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Boserolimab

Phase 1

Pharmacokinetics | Small molecule | Oncology |Merck & Company, Inc.|Last Updated: Nov 5, 2025

Success Probability

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Market & Valuation

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Trial Design

RandomizedCONTROLLED
Total Trials1
Total Enrollment182

FDA Designations

No designations recorded

Clinical trial landscape

Boserolimab · 1 trial · 4 indications

Phase 1 1
NCT03396445Study of Boserolimab (MK-5890) as Monotherapy and in Combination With Pembrolizumab (MK-3475) in Adults With Advanced Solid Tumors (MK-5890-001)Pharmacokinetics
COMPLETED182 Analytics
PHASE1COMPLETED
Study of Boserolimab (MK-5890) as Monotherapy and in Combination With Pembrolizumab (MK-3475) in Adults With Advanced Solid Tumors (MK-5890-001)
PharmacokineticsUnlock trial analytics

Study Endpoints

Primary Endpoints

Number of Participants Who Experienced a Dose-Limiting Toxicity (DLT)
Up to 21 days in Cycle 1

DLTs were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 5. A DLT was defined as any of the following events: Grade 4 nonhematologic toxicity; Grade 4 hematologic toxicity lasting ≥7 days, except thrombocytopenia; Grade 4 thrombocytopenia; Grade 3 thrombocytopenia requiring a platelet transfusion; Nonhematologic adverse event (AE) Grade ≥3, with exceptions; Grade 3 or 4 nonhematologic laboratory abnormality; Prolonged delay (\>2 weeks) in initiating Cycle 2 due to treatment-related toxicity; Treatment-related toxicity resulting in study drug discontinuation during the DLT evaluation period; Missing \>25% of any study drug during the DLT evaluation period due to a treatment-related AE; or Grade 5 toxicity. The number of participants who experienced one or more DLTs is reported.

Number of Participants With One or More AEs
Up to approximately 78 months

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who experienced one or more AEs is reported.

Number of Participants Who Discontinued Study Treatment Due to an AE
Up to 23 months

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who discontinued study treatment due to an AE is reported.

Secondary Endpoints

Area Under the Concentration-Time Curve From Time 0 to Last Quantifiable Concentration (AUC0-last) of Boserolimab
Predose Day 1 Cycle 1 and at designated timepoints up to Day 1 Cycle 2
Area Under the Concentration-Time Curve From Time 0 to 3 Weeks (AUC0-3w) of Boserolimab
Predose Day 1 Cycle 1 and at designated timepoints up to Day 1 Cycle 2
Area Under the Concentration-Time Curve From Time 0 to 6 Weeks (AUC0-6w) of Boserolimab
Arms 2c and 4 (Cycle = 6 weeks): Predose, at start & end of infusion on Day 1 Cycle 1, Days 2, 3, 8, 15, 22 of Cycle 1, and predose on Day 1 Cycle 2
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Study Design & Arms

