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

A Phase I/II, Randomized, Open-label Platform Study Utilizing a Master Protocol to Study Belantamab Mafodotin (GSK2857916) as Monotherapy and in Combination With Anti-Cancer Treatments in Participants With Relapsed/Refractory Multiple Myeloma (RRMM)-DREAMM5 - Sub-study 2 - Belantamab Mafodotin and Feladilimab (GSK3359609) in Combination

Status
Active, not recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07217119
Enrollment
25
Registered
2025-10-15
Start date
2019-11-26
Completion date
2027-03-11
Last updated
2026-06-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Multiple Myeloma

Keywords

Belantamab Mafodotin, Feladilimab, GSK2857916, GSK3359609, Multiple myeloma

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).

Interventions

DRUGBelantamab mafodotin

Belantamab mafodotin will be administered.

Feladilimab will be administered.

Sponsors

GlaxoSmithKline
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* 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.

Exclusion criteria

* 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. For participants receiving nirogacestat, HIV drugs that are strong Cytochrome P450 3A4 (CYP3A4) inhibitors are prohibited. HIV drugs that are moderate CYP3A4 inhibitors, while permitted, should be co-administered with caution and must be accompanied by nirogacestat dose modifications. * Participants with autoimmune disease (current or history) or syndrome that required systemic treatment within the past 2 years. * Recent (within the past 6 months) history of symptomatic pericarditis.

Design outcomes

Primary

MeasureTime frameDescription
Dose Expansion (DE) Phase: Number of Participants With Dose Limiting Toxicities (DLTs)Up to 28 daysCriteria for dose-limiting toxicity (DLT) included hematologic indicators such as Grade 3-5 febrile neutropenia and thrombocytopenia with bleeding. Non-hematologic criteria, excluding corneal toxicity, comprise Grade 3-5 toxicities, with exceptions for manageable nausea, vomiting, or diarrhea, controlled Grade 3 hypertension, and events linked to disease progression. Tumor lysis syndrome (TLS) of Grade 3 or 4, successfully managed within 7 days without end-organ damage, is considered. Corneal toxicity, assessed by the GSK corneal grading scale at Grade 4, is a DLT. Other organ-specific toxicities, notably liver toxicity meeting GSK stopping criteria, also qualify as DLT severity was graded using National Cancer Institute (NCI) - Common Terminology Criteria for Adverse Events (CTCAE) version (v) 5.0.
DE Phase: Number of Participants With Adverse Events (AEs)Up to approximately 281 weeksAn AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. AEs were coded using the Medical Dictionary for Regulatory Activities (MedDRA) coding system.
DE Phase: Number of Participants With Worst-Case Hematology Results by Maximum Grade Increase Post - Baseline Relative to BaselineBaseline (Day 1) and up to approximately 281 weeks.Blood samples were collected for evaluation of hematology parameters including Anemia, Hemoglobin increased (HbI), Lymphocyte count decreased (LyD), Lymphocytes count increased (LyI), Neutrophils count decreased (NeuD), Platelet count decreased (PD), Leukocytosis (LC) and White blood cell decreased (WBCD). The laboratory parameters were graded according to CTCAE v5.0. Grade 1 (G1): mild; Grade 2 (G2): moderate; Grade 3 (G3): severe; Grade 4 (G4) life-threatening or disabling. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade. Any worst-case post baseline increases to G1, G2, G3, and G4 are presented. Baseline value was defined as the most recent, non-missing value from a local laboratory prior to the first dose of study treatment.
DE Phase: Number of Participants With Worst-Case Chemistry Results by Maximum Grade Increase Post - Baseline Relative to BaselineBaseline (Day 1) and up to approximately 281 weeks.Blood samples were collected for the analysis of following chemistry parameters: Hypoglycemia (HypoG), hypoalbuminemia (HypoA), creatine kinase increased (CPKI), hyperkalemia, blood lactate dehydrogenase increased (LDHI), hypermagnesemia (HyperM), hypomagnesemia (HypoM), hypernatremia (HyperN), hypercalcemia (HyperC), hypocalcemia (HypoC) and chronic kidney disease (CKD). ). The laboratory parameters were graded according to CTCAE v 5.0. G1: mild; G2: moderate; G3: severe; G4: life-threatening or disabling. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade. Any worst-case post baseline increase to G1, G2 and G3 are presented. The laboratory parameters were graded according to CTCAE v 5.0.
Cohort Expansion (CE) Phase: Overall Response Rate (ORR)Up to approximately 281 weeks.Overall Response Rate (ORR) was defined as the percentage of participants with a confirmed Partial Response (PR) or better as the best overall response (i.e., PR, Very Good Partial Response \[VGPR\], Complete Response \[CR\], and stringent Complete Response \[sCR\]), as assessed by the investigator per international myeloma working group (IMWG) (2016). PR is defined as ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to \<200 mg/24 h. VGPR is defined as serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component \<100 mg/24 h. CR is defined as negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND \<5% plasmacytomas in the bone marrow. sCR is defined as CR as above PLUS normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence.

