ImmunoGen, Inc. (NASDAQ:IMGN) Presents Phase 1 Biopsy Expansion Cohort Data At The Society Of Gynecologic Oncology Annual Meeting

ImmunoGen, Inc. (NASDAQ:IMGN) has announced that data from Phase 1 of mirvetuximab soravtansine (IMGN853) has shown that the archival tumor tissue is able to identify patients suffering from folate receptor alpha (FRα)-positive platinum-resistant ovarian cancer. The company will be presenting the data at the Society of Gynecologic Oncology (SGO) Annual Meeting which is scheduled for March 12-15 in National Harbor, MD.

Comparing the levels of FRα in pre-treatment biopsies against archival samples confirms the use of archival tumor tissue in selecting the patients. Out of the 21 pre-treatment samples evaluated, 15 were eligible for the biopsy expansion cohort. This translates to a concordance level of 71% with archival tumor tissues. 22% of the patients admitted failed to meet the pre-treatment biopsies required to evaluate the FRα immunohistochemistry because they had less tumor cells in the specimen. In addition, biopsies taken before and after two mirvetuximab soravtansine doses revealed similar levels of FRα expression.

The data also support using a pre-treatment biopsy for selection of patients in the event that archival tumor tissue cannot be used for evaluation.  According to ImmunoGen Vice President and Chief Medical Officer Anna Berkenblit, the results that will be presented at SGO are in line with the company’s strategy to select patients for admission in the Phase 3 FORWARD I trial. The data also show that mirvetuximab soravtansine has higher levels of tolerance.

A total of 27 heavily pretreated patients among them patients with as much as 11 previous therapies were admitted for the biopsy expansion cohort basing on levels of FRα expression in the archival tumor tissue. Patients were subjected to pre-treatment biopsy before being administered with mirvetuximab soravtansine in addition to another post-treatment biopsy fare receiving two mirvetuximab soravtansine doses.

The cohort’s safety profile concurred with what was reported in the patients treated with mirvetuximab soravtansine during the Phase 1 trial which exhibited a lot of Grade 1 and 2 adverse events. Going by the FRα expression in both pre-treatment and archival biopsies, the data also showed an increase in anti-tumor activity with higher levels of FRα expression.

In the six month-period, operating expenses stood at $89.0 million which is below the $89.7 million reported for the six months from the previous financial year.  The current period’s operating expenses is inclusive of the $66.6 million for research and development compared to the $73.3 million reported in the previous period. The change is as a result of a reduction in third party costs from activities carried out in the previous period to support mirvetuximab soravtansine development, reduction in costs related to production of clinical materials on behalf of partners as well as a decrease in antibody and cytotoxic costs as a result of timing of supply requirements.

On the financial front, the company reported revenue from the six-month period ended ended December 31 2016 amounting to $21.5 million. This is in comparison to the $32.9 million reported the same period the previous year. Fees from license and milestone during the period amounted to $5 million compared to the $8.6 million that the company received from Takeda as well as the $8 million that was received from partner milestone payments before the period.  The current period, the company’s revenue include $12.9 million worth of non-cash revenues as compared to $12.0 million worth of non-cash revenues and $0.2 million in cash royalty revenues in the previous period. The current period revenue also includes $2.8 million worth of research and development as well as the $0.7 million for purchase of clinical material. This is in comparison to the $1.6 million and $2.3 million respectively that were reported in the previous period.