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Letetresgene Autoleucel Engineered T Cells Alone and in Combination With Pembrolizumab in NY-ESO-1 Positive Multiple Myeloma

Open-Label Pilot Study to Assess the Safety, Tolerability and Antitumor Activity of Genetically Engineered NY-ESO-1 Specific (c259) T Cells Alone or in Combination With Pembrolizumab in HLA-A2+ Subjects With NY-ESO-1 and/or LAGE-1a Positive Relapsed and Refractory Multiple Myeloma

Status
Terminated
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03168438
Enrollment
6
Registered
2017-05-30
Start date
2017-08-18
Completion date
2020-11-05
Last updated
2022-01-11

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

Conditions

Neoplasms

Keywords

Relapsed and Refractory Multiple Myeloma, T Cell Receptor, Immuno-oncology, NY-ESO-1, Leukapheresis, Adoptive TCR T-cell therapy, Letetresgene autoleucel

Brief summary

This trial will evaluate safety, tolerability, and efficacy of letetresgene autoleucel (GSK3377794) with or without pembrolizumab in participants with relapsed and refractory multiple myeloma.

Interventions

Letetresgene autoleucel (GSK3377794) as an IV infusion

DRUGLetetresgene autoleucel with pembrolizumab

Letetresgene autoleucel (GSK3377794) as an IV infusion, followed by pembrolizumab every 3 weeks

DRUGFludarabine

Fludarabine will be used as lymphodepleting chemotherapy and will be administered via IV route.

DRUGCyclophosphamide

Cyclophosphamide will be used as lymphodepleting chemotherapy and will be administered via IV route.

DRUGPembrolizumab

Pembrolizumab is available as an IV infusion

Sponsors

Merck Sharp & Dohme LLC
CollaboratorINDUSTRY
GlaxoSmithKline
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Age \>=18 years of age or older on the date of signing informed consent. * Histologically confirmed diagnosis of secretory multiple myeloma with myeloma markers at levels defined in the protocol. * Documented diagnosis of relapsed and refractory multiple myeloma (RRMM) (at least 3 prior regimens and responsive to at least 1, and refractory to most recent prior therapies, which must have included one or more than one drug from each of the following drug classes: an immunomodulatory imide drug (IMiD), proteasome inhibitor, alkylator (unless the participant is ineligible or contraindicated to receive an alkylator), CD 38 monoclonal antibody, and glucocorticoid as separate lines or a combined line of therapy.- Left ventricular ejection fraction (LVEF) \>= 50%. Lower LVEF (\>= 40%) permissible if formal cardiologic evaluation reveals no evidence for clinically significant functional impairment. * Meets protocol criteria for patients who have previously received checkpoint inhibitors or other immuno-oncology agents. * ECOG Performance Status 0 or 1. * Participant is HLA-A\*02:01, HLA-A\*02:05, and/or HLA-A\*02:06 positive as determined by a designated central laboratory. * Participant has confirmed sufficient expression of NY-ESO-1 and/or LAGE-1a as determined by a designated central laboratory. * In the Investigator's opinion, the participant is fit for cell collection. * Participant has adequate organ function and cell counts as described in the protocol. * Participants previously treated with BCMA therapy (BCMA chimeric antigen receptor (CAR)-T, antibody-drug conjugate (ADC), or other type of BCMA-targeted therapy) must have progressed from this therapy prior to attending the Baseline visit prior to beginning lymphodepletion. * Contraception use by male and female participant meets protocol requirements.

Exclusion criteria

* Has only plasmacytomas, plasma cell leukemia, monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), non-secretory myeloma or primarily amyloidosis. * Previously received anti- programmed death (PD)-1, anti-PD-ligand (L)1, or anti-PD-L2 inhibitor. * Previously participated in Merck pivotal trial NCT02576977: Study of Pomalidomide and Low Dose Dexamethasone With or Without Pembrolizumab in Refractory or RRMM. * Had a prior allogeneic stem cell transplant. * Has ongoing toxicity from previous anticancer therapy. * Had a major surgery within 4 weeks prior to enrollment. * Has history of allergic reactions to fludarabine, cyclophosphamide or agents similar to fludarabine, cyclophosphamide or other agents used in the study. * Known history of myelodysplasia. * Current active liver or biliary disease. * Known history of chronic active hepatitis or liver cirrhosis. * Participant has an active viral infection. * History of severe immune disease, including non-infectious pneumonitis, requiring steroids or other immunosuppressive treatments. * Active immune-mediated diseases. * Prior or active demyelinating disease. * Evidence or history of significant cardiac disease. * Evidence or history of other significant, hepatic, renal, ophthalmologic, psychiatric, or gastrointestinal disease. * Participants with concomitant second malignancies (except adequately treated non-melanomatous skin cancers, carcinoma in situ of the breast, treated superficial bladder cancer or prostate cancer, or in situ cervical cancers ) not in complete remission. * Known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Participants with previously treated brain metastases may be eligible. * Active bacterial or systemic viral or fungal infections. * Pregnant or breastfeeding. * Cannot meet washout periods for prior radiotherapy, chemotherapy or other protocol-specified therapies. * More than 2 years have passed since the participant's last leukapheresis collection.

