Acalabrutinib Plus Rituximab “Highly Effective” in Older MCL Patients

Blue and yellow capsules
Blue and yellow capsules
Acalabrutinib and rituximab can yield early complete responses in older patients with previously untreated mantle cell lymphoma.

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 (ClinicalTrials.gov 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%).

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.

Reference

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