Pacritinib in Combination With a BTK Inhibitor for the Treatment of Patients With Relapsed or Refractory Mantle Cell Lymphoma

Inclusion Criteria: * Documented informed consent of the participant and/or legally authorized representative * Be willing to provide tissue from a fresh core or excisional biopsy (performed as standard of care) of a tumor lesion prior to starting study therapy or from diagnostic tumor biopsies * If unavailable, exceptions may be granted with study principal investigator (PI) approval * Age: ≥ 18 years * Eastern Cooperative Oncology Group (ECOG) ≤ 2 * Histologically confirmed diagnosis of mantle cell lymphoma according to the World Health Organization (WHO) classification with a characteristic immunophenotypic profile with CD5+, CD20+, and with either cyclin D1 expression by immunohistochemistry (IHC), or positive by fluorescence in situ hybridization (FISH) or cytogenetics for the t(11,14) translocation, or both. Patients whose tumor is negative for cyclin D1 expression are allowed providing hemato-pathology confirmation of the diagnosis of MCL * Relapsed or refractory disease after at least 1 prior line of systemic therapy * Relapse must have been confirmed histologically with hematopathology review. Exceptions may be granted with study PI approval * Patient must be receiving treatment with single agent ibrutinib or another covalent BTK inhibitor (e.g., acalabrutinib, zanubrutinib), and must have previously achieved complete response (CR) or partial response (PR) to the BTK inhibitor, and must show evidence of progressive MCL at the time of enrollment * Radiographi…