Bendamustine and rituximab was the most used frontline regimen, while BTK inhibitors were the most used agents in later lines of therapy
The presence of chromosome 17p deletion or TP53 mutation did not shorten the overall survival in BTK inhibitor-treated patients.
Mantle cell lymphoma (MCL) is considered incurable with the available chemoimmunotherapy approaches, and therefore newer, effective targeted therapies such as Bruton Tyrosine Kinase (BTK) inhibitors are increasingly used in MCL as chronic suppressive therapy, especially in the elderly. We aimed to describe the treatment patterns in MCL at different lines of therapy with a focus on BTK inhibitor use and compare outcomes with known prognostic factors using a nationwide Flatiron Health electronic health record (EHR)-derived de-identified database. We analyzed patient-level data from the period of 2011 to 2021. In this study of 4336 patients with MCL, we found that bendamustine plus rituximab chemotherapy was the most commonly used frontline regimen (42%). Maintenance rituximab or consolidative autologous stem cell transplant (ASCT) was administered to 31% of all patients. Also, for patients who received ASCT as consolidation therapy, only 34% subsequently received rituximab maintenance. BTK inhibitors were the most preferred agents in second or later lines of therapy (n=933, 57%), followed by bortezomib, lenalidomide, and venetoclax, respectively. Among patients treated with BTK inhibitors, the median real-world overall survival (rwOS) was 35 months (95%CI 27-50), 24 months (95%CI 22 - 30), and 18 months (95% CI 14 - 21), for first line, second line and for third or later line of therapy, respectively. Patients with deletion 17p/TP53 mutation and blastoid variant MCL had poor outcomes; however, BTK inhibitors appeared to mitigate the negative influence of del17p/TP53 mutated MCL with an HR of 1.17 (95%CI 0.88 - 1.55) on multivariable analysis.