Fixed Duration vs Continuous Anti-CD38 Antibody Therapy Among Transplant Ineligible Older Adults With Newly-Diagnosed Multiple Myeloma

Inclusion Criteria:

• Participants with newly diagnosed multiple myeloma that are transplant-ineligible

• Measurable disease at the time of diagnosis, as defined by at least one of thefollowing criteria: Serum monoclonal protein (M-protein) ≥ 5 g/L; Urine M-protein ≥ 200 mg/24 hours; Involved serum free light chain measurement ≥ 100 mg/L, providedserum FLC ration is abnormal; For IgA patients whose disease can only be reliablymeasured by serum quantitative immunoglobulin ≥ 750 mg/dL

• Completed 18-20 cycles of daratumumab-lenalidomide-dexamethasone orisatuximab-lenalidomide-dexamethasone.

• Obtained at least a partial response per the standard 2016 IMWG criteria

• ECOG performance status 0-3

• Participant is able (i.e. sufficiently fluent) and willing to complete the qualityof life and/or health utility questionnaires in English, French, or a providedvalidated language.

• Participant consent must be appropriately obtained in accordance with applicablelocal and regulatory requirements.

• Participants must be accessible for treatment and follow-up.

• In accordance with CCTG policy, protocol treatment is to begin within 2 working daysof participant enrollment.

• Participants of childbearing potential must have agreed to use a highly effectivecontraceptive method.

Exclusion Criteria:

• Known history of concurrent amyloid light chain amyloidosis, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skinchanges), and Waldenstrom's macroglobulinemia.

• Patients receiving concurrent treatment with other anti-cancer therapy that wouldimpact the ability to comply with protocol treatment are ineligible. Note:Participants with a prior or concurrent malignancy whose natural history ortreatment does not have the potential to interfere with the safety or efficacyassessment of protocol treatment are eligible for this trial

• Active, uncontrolled bacterial, fungal, or viral infection within 7 days prior toenrollment.

• Known human immunodeficiency virus (HIV) with CD4 count < 350 cells/microliter. Notethat patients who are HIV positive are eligible, provided:

• They are under treatment with antiretroviral therapy for at least 4 weeks priorto enrollment, with acceptable pharmacokinetic interactions and minimaloverlapping toxicity with protocol therapy AND

• HIV viral load must be < 400 copies/ml within 16 weeks prior to enrollment AND

• No history of opportunistic infections within the past year.