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How long does it take for Keytruda to work?

Medically reviewed by Carmen Pope, BPharm. Last updated on Nov 3, 2023.

Official answer


The time it takes for Keytruda to work can vary based on the type and stage of cancer. Typically, a response to treatment becomes apparent within 2-4 months of starting Keytruda. This timeframe is referred to as "time to response," which measures when a patient's cancer begins to show signs of responding to the treatment. You can find the specific "time to response" data from clinical trials in the table below.

Keytruda (pembrolizumab) is a medication used to treat various types of cancer. It's administered through a 30-minute intravenous infusion every 3-6 weeks. Keytruda is a type of immunotherapy that helps your immune system target cancer cells that may be hiding.

Time to response following treatment with Keytruda

Cancer Type
(Trial name)
Median Time to Response
Keytruda: 85-86 days (range 32-251)
Yervoy (ipilimumab): 87 days (range 80-250)
Keytruda: 13-15 weeks (IQR 12-18)
Investigator-choice (paclitaxel plus carboplatin, paclitaxel, carboplatin, dacarbazine, or oral temozolomide): 13 weeks (12-18)
Non-small cell lung cancer
Keytruda + pemetrexed + cisplatin or carboplatin: 1.4 months (1.2-3.0)
Placebo + Alimta (pemetrexed) + cisplatin or carboplatin: 1.4 months (1.2-4.9)
Non-small cell lung cancer
Keytruda + carboplatin + paclitaxel or Abraxane (nanoparticle albumin-bound paclitaxel): 1.4 months
Placebo + carboplatin + paclitaxel or Abraxane: 1.4 months
Non-small cell lung cancer
Keytruda: 2.2 months
Investigator-choice (carboplatin plus pemetrexed, cisplatin plus pemetrexed, carboplatin plus gemcitabine, cisplatin plus gemcitabine, or carboplatin plus paclitaxel): 2.2 months
Head and neck squamous cell cancer
Keytruda: 2 months (2-17)
Classical Hodgkin lymphoma
Keytruda: 2.8 months (1.0-31.2)
Adcetris (brentuximab vedotin): 2.8 months (1.0-7.3)
Classical Hodgkin lymphoma
Keytruda: 2.8 months (2.1-16.5)
Primary mediastinal large B-cell lymphoma
Keytruda: 2.9 months (2.4-8.5)
Urothelial Carcinoma
Keytruda: 2.1 months (1.3-9.0)
Urothelial Carcinoma
Keytruda: 2.1 months (1.4-6.3)
Investigator-choice (paclitaxel, Taxotere (docetaxel), Javlor (vinflunine)): 2.1 months (1.7-4.9)
Microsatellite instability-high or mismatch repair deficient cancer
Keytruda: Following ≥2 prior lines of standard chemotherapy - 4.3 months (1.8-24.9)
Following ≥1 prior lines of standard chemotherapy - 3.9 months (1.8-12.5)
Microsatellite instability-high or mismatch repair deficient cancer
Keytruda: 2 months (2-17)
Microsatellite instability-high or mismatch repair deficient cancer
Keytruda: 2 months (1.7-3.7)
Microsatellite instability-high or mismatch repair deficient cancer
Keytruda: 2.1 months
Microsatellite instability-high or mismatch repair deficient colorectal cancer
Keytruda: 2.2 months (1.8-18.8)
5-fluorouracil–based therapy with or without Avastin (bevacizumab) or Erbitux (cetuximab): 2.1 (1.7-24.9)
Gastric cancer
Keytruda: 2.1 months (1.7-6.6)
Esophageal cancer
Keytruda: 4.1 months (2.0-6.3)
Hepatocellular carcinoma
Keytruda: 2.1 months (1.8-4.8)
Merkel cell carcinoma
Keytruda: 2.8 months (1.5-9.7)
Renal cell carcinoma
Keytruda + Inlyta (axitinib): 2.8 months (1.5-16.6)
Sutent (sunitinib): 2.9 months (2.1-15.1)
Endometrial carcinoma
Keytruda + Lenvima (lenvatinib): 2.1 months
Investigator choice (doxorubicin or paclitaxel): 2.1 months
Cutaneous squamous cell carcinoma
Keytruda: 2.0 months (1.4-3.3)
Biliary tract cancer
Not reported

Related Questions

  • Keytruda Product Label. Revised 10/2023.
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  • OncLive. Pembrolizumab Approved in Europe for Adult and Pediatric Relapsed/Refractory Classical Hodgkin Lymphoma. March 17, 2021. Available from:
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  • FDA Approves Merck’s Keytruda (pembrolizumab) Plus Gemcitabine and Cisplatin as Treatment for Patients With Locally Advanced Unresectable or Metastatic Biliary Tract Cancer. Nov 1, 2023.

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