Rina-S Generates Antitumor Activity in Heavily Pretreated Ovarian Cancer

Treatment with rinatabart sesutecan (Rina-S), a folate receptor-alpha (FRα)-targeted TOP1 antibody-drug conjugate, showed antitumor activity among heavily pretreated patients with advanced ovarian cancer, according to data from the phase 2 RAINFOL-01 study.

Updated results from RAINFOL-01 showed that heavily pretreated patients with advanced ovarian cancer who were treated with Rina-S at 120 milligrams per square meter achieved a confirmed objective response rate of 55.6%, with median duration of response not yet reached, regardless of folate receptor alpha (FRα) expression levels. FRα, according to the National Institute of Health, is a protein found on many cancer cells, making it a target for cancer treatment. It is produced by the FOLR1 gene and can help develop therapies that specifically attack cancer while sparing healthy cells.

To delve deeper in the importance of targeting FRα, and the difference targeted therapies can make in cancer treatment, Dr. Elizabeth K. Lee sat down for an interview with CURE. In the interview, she delved into detail on the RAINFOL-01 clinical trial and expanded on FRα testing.

Lee is a medical oncologist and physician in the gynecologic oncology program at Dana-Farber Cancer Institute, in Boston, and she serves as the gynecologic oncology program's liaison to the Center for Cancer Therapeutics Innovation. She is also an instructor in medicine at Harvard Medical School.

Transcript:

Testing for FRα is now part of our standard of care testing, and really that should be considered. [I do this] in my clinical practice for anyone with a recurrence; I also tend to do this for some with advanced disease at the [time of] diagnosis because of the increased likelihood of a disease recurrence. The FDA approved drug right now is Elahere [mirvetuximab], and so that has a companion diagnostic assay that any medical oncology provider can order for their patient with ovarian cancer to get that information. Where Elahere is approved is for those patients who have expression levels of 75% at a score of PS2 plus or greater, so that's where they can get that information: Do they qualify for Elahere if they meet that threshold, or do they not?

It is important to understand the landscape as well, [especially with] the phase 2 data of the combination of Elahere and Avastin [bevacizumab]. That combination is within our National Comprehensive Cancer Network guidelines for patients who have expression levels that don't meet that 75% cut off. I think that's also just a weird, little [nuanced] part related to the current FRα approved [therapy].

Having that information is important because it also means that you can potentially consider trials like RAINFOL-01 for patients with ovarian cancer who may have already received Elahere and subsequently progressed, or who cannot access Elahere and Avastin as a combination. Because it is still phase 2 data, it is not currently under an FDA label, even though it is within National Comprehensive Cancer Network guidelines. Sometimes there may be some insurance issues because it's not technically on a label, and so [patient’s] may not be able to access Elahere.

Knowing that FRα testing, which is available [as a] diagnostic, can open up clinical trial options.

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