To Evaluate Safety, Tolerability, and Clinical Activity of the Antibody-drug Conjugate, GSK2857916 Administered in Combination With Lenalidomide Plus Dexamethasone (Arm A), or in Combination With Bortezomib Plus Dexamethasone (Arm B) in Participants With Relapsed/Refractory Multiple Myeloma (RRMM)

GlaxoSmithKline153 enrolled

Overview

This study will evaluate the safety and tolerability profile of belantamab mafodotin when administered in combination with approved regimens of either Lenalidomide Plus Dexamethasone \[Len/Dex (Treatment A)\] or Bortezomib Plus Dexamethasone \[Bor/Dex (Treatment B)\] in participants with RRMM, i.e., those who have relapsed or who are refractory to at least 1 line of approved therapy. Participants receiving treatment A, may continue combination treatment until the occurrence of progressive disease (PD), intolerable adverse events (AEs ), consent withdrawal, death or end of study. The participants receiving treatment B, may continue combination treatment for a total of up to 8 cycles. After 8 cycles of combination therapy, the participants will continue treatment with belantamab mafodotin, as a monotherapy until the occurrence of PD, intolerable AEs, consent withdrawal, death or end of study.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

153

Conditions

Multiple Myeloma

Interventions

Selected doses of belantamab mafodotin will be administered as an infusion.

LenalidomideDRUG

Lenalidomide will be administered as 25 or 10 mg,orally, with belantamab mafodotin and dexamethasone.

DexamethasoneDRUG

Dexamethasone will be administered as 20 or 40 mg, orally with belantamab mafodotin.

