The developer of the Promega OncoMate MSI Dx Analysis System recently announced the FDA’s approval of the system identifying patients who may benefit from the combination of Lenvatinib (Lenvima) and pembrolizumab (Keytruda), the “combination”. According to BioSpace.com, the referenced patients are exhibiting microsatellite-stable endometrial carcinoma (MSS) which is a type of uterine cancer.
OncoMate MSI Dx Analysis System is a polymerase chain reaction (PCR)–based assay that evaluates microsatellite stability status in tumor tissue. This approval was supported in collaboration with Merck, the marketer of pembrolizumab and lenvatinib.
A polymerase chain reaction (PCR)-based assay is defined as a laboratory technique that uses the PCR method to make millions, or perhaps billions of copies of a specific DNA segment from a sample. The copies are then analyzed to diagnose disease, identify genetic disorders, detect pathogens or for various other applications in forensics.
The combination was investigated in phase three KEYNOTE-775 (NCT03517449). The aforementioned FDA approval (July 21, 2021) was based on the results of the KEYNOTE-775 trial and published in the NEJM in January 2022.
The Trial
The Study compared patients receiving the combination against patients receiving chemotherapy. Overall Response Rate (ORR), safety and health-related-quality of life were secondary end points. Whereas the median overall survival (OS) was 17.4 months vs. 12.0 months.
For patients diagnosed with advanced mismatch repair-proficient endometrial cancer and who received a minimum of one platinum-based regimen of chemotherapy plus the combination, the median progression-free survival (PFS) was reported to be 6.6 months compared to 3.8 months with chemotherapy. Whereas the median overall survival (OS) was 17.4 months vs. 12.0 months.
The Keynote pMMR trial involved 697 patients of whom a total of 346 were to receive 200 mg of pembrolizumab via a 30-minute intravenous line every three weeks plus 20 mg of oral Lenvatinib daily against 351 patients receiving chemotherapy.
Except for patients diagnosed with sarcoma or carcinosarcoma, patients eighteen years or older who experienced progression after at least one line of chemotherapy (platinum-based) were eligible.
Results of the Study – Overall Survival (OS) and Progression-Free Survival (PFS)
The safety treatment duration was 231 days for the combination group vs. 104.5 days for the chemotherapy group. The trial’s secondary endpoints involved ORR (Overall Response Rate) health related to quality of life and safety. The combination group experienced 99.8% vs 99.5% by the chemotherapy group.
Hypertension, hypothyroidism and diarrhea were the most common AEs reporting 64.0%, 57.4%, and diarrhea 54.2% in that order.
Patients in ninety-five percent of both groups completed the Quality-of-Life Questionnaire. There were no substantial differences observed in the QLQ-C30 health status between groups.
