SAN DIEGO Chemotherapy-free induction with ibrutinib and rituximab is efficacious and well-tolerated among young patients with newly diagnosed mantle cell lymphoma, according to preliminary findings presented at the American Society of Hematology (ASH) 58th Annual Meeting and Exposition.1

“Frontline therapy is the most important therapy for mantle cell lymphoma,” said principal investigator Michael Wang, MD, department of stem cell transplantation and cellular therapy, The University of Texas MD Anderson Cancer Center, Houston. “Frontline therapy could kill all MCL cells at the first strike, eliminate any change for secondary resistance, cause long-term remissions and, if ideally optimized, become a shortcut to cure MCL.”

To evaluate chemotherapy-free induction among young and fit patients, researchers enrolled 50 patients aged 65 years or younger with newly diagnosed mantle cell lymphoma. In part 1, patients received ibrutinib plus rituximab induction therapy until best response, followed by a shortened course of intense chemoimmunotherapy in part 2.

Patients then received intense consolidation therapy consisting of rituximab plus cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD), alternating every 28 days with rituximab plus high-dose methotrexate and cytarabine.

If in complete remission after initial ibrutinib and rituximab treatment, patients received 4 additional treatments of intense chemoimmunotherapy. If patients had a partial response or progression, and were responding to intensive chemoimmunotherapy, they received 2 cycles of chemoimmunotherapy.

All of the 45 evaluable patients achieved a response in part 1, including complete remissions in 73% and partial remissions in 27%. Thirty-three patients have completed both part 1 and part 2.

Toxicity after intensive chemoimmunotherapy in shortened cycles was improved compared with historical controls, though longer follow-up is needed to fully understand the safety of this approach.

RELATED: VcR-CVAD Regimen Induces Durable Remissions in Mantle Cell Lymphoma

“This is the first time for chemotherapy-free therapy to achieve an overall response rate of 100%; it is unprecedented efficacy at frontline in young patients with mantle cell lymphoma,” Dr Wang concluded. “This may provide a window of opportunity to reduce frontline chemotherapy with improved efficacy and reduced toxicities.

Reference

  1. Wang M, Lee HJ, Thirumurthi S, et al. chemotherapy-free induction with ibrutinib-rituximab followed by shortened cycles of chemo-immunotherapy consolidation in young, newly diagnosed mantle cell lymphoma patients: A phase II clinical trial. Paper presented at: American Society of Hematology (ASH) 58th Annual Meeting and Exposition; December 3-6, 2016; San Diego, CA.