Secondary

MeasureTime frameDescription
DE Phase: Overall Response Rate (ORR)Up to approximately 281 weeks.Overall Response Rate (ORR) was defined as the percentage of participants with a confirmed Partial Response (PR) or better as the best overall response (i.e., PR, Very Good Partial Response \[VGPR\], Complete Response \[CR\], and stringent Complete Response \[sCR\]), as assessed by the investigator per international myeloma working group (IMWG) (2016). PR is defined as ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to \<200 mg/24 h. VGPR is defined as serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component \<100 mg/24 h. CR is defined as negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND \<5% plasmacytomas in the bone marrow. sCR is defined as CR as above PLUS normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence.
CE Phase: Clinical Benefit Rate (CBR)Up to approximately 281 weeks.Clinical benefit rate is defined as the percentage of participants with a confirmed minimal response (MR) or better according to the IMWG Response Criteria. MR is \>= 25% but \< 49% reduction of serum M-protein and reduction in 24-hour urinary M-protein by 50-89%.
DE Phase: Percentage of Participants Achieving Stringent Complete Response (SCR), Complete Response (CR), Very Good Partial Response (VGPR) and Partial Response (PR)Up to approximately 281 weeks.Partial Response \[PR\], Very Good Partial Response \[VGPR\], Complete Response \[CR\], and stringent Complete Response \[sCR\] were assessed by the investigator per IMWG (2016). PR defined as ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to \<200 mg/24 h. VGPR defined as serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component \<100 mg/24 h. CR defined as negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND \<5% plasmacytomas in the bone marrow. sCR defined as CR as above PLUS normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence.
CE Phase: Percentage of Participants Achieving SCR, CR, VGPR and PRUp to approximately 281 weeks.Partial Response \[PR\], Very Good Partial Response \[VGPR\], Complete Response \[CR\], and stringent Complete Response \[sCR\] were assessed by the investigator per IMWG (2016). PR defined as ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to \<200 mg/24 h. VGPR defined as serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component \<100 mg/24 h. CR defined as negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND \<5% plasmacytomas in the bone marrow. sCR defined as CR as above PLUS normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence.
DE Phase: Plasma Concentration of Belantamab Mafodotin Antibody-Drug Conjugate (ADC)Predose, end of infusion (EOI), 2 and 24 hours postdose on Cycle (C) 1 Day (D) 1; anytime sample at C1 D4 and D8; Predose and EOI on D1 of C2, C4, C6, C9, C12; Predose on C18 D1; and at end of treatment (EoT, up to approximately 281 weeks.)Blood samples were collected for PK analysis of belantamab mafodotin Antibody-Drug Conjugate (ADC). Only those participants who were measured and analyzed (i.e., contributed data reported in the table) were included in the Overall Number of Participants Analyzed field. 'Number Analyzed' signifies participants evaluable for the specified timepoints.
CE Phase: Plasma Concentrations of Belantamab Mafodotin Antibody-Drug Conjugate (ADC)Up to approximately 281 weeks.Blood samples were planned to be collected for PK analysis of Belantamab Mafodotin Antibody-Drug Conjugate (ADC).
DE Phase: Plasma Concentration of Belantamab Mafodotin Total AntibodyPredose, EOI, 2 and 24 hours postdose on C1 D1, anytime sample at C1 D4, D8; Predose and EOI on D1 of C2, C4, C6, C9, C12; Predose on C18 D1; and at EoT (up to approximately 281 weeks.)Blood samples were collected for PK analysis of Belantamab mafodotin total antibody.
CE Phase: Plasma Concentration of Belantamab Mafodotin Plasma Total AntibodyUp to approximately 281 weeks.Blood samples were planned to be collected for PK analysis of Belantamab mafodotin plasma total antibody.
DE Phase: Plasma Concentrations of Belantamab Mafodotin Cys- Monomethyl Auristatin-F (Cys-mcMMAF)Predose, EOI, 2 and 24 hours postdose on C1 D1, anytime sample at C1 D4, D8; Predose and EOI on D1 of C2, C4, C6, C9, C12; Predose on C18 D1; and at EoT (up to approximately 281 weeks)Blood samples were collected for PK analysis of belantamab mafodotin cys- monomethyl auristatin-F (cys-mcMMAF).
