A Study of Daratumumab Plus Lenalidomide Versus Lenalidomide Alone as Maintenance Treatment in Participants With Newly Diagnosed Multiple Myeloma Who Are Minimal Residual Disease Positive After Frontline Autologous Stem Cell Transplant

Inclusion Criteria:

• Must have newly diagnosed multiple myeloma with a history of a minimum of 4 cyclesof induction therapy, have received high-dose therapy (HDT) and autologous stem celltransplantation (ASCT) within 12 months of the start of induction therapy, and bewithin 6 months of ASCT on the date of randomization

• Must have a very good partial response (VGPR) or better response assessed perInternational Myeloma Working Group (IMWG) 2016 criteria at the time ofrandomization

• Must have archived bone marrow samples collected before induction treatment (thatis, at diagnosis) or before transplant (for example, at the end of induction) orhave existing results on the index multiple myeloma clone based on AdaptiveBiotechnologies' next generation sequencing (NGS)-based minimal residual disease (MRD) assay. Archived bone marrow samples will be used for calibration of myelomaclonal cells to facilitate assessment of primary end point by NGS. If an existingresult on index myeloma clone is available from Adaptive Biotechnologies' NGS-basedMRD assay, as part of institutional procedures, an archived bone marrow sample isnot required as long as Adaptive Biotechnologies is able to retrieve historicalresults on the index myeloma clone form the clinical database. Any one of thefollowing archived samples are required: (a) Greater than 1 milliliter (mL) viablefrozen bone marrow aspirated aliquot (preferred) collected in anethylenediaminetetra-acetic acid (EDTA) tube, frozen, and stored at a temperature of -80 centigrade (°C), or; (b) Non-decalcified diagnostic bone marrow aspirate clotsections (block or slides) for MRD assessment: (i) A formalin fixed paraffinembedded (FFPE) block of bone marrow aspirate clot, or slides (preferably 5, ifavailable), 5 micrometer each, of non-decalcified bone marrow, or; (ii) Slides (preferably 5, if available), bone marrow aspirate smear; (iii) Please note, bonemarrow core sections are not acceptable samples for analysis; (iv) In exceptionalcircumstances when index myeloma clone cannot be identified from the archived bonemarrow sample, a post-transplant sample can be used to identify myeloma clone withpermission from the sponsor

• Must have residual disease as defined by detectable MRD (Adaptive Biotechnologies'NGS based MRD assay)

• Must have an Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1, or 2

Exclusion Criteria:

• A history of malignancy (other than multiple myeloma) unless all treatment of thatmalignancy was completed at least 2 years before consent and the participant has noevidence of disease before the of date of randomization. Exceptions are squamous andbasal cell carcinomas of the skin, carcinoma in situ of the cervix or breast, orother non-invasive lesion that in the opinion of the investigator, with concurrencewith the sponsor's medical monitor, is considered cured with minimal risk ofrecurrence within 3 years

• Must not have progressed on multiple myeloma (MM) therapy at any time prior toscreening

• Have had prior treatment/therapy with: (a) Daratumumab or any other anti-cluster ofdifferentiation 38 (CD38) therapies, (b) Focal radiation therapy within 14 daysprior to randomization with the exception of palliative radiotherapy for symptomaticmanagement but not on measurable extramedullary plasmacytoma. Radiotherapy within 14days prior to randomization on measurable extramedullary plasmacytoma is notpermitted even in the setting of palliation for symptomatic management, or (c)Plasmapheresis within 28 days of randomization

• Be exhibiting clinical signs of meningeal or central nervous system involvement dueto multiple myeloma

• Have known chronic obstructive pulmonary disease (COPD) with a forced expiratoryvolume in 1 second (FEV1) less than (<) 50 percent (%) of predicted normal

• Have known moderate or severe persistent asthma within the past 2 years or currentuncontrolled asthma of any classification

• Have any of the following: (a) Known history of seropositivity for humanimmunodeficiency virus (HIV); (b) Seropositive for hepatitis B (defined by apositive test for hepatitis B surface antigen [HBsAg]. Participants with resolvedinfection (that is, participants who are HBsAg negative but positive for antibodiesto hepatitis B core antigen [anti-HBc] and/or antibodies to hepatitis B surfaceantigen [anti-HBs]) must be screened using real-time polymerase chain reaction (PCR)measurement of hepatitis B virus (HBV) DNA levels. Those who are PCR positive willbe excluded. EXCEPTION: Participants with serologic findings suggestive of HBVvaccination (anti-HBs positivity as the only serologic marker) AND a known historyof prior HBV vaccination, do not need to be tested for HBV DNA by PCR; (c)Seropositive for hepatitis C (anti-hepatitis C virus [HCV] antibody positive orHCV-RNA quantitation positive), except in the setting of a sustained virologicresponse, defined as aviremia at least 12 weeks after completion of antiviraltherapy)