Severance Hospital said its research team proved in a study that giving immune checkpoint inhibitors to advanced ovarian cancer patients before surgery increased their progression-free survival (PFS) by 1.5 times, compared to conventional treatment. 

The research team, led by Professor Lee Jung-yun at the Department of Obstetrics and Gynecology of Yonsei University College of Medicine, and Professor Park Jun-sik at the Severance Biomedical Science Institute of Yonsei University College of Medicine, recently published their study in the Journal for ImmunoTherapy of Cancer. 

Generally, advanced ovarian cancer is treated with surgery and chemotherapy to remove the tumor directly. 

However, in stage 3 ovarian cancer, cancer cells usually remain even after treatment and recurrence is frequent, resulting in an average PFS of only 12 months after treatment.

The research team treated 23 patients with stage 3 or higher stage ovarian cancer with two immune checkpoint inhibitors, dubalumab and tremelimumab, combined with neoadjuvant chemotherapy (NAC), followed by interval debulking surgery (IDS).

Durvalumab binds to the PD-L1 protein to help the immune system kill cancer cells, and tremelimumab binds to the CTLA-4 protein on T-cells to increase their attack on cancer cells.

The treatment showed noticeable results. Overall tumor size was reduced by more than 30 percent from the initial diagnosis, and four patients achieved pathologic complete remission.

In addition, their PFS averaged 17.5 months, nearly 1.5 times longer than the conventional PFS of patients with stage 3 or higher ovarian cancer. Nine of the 23 patients had long-term PFS, with no cancer detected for more than 30 months.

The study is titled, "Phase II study of durvalumab and tremelimumab with front-line neoadjuvant chemotherapy in patients with advanced-stage ovarian cancer: primary analysis in the original cohort of KGOG3046/TRU-D."