CE Phase: Plasma Concentrations of Belantamab Mafodotin Cys- Monomethyl Auristatin-F (Cys-mcMMAF)Up to approximately 281 weeks.Blood samples were planned to be collected for PK analysis of Belantamab Mafodotin Cys- Monomethyl Auristatin-F (Cys-mcMMAF)
DE Phase: Feladilimab Concentration When Administered in Combination With Belantamab MafodotinPredose, EOI, 2 and 24 hours postdose on C1 D1, anytime sample at C1 D4, D8; Predose and EOI on D1 of C2, C4, C6, C9, C12; Predose on C18 D1; and at EoT (up to approximately 281 weeks)Blood samples were collected for PK analysis of Feladilimab when administered intravenously in combination with belantamab mafodotin.
CE Phase: Feladilimab Concentration When Administered in Combination With Belantamab MafodotinUp to approximately 281 weeks.Blood samples were planned to be collected for PK analysis Feladilimab when administered intravenously in combination with belantamab mafodotin.
DE Phase: Number of Participants With Post-baseline Positive Anti-drug Antibodies (ADAs) Against Belantamab MafodotinUp to approximately 281 weeksSerum samples were collected for the analysis of the presence of ADAs using validated immunoassays. All samples were tested in screening assay, and positive samples were further characterized for antibody titers.
CE Phase: Number of Participants With Post-baseline Positive ADAs Against Belantamab MafodotinUp to approximately 281 weeksSerum samples were to be collected for the analysis of the presence of ADAs using validated immunoassays. All samples were to be further tested in screening assay, and positive samples were further to be characterized for antibody titers.
DE Phase: Titer of ADAs Against Belantamab MafodotinUp to approximately 281 weeksSerum samples were collected for the analysis of the presence of ADAs using validated immunoassays. All samples were tested in screening assay, and positive samples were further characterized for antibody titers.
CE Phase: Titer of ADAs Against Belantamab MafodotinUp to approximately 281 weeksSerum samples were to be collected for the analysis of the presence of ADAs using validated immunoassays. All samples were to be further tested in screening assay, and positive samples were further to be characterized for antibody titers.
DE Phase: Number of Participants With Post-baseline Positive ADAs Against FeladilimabUp to approximately 281 weeksSerum samples were collected for the analysis of the presence of ADAs using validated immunoassays. All samples were to be further tested in screening assay, and positive samples were further to be characterized for antibody titers.
CE Phase: Number of Participants With Post-baseline Positive ADAs Against FeladilimabUp to approximately 281 weeks.Serum samples were to be collected for the analysis of the presence of ADAs using validated immunoassays. All samples were tested in screening assay, and positive samples were further characterized for antibody titers.
DE Phase: Titre of ADAs Against FeladilimabUp to approximately 281 weeksSerum samples were collected for the analysis of the presence of ADAs using validated immunoassays. All samples were tested in screening assay, and positive samples were further characterized for antibody titers.
CE Phase: Titer of ADAs Against FeladilimabUp to approximately 281 weeks.Serum samples were to be collected for the analysis of the presence of ADAs using validated immunoassays. All samples were tested in screening assay, and positive samples were further characterized for antibody titers.
DE Phase: Number of Participants With Adverse Events of Special Interest (AESI)Up to approximately 281 weeks.An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Adverse Events of Special Interest (whether serious or non serious) were collected.
CE Phase: Number of Participants With AESIUp to approximately 281 weeks.An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Adverse Events of Special Interest (whether serious or non serious) were planned to be collected.
DE Phase: Number of Participants With Any Corneal Events by Maximum Grade as Per CTCAE GradeUp to approximately 281 weeks.The corneal events were graded according to CTCAE version 5. Grade 1: mild; Grade 2: moderate; Grade 3: severe or medically significant. Grade 4: Life-threatening consequences; Grade 5: Death related to AE. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade. Results are presented for number of participants with any corneal events by maximum grade as per CTCAE grade version (v) 5.0.
