Sub-study of Belantamab Mafodotin (GSK2857916) in Combination With Feladilimab (GSK3359609) in Participants With RRMM

NCT07217119 | Active Not Recruiting Phase 1 FDA Drug

• 2 other identifiers: 208887 Sub Study 22023-509550-55-00
• Study Type: interventional
• Target: 25
• Locations: 8 countries
• Sites: 11

Brief Summary

The primary purpose is to determine the safety and tolerability of belantamab mafodotin in combination with feladilimab (GSK3359609), and to establish the recommended Phase 2 dose (RP2D) for the combination treatment to explore in the cohort expansion (CE) phase in participants with RRMM. This study is a sub study of the Master protocol (NCT04126200).

Conditions

Multiple Myeloma

Keywords

Belantamab Mafodotin; Feladilimab; GSK2857916; GSK3359609; Multiple myeloma

Outcome Measures

Primary Outcomes (4)

• Dose Exploration (DE) Phase: Number of participants with dose limiting toxicities (DLTs)

  Up to 21 days

• DE Phase: Number of participants with adverse events (AEs)

  Up to approximately 281 weeks

• DE Phase: Number of participants with clinically significant changes in hematology, clinical chemistry, and urinalysis lab parameters

  Up to approximately 281 weeks

• Cohort Expansion (CE) Phase: Overall Response Rate (ORR)

  ORR is defined as the percentage of participants with a confirmed Partial response (PR) or better as the best overall response (BOR), according to the International Myeloma Working Group (IMWG) Response Criteria.

  Up to approximately 281 weeks

Secondary Outcomes (36)

• DE Phase: Overall Response Rate

  Up to approximately 380 weeks

• CE Phase: Clinical Benefit Rate (CBR)

  Up to approximately 380 weeks

• DE Phase: Number of participants achieving Partial Response (PR)

  Up to approximately 380 weeks

• CE Phase: Number of participants achieving PR

  Up to approximately 380 weeks

• DE Phase: Number of participants achieving Very Good Partial Response (VGPR)

  Up to approximately 380 weeks

Study Arms (1)

Belantamab mafodotin + Feladilimab

EXPERIMENTAL

Drug: Belantamab mafodotin; Drug: Feladilimab

Interventions

Belantamab mafodotin DRUG

Belantamab mafodotin will be administered.

Also known as: GSK2857916

Belantamab mafodotin + Feladilimab

Feladilimab DRUG

Feladilimab will be administered.

Also known as: GSK3359609

Belantamab mafodotin + Feladilimab

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participant must be 18 years of age inclusive or older, at the time of signing the informed consent.
• Participants must have histologically or cytologically confirmed diagnosis of Multiple Myeloma (MM), as defined by the IMWG.
• Participants having at least 3 prior lines of prior anti-myeloma treatments including an immunomodulating agent (IMID) a proteasome inhibitor (PI) and an anti-CD38 monoclonal antibody.
• Participants with a history of autologous stem cell transplant are eligible for study participation when, transplant was \>100 days prior to study enrolment and with no active infection(s).
• Participants with Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, unless ECOG less than equal to (\<=)2 is due solely to skeletal complications and/or skeletal pain due to MM.
• Participants with measurable disease defined as at least one of the following: Serum M-protein greater than equal to (\>=)0.5 gram per deciliter (\>=5 gram per liter) or Urine M-protein \>=200 milligrams (mg) per 24 hours or Serum free light chain (FLC) assay: Involved FLC level \>=10 mg per deciliter (\>=100 mg per Liter) and an abnormal serum FLC ratio (\<0.26 or \>1.65).
• Participants who have tested positive for Hepatitis B core antibody (HBcAb) can be enrolled if the following criteria are met: Serology result HBcAb+, Hepatitis B surface antigen (HBsAg)-; HBV deoxyribonucleic acid (DNA) undetectable during screening.
• Participants who are currently receiving physiological doses oral steroids (\<10 mg/day), inhaled steroids or ophthalmalogical steroids.