BortezomibDRUG

Bortezomib will be administered as 1.3 mg/m\^2, as SC or IV, with belantamab mafodotin and dexamethasone.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Capable of giving signed informed consent. * Male or female, 18 years or older (at the time consent is obtained). * Have confirmed diagnosis of Multiple Myeloma (MM) as defined by the IMWG. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 for Arm A and 0 to 2 for Arm B. * Have undergone stem cell transplant (SCT), or are considered transplant ineligible. * Have been previously treated with at least 1 prior line of MM therapy, and must have documented disease progression during or after their most recent therapy. * Must have at least ONE aspect of measurable disease, defined as one the following: Urine M-protein excretion \>=200 milligram (mg)/24 hours, or; Serum M-protein concentration \>=0.5 gram (g)/deciliter (dL) (\>=5.0 g/Liter), or; Serum free light chain (FLC) assay: involved FLC level \>=10 mg/dL (\>=100 mg/L) and an abnormal serum FLC ratio (\<0.26 or \>1.65). * Participants with a history of autologous SCT, are eligible for study participation provided the following eligibility criteria are met: Autologous SCT was \>100 days prior to study enrollment; No active bacterial, viral, or fungal infection(s) present; Participant meets the remainder of the eligibility criteria. * All prior treatment-related toxicities (defined by National Cancer Institute Common Toxicity Criteria for Adverse Events \[NCI-CTCAE\], Version 4.03, 2010) must be Grade \<= 1 at the time of enrollment, except for alopecia. Participants with Grade 2 neuropathy can be enrolled into Len/Dex treatment arm, but not into Bor/Dex treatment arm. * Adequate organ system functions as defined by the laboratory assessments. * The contraceptions used by female participants be consistent with local regulations, regarding methods of contraception for those participating in clinical studies. A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: is not a woman of child bearing potential (WOCBP) or Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of \<1% per year), preferably with low user dependency, during the intervention period and for at least 4 months after the last dose of belantamab mafodotin and agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during this period. The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy. WOCBP Participants Assigned to Arm A: * Due to lenalidomide being a thalidomide analogue with risk for embryo-fetal toxicity and prescribed under a pregnancy prevention/controlled distribution program, WOCBP participants will be eligible if they commit either to abstain continuously from heterosexual sexual intercourse or to use two methods of reliable birth control (one method that is highly effective; beginning 4 weeks prior to initiating treatment with lenalidomide, during therapy, during dose interruptions and continuing for 4 weeks following discontinuation of lenalidomide treatment. Thereafter, WOCBP participants must use a contraceptive method that is highly effective (with a failure rate of \<1% per year) for a further 3 months, and agree not to donate eggs (ova, oocytes) for the purpose of reproduction during this period: Two negative pregnancy tests must be obtained prior to initiating lenalidomide therapy. The first test should be performed within 10-14 days and the second test within 24 hours prior to prescribing lenalidomide therapy. WOCBP Participants Assigned to Arm B * WOCBP assigned to Arm B must have a negative highly sensitive serum pregnancy test within 72 hours of dosing on C1D1 and agree to use effective contraception during the study and for 4 months after the last dose of belantamab mafodotin or 7 months from the last dose of bortezomib, whichever is longer. * Male participants using contraception should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. * Male participants are eligible to participate if they agree to the following: Arm A: from the time of first dose of study until 6 months after the last dose of belantamab mafodotin 4 weeks after the last dose of lenalidomide, whichever is longer, to allow for clearance of any altered sperm. Arm B: from the time of first dose of study until 6 months after the last dose of belantamab mafodotin or 4 months from the last dose of bortezomib (whichever is the longer) to allow for clearance of any altered sperm. * Male participants must agree to refrain from donating sperm and either be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent OR Must agree to use contraception/barrier as detailed below. * Agree to use a male condom even if they have undergone a successful vasectomy and female partner to use an additional highly effective contraceptive method with a failure rate of \<1% per year when having sexual intercourse. Male participants should also use a condom with pregnant females. If the female partner of the male participant is pregnant at the time of enrollment, or becomes pregnant during the trial, the male participant must agree to remain abstinent (if it is consistent with their preferred and usual lifestyle) or use a male condom. Exclusion Criteria: * Systemic anti-myeloma therapy (including systemic steroids) within \<=14 days, or plasmapheresis within 7 days prior to the first dose of study drug. * Use of an investigational drug within 14 days or five half-lives (whichever is longer) preceding the first dose of study drug. * Prior treatment with a monoclonal antibody within 30 days of receiving the first dose of study drugs. * Prior allogenic stem cell transplant. Note: Participants who have undergone syngeneic transplant will be allowed only if they have no history and no currently active, graft versus host disease (GvHD). * Evidence of active mucosal or internal bleeding. * Any major surgery within the last four weeks. * 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 are eligible, provided they fulfill criteria. * Any serious and/or unstable pre-existing medical, psychiatric disorder or other conditions (including lab abnormalities) that could interfere with participant's safety, obtaining informed consent or compliance to the study procedures. * Current active liver or biliary disease (with the exception of Gilbert's syndrome or asymptomatic gallstones, or otherwise stable chronic liver disease per investigator's assessment). * Participants with invasive malignancies other than multiple myeloma are excluded, unless the second malignancy has been considered medically stable for at least 2 years. The participant must not be receiving active therapy, other than hormonal therapy for this disease. Note: Participants with curatively treated non-melanoma skin cancer are allowed without a 2-year restriction. * Evidence of cardiovascular risk including any of the following: Evidence of current clinically significant uncontrolled arrhythmias, including clinically significant ECG abnormalities including 2nd degree (Type II) or 3rd degree atrioventricular (AV) block; History of myocardial infarction, acute coronary syndromes (including unstable angina), coronary angioplasty, or stenting or bypass grafting within 3 months of Screening; Class III or IV heart failure as defined by the New York Heart Association functional classification system; Uncontrolled hypertension. * Known immediate or delayed hypersensitivity reaction or idiosyncratic reaction to drugs chemically related to belantamab mafodotin, or any of the components of the study treatment. * Pregnant or lactating female. * Active infection requiring treatment. * Known Human immunodeficiency virus (HIV) infection. * Presence of hepatitis B surface antigen (HBsAg), or hepatitis B core antibody (HBcAb at Screening or within 3 months prior to first dose of study treatment). * Current corneal disease except for mild punctuate keratopathy. * Positive hepatitis C antibody test result or positive hepatitis C Ribonucleic acid (RNA) test result at Screening or within 3 months prior to first dose of study treatment. * Current corneal disease except for mild punctute keratopathy. * Participants Assigned to Treatment A (belantamab mafodotin plus Len/Dex): Participants unable to tolerate antithrombotic prophylaxis must be excluded; Discontinuation of prior treatment with lenalidomide due to intolerable AEs. * Participants Assigned to Treatment B (belantamab mafodotin plus Bor/Dex): Unacceptable AEs from previous bortezomib treatment; Ongoing Grade 2 or higher peripheral neuropathy or neuropathic pain from previous bortezomib treatment; Intolerance or contraindications to anti-viral prophylaxis.

