlier than expected.”
Mirvetuximab soravtansine is an antibody-drug conjugate targeting the folate receptor alpha (FRα). This means the drug combines an antibody against this receptor bound to a toxic compound. Once the antibody binds to a cell positive for FRα, it releases its payload, killing the cancer cell without harming healthy cells.
It is estimated that approximately 60 percent of ovarian cancers have medium or high FRα expression.
The U.S. Food and Drug Administration and the European Medicines Agency have both granted orphan drug designation to mirvetuximab soravtansine as a treatment for ovarian cancer.
Data from a Phase 1 trial (NCT01609556) revealed encouraging preliminary anti-tumor activity, with two epithelial ovarian cancer patients achieving partial tumor responses. The therapy was also well-tolerated and had a manageable safety profile.
These positive findings led ImmunoGen to launch the FORWARD I trial in collaboration with the Gynecologic Oncology Group Foundation. It was designed to test if mirvetuximab soravtansine is better than chemotherapy at delaying disease progression or death in platinum-resistant and FRα-positive ovarian cancer patients who have not responded to prior lines of therapy.
FORWARD was expected to enroll about 333 participants across 125 clinical sites in North America and Europe.
Participants are randomized to receive the investigative therapy once every three weeks or a standard chemotherapy — Taxol (paclitaxel), pegylated liposomal doxorubicin, or Hycamtin (topotecan) — for up to two years.
In addition to measuring the time to disease progression or death, researchers will also evaluate the objective response rate, overall survival, and quality of life. Results are expected to support the approval of mirvetuximab soravtansine as treatment for patients with platinum-resistant ovarian cancer.
Combinations of mirvetuximab soravtansine with available therapies are also being assessed in platinum-resistant and platinum-sensitive cancers in the Phase 1b/2 FORWARD II trial (NCT02606305).