The U.S. Food and Drug Administration (FDA) has granted approval for a new subcutaneous formulation of Merck’s cancer immunotherapy Keytruda, now marketed as Keytruda Qlex.

Unlike the standard intravenous infusion, which typically takes around 30 minutes, the new injection can be administered in just one to two minutes depending on the dose. The approved dosing regimen is 395 mg every three weeks or 790 mg every six weeks.

This approval applies to adult and paediatric patients aged 12 and above across most solid tumour indications for which intravenous pembrolizumab (Keytruda) is already authorised. Clinical studies confirmed that the subcutaneous version is comparable to the IV formulation in terms of efficacy, safety and pharmacokinetics.

Merck plans to launch Keytruda Qlex in the United States by late September. The company expects that within two years, the new formulation will account for 30–40% of overall Keytruda use.

The approval is viewed as a key strategic step for Merck to strengthen its position as Keytruda faces patent expiry in 2028, when biosimilar competition is expected to intensify.