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Up to 108 weeksAn AE is any untoward medical occurrence in a participant or clinical investigation participant who received a study treatment and the event need not necessarily have a causal relationship with study treatment. An SAE is any AE that results in death; is life-threatening; requires hospitalization or prolongation of existing hospitalization; results in a persistent or significant disability; is a congenital anomaly/birth defect; is clinically significant or requires intervention to prevent one of the outcomes listed before.
Number of Participants With Treatment Limiting Toxicities-GSK3377794+Pembrolizumab Arm OnlyUp to 3 weeksThe following toxicities were considered to be treatment limiting toxicities: any \>=Grade 4 AE; Grade 3 non-infectious pneumonitis and any other Grade 3 AE (excluding pneumonitis), that did not improve to Grade 2 within 7 days after onset despite medical management and supportive care. Exceptions included the following: Grade 3 or 4 leukopenia, lymphopenia, neutropenia, or febrile neutropenia; Grade 3 or 4 thrombocytopenia not associated with significant bleeding; Grade 3 anemia; Grade 4 cytokine release syndrome (CRS) or toxicities related to CRS that resolved to Grade \<=2 within 7 days; other Grade 3 laboratory abnormality determined to be not clinically significant by the Investigator; Grade 3 or 4 fever and chills; Grade 3 or 4 hypoalbuminemia or abnormal electrolytes that responded to supplementation/correction; AE related to the cancer or its progression.
Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineUp to 108 weeksBlood samples were collected for the assessment of following clinical chemistry parameters: glucose, albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, potassium, magnesium, phosphate, sodium and calcium. Laboratory parameters were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.
Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineUp to 108 weeksBlood samples were collected for the assessment of following hematology parameters: hemoglobin, lymphocytes, neutrophils, platelets and leukocytes. Laboratory parameters were graded according to NCI-CTCAE version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.
Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselineUp to 108 weeksBlood samples were collected for the assessment of following coagulation parameters: prothrombin time and partial thromboplastin time (PTT). A laboratory value that is outside the normal range is considered either high abnormal (value above the upper limit of the normal range) or low abnormal (value below the lower limit of the normal range). Participants were counted twice if the participant had values in 'Decreased to low' and 'Increased to high' during the post-Baseline period. Data for worst case post Baseline is presented.
Number of Participants With Worst-case Post Baseline Abnormal Electrocardiogram (ECG) FindingsUp to 108 weeksECG was recorded using an ECG machine that automatically calculated the heart rate and measured PR, RR, QRS and QT duration corrected for heart rate by Fridericia's formula (QTcF) intervals. Data for number of participants with abnormal clinically significant ECG findings for worst case post-Baseline has been presented. Clinically significant abnormal laboratory findings are those which are not associated with the underlying disease, unless judged by the investigator to be more severe than expected for the participant's condition.

Secondary

MeasureTime frameDescription
Overall Response RateUp to 108 weeksOverall response rate is defined as the percentage of participants with a best overall response (BOR) of confirmed stringent complete response (sCR), complete response (CR), very good partial response (VGPR), or partial response (PR) per International Myeloma Working Group (IMWG) Response Criteria (2016); where, PR: \>=50% reduction of serum M-Protein and reduction in 24-hour urinary M-protein by \>=90% or to \<200 milligrams (mg) per 24 hours; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or 90% or greater reduction in serum M-protein plus urine M-protein level \<100 mg per 24 hours; CR: Negative immunofixation on the serum and urine and disappearance of any soft tissue plasmacytomas and \<= 5% plasma cells in bone marrow; or sCR: CR as defined by normal free light chain (FLC) ratio and absence of clonal cells by immunohistochemistry. Confidence intervals were calculated using the exact (Clopper-Pearson) method.
Area Under the Plasma Concentration-time Curve From Zero to Day 28 (AUC[0-28])Up to Day 28Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.
Time to ResponseUp to 108 weeksTime to response is defined as the time interval (in months) from T-cell infusion to initial date of documented confirmed response (PR or better) in the subset of participants who showed a confirmed BOR of PR or better by Investigator assessment per IMWG (2016).
Duration of ResponseUp to 108 weeksDuration of response is defined as the interval between the initial date of the confirmed response (sCR, CR, VGPR, or PR) and the initial assesment date of confirmed progressive disease or death among participants with a confirmed response per IMWG (2016).
Progression-free SurvivalUp to 108 weeksProgression Free Survival is defined as the interval between the date of T-cell infusion and the initial assessment date of confirmed progressive disease as assessed by the investigator per IMWG (2016) or date of death. Progressive disease is defined as an increase of 25% from lowest confirmed response value in 1 or more of the following criteria: Serum M-protein with absolute increase of \>=0.5 grams per deciliter (g/dL); Serum M-protein increase \>=1 g/dL if the lowest M-component was \>=5 g/dL; Urinary M-protein (absolute increase must be \>=200 mg per 24 hours).
Maximum Persistence (Cmax) of GSK3377794Up to 108 weeksBlood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in deoxyribonucleic acid (DNA) extracted from peripheral blood mononuclear cell (PBMC).
Time to Maximum PersistenceUp to 108 weeksBlood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.