You may not qualify if:

• Participants with current corneal epithelial disease except mild punctate keratopathy.
• Participants with evidence of cardiovascular risk.
• Participants with known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to belantamab mafodotin or any of the components of the study treatment. History of severe hypersensitivity to other mAb.
• Participants with active infection requiring antibiotic, antiviral, or antifungal treatment.
• Participants with other monoclonal antibodies within 30 days or systemic anti-myeloma therapy within \<14 days.
• Participants with prior radiotherapy within 2 weeks of start of study therapy.
• Participants with prior allogeneic transplant are prohibited.
• Participants who have received prior Chimeric Antigen T cell therapy (CAR-T) therapy with lymphodepletion with chemotherapy within 3 months of screening.
• Participants with any major surgery (other than bone-stabilizing surgery) within the last 30 days.
• Participants with prior treatment with an investigational agent within 14 days or 5 half-lives of receiving the first dose of study drugs, whichever is shorter.
• Participants with \>=grade 3 toxicity considered related to prior check-point inhibitors and that led to treatment discontinuation.
• Participants who have received transfusion of blood products within 2 weeks before the first dose of study drug.
• Participants must not receive live attenuated vaccines within 30 days prior to first dose of study treatment or whilst receiving belantamab mafodotin +- partner agent in any sub-study arm of the platform trial and for at least 70 days following last study treatment.
• Participants with presence of active renal condition (infection, requirement for dialysis or any other condition that could affect participant's safety). Participants with isolated proteinuria resulting from MM.
• Participants with known human immunodeficiency virus (HIV) infection, unless the participant can meet all criteria: a) established anti-retroviral therapy for at least 4 weeks and HIV viral load\<400 copies/milliliter (mL) b) cluster of differentiation 4 plus (CD4+) T-cell (CD4+) counts \>= 350 cells/microliter (µL) c) No history of Acquired immunodeficiency syndrome (AIDS)-defining opportunistic infections within the last 12 months in which case the participant would be eligible for CE Phase only.

Sponsors & Collaborators

• GlaxoSmithKline: lead

Study Sites (11)

GSK Investigational Site

Atlanta, Georgia, 30322, United States

Location

GSK Investigational Site

Madison, Wisconsin, 53792, United States

Location

GSK Investigational Site

Fitzroy, Victoria, 3065, Australia

Location

GSK Investigational Site

Melbourne, Victoria, 3000, Australia

Location

GSK Investigational Site

Vancouver, British Columbia, V5Z1M9, Canada

Location

GSK Investigational Site

Toronto, Ontario, M5G2M9, Canada

Location

GSK Investigational Site

Villejuif, 94805, France

Location

GSK Investigational Site

Hamburg, 22083, Germany

Location

GSK Investigational Site

Utrecht, 3584CX, Netherlands

Location

GSK Investigational Site

Pamplona Navarra, 31008, Spain

Location

GSK Investigational Site

Stockholm, SE-141 86, Sweden

Location

MeSH Terms

Conditions

Multiple Myeloma

Interventions

belantamab mafodotin

Condition Hierarchy (Ancestors)

Neoplasms, Plasma Cell; Neoplasms by Histologic Type; Neoplasms; Hemostatic Disorders; Vascular Diseases; Cardiovascular Diseases; Paraproteinemias; Blood Protein Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Hemorrhagic Disorders; Lymphoproliferative Disorders; Immunoproliferative Disorders; Immune System Diseases

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR
• Expanded Access: Yes

Study Record Dates

• First Submitted: October 13, 2025
• First Posted: October 15, 2025
• Study Start: November 26, 2019
• Primary Completion: April 17, 2025
• Study Completion (Estimated): March 11, 2027
• Last Updated: October 15, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1); ES (1); CA (2); SE (1); DE (1); US (2); NL (1); AU (2)