Posted: Tuesday, July 12, 2022
According to the multicenter phase II IMCL-2015 trial, which was published in the Journal of Clinical Oncology, front-line treatment with ibrutinib plus rituximab resulted in high rates of complete responses and undetectable measurable (also referred to as minimal) residual disease (MRD) in patients with indolent clinical types of mantle cell lymphoma. Eva Giné, MD, of the Hospital Clínic of Barcelona, and colleagues noted that these outcomes allow for treatment interruption for many responders.
“The duration of molecular and clinical responses after ibrutinib discontinuation will be a key aspect to define the final role of such individualized approaches,” the investigators remarked. “Some patients, particularly those with a TP53 mutation, may not be good candidates for treatment discontinuation, even in the case of molecular response.”
A total of 50 patients with treatment-naive mantle cell lymphoma were administered 560 mg of oral ibrutinib once daily and a total of eight doses of 375 mg/m2 of intravenous rituximab. After 2 years, treatment with ibrutinib may be discontinued with sustained undetectable MRD.
After 12 cycles of treatment, the overall response rate was 84%; this included 40 patients with a complete response. A total of 87% of patients achieved undetectable MRD in the peripheral blood. Per the protocol, treatment with ibrutinib was discontinued in 24 of the 35 evaluable patients who achieved sustained undetectable MRD after 2 years. Four patients experienced disease progression, three of whom presented with non-nodal disease, TP53 mutations, and carried high genomic complexity at enrollment. No unexpected toxicity was observed, except for one patient with severe aplastic anemia.
“Future randomized studies are guaranteed to explore the final role of targeted therapies in the front-line treatment of patients with mantle cell lymphoma,” the investigators concluded.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.