Countries

United States

Participant flow

Recruitment details

This was a pilot study to assess safety and tolerability of genetically engineered New York esophageal squamous cell carcinoma 1 (NY-ESO-1) (c259) T Cells Alone or in combination with pembrolizumab in participants with relapsed/refractory multiple myeloma. The study was conducted in the United States.

Pre-assignment details

A total of 127 participants were screened of which 6 participants were enrolled in the study. The study was terminated due to challenging screening and enrollment combined with a rapidly changing treatment landscape.

Participants by arm

ArmCount
GSK3377794
Eligible participants underwent leukapheresis to manufacture engineered T-cells. Participants then underwent lymphodepleting chemotherapy with cyclophosphamide and fludarabine followed by a single intravenous (IV) infusion of GSK3377794.
3
GSK3377794+Pembrolizumab
Eligible participants underwent leukapheresis to manufacture engineered T-cells. Participants then underwent lymphodepleting chemotherapy with cyclophosphamide and fludarabine followed by a single IV infusion of GSK3377794 in combination with pembrolizumab 200 milligrams (mg) administered as an IV infusion every 3 weeks up to Week 108.
3
Total6

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLong term follow-up declined, study terminated by sponsor01

Baseline characteristics

CharacteristicGSK3377794GSK3377794+PembrolizumabTotal
Age, Continuous66.0 Years
STANDARD_DEVIATION 11.27
64.3 Years
STANDARD_DEVIATION 2.52
65.2 Years
STANDARD_DEVIATION 7.36
Race/Ethnicity, Customized
White
3 Participants3 Participants6 Participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
3 Participants3 Participants6 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
2 / 30 / 3
other
Total, other adverse events
3 / 33 / 3
serious
Total, serious adverse events
2 / 32 / 3

Outcome results

Primary

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

An AE is any untoward medical occurrence in a participant or clinical investigation participant who received a study treatment and the event need not necessarily have a causal relationship with study treatment. An SAE is any AE that results in death; is life-threatening; requires hospitalization or prolongation of existing hospitalization; results in a persistent or significant disability; is a congenital anomaly/birth defect; is clinically significant or requires intervention to prevent one of the outcomes listed before.

Time frame: Up to 108 weeks

Population: Intent-To-Treat (ITT) Population comprised of all participants who underwent leukapheresis

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Any AE3 Participants
GSK3377794Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Any SAE2 Participants
GSK3377794+PembrolizumabNumber of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Any AE3 Participants
GSK3377794+PembrolizumabNumber of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)Any SAE2 Participants
Primary

Number of Participants With Treatment Limiting Toxicities-GSK3377794+Pembrolizumab Arm Only

The following toxicities were considered to be treatment limiting toxicities: any \>=Grade 4 AE; Grade 3 non-infectious pneumonitis and any other Grade 3 AE (excluding pneumonitis), that did not improve to Grade 2 within 7 days after onset despite medical management and supportive care. Exceptions included the following: Grade 3 or 4 leukopenia, lymphopenia, neutropenia, or febrile neutropenia; Grade 3 or 4 thrombocytopenia not associated with significant bleeding; Grade 3 anemia; Grade 4 cytokine release syndrome (CRS) or toxicities related to CRS that resolved to Grade \<=2 within 7 days; other Grade 3 laboratory abnormality determined to be not clinically significant by the Investigator; Grade 3 or 4 fever and chills; Grade 3 or 4 hypoalbuminemia or abnormal electrolytes that responded to supplementation/correction; AE related to the cancer or its progression.

