ImmunoGen Inc. said its experimental cancer drug showed positive results in early stage combination studies in certain types of ovarian cancer patients.
The Forward II study evaluated mirvetuximab soravtansine, or IMGN853, in combination with Roche Holding AG's Avastin in patients with folate receptor alpha-positive, or FRa, ovarian cancer — a type of ovarian cancer in which a folate-binding protein is produced in abnormally large amounts and so can be used as a marker to help in tumor classification to aid treatment.
The phase 1b/2 study trial confirmed that the combination's overall response rate in 23 patients with medium or high FRa levels, who have received up to three previous treatment regimes, was 48% with a median progression-free survival, or PFS — period of time the patients see no worsening of disease — of 9.9 months and a median duration of response of 10.6 months.
The combination also confirmed that the overall response rate — the percentage of patients whose tumors shrank by a predefined amount and for a minimum amount of time — in 54 such patients was 43% with a median PFS of 7.8 months. Patients in this cohort had received three lines of treatments, with 58% of patients having received Avastin.
"The promising new data reported in the Foward II Avastin and carboplatin arms support the potential of mirvetuximab combinations in earlier lines of therapy. Together, these results have informed the triplet combination study with mirvetuximab plus carboplatin and Avastin, which we initiated last quarter," said Anna Berkenblit, Chief Medical Officer of ImmunoGen.
Results from this early stage trial will be presented at the 2018 American Society of Clinical Oncology meeting to be held June 1-5 in Chicago.
Mirvetuximab soravtansine is also being evaluated in an early stage dose-escalation study with Merck & Co. Inc.'s cancer drug Keytruda. Results from that trial showed that the overall response rate from 10 patients was 80% with a median PFS of 15 months, while a median duration of response not reached.