First ever FDA-approval of immunotherapy plus chemotherapy combination for advanced mesothelioma
Today, the U.S. Food and Drug Administration (FDA) approved the third ever treatment for mesothelioma. As of today, in addition to the standard chemotherapy regimen and the immunotherapy regimen, the combination of immunotherapy plus standard chemotherapy is available to clinicians for the treatment of patients with advanced or metastatic mesothelioma in a first line setting.
Keytruda, which is the industry name for Merck’s pembrolizumab agent was approved after a positive 2023 Italian/Canadian collaborative study demonstrating a survival improvement for their immuno-chemotherapy combination.
About the clinical trial
The IND.227 clinical trial had enrolled 440 treatment-naive patients randomizing them into two groups, one of which was experimental. The first group received only standard chemotherapy, while the second group received chemotherapy plus Keytruda (pembrolizumab). The experimental arm saw a one month survival improvement (17.3 months’ survival as opposed to 16.1 months for the chemotherapy alone arm). However, as is the case with other immunotherapy data in mesothelioma, patients with the more aggressive types of mesothelioma (biphasic and sarcomatoid) gained the most from the immunotherapy addition. For this group, the survival benefit exceeded 4 months over the survival of their peers in the non-experimental treatment arm, an improvement which ultimately also led to this approval.
About pembrolizumab (Keytruda)
Pembrolizumab is an immunotherapy agent known as a checkpoint inhibitor. Checkpoints are proteins located on t-cells that, when bound together with partner proteins on the tumor cell, disable the immune response of the t-cell against the tumor cell. It functions sort of like a handshake. Disrupting this process, or inhibiting this connection, allows the t-cells to recognize the tumor as a foreign entity and kill it. The class of drugs called checkpoint inhibitors bind to these checkpoint proteins (known as PD-1 and PDL-1, depending on their location) so that no handshake can occur, thus effectively taking the breaks off the immune system.
About mesothelioma treatment
Mesothelioma treatment has lagged behind other cancers. Its first FDA-approval came in 2004 when Alimta plus cisplatin chemotherapy extended median survival by 3 months (from 9 months to 12 months). For over 16 years, mesothelioma didn’t see any new treatments added to its line-up until 2020 when a landmark study of two immunotherapy agents, nivolumab and ipilimumab (Opdivo/Yervoy) by Bristol Myers Squibb, demonstrated a significant improvement in overall survival of over 4 months (from 14.1 months to 18.1 months), leading to its approval shortly thereafter. This third approval is a therefore a welcome addition to the treatment arsenal for mesothelioma.
