A real-world study provides a benchmark for survival in patients with relapsed or refractory mantle cell lymphoma (MCL) for whom Bruton tyrosine kinase (BTK) inhibitor treatment has failed, according to researchers.
The researchers observed a median overall survival (OS) of nearly 2 years for patients who received treatment after BTK inhibitor failure. In contrast, the median OS was less than 6 months for patients who received no treatment after failure of BTK inhibitor therapy. These findings were published in the British Journal of Haematology.
This retrospective study, called SCHOLAR-2 (ClinicalTrials.gov Identifier: NCT04680442), included 240 patients with relapsed or refractory MCL. The patients had received BTK inhibitor-based therapy from July 2012 to July 2018 and had experienced progression on the treatment or discontinued BTK inhibitor therapy due to intolerance.
There were 236 patients with available data on all pre-BTK inhibitor therapies. In this group, 38.1% had received prior bendamustine plus rituximab, 51.7% had received cytarabine-containing regimens, and 58.9% had received other chemotherapy, with or without antibodies.
Of all 240 patients, 93.8% received 1 BTK inhibitor regimen, 5.8% received 2 lines of BTK inhibitor therapy, and 0.4% received 3 lines of BTK inhibitor therapy. Among 133 patients who were evaluable for response, the best objective response rate to BTK inhibitor therapy was 34.6%.
After discontinuing BTK inhibitor therapy, 91 patients did not receive any additional systemic treatment. The median duration of BTK inhibitor treatment in this group was 3.8 months. Most of these patients (73.6%) discontinued BTK inhibitor treatment due to disease progression, and 26.4% did so due to intolerance.
There were 149 patients who did receive additional systemic anticancer treatment after discontinuing BTK inhibitor therapy. In this group, the median duration of BTK inhibitor therapy was 7.1 months. Most of these patients (85.2%) discontinued BTK inhibitor treatment due to disease progression, and 14.8% discontinued due to intolerance.
Among the patients with post-BTK inhibitor therapy, 61.7% received 1 subsequent treatment, 16.8% received 2 subsequent treatments, and 14.8 received 3 subsequent treatments. The most common post-BTK inhibitor treatments were lenalidomide-containing regimens (17.4%) and bendamustine plus rituximab (16.8%). None of the patients received chimeric antigen receptor T-cell therapy.
Among all 240 patients, the median OS from the start of first BTK inhibitor therapy was 14.6 months. The median OS was 5.5 months in patients who did not receive treatment after BTK inhibitor therapy and 23.8 months in patients who did.
The estimated 1-year OS rate was 69.1% in patients who received post-BTK inhibitor therapy and 34.4% in those who did not. The estimated 2-year OS rate was 50.0% and 17.2%, respectively.
Disclosures: This research was supported by Kite. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Hess G, Dreyling M, Oberic L, et al. Real-world experience among patients with relapsed/refractory mantle cell lymphoma after Bruton tyrosine kinase inhibitor failure in Europe: The SCHOLAR-2 retrospective chart review study. Br J Haematol. Published online October 18, 2022. doi:10.1111/bjh.18519