A Study to Learn About the Effects of Cemsidomide in Combination With Elranatamab in Relapsed/Refractory Multiple Myeloma Subjects

A Phase 1B, Open-label, Multicenter Study to Evaluate the Safety and Preliminary Efficacy of Cemsidomide in Combination With Elranatamab in Relapsed/Refractory Multiple Myeloma Subjects

The main purpose of the study is to understand the safety and tolerability of cemsidomide when given along with elranatamab in subjects with relapsed or refractory multiple myeloma.

The first part of the study will evaluate different dose levels of cemsidomide in combination with elranatamab in a limited number of subjects. Approximately 3 different dose levels of cemsidomide in combination with elranatamab may be explored. Once a dose level is determined safe, additional subjects may be enrolled through expansion of the dose level. This expansion will provide further exploration of the safety and evaluation of preliminary antimyeloma activity.

Cemsidomide will be taken orally each cycle for 14 days on/14 days off (1 cycle=28 days). Elranatamab will be administered by subcutaneous injection twice a month. Dexamethasone will be administered weekly until a confirmed response but no longer than 4 cycles.

Study Overview

• Status: Recruiting
• Conditions: Multiple Myeloma (MM)
• Intervention / Treatment: Drug: Cemsidomide; Biological: Elranatamab

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Study Medical Officer; Phone Number: (617) 231-0700; Email: clinicaltrials@c4therapeutics.com

Study Locations

• United States
  • Arizona
    • Gilbert, Arizona, United States, 85234
      • Not yet recruiting
      • Banner MD Anderson Cancer Center
  • California
    • Santa Monica, California, United States, 90404
      • Not yet recruiting
      • UCLA Health, Jonsson Comprehensive Cancer Center
  • Florida
    • Tampa, Florida, United States, 33606
      • Not yet recruiting
      • Tampa General Hospital
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Recruiting
      • Winship Cancer Institute, Emory University
  • Illinois
    • Maywood, Illinois, United States, 60153
      • Not yet recruiting
      • Loyola University Medical Center
  • Indiana
    • Indianapolis, Indiana, United States, 46202
      • Not yet recruiting
      • Indiana University
  • Kentucky
    • Louisville, Kentucky, United States, 40207
      • Not yet recruiting
      • Norton Cancer Institute St. Matthews
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • Not yet recruiting
      • University of Maryland Greenbaum Comprehensive Cancer Center
  • Michigan
    • Grand Rapids, Michigan, United States, 49546
      • Recruiting
      • START Midwest
  • Nebraska
    • Omaha, Nebraska, United States, 68105
      • Not yet recruiting
      • University of Nebraska
  • New Hampshire
    • Lebanon, New Hampshire, United States, 03756
      • Not yet recruiting
      • Dartmouth-Hitchcock Medical Center
  • New York
    • Brooklyn, New York, United States, 11203
      • Not yet recruiting
      • Perlmutter Cancer Center at NYU Langone Hospital
    • New York, New York, United States, 10021
      • Not yet recruiting
      • Memorial Sloan Kettering Cancer Center
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Not yet recruiting
      • Duke Cancer Center
  • Texas
    • Houston, Texas, United States, 77030
      • Not yet recruiting
      • MD Anderson Cancer Center
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • Not yet recruiting
      • Huntsman Cancer Institute, University of Utah

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of multiple myeloma as defined by IMWG criteria
• Measurable disease based on IMWG criteria
• Received 2-4 prior lines of therapy (escalation part) and 1-3 prior lines of therapy (expansion part) for multiple myeloma, consisting of at least 1 immunomodulatory drug (i.e., IKZF 1/3 degrader)
• ECOG performance status 0-2

Exclusion Criteria:

• Active plasma cell leukemia, Smoldering multiple myeloma, POEMS Syndrome, systemic light chain amyloidosis, MDS
• Stem cell transplant within 12 weeks prior to enrollment or active graft vs host disease
• Participants with any active, uncontrolled bacterial, fungal, or viral infection
• Prior treatment with a BCMA-directed TCE or BCMA-directed CAR-T therapy
• Administration with an investigational product within 30 days preceding the first dose of study intervention
• Inability or difficulty swallowing tablets, malabsorption syndrome, or any disease or medical condition significantly affecting gastrointestinal function

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Non-randomized cemsidomide (tablet) plus elranatamab (subcutaneous injection)	Drug: Cemsidomide; IKZF1/3 degrader; Biological: Elranatamab; • BCMA-CD3 bispecific antibody; Other Names: o PF-06863135 o ELREXFIO

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety and tolerability of cemsidomide in combination with elranatamab	Dose limiting toxicity rate	Cycle 1 approximately 28 days
Safety and tolerability of cemsidomide in combination with elranatamab	Frequency and severity of AEs	Baseline through 30 days after discontinuation of study treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assess antimyeloma activity	Objective Response Rate (ORR) per IMWG criteria	Approximately 2 years
Evaluate the PK of cemsidomide and elranatamab	Pre and post dose concentrations of cemsidomide	Approximately 4 months
Evaluate the PK of cemsidomide and elranatamab	Pre dose concentrations of elranatamab	Approximately 2 years
Assess the immunogenicity of elranatamab	Percent of participants with positive anti-drug antibodies to elranatamab	Approximately 2 years

Collaborators and Investigators

• Sponsor: C4 Therapeutics, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): February 6, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): June 1, 2029

Study Registration Dates

• First Submitted: December 1, 2025
• First Submitted That Met QC Criteria: December 1, 2025
• First Posted (Actual): December 12, 2025

Study Record Updates

• Last Update Posted (Actual): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: multiple myeloma, cemsidomide, CFT7455, elranatamab, PF-06863135, relapsed, refractory, RRMM, BCMA, bispecific antibody, BiTE, TCE, ELREXFIO
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Wounds and Injuries; Pathologic Processes; Neoplasms; Disease Attributes; Immune System Diseases; Neoplasms by Histologic Type; Hematologic Diseases; Chemically-Induced Disorders; Lymphoproliferative Disorders; Immunoproliferative Disorders; Neoplasms, Plasma Cell; Hemostatic Disorders; Paraproteinemias; Blood Protein Disorders; Hemorrhagic Disorders; Poisoning; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; Recurrence; Multiple Myeloma; Bites and Stings
• Other Study ID Numbers: CFT7455-1102

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No