Locations (26)

GSK Investigational Site

Birmingham, Alabama, United States

GSK Investigational Site

Goodyear, Arizona, United States

GSK Investigational Site

Atlanta, Georgia, United States

GSK Investigational Site

Indianapolis, Indiana, United States

GSK Investigational Site

Lansing, Michigan, United States

GSK Investigational Site

St Louis, Missouri, United States

GSK Investigational Site

Grand Island, Nebraska, United States

GSK Investigational Site

Hackensack, New Jersey, United States

GSK Investigational Site

New York, New York, United States

GSK Investigational Site

The Bronx, New York, United States

...and 16 more locations

Outcomes

Primary Outcomes

Number of Participants With Dose Limiting Toxicities (DLTs), Treatment A

DLT is an adverse event (AE) that is considered by the investigator to be clinically relevant and attributed to the study therapy during the 28 day DLT period and meets at least one of the DLT criteria: Grade 3 or greater febrile neutropenia lasting \>48 hours (h) despite adequate treatment; Grade 4 thrombocytopenia \<25,000/mm\^3 accompanied by significant bleeding; any Grade 3 or greater non-hematologic laboratory value (if laboratory abnormality persist \>48 h despite supportive treatment or abnormality leading to hospitalisation); non-hematologic toxicity which does not resolve with appropriate supportive treatment within 48 h, Grade 4 corneal adverse events; and other organ specific toxicities (liver toxicity that causes discontinuation of treatment).

Time frame: Up to 28 days

Number of Participants With DLTs, Treatment B

DLT is an adverse event (AE) that is considered by the investigator to be clinically relevant and attributed to the study therapy during the 21 day DLT period and meets at least one of the DLT criteria: Grade 3 or greater febrile neutropenia lasting \>48 hours (h) despite adequate treatment; Grade 4 thrombocytopenia \<25,000/mm\^3 accompanied by significant bleeding; any Grade 3 or greater non-hematologic laboratory value (if laboratory abnormality persist \>48 h despite supportive treatment or abnormality leading to hospitalisation); non-hematologic toxicity which does not resolve with appropriate supportive treatment within 48 h, Grade 4 corneal adverse events; and other organ specific toxicities (liver toxicity that causes discontinuation of treatment).

Time frame: Up to 21 days

Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. SAE is defined as any untoward medical occurrence that, at any dose results in death, Is life-threatening, Requires inpatient hospitalization or prolongation of existing hospitalization, Results in persistent disability/incapacity or Is a congenital anomaly/birth defect, Other situations which involve medical or scientific judgment or is associated with liver injury and impaired liver function. SAEs are subset of AEs. A summary of number of participants with any AEs and SAEs are presented. AEs were coded using the Medical Dictionary for Regulatory Affairs (MedDRA dictionary).

Time frame: Up to approximately 4.5 years

Number of Participants With Worst-Case Amount of Increase From Baseline Value in Corrected QT Interval Using Fredericia's Formula (QTcF)

12-lead electrocardiogram (ECGs) were obtained using an automated ECG machine that automatically calculated the QTcF intervals. QTc values are categorized into the clinical concern ranges which are specific to changes in QTc: 31-60 milliseconds (msec), and \>60 msec, and \>530msec. An increase is defined relative to Baseline. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits. Data of number of participants with worst-case increase post baseline is presented.

Time frame: Up to approximately 4.5 years

Number of Participants With Worst-case Grade Change From Baseline in Hematology Parameters

Blood samples were collected for analysis of following hematology parameters: Hemoglobin (hemoglobin increased and anemia), Lymphocytes (lymphocyte count increased and lymphocyte count decreased), Neutrophils, Platelets and Leukocytes (leukocytosis and white blood cells decreased). The laboratory parameters were graded according to Common Terminology Criteria for Adverse Events (CTCAE) version (v) 4.03. Grade (G) 1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits. Any worst-case post baseline increases in grade along with any increase to a maximum G3 and a maximum G4 are presented.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Number of Participants With Worst-case Change Post-baseline in Hematology Parameters

Blood samples were collected for the analysis of following hematology parameters: basophils, eosinophils, hematocrit, mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), monocytes, erythrocytes and reticulocyte. The summaries of worst-case change from baseline with respect to normal range was analyzed for only those laboratory tests that were not gradable by CTCAE version 4.03. The number of participants with decreases to low from baseline, changes to normal or no changes from baseline, and increases to high values from baseline have been presented. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Number of Participants With Worst-case Grade Change From Baseline in Clinical Chemistry Parameters

