A Phase 2 Study of Petosemtamab in Combination with Pembrolizumab in Adults with NSCLC

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Merus B.V.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Not possible to specify

Trial duration

27 Apr 2026 → ongoing

Decision date (initial)

2026-04-09

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

No

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Pharmacogenomic, Safety, Pharmacokinetic, Efficacy

To assess antitumor activity of petosemtamab in combination with pembrolizumab in NSCLC

Secondary objectives 6

1. To further assess antitumor activity of petosemtamab in combination with pembrolizumab in NSCLC
2. To assess the safety and tolerability of petosemtamab in combination with pembrolizumab in NSCLC
3. To characterize the PK of petosemtamab in combination with pembrolizumab in NSCLC
4. To characterize the immunogenicity of petosemtamab in combination with pembrolizumab in NSCLC
5. To correlate biomarkers in tumor samples
6. Please refer to protocol for further objective

Conditions and MedDRA coding

Non Small Cell Lung Cancer

Regulatory references

Plan to share IPD

No

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 8

1. 1. Able to provide written informed consent and is willing and able to comply with all study procedures and contraception requirements (see Appendix 4)
2. 6. Adequate hematologic function as defined below: a. Platelet count ≥ 100 × 109/L (without transfusion within the past 7 days) b. ANC ≥ 1.5 × 109/L c. Hemoglobin ≥ 9 g/dL (without transfusion within the past 7 days)
3. 7. Creatinine clearance ≥ 60 mL/min calculated according to the Cockroft and Gault formula
4. 2. Age ≥ 18 years at the signing of ICF
5. 3. At least 1 measurable lesion as defined by RECIST 1.1 by radiologic methods and confirmed by the Investigator to meet both of the following criteria: a. Non-nodal lesion that measures ≥ 10 mm in the longest diameter or lymph node lesion that measures ≥ 15 mm in the short axis b. The lesion is suitable for repeat measurement using CT/MRI. Lesions that have had external beam radiotherapy or locoregional therapy must show radiographic evidence of subsequent growth.
6. 4. ECOG performance status of 0 or 1
7. 5. Life expectancy ≥ 12 weeks, in the opinion of the Investigator
8. 8. Please refer to the protocol for further criteria

Exclusion criteria 3

1. 1. Has untreated CNS metastases and/or carcinomatous meningitis a. Participants whose brain metastases have been treated may participate provided they show radiographic stability (defined as 2 brain images, both obtained after treatment to the brain metastases at least 4 weeks apart, that show no evidence of intracranial progression) b. In addition, any neurologic symptoms that developed either as a result of the brain metastases or their treatment must have returned to baseline or resolved. Any steroids administered as part of this therapy must be completed at least 3 days prior to study medication.
2. 2. Participation in an interventional clinical study with any investigational drug within 4 weeks prior to the first dose of study treatment OR participation in any clinical study with petosemtamab at any time prior to the first dose of study treatment, regardless of whether petosemtamab was received
3. 3. Please refer to the protocol for further criteria

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. ORR per Investigator assessment using RECIST 1.1

Secondary endpoints 4

1. DoR per Investigator assessment using RECIST 1.1 • DCR per Investigator assessment using RECIST 1.1 • CBR per Investigator assessment using RECIST 1.1 • PFS per Investigator assessment using RECIST 1.1 • OS
2. • AEs • Clinical laboratory data
3. Integrated analysis using population PK model approach
4. Please refer to Protocol for further secondary end points

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 2

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Merus B.V.

Sponsor organisation

Merus B.V.

Address

Floor 3rd And 4th, Uppsalalaan 17 Uppsalalaan 17

City

Utrecht

Postcode

3584 CT

Country

Netherlands

Scientific contact point

Organisation

Merus N.V.

Contact name

Clinical Trial Information

Public contact point

Organisation

Merus N.V.

Contact name

Clinical Trial Information

Locations

6 EU/EEA countries · 38 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 39 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

2 submissions — initial application plus substantial / non-substantial modifications