For the first-line treatment of patients with unresectable or metastatic MSI-H (microsatellite instability-high) or dMMR (mismatch repair deficient) colorectal cancer, the United States Food and Drug Administration (US FDA) granted its approval to pembrolizumab on 29 June 2020.
A multicentre, open-label, active-controlled, randomized study recruiting 307 patients having MSI-H/dMMR colorectal cancer was conducted. Using polymerase chain reaction (PCR) or immunohistochemistry (IHC), MSI or MMR tumor status was assessed locally.
Participants were randomly assigned to receive either treatment with pembrolizumab 200 mg intravenously (iv.) every three weeks or treatment with investigator’s choice of mFOLFOX6/FOLFIRI ± bevacizumab or cetuximab administered iv. every two weeks. At the time of disease progression, the patients randomized to chemotherapy were administered with pembrolizumab.
Progression-free survival (PFS) and overall survival (OS) were the main efficacy outcome measures. Median PFS was more in the pembrolizumab group than the chemotherapy group as shown in the following table:
|Pembrolizumab group||Chemotherapy group|
|Median PFS||16.5 months||8.2 months|
The OS data were not mature at the time of the PFS analysis. In ≥20% of patients receiving pembrolizumab as a single agent, the most common adverse reactions reported are abdominal pain, musculoskeletal pain, fatigue, reduced appetite, diarrhea, pruritus, nausea, pyrexia, rash, cough, constipation, and dyspnea.
For managing colorectal cancer, the dose of pembrolizumab is suggested to be 200 mg every 3 weeks or 400 mg every 6 weeks. Pembrolizumab is a promising therapeutic agent for metastatic MSI-H or dMMR colorectal cancer.
|Link:||https://www.fda.gov/drugs/drug-approvals-and-databases/fda-approves-pembrolizumab-first-line-treatment-msi-hdmmr-colorectal-cancer#:~:text=On%20June%2029%2C%202020%2C%20the,deficient%20(dMMR)%20colorectal%20cancer. [Last accessed on: 14 July, 2020]|
|Original title of the article||FDA approves pembrolizumab for first-line treatment of MSI-H/dMMR colorectal cancer|