Time frame: Up to 3 weeks

Population: ITT Population. Treatment limiting toxicities were assessed in GSK3377794+pembrolizumab arm only.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Treatment Limiting Toxicities-GSK3377794+Pembrolizumab Arm Only0 Participants
Primary

Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to Baseline

Blood samples were collected for the assessment of following clinical chemistry parameters: glucose, albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, potassium, magnesium, phosphate, sodium and calcium. Laboratory parameters were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.

Time frame: Up to 108 weeks

Population: Modified ITT Population comprised of all participants in the ITT Population who received the NY-ESO-1c259T infusion.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineGlucose (Hypoglycemia)0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePotassium (Hypokalemia)1 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineAST increased0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineMagnesium (Hypermagnesemia)0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineALP increased1 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineMagnesium (Hypomagnesemia)2 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineBilirubin increased0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePhosphate (Hypophosphatemia)2 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineAlbumin (Hypoalbuminemia)3 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineSodium (Hypernatremia)0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCreatinine increased1 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineSodium (Hyponatremia)2 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineALT increased0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCalcium (Hypercalcemia)1 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePotassium (Hyperkalemia)0 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCalcium (Hypocalcemia)2 Participants
GSK3377794Number of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineGlucose (Hyperglycemia)2 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCalcium (Hypocalcemia)3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineGlucose (Hyperglycemia)2 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineGlucose (Hypoglycemia)0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineAlbumin (Hypoalbuminemia)2 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineALP increased1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineALT increased1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineAST increased1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineBilirubin increased1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCreatinine increased3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePotassium (Hyperkalemia)0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePotassium (Hypokalemia)2 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineMagnesium (Hypermagnesemia)0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineMagnesium (Hypomagnesemia)1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselinePhosphate (Hypophosphatemia)2 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineSodium (Hypernatremia)0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineSodium (Hyponatremia)1 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Chemistry Results by Any Grade Increase Post-Baseline Relative to BaselineCalcium (Hypercalcemia)0 Participants
Primary

Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to Baseline

Blood samples were collected for the assessment of following hematology parameters: hemoglobin, lymphocytes, neutrophils, platelets and leukocytes. Laboratory parameters were graded according to NCI-CTCAE version 4.03 where, Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. An increase in grade is defined as an increase in CTCAE grade relative to Baseline grade. Data for any grade increase at worst case post Baseline is presented.

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLeukocyte count decreased3 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineHemoglobin (Anemia)2 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineHemoglobin increased0 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLymphocyte count decreased3 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLymphocyte count increased0 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineNeutrophil count decreased3 Participants
GSK3377794Number of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselinePlatelet count decreased3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLeukocyte count decreased3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLymphocyte count increased0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineHemoglobin (Anemia)3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselinePlatelet count decreased3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineHemoglobin increased0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineNeutrophil count decreased3 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Hematology Results by Any Grade Increase Post-Baseline Relative to BaselineLymphocyte count decreased3 Participants
Primary

Number of Participants With Worst-case Post Baseline Abnormal Electrocardiogram (ECG) Findings

ECG was recorded using an ECG machine that automatically calculated the heart rate and measured PR, RR, QRS and QT duration corrected for heart rate by Fridericia's formula (QTcF) intervals. Data for number of participants with abnormal clinically significant ECG findings for worst case post-Baseline has been presented. Clinically significant abnormal laboratory findings are those which are not associated with the underlying disease, unless judged by the investigator to be more severe than expected for the participant's condition.

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Worst-case Post Baseline Abnormal Electrocardiogram (ECG) Findings0 Participants
GSK3377794+PembrolizumabNumber of Participants With Worst-case Post Baseline Abnormal Electrocardiogram (ECG) Findings1 Participants
Primary

Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to Baseline

Blood samples were collected for the assessment of following coagulation parameters: prothrombin time and partial thromboplastin time (PTT). A laboratory value that is outside the normal range is considered either high abnormal (value above the upper limit of the normal range) or low abnormal (value below the lower limit of the normal range). Participants were counted twice if the participant had values in 'Decreased to low' and 'Increased to high' during the post-Baseline period. Data for worst case post Baseline is presented.

Time frame: Up to 108 weeks

Population: Modified ITT Population. Only those participants with data available at the specified time point is reported

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselineProthrombin Time; decrease to low0 Participants
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselineProthrombin Time; To normal or no change0 Participants
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselineProthrombin Time; increase to high1 Participants
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselinePTT; decrease to low0 Participants
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselinePTT; To normal or no change1 Participants
GSK3377794Number of Participants With Worst-case Results for Coagulation Parameters Relative to Normal Range Post-Baseline Relative to BaselinePTT; increase to high0 Participants
Secondary

Area Under the Plasma Concentration-time Curve From Zero to Day 28 (AUC[0-28])

Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.