Blood samples were collected for analysis of following clinical chemistry parameters: Hyperglycemia, Hypoglycemia, Albumin, Alkaline Phosphatase, Alanine Aminotransferase (ALT), Aspartate Aminotransferase, (AST), Bilirubin, Creatine Kinase (CK), Creatinine, Gamma Glutamyl Transferase (GGT), Hyperkalemia, Hypokalemia, Hypermagnesemia, Hypomagnesemia, Phosphate, Hypernatremia, Hyponatremia, Urate, Hypercalcemia and Hypocalcemia. Laboratory parameters were graded according to CTCAE v4.03. Grade (G) 1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits. Any worst-case post baseline increases in grade along with any increase to a maximum G3 and a maximum G4 are presented.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Number of Participants With Worst-case Change Post-baseline in Clinical Chemistry Parameters

Blood samples were collected for analysis of following clinical chemistry parameters: Direct Bilirubin (DB), Calcium, Chloride, Carbon Dioxide (CO2), lactate dehydrogenase (LDH) and Protein. The summaries of worst-case change from baseline with respect to normal range was analyzed for only those laboratory tests that were not gradable by CTCAE version 4.03. The number of participants with decreases to low from baseline, changes to normal or no changes from baseline, and increases to high values from baseline have been presented. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Number of Participants With Worst-case Change Post Baseline Urinalysis Results: Occult Blood and Protein

Urine samples were collected to analyze presence of occult blood and protein in urine by dipstick method. Data for worst-case post baseline urinalysis results is presented. Result for urinalysis parameters were recorded as no change/decreased and increase to trace, 1+, 2+, 3+, \>3+ indicating proportional concentrations in the urine sample. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Change From Baseline in Urine Potential of Hydrogen (pH)

Urine samples were collected to analyze urine pH levels. Baseline (Day 1) was defined as latest pre-dose assessment with non-missing value, including unscheduled visits.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Change From Baseline in Urine Specific Gravity

Urine samples were collected to analyze urine specific gravity using dipstick method. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including unscheduled visits.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP)

Blood pressures (DBP and SBP) were measured after resting for at least 5 minutes in a supine or semi-recumbent position. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including unscheduled visits. Change from Baseline was calculated as post-dose visit value minus Baseline value.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Change From Baseline in Vital Signs : Pulse Rate

Pulse rate was measured after resting for at least 5 minutes in a supine or semi-recumbent position. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including unscheduled visits. Change from Baseline was calculated as post-dose visit value minus Baseline value.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Change From Baseline in Vital Signs : Temperature

Temperature was measured after resting for at least 5 minutes in a supine or semi-recumbent position. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including unscheduled visits. Change from Baseline was calculated as post-dose visit value minus Baseline value.

Time frame: Baseline (Day 1) and up to approximately 4.5 years

Overall Response Rate (ORR) as Defined by the International Myeloma Working Group (IMWG) Uniform Response Criteria for Multiple Myeloma (MM)

ORR was defined as the percentage of participants with a confirmed partial response (PR) or better (i.e., PR, very good partial response \[VGPR\], complete response \[CR\] and stringent complete response \[sCR\]), according to the International Myeloma Working Group (IMWG) Response Criteria. CR: negative immunofixation of serum and urine and disappearance of any soft tissue plasmacytomas and \<5% plasmacytomas in the bone marrow; sCR: stringent complete response, CR as above plus normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence; VGPR: 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; PR: \>=50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by \>=90% or to \<200 mg/24 h. Confidence intervals were based on the exact method.

Time frame: Up to approximately 4.5 years

Secondary Outcomes

Maximum Observed Concentration (Cmax) for Belantamab Mafodotin Antibody-drug Conjugate (ADC), Treatment A

Blood samples were collected at indicated timepoints for pharmacokinetic (PK) analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 hours post-dose on Cycle 1 Day 1 and Cycle 1 Day 8

Area Under the Concentration Time Curve (AUC) From Time 0 to 504 Hours (0-504h) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21

AUC (0-672h) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21; Cycle 1 Day 28

Time to Reach Maximum Observed Concentration (Tmax) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 8

Time of Last Observed Quantifiable Concentration (Tlast) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods. Tlast is the time of last observed quantifiable concentration of belantamab mafodotin in Cycle 1 which extended beyond protocol defined duration for some participants across treatment groups.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21; Cycle 1 Day 29; pre-dose Cycle 2 Day 28

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.

