ASH 2024: Real-World Clinical Outcomes With Novel Therapies in Relapsed/Refractory MCL Vary Based on Race and Ethnicity

The treatment for relapsed/refractory mantle cell lymphoma (MCL) has been revolutionized by the emergence of novel therapies such as Bruton’s tyrosine kinase inhibitors (BTKis). While these agents have shown promise in clinical trials, it is unclear how these therapies are used in the real-world setting. Investigators therefore analyzed de-identified electronic health records from the United States Flatiron Health database to assess clinical outcomes and treatment patterns in patients with relapsed/refractory MCL. Results from this study were presented by Foundation Mantle Cell Lymphoma Consortium (MCLC) Executive Committee member Tycel Phillips, MD of City of Hope.

The analysis included results from 1377 patients with relapsed/refractory MCL who had received at least 2 lines of therapy. Treatments were classified into two groups: novel therapies (including BTKis, BCL2 inhibitors, lenalidomide, bortezomib, and chimeric antigen receptor (CAR) T-cell therapies) and chemoimmunotherapy (any chemoimmunotherapy plus an anti-CD20 antibody). The most common second-line treatments BTKis (acalabrutinib, ibrutinib, and zanubrutinib), along with bendamustine-rituximab and R-CHOP. Other therapies used in later lines of therapy included brexucabtagene autoleucel.

In the second-line setting, 70% of patients received a novel therapy and 30% received chemoimmunotherapy. Median time to next treatment was longer with novel therapies (11.9 months) than with chemoimmunotherapy (9.9 months). Median overall survival, however, was longer with chemoimmunotherapy (43.0 months) compared with novel therapy (35.6 months). Similar trends were observed in the third-line treatment setting with regard to time to next treatment, however overall survival trends were reversed.

The researchers concluded that use of novel therapies in the second line and beyond was associated with a trend towards improved time to next treatment and overall survival among most patients. They acknowledged, however, that there were notable differences in results observed based on racial or ethnic status. For instance, though time to next treatment was higher with novel second-line therapies than with chemoimmunotherapy
in non-Latinx White, Black, and Asian patients, this trend was reversed in Latinx patients. Likewise, while White and Latinx patients had higher median overall survival with chemoimmunotherapy than with novel therapies, the opposite was seen in Black and Asian patients. They noted that further research is needed to understand these differences in real-world treatment patterns and outcomes.

This study also included contributions from Foundation grantees Jia Ruan, MD of Weill Cornell Medicine; Anita Kumar, MD of Memorial Sloan Kettering Cancer Center; Yucai Wang, MD, PhD of Mayo Clinic, Rochester; and Manali Kamdar, MD, MBBS of University of Colorado.