Ovarian cancer is a deadly disease that affects one in 78 women. While therapies that activate the immune system have been effective in other types of cancers, patients with ovarian cancer have seen little benefit from these therapies. The Cancer Vaccine Institute is working hard to change outcomes for ovarian cancer patients. In addition to developing therapeutic ovarian cancer vaccines, the CVI also conducts clinical trials on other immune therapies intended to boost the anti-cancer immune response. The CVI’s Dr. John Liao recently published such a study in the Journal for ImmunoTherapy of Cancer that combined the use of an immune therapy called PD-1/PD-L1 inhibitors, with a low dose of carboplatin chemotherapy in women whose cancers had become resistant to platinum chemotherapy. Dr. Liao and colleagues showed that the combination was able to show a partial response in 10% of patients and stabilize disease in 51% of patients. The results of this study have led us to test the combination of Pembrolizumab with carboplatin in another clinical trial. The new study is for women with ovarian cancer who have completed their initial (frontline) therapy subsequently have increasing levels of CA-125, indicating a potential cancer recurrence, but don’t show evidence of disease by imaging. This trial is open and currently recruiting patients.
More details about Dr. Liao’s recently published study
Platinum chemotherapy is commonly used to treat ovarian cancer. Most patients respond well to the drug initially, but will later become resistant. In the past few years studies using PD-1/PD-L1 inhibitor therapies have shown little ability to improve progression free survival in recurrent ovarian cancer. Interestingly, studies have also shown that platinum chemotherapies can stimulate the immune system in several ways, including increasing anti-cancer immune cells. Dr. Liao and colleagues hypothesized that combining the PD-1/PD-L1 inhibitor, Pembrolizumab with low dose carboplatin may synergize to give a stronger anti-cancer immune response than either treatment alone. To test this hypothesis, 29 women who had recurrent ovarian cancer, that had become resistant to platinum chemotherapy, were treated with a combination of Pembrolizumab and low dose carboplatin in a phase I/II clinical trial. They monitored changes in tumor lesions using imaging and also tested for immune system markers in patient blood. They found that the combination treatment was well tolerated by patients. Importantly, 10% of patients showed a partial response and 51% had stable disease after treatment. More than half of the patients also had reduction in the size of tumor lesions. Overall, the study showed that this combination strategy may improve the effectiveness of PD-1/PD-L1 inhibitors in a subset of patients.
Read the paper: https://jitc.bmj.com/content/9/9/e003122
More information on our currently open Pembrolizumab/Carboplatin study is available on the CVI clinical trials website or clinicaltrials.gov.