Pembrolizumab

For an informed discussion with your doctor or pharmacist. This information collection is not a clinically validated interaction checker. Missing data do not establish safety. Do not change or stop prescribed medicines on the basis of this information. The findings apply to the specific conditions studied; laboratory and animal studies cannot be directly extrapolated to humans.

Active substance: Pembrolizumab

Examples of brand names: Keytruda [EU]

ATC code: L01FF02

Main use (for orientation): Selected cancers, e.g. melanoma, NSCLC, renal cell carcinoma; stage/biomarkers/combination are decisive

Documented research summary

NSCLC observational study with pembrolizumab: no significant difference in time to progression; cannabis was not an independent mortality predictor in multivariable analysis. Unequal baseline groups limit the conclusion. Do not count mouse THC plus anti-PD1 as a clinical pembrolizumab interaction. Additional CCTG context analysis concerns durvalumab/tremelimumab, not pembrolizumab; see B0530.

Uncertainties and limitations

Corrected to intravenous KEYTRUDA; automatically found QLEX (pembrolizumab plus berahyaluronidase, subcutaneous) explicitly NOT used as a single-ingredient preparation.

Shared enzymes must not be equated with clinical evidence of an interaction; CBD/THC findings cannot be extrapolated to other cannabinoids.

Separately recorded findings

2 separately recorded findings. Each statement applies to its documented study context.

Cannabis (variable composition) – clinical signals

Finding ID: B0100

Type of result: Context-specific finding; read the limitations

Observation: Not an independent mortality predictor in multivariable analysis; progression time not significantly different.

Mechanism: Possible immunological pharmacodynamic interaction assessed

Study type: Retrospective clinical cohort and separate mouse experiments; online 2022

Context studied: 201 people with metastatic NSCLC; 102 cannabis users.

Clinical interpretation: Individual medical / pharmaceutical assessment; do not use as dosage instructions

Limitations and uncertainties: Different baseline burden. Non-significance does not establish equivalence/safety; mouse data are not human evidence.

Original sources for this finding: The use of medical cannabis concomitantly with immune checkpoint inhibitors in non-small cell lung cancer: A sigh of relief? [EX12]

Cannabis/marijuana, composition not standardised – clinical signals

Finding ID: B0240

Type of result: Clinical observational

Observation: No significant overall-survival association (HR 0.93; 95% CI 0.58–1.49).

Mechanism: Observed overall-survival association during mixed immune-checkpoint-inhibitor therapy

Study type: Retrospective head-and-neck squamous-cell carcinoma cohort

Context studied: 201 people: 100 pembrolizumab, 91 nivolumab, 10 nivolumab plus ipilimumab; 47 cannabis users; the same cohort in both drug rows.

Clinical interpretation: No causal interaction proven

Limitations and uncertainties: Not an antibody-specific effect or confirmation of equivalence/safety; PPR623349 is the same study.

Original sources for this finding: Impact of Tobacco, Marijuana, and Alcohol Use on Overall Survival in Recurrent Metastatic Head and Neck Cancer Patients Treated With Immune Checkpoint Inhibitors. [BMED39704258]

References and access status

[V2_LABEL_D0451_Human] KEYTRUDA (pembrolizumab) injection, for intravenous use

Original source / bibliographic reference

Authors: Merck Sharp & Dohme LLC

Year: 2026

Source type: Official US SPL / DailyMed

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

[EX12] The use of medical cannabis concomitantly with immune checkpoint inhibitors in non-small cell lung cancer: A sigh of relief?

Original source / bibliographic reference

Authors: Waissengrin B; Leshem Y; Taya M; Meiri D; Merimsky O; Shamai S; Wolf I; Rubinek T

Year: 2023

Source type: Retrospective clinical cohort and separate mouse experiments; online 2022

DOI: 10.1016/j.ejca.2022.11.022

PMID: 36535195

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[BMED39704258] Impact of Tobacco, Marijuana, and Alcohol Use on Overall Survival in Recurrent Metastatic Head and Neck Cancer Patients Treated With Immune Checkpoint Inhibitors.

Original source / bibliographic reference

Authors: Alsavaf MB, Issa M, Klamer BG, Husain M, Dibs K, Pan X, Grecula JC, Old MO, Konieczkowski D, Mitchell DL, Baliga S, Carrau RL, Rocco JW, Bonomi M, Blakaj DM, Bhateja P.

Year: 2025

Source type: Publication; title and abstract reviewed

DOI: 10.1111/ajco.14135

PMID: 39704258

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

[V4_CCTG_40184324] Effects of cannabinoids on immune checkpoint inhibitor response: CCTG pooled analysis of individual patient data

Original source / bibliographic reference

Authors: Coschi CH; Ding K; Tong J; Tu D; O'Callaghan C; Leighl NB; Vera-Badillo F; Juergens RA; Hao D; Seymour L; Renouf DJ; Chen E; Gaudreau PO; Fung AS

Year: 2025

Source type: Retrospective exposure analysis of pooled individual data

DOI: 10.1080/1750743X.2025.2485012

PMID: 40184324

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

Research as of 23 October 2026. Not all original full texts could be reviewed in full. Source accessibility and the strength of scientific evidence must be assessed separately. An accessible link does not establish medical approval; a bibliographic record with an abstract does not replace the original full text.

Drug search and explanation of the evidence · Guide: cannabinoids and medicines · Author and responsibility