A Study of Mavorixafor in Combination With Ibrutinib in Participants With Waldenstrom's Macroglobulinemia (WM) Whose Tumors Express Mutations in MYD88 and CXCR4

Exclusion Criteria

• •Participants with symptomatic hyperviscosity syndrome; participants who undergo plasmapheresis for hyperviscosity may be considered for enrollment once IgM level is under 4,000 mg/dl
• •Participants who have known hypersensitivity to mavorixafor or any of its components or to ibrutinib
• •Participants who have previously received a CXCR4 inhibitor or a BTK inhibitor
• •Participants who are pregnant or breastfeeding
• •Participants with an infection requiring intravenous antibiotics or hospitalization at the scheduled time of the first administration of protocol therapy
• •Participants with glycated hemoglobin (HbA1c) \>6.5%
• •Participants with central nervous system (CNS) lymphoma; participants with suspected CNS lymphoma should undergo appropriate diagnostic studies (magnetic resonance imaging, lumbar puncture) before enrollment to determine if CNS lymphoma is present
• •Participants with ongoing acute clinical AEs of National Cancer Institute Common Terminology Criteria for AEs (NCI CTCAE) Grade \>1 resulting from prior cancer therapies or participants receive prior chemotherapy within 2 weeks of initial dosing or prior autologous hematopoietic stem cell transplantation (auto-HSCT) within 6 weeks of initial dosing
• •Participants with a history of, or positive serologies for, human immunodeficiency virus (HIV), hepatitis B or hepatitis C infection (participants with HBsAb positivity due to a hepatitis B virus \[HBV\] vaccination are eligible)
• •Participants who have had within the past 6 months, the occurrence or persistence of one or more of the following medical conditions that could not be controlled with usual medical care (for example; required emergency care or hospitalization): hypertension, diabetes, unstable angina, seizure disorder, or myocardial infarction
• •Participants with clinically significant cardiac disease, including congestive heart failure consistent with New York Heart Association Class 3 or 4; uncontrolled hypertension, clinically significant angina, clinically significant arrythmias including a history of atrial fibrillationin the last 2 years, corrected QT interval using Fridericia formula of \>470 milliseconds (msec) or a history of prolonged QT syndrome
• •Participants who have had within the past 6 months the occurrence of one or more of the following events: cerebrovascular accident, deep vein thrombosis, pulmonary embolism, hemorrhage (NCI CTCAE Grade 3 or Grade 4), or chronic liver disease (meeting criteria for Child-Pugh Class B or C)
• •Participants with prior organ transplantation (prior auto-HSCT are eligible)
• •Participants who have an uncontrolled bleeding disorder or require an anticoagulant at the time of study treatment
• •Participants with active autoimmune disease requiring systemic steroid administration
• •Participants with active second malignancies. (except: malignancies that were treated curatively and have not recurred within 2 years prior to study treatment; completely resected basal cell and squamous cell skin cancers; any non-hematological malignancy considered to be indolent and that has never required therapy; and completely resected carcinoma in situ of any type)
• •Participants who have received an investigational agent within 5 half-lives of the agent; if the half-life of the agent is unknown, participants must wait 4 weeks
• •Participants who require strong or moderate inhibitors or inducers of CYP3A4 and potent P-gp inhibitors
• •Participants who require medications which are classified as sensitive CYP2D6 substrates
• •Participant who have received in the 2 weeks preceding the first dose of protocol treatment, any of the following agents:
• •i) Granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor ii) Systemic corticosteroids in a dose of \>10 mg equivalent of prednisone daily; topical, ophthalmic, intranasal, and inhalational corticosteroids are permitted iii) Any other immunomodulating agents, including but not limited to interferon alpha, interleukin (IL)-2, mycophenolate, antibodies to tumor necrosis factor (TNF)-α, soluble TNF receptors, Janus kinase inhibitors, or IL-23 antagonists
• •Participants with any other medical, personal, social, or psychiatric condition that, in the opinion of the Investigator, may potentially compromise the safety or compliance of the participant or precludes the participant's participation in the study