Trough Concentration Prior to the Next Dose for Each Cycle (Ctrough) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Cycle 1: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Days 1 and 8; Weeks 5, 9, and 13: Pre-Dose and Post-Dose on Days 1 and 8

Observed Plasma Concentration at the End of Infusion (C-EOI) for Belantamab Mafodotin ADC, Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Cycle 1: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Days 1 and Day 8; Weeks 5, 9, and 13: Pre-Dose and Post-Dose on Days 1 and 8

Cmax for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 8

AUC (0-504h) for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 21

AUC (0-1008h) for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods. AUC(0-1008h) was derived only for Belantamab mafodotin 1.9 mg/kg STRETCH + Bor/Dex, Belantamab mafodotin 2.5 mg/kg StepDown STRETCH + Bor/Dex and Belantamab mafodotin 2.5 mg/kg STRETCH + Bor/Dex cohorts.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 11; Cycle 1 Day 22; Pre-Dose and Post-Dose on Week 5 Day 7

Tmax for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 8

Tlast for Belantamab Mafodotin ADC, Treatment B

Time frame: Pre-Dose Cycle 1 Day 1 to pre-dose Cycle 5 Day 1

Ctrough for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, Post-Dose 0, 2 and 24 Hour on Cycle 1 Day 1 and Cycle 1 Day 8; Pre-Dose and Post-Dose on Week 4 Day 1, Week 7 Day 1, Week 10 Day 1, Week 13 Day 1, Week 13 Day 8

C-EOI for Belantamab Mafodotin ADC, Treatment B

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, Post-Dose 0, 2 and 24 Hour on Cycle 1 Day 1 and Cycle 1 Day 8; Pre-Dose and Post-Dose on Week 4 Day 1, Week 7 Day 1, Week 7 Day 8, Week 7 Day 11, Week 10 Day 1, Week 10 Day 8, Week 13 Day 1, Week 13 Day 8

Cmax for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 8

AUC (0-504h) for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21

AUC (0-672h) for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21; Cycle 1 Day 28

AUC (0-1008h) for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods. AUC(0-1008) was derived only for Belantamab mafodotin 1.9mg/kg + Len/Dex STRETCH cohort.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 29; Pre-Dose and Post-Dose on Week 5 Day 7

AUC(0-1344h) for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods. AUC(0-1344) was derived only for Belantamab mafodotin 1.9mg/kg + Len/Dex STRETCH cohort.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1; Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 29; Pre-Dose and Post-Dose on Week 7 Day 7

Tmax for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 8

Tlast for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected for PK analysis. PK parameter was determined using standard non-compartmental methods. Tlast is the time of last observed quantifiable concentration of belantamab mafodotin in Cycle 1 which extended beyond protocol defined duration for some participants across treatment groups.

Time frame: Pre-Dose, 0, 2 and 24 Hours Post-Dose on Cycle 1 Day 1 and Cycle 1 Day 4; Cycle 1 Day 8; Cycle 1 Day 11; Cycle 1 Day 15-21; Cycle 1 Day 29; pre-dose Cycle 2 Day 28; pre-dose Cycle 3 Day 8

Ctrough for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, Post-Dose 0, 2 and 24 Hour on Cycle 1 Day 1 and Cycle 1 Day 8; Pre-Dose and Post-Dose on Week 5 Day 1, Week 5 Day 8, Week 9 Day 1, Week 9 Day 8, Week 13 Day 1, Week 13 Day 8

C-EOI for Belantamab Mafodotin (Total Antibody), Treatment A

Blood samples were collected at indicated timepoints for PK analysis. PK parameter was determined using standard non-compartmental methods.

Time frame: Pre-Dose, Post-Dose 0, 2 and 24 Hour on Cycle 1 Day 1 and Cycle 1 Day 8; Pre-Dose and Post-Dose on Week 5 Day 1, Week 5 Day 8, Week 9 Day 1, Week 9 Day 8, Week 13 Day 1, Week 13 Day 8

Cmax for Belantamab Mafodotin (Total Antibody) Treatment B