CE Phase: Number of Participants With Any Corneal Events by Maximum Grade as Per CTCAE GradeUp to approximately 281 weeks.The corneal events were graded according to CTCAE version 5. Grade 1: mild; Grade 2: moderate; Grade 3: severe or medically significant. Grade 4: Life-threatening consequences; Grade 5: Death related to AE. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade. Results are presented for number of participants with any corneal events by maximum grade as per CTCAE grade version (v) 5.0.
CE Phase: Progression-free Survival (PFS)Up to approximately 281 weeks.PFS is defined as the time from randomization until the earliest date of confirmed progressive disease (PD) per IMWG, or death due to any cause.
CE Phase: Duration of Response (DoR)Up to approximately 281 weeks.DoR is defined as the time from first documented evidence or PR or better until progressive disease per IMWG or death due to progressive disease among participants who achieve confirmed partial response or better.
CE Phase: Time to Response (TTR)Up to approximately 281 weeks.TTR is defined as the time between the date of randomization and the first documented evidence of response (PR or better), among participants who achieve a response (confirmed PR or better).
CE Phase: Overall Survival (OS)Up to approximately 281 weeks.OS is defined as the time from randomization until death due to any cause.
CE Phase: Number of Participants With AEs and SAEsUp to approximately 281 weeks.An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that; results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect, other situations judged by physician, is associated with liver injury and impaired liver function. AEs and SAEs were planned to be coded using the Medical Dictionary for Regulatory Activities (MedDRA) coding system.
CE Phase: Number of Participants With AEs Leading to DiscontinuationUp to approximately 281 weeks.An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Number of participants with AEs leading to discontinuation were to be evaluated.
CE Phase: Number of Participants With AEs Leading to Dose Reduction or DelayUp to approximately 281 weeks.Number of participants with dose reduction or delay were to be evaluated.
CE Phase: Number of Participants With Clinically Significant Changes in Hematology Lab ParametersBaseline (Day 1) and up to approximately 281 weeks.Blood samples were to be collected for the analysis of hematology parameters. The laboratory parameters were to be graded according to CTCAE version 5.0. Grade 1 (G1): mild; Grade 2 (G2): moderate; Grade 3 (G3: severe or medically significant; Grade 4 (G4): Life-threatening consequences; Grade 5 (G5): Death related to AE. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade.
CE Phase: Number of Participants With Clinically Significant Changes in Clinical Chemistry Lab ParametersBaseline (Day 1) and up to approximately 281 weeks.Blood samples were to be collected for the analysis of chemistry parameters. The laboratory parameters were to be graded according to CTCAE version 5.0. G1: mild; G2: moderate; G3: severe or medically significant; Grade 4: Life-threatening consequences; Grade 5: Death related to AE. Higher grade indicates greater severity and an increase in CTCAE grade was defined relative to the Baseline grade.

Countries

Australia, Canada, France, Germany, Netherlands, Spain, Sweden, United States

Participant flow

Recruitment details

This is a sub-study of the master study NCT04126200. The study was planned to include two phases - Dose Escalation (DE) and Cohort Expansion (CE) and no participants from this sub study were enrolled in CE phase as CE Phase was not initiated due to business strategic reason.

Pre-assignment details

The results presented are based on the data cut-off date of 17 Apr 2025. Those participants still benefiting from study drug in the opinion of their treating physician continued to receive study drug in Post Analysis Continuation of Treatment (PACT) phase and their safety data will be provided within a year of study completion.

Baseline characteristics

Characteristic
Age, Continuous65.6 YEARS
STANDARD_DEVIATION 8.7
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
1 Participants
Race (NIH/OMB)
Black or African American
1 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
21 Participants
Sex: Female, Male
Female
6 Participants
Sex: Female, Male
Male
4 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
7 / 96 / 102 / 6
other
Total, other adverse events
9 / 99 / 106 / 6
serious
Total, serious adverse events
3 / 96 / 101 / 6

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 26, 2026