AllocationRANDOMIZED
MaskingNONE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Arm 1 Boserolimab 2 mg Q3WEXPERIMENTALParticipants receive boserolimab 2 mg via intravenous (IV) infusion once every 3 weeks (Q3W) on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1 Boserolimab 7 mg Q3WEXPERIMENTALParticipants receive boserolimab 7 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1 Boserolimab 20 mg Q3WEXPERIMENTALParticipants receive boserolimab 20 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1 Boserolimab 70 mg Q3WEXPERIMENTALParticipants receive boserolimab 70 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1 Boserolimab 200 mg Q3WEXPERIMENTALParticipants receive boserolimab 200 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1 Boserolimab 700 mg Q3WEXPERIMENTALParticipants receive boserolimab 700 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 1a Boserolimab 30 mg Q3W (Endometrial)EXPERIMENTALParticipants with endometrial cancer receive boserolimab 30 mg via IV infusion once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2 Boserolimab 2 mg Q3W + Pembrolizumab 200 mg Q3WEXPERIMENTALParticipants receive separate IV infusions of boserolimab 2 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2 Boserolimab 7 mg Q3W + Pembrolizumab 200 mg Q3WEXPERIMENTALParticipants receive separate IV infusions of boserolimab 7 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2 Boserolimab 20 mg Q3W + Pembrolizumab 200 mg Q3WEXPERIMENTALParticipants receive separate IV infusions of boserolimab 20 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2 Boserolimab 70 mg Q3W + Pembrolizumab 200 mg Q3WEXPERIMENTALParticipants receive separate IV infusions of boserolimab 70 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2 Boserolimab 200 mg Q3W + Pembrolizumab 200 mg Q3WEXPERIMENTALParticipants receive separate IV infusions of boserolimab 200 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2a Boserolimab 30 mg Q3W + Pembrolizumab 200 mg Q3W (TNBC)EXPERIMENTALParticipants with triple-negative breast cancer (TNBC) receive separate IV infusions of boserolimab 30 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2b Boserolimab 30 mg Q3W + Pembrolizumab 200 mg Q3W (Endometrial)EXPERIMENTALParticipants with endometrial cancer receive separate IV infusions of boserolimab 30 mg and pembrolizumab 200 mg. Boserolimab and pembrolizumab are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Each cycle is 3 weeks long.
Arm 2c Boserolimab 30 mg Q6W + Pembrolizumab 400 mg Q6W (Endometrial)EXPERIMENTALParticipants with endometrial cancer receive separate IV infusions of boserolimab 30 mg and pembrolizumab 400 mg. Boserolimab was administered once every 6 weeks (Q6W) on Day 1 of each cycle for a total of up to approximately 4 cycles (up to approximately 6 months). Pembrolizumab is administered once Q6W on Day 1 of each cycle for a total of up to approximately 18 cycles (up to approximately 27 months). Each cycle is 6 weeks long.
Arm 3 Boserolimab 30 mg Q3W + Pembrolizumab 200 mg Q3W + Pemetrexed + Carboplatin (NSCLC)EXPERIMENTALParticipants with non-small cell lung cancer (NSCLC) receive separate IV infusions of boserolimab 30 mg, pembrolizumab 200 mg, pemetrexed 500 mg/m\^2, and carboplatin area under the curve (AUC) 5 mg/mL/min. Boserolimab is administered once Q3W on Day 1 of each cycle for a total of up to approximately 8 cycles (up to approximately 6 months). Pembrolizumab and pemetrexed are administered once Q3W on Day 1 of each cycle for a total of up to approximately 35 cycles (up to approximately 2 years). Carboplatin is administered once Q3W on Day 1 of each cycle for a total of up to approximately 4 cycles (up to approximately 3 months). Each cycle is 3 weeks long.
Arm 4 Boserolimab 30 mg Q6W + Pembrolizumab 400 mg Q6W + Nab-paclitaxel (TNBC)EXPERIMENTALParticipants with TNBC receive separate IV infusions of boserolimab 30 mg, pembrolizumab 400 mg, and nab-paclitaxel 100 mg/m\^2. Boserolimab and pembrolizumab are administered once Q6W on Day 1 of each cycle for a total of up to approximately 18 cycles (up to approximately 27 months). Nab-paclitaxel is administered on a 3-weeks on/1-week off schedule every 28 days (Days 1, 8, 15, 29, and 36 of odd-numbered cycles and Days 1, 15, 22, and 29 of even-numbered cycles). Each cycle is 6 weeks long

Interventions

NameTypeDescription
BoserolimabDRUGIV infusion
PembrolizumabBIOLOGICALIV infusion
PemetrexedDRUGIV infusion
CarboplatinDRUGIV infusion
Nab-paclitaxelDRUGIV infusion
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites18

Inclusion Criteria: * Arms 1 \& 2: Histologically or cytologically confirmed advanced/metastatic solid tumor by pathology report and has received or been intolerant to all treatment known to confer clinical benefit * Arm 3: Histologically or cytologically confirmed diagnosis of stage IV (M1a or M1b...

Countries:United StatesChileIsraelNetherlandsSouth KoreaSpainTaiwan
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Frequently asked questions about Boserolimab

What is Boserolimab used for?

Boserolimab is an investigational small molecule antibody being studied for pharmacokinetics in oncology. A Phase 1 trial evaluated it as a monotherapy and in combination with pembrolizumab in adults with advanced solid tumors, including non-small-cell lung cancer and triple negative breast cancer.

What does Boserolimab target?

Boserolimab is a monoclonal antibody, indicated by its -mab suffix, but its specific molecular target is not disclosed in the available information. The drug is being studied for its pharmacokinetic profile in oncology settings.

Who makes Boserolimab?

Boserolimab is being developed by Merck & Company, Inc., traded on the New York Stock Exchange under the ticker MRK. The company conducted a Phase 1 clinical trial of the drug in advanced solid tumors.

What phase is Boserolimab in?

Boserolimab is in Phase 1 clinical development. The single completed Phase 1 trial, NCT03396445, enrolled 182 participants and evaluated the drug as monotherapy and in combination with pembrolizumab in adults with advanced solid tumors.

What clinical trials is Boserolimab in?

Boserolimab has one completed clinical trial, NCT03396445, titled 'Study of Boserolimab (MK-5890) as Monotherapy and in Combination With Pembrolizumab (MK-3475) in Adults With Advanced Solid Tumors (MK-5890-001)'. The Phase 1 trial enrolled 182 participants across the United States, Chile, Israel, Netherlands, South Korea, Spain, and Taiwan.

Is Boserolimab the same as MK-5890?

Yes, Boserolimab is also known as MK-5890. The clinical trial NCT03396445 refers to the drug as Boserolimab (MK-5890) and studies it as monotherapy and in combination with pembrolizumab (MK-3475) in advanced solid tumors.