Time frame: Up to Day 28

Population: Modified ITT Population

ArmMeasureValue (GEOMETRIC_MEAN)Dispersion
GSK3377794Area Under the Plasma Concentration-time Curve From Zero to Day 28 (AUC[0-28])463989.35 Days*Copies per microgram genomic DNAGeometric Coefficient of Variation 237
GSK3377794+PembrolizumabArea Under the Plasma Concentration-time Curve From Zero to Day 28 (AUC[0-28])1498869.21 Days*Copies per microgram genomic DNAGeometric Coefficient of Variation 90.4
Secondary

Duration of Response

Duration of response is defined as the interval between the initial date of the confirmed response (sCR, CR, VGPR, or PR) and the initial assesment date of confirmed progressive disease or death among participants with a confirmed response per IMWG (2016).

Time frame: Up to 108 weeks

Population: Modified ITT Population. Only those participants with a confirmed response per IMWG 2016 were analyzed.

ArmMeasureValue (MEDIAN)
GSK3377794Duration of Response2.1 Months
GSK3377794+PembrolizumabDuration of Response2.1 Months
Secondary

Maximum Persistence (Cmax) of GSK3377794

Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in deoxyribonucleic acid (DNA) extracted from peripheral blood mononuclear cell (PBMC).

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureValue (GEOMETRIC_MEAN)Dispersion
GSK3377794Maximum Persistence (Cmax) of GSK337779438509.67 Copies per microgram genomic DNAGeometric Coefficient of Variation 160.5
GSK3377794+PembrolizumabMaximum Persistence (Cmax) of GSK337779489640.56 Copies per microgram genomic DNAGeometric Coefficient of Variation 84.8
Secondary

Overall Response Rate

Overall response rate is defined as the percentage of participants with a best overall response (BOR) of confirmed stringent complete response (sCR), complete response (CR), very good partial response (VGPR), or partial response (PR) per International Myeloma Working Group (IMWG) Response Criteria (2016); where, PR: \>=50% reduction of serum M-Protein and reduction in 24-hour urinary M-protein by \>=90% or to \<200 milligrams (mg) per 24 hours; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or 90% or greater reduction in serum M-protein plus urine M-protein level \<100 mg per 24 hours; CR: Negative immunofixation on the serum and urine and disappearance of any soft tissue plasmacytomas and \<= 5% plasma cells in bone marrow; or sCR: CR as defined by normal free light chain (FLC) ratio and absence of clonal cells by immunohistochemistry. Confidence intervals were calculated using the exact (Clopper-Pearson) method.

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureValue (NUMBER)
GSK3377794Overall Response Rate33.3 Percentage of participants
GSK3377794+PembrolizumabOverall Response Rate66.7 Percentage of participants
Secondary

Progression-free Survival

Progression Free Survival is defined as the interval between the date of T-cell infusion and the initial assessment date of confirmed progressive disease as assessed by the investigator per IMWG (2016) or date of death. Progressive disease is defined as an increase of 25% from lowest confirmed response value in 1 or more of the following criteria: Serum M-protein with absolute increase of \>=0.5 grams per deciliter (g/dL); Serum M-protein increase \>=1 g/dL if the lowest M-component was \>=5 g/dL; Urinary M-protein (absolute increase must be \>=200 mg per 24 hours).

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureValue (MEDIAN)
GSK3377794Progression-free Survival2.79 Months
GSK3377794+PembrolizumabProgression-free Survival2.78 Months
Secondary

Time to Maximum Persistence

Blood samples were collected to measure persistence of infused GSK3377794 using polymerase chain reaction of a vector specific sequence in DNA extracted from PBMC.

Time frame: Up to 108 weeks

Population: Modified ITT Population

ArmMeasureValue (MEDIAN)
GSK3377794Time to Maximum Persistence8.0 Days
GSK3377794+PembrolizumabTime to Maximum Persistence8.0 Days
Secondary

Time to Response

Time to response is defined as the time interval (in months) from T-cell infusion to initial date of documented confirmed response (PR or better) in the subset of participants who showed a confirmed BOR of PR or better by Investigator assessment per IMWG (2016).

Time frame: Up to 108 weeks

Population: Modified ITT Population. Only those participants with a confirmed response per IMWG 2016 were analyzed.

ArmMeasureValue (MEDIAN)
GSK3377794Time to Response0.7 Months
GSK3377794+PembrolizumabTime to Response0.7 Months

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026