Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

A phase 1/2 study of mRNA-2808 in participants with relapsed or refractory multiple myeloma (145888)

Hans C Lee 1 , Luciano J Costa 2 , Binod Dhakal 3 , Christopher J Ferreri 4 5 , Nisha Joseph 6 , Alexander Lesokhin 7 , Darren Pan 8 , Sandra Susanibar-Adaniya 9 , Cesar Rodriguez Valdes 10 , Qiang Zhao 11 , Alyssa Flynn 11 , Khaja Waheeduddin Syed 11 , Namhee Kwon 11 , Brendan M Weiss 12 , Noopur Raje 12 , Claire L Borg 13
  1. Sarah Cannon Research Institute, Nashville, TN, USA
  2. University of Alabama at Birmingham, Birmingham, AL, USA
  3. Medical College of Wisconsin, Milwaukee, WI, USA
  4. Atrium Health Levine Cancer Institute, Charlotte, NC, USA
  5. Wake Forest University School of Medicine, Charlotte, NC, USA
  6. Emory University, Atlanta, GA, USA
  7. Memorial Sloan Kettering Cancer Center, New York, NY, USA
  8. University of California, San Francisco, CA, USA
  9. University of Pennsylvania, Philadelphia, PA, USA
  10. Mount Sinai, New York, NY, USA
  11. Moderna Inc, Cambridge, MA, USA
  12. Massachusetts General Hospital, Boston, MA, USA
  13. Moderna Australia, Melbourne, Victoria, Australia. Presenting on behalf of the authors.

Aims: Multiple myeloma (MM) remains mostly incurable and relapsed or refractory multiple myeloma (RRMM) remains a significant unmet need. mRNA-2808 is an intravenously (IV) administered mRNA-encoded, multiplexed T-cell engager (TCE) that delivers in vivo translation of three distinct TCEs targeting BCMA, GPRC5D, and FcRH5. This multiplexed approach aims to enhance immune-mediated cytotoxicity, overcome tumor heterogeneity and target-mediated resistance. Pre-clinical studies demonstrated efficient in vivo translation of TCEs, potent activity against primary MM cells ex vivo and murine tumor xenografts in vivo, and target-cell depletion in non-human primates.  supporting clinical evaluation of mRNA-2808.

Methods: This ongoing, first-in-human, open-label, multicenter Phase 1/2 study evaluates safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of mRNA-2808 in participants with RRMM. Eligibility criteria include prior exposure to a proteasome inhibitor, IMiD, and anti-CD38 monoclonal antibody, are either triple-class refractory or have progressed on or within 60 days of their last therapy, have measurable disease (bone marrow plasma cells >30% or plasmacytoma ≥2cm), and ECOG PS 0-2. Prior BCMA-, GPRC5D-, or FcRH5-targeted therapy is allowed. Part 1 uses dose escalation (accelerated and standard titration phases, with optional step-up dosing), to determine the recommended Phase 2 dose(s) (RP2D) and Part 2 (dose expansion) to further assess safety and efficacy. During the standard titration phase, dosing decisions will be guided by a Bayesian optimal interval design based on the observed dose-limiting toxicity (DLT) rate and Safety Review Committee recommendations. mRNA-2808 will be administered IV weekly during Cycle 1 (28-day cycles), then every 2 weeks through Cycle 12 or every 4-weeks for participants achieving at least a partial response by the end of Cycle 5 at the Investigator’s discretion. Exploratory endpoints will evaluate surrogates of efficacy, mechanism of action, and exposure. Dose Levels 1 and 2 have been completed without DLT and dose escalation is ongoing. (NCT07116616)

  1. © 2026 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2026 ASCO Annual Meeting. All rights reserved.