The results of a multisite clinical trial overseen by University of Colorado Cancer Center member Bradley Corr, MD, could offer new hope to patients with metastatic and recurrent uterine cancer, also known as endometrial cancer.
The study, which was presented at the Society of Gynecologic Oncologists annual meeting this week, collected results from 79 patients at four U.S. sites over several years, shows that the oral drug rucaparib, part of a class of drugs known as PARP inhibitors, extends progression-free survival for an average of 19 months longer than surveillance alone. Surveillance is the current standard of care for uterine cancer patients who have completed the chemotherapy portion of their treatment.
“This phase 2 randomized placebo controlled trial examined the use of rucaparib versus placebo as a maintenance therapy for patients who had one or two prior lines of chemotherapy,” says Corr, associate professor and director of clinical research for the Division of Gynecologic Oncology at the CU School of Medicine.
“What we were able to demonstrate is that we improved patients’ progression-free survival, meaning time without recurrence or progression, by an average of 19 months. Patients on placebo had a progression-free survival of nine months, whereas it was 28 months for those who had received rucaparib. This is very significant for our patients and for their care.”
Creating maintenance therapy for uterine cancer
Corr says the unfortunate reality of uterine/endometrial cancer is that the disease eventually returns in most people who present with later stage disease. However, the use of rucaparib, a drug already approved for use in breast, ovarian, and prostate cancer, extends the time before patients experience recurrence. There are currently no approved maintenance therapies for metastatic and recurrent endometrial cancer.
“In other tumors, PARP inhibitor responses are typically tied to BRCA gene mutations or mutations in the tumor called homologous recombination deficiency,” Corr says. “We suspect there are alternative DNA damage pathways that make endometrial cancer susceptible to PARP inhibition as well.”
For the next step in their research, Corr and his team plan to perform a full molecular analysis of the tumors and patients involved with the trial. They want not only to identify the patients who benefited from rucaparib treatment, but also to learn more about the patients who didn't benefit from the therapy.
Endometrial, or uterine, cancer affects more than 60,000 women in the U.S. each year. It is one of the few cancers in which incidence is increasing. Survival for early-stage endometrial cancer remains high at more than 80%; however, survival rates for advanced uterine cancer decrease substantially.
