Inclusion Criteria:

          -  Participants must be able to sign informed consent

          -  Participants must have a clinicopathological diagnosis of WM and must meet the
             criteria for treatment using consensus panel criteria from the Second International
             Workshop on Waldenstrom's Macroglobulinemia

          -  Participant' WM must have confirmed MYD88L265P and CXCR4WHIM mutations

          -  Participants must have measurable disease, defined as the presence of serum IgM with a
             minimum IgM level of greater than or equal to (≥) 2 * the upper limit of normal (ULN)

          -  Participants may be treatment naïve or have received up to 3 prior treatment regimens
             for WM

          -  Participants must have an ECOG performance status of 0 or 1

          -  Participants must meet the following organ and bone marrow requirements:

             i) Absolute neutrophil count greater than (>) 1,000/microliter (μL) ii) Platelet count
             ≥50,000/μL (platelet transfusion-independent) iii) Hgb ≥8 grams/deciliter (gm/dL) iv)
             Aspartate aminotransferase and alanine aminotransferase less than or equal to (≤) 2.5
             * the ULN and serum total bilirubin ≤1.5 * the ULN, unless secondary to known
             Gilbert's Syndrome or hepatic infiltration by WM, in which case the total bilirubin
             must be ≤3 * the ULN and direct bilirubin ≤1.5 × the ULN v) Serum lipase ≤1.5 * the
             ULN vi) Serum creatinine ≤2 * the ULN or a creatinine clearance of ≥30 milliliters
             (ml)/minute based on the Cockcroft-Gault equation

          -  Women of child-bearing potential (WOCBP) must have a negative pregnancy test

          -  WOCBP who are heterosexually active and male participants with female sexual partners
             of childbearing potential must agree to use an effective method of contraception (for
             example; oral contraceptives, double-barrier methods such as a condom and a diaphragm,
             intrauterine device) during the study and for 4 weeks after the last dose of study
             medication, or to abstain from sexual intercourse for this time; a woman not of
             childbearing potential is one who has undergone a bilateral oophorectomy or who is
             postmenopausal, defined as the absence of menstrual periods for 12 consecutive months

          -  Participants must be willing and capable of complying with the requirements of the
             study

        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, patients 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