Ibrutinib Approval Pending for Marginal Zone Lymphoma

A new treatment option for patients with marginal zone lymphoma (MZL) may soon be available. A supplemental New Drug Application has been submitted to the US Food and Drug Administration for MZL, and if approved, ibrutinib (Imbruvica) will be the first therapy specifically approved for patients with MZL, a slow-growing form of non-Hodgkin lymphoma, and yet another indication for the medication. Currently, the drug is approved for mantle cell lymphoma (MCL), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and Waldenström’s macroglobulinemia (WM).

MZL, a B-cell malignancy, may soon be treated with ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor that shows promise in patients with MZL who have received at least one prior therapy. MZL is a B-cell lymphoma arising from lymphocytes at the margins, or edges of lymph nodes and various tissues, including the stomach, salivary glands, thyroid gland, eyes, lungs, and spleen; it accounts for approximately 12% of all cases of non-Hodgkin lymphoma in adults. Thus far, this lesser known lymphoma does not have an established course of treatment.

“We are encouraged by the results of this study of ibrutinib in yet another type of B-cell malignancy,” said Peter F. Lebowitz, MD, PhD, Global Oncology Head at Janssen, in a news release. “This FDA submission represents an exciting and important step towards a potential new treatment option for MZL patients who currently have a great unmet need. Currently there are no therapies approved for this rare form of cancer.”

The PCYC-1121 trial enrolled 63 patients with MZL from across the globe who had received at least one prior therapy, including splenic MZL (SMZL), nodal MZL (NMZL), and extranodal MZL (EMZL). Patients received ibrutinib 560 mg orally, once daily until progression or unacceptable toxicity. The primary endpoint of the study was overall response rate as assessed by an Independent Review Committee.

The use of this treatment is not without some risks. Adverse reactions (≥20%) in patients with B-cell malignancies (MCL, CLL/SLL), and WM) were neutropenia (64%), thrombocytopenia (63%), diarrhea (43%), anemia  (41%), musculoskeletal pain (30%), rash (29%), nausea (29%), bruising (29%), fatigue (27%), hemorrhage (21%), and pyrexia (21%).

This study is ongoing, but not recruiting participants.