MSD presented the results of the study, KEYNOTE-177, which pembrolizumab was used as first-line therapy in patients with inoperable or metastatic colorectal cancer with high level microsatellite instability (MSI-H) or disturbances in the DNA repair system (dMMR). The study shows that monotherapy ambrosianeum reduced the risk of disease progression or death by 40 % (RR = 0,60 [95 % CI; 0,45–0,80; p = 0,0002]) and provided a median survival without progression (VBP) of 16.5 months, compared with 8.2 months in the use of chemotherapy (at the choice of the researcher: mFOLFOX6 or FOLFIRI in combination with bevacizumab or cetuximab), which is the standard therapy in such patients. The study will continue to assess overall survival (OS) – second primary endpoint.
The safety profile of ambrosianae demonstrates a low incidence of adverse events (AES) ≥ grade 3 severity related to treatment, compared to chemotherapy (22% versus 66 %, respectively), thus a new AES was not observed. Immune-mediated AES and infusion reactions was observed in 31% of patients in the treatment group ambrosianeum, and 13 % of patients in the chemotherapy group. The most common immune-mediated adverse events in the treatment group ambrosianeum was hypothyroidism (12 %) and colitis (7 %), and in the group of chemotherapy – infusion reaction (8 %).
In may 2017 pembrolizumab became the first anticancer drug that was approved by the FDA for the treatment of patients with any type of malignant tumors with MSI-H or dMMR after prior systemic therapy.