FDA grants full approval to Keytruda and Keytruda Qlex for TMB-high advanced solid tumours with updated biomarker threshold

The FDA has converted Keytruda's tumour-mutational-burden-high solid tumour indication to traditional approval, extending the authorisation to Keytruda Qlex and updating the biomarker threshold.

Keytruda (pembrolizumab) and Keytruda Qlex (pembrolizumab and berahyaluronidase alfa-pmph) are authorised for previously treated adults and children with unresectable or metastatic TMB-high solid tumours, defined as at least 13 mutations per megabase using an FDA-authorised test, when satisfactory alternative treatments are unavailable.

The decision replaces an earlier accelerated approval and raises the biomarker threshold from 10 to 13 mutations per megabase, supported by KEYNOTE-158 data showing a 36% objective response rate among 220 patients, with 58% of responders maintaining responses for at least 12 months.

Field	Content
Article Type	Approvals
Regulatory Authority	U.S. Food and Drug Administration
Regulatory Decision	Traditional approval replacing an earlier accelerated approval
Approval Date	16 October 2026
Company	Merck & Co.
Approved Products	Keytruda; Keytruda Qlex
Keytruda Active Ingredient	Pembrolizumab
Keytruda Qlex Active Ingredients	Pembrolizumab and berahyaluronidase alfa-pmph
Therapeutic Area	Oncology
Approved Indication	Previously treated unresectable or metastatic tumour-mutational-burden-high solid tumours without satisfactory alternative treatment options
Patient Population	Adults and children meeting the approved biomarker and prior-treatment criteria
Biomarker	Tumour mutational burden-high (TMB-H)
Updated TMB Threshold	At least 13 mutations per megabase
Previous TMB Threshold	At least 10 mutations per megabase
Biomarker Testing	FDA-authorised test
Prior Treatment Requirement	Previously treated disease
Alternative Treatment Requirement	No satisfactory alternative treatment options
Supporting Clinical Study	KEYNOTE-158
Study Population	220 patients in the reported efficacy analysis
Objective Response Rate	36%
Response Durability	58% of responders maintained responses for at least 12 months
Threshold Change Rationale	Efficacy was not confirmed in the subgroup with TMB of 10 to below 13 mutations per megabase
Regulatory History	Conversion of an earlier accelerated approval to traditional approval with a revised biomarker threshold
Geography	United States
What Happened	The FDA granted traditional approval to Keytruda and Keytruda Qlex for eligible patients with TMB-high unresectable or metastatic solid tumours.
Why It Matters	The decision confirms a biomarker-directed, tumour-agnostic treatment indication while refining the population based on observed efficacy.
Clinical Evidence	KEYNOTE-158 reported a 36% objective response rate in 220 patients and response duration of at least 12 months in 58% of responders.
Key Takeaway	Traditional approval now applies to Keytruda and Keytruda Qlex for eligible TMB-high advanced solid tumours using a threshold of at least 13 mutations per megabase.
What to Watch	Updated biomarker testing practices, clinical guideline revisions, treatment selection, real-world outcomes and adoption of the revised threshold.
Primary Source	U.S. Food and Drug Administration
Primary Source URL	https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-traditional-approval-pembrolizumab-or-pembrolizumab-and-berahyaluronidase-alfa-pmph
Relevant Date	16 October 2026

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