Treatment with acalabrutinib and rituximab can yield early complete responses (CRs) in older patients with previously untreated mantle cell lymphoma (MCL), a phase 2 study suggests.

Preetesh Jain, MD, PhD, of the University of Texas MD Anderson Cancer Center in Houston, presented these findings at the International Conference on Malignant Lymphoma 2023.

The single-arm trial ( Identifier: NCT05214183) enrolled 50 patients with previously untreated MCL. The patients’ median age was 69 (range, 65-81) years. Patients had low-risk (n=4), intermediate-risk (n=35), or high-risk (n=11) disease per simplified MIPI stratification guidelines. Most had bone marrow involvement (90%) and gastrointestinal involvement (75%).

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Patients received acalabrutinib at 100 mg twice daily until disease progression or any other reason for discontinuation. They also received rituximab at 375 mg/m2 weekly for the first month, then once a month for 12 months, and once every 2 months for an additional 12 months (for a total of 24 months).

In 49 evaluable patients, the objective response rate (ORR) at 12 weeks was 92%, and the CR rate at 12 weeks was 74%. The best ORR was 92%, and the best CR rate was 92%. The median number of cycles to reach CR was 3 (range 2-7).

At last follow-up, 60% of evaluable patients (19/32) were negative for minimal residual disease.

In all 50 patients, at a median follow-up of 17 months, the median progression-free survival (PFS) and overall survival (OS) were not reached. The 2-year PFS rate was 92%, and the 2-year OS rate was 96%.

The most common adverse events (AEs) were fatigue (78%), myalgia (62%), headache (34%), COVID-19 (32%), and bruising (28%). The most common grade 3-4 AEs were thrombocytopenia (4%), fatigue (4%), headache (4%), and COVID-19 (4%).

Three patients died. One patient died of primary refractory disease, 1 died in CR of an unknown cause, and 1 died of RASopathy/chronic myelomonocytic leukemia.  

“Overall, the combination is a highly effective, easily administered, chemo-free therapy option inducing deep CR early on at 12 weeks,” Dr Jain said.

He noted that the AE profile was “generally favorable,” but longer follow-up is needed to better understand the safety of the combination as well as the risk of second cancers and relapses.

Disclosures: This research was supported by AstraZeneca. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Jain P, Ok CY, Fetooh A, et al. Acalabrutinib with rituximab as first-line therapy for older patients with mantle cell lymphoma–A phase II clinical trial.  ICML 2023. June 13-17, 2023. Abstract 99.

This article originally appeared on Cancer Therapy Advisor