FILE PHOTO: Merck logo is seen in this illustration taken March 26, 2025. REUTERS/Dado Ruvic/Illustration/File Photo

By Kamal Choudhury and Sriparna Roy

(Reuters) -The U.S. Food and Drug Administration said on Friday it has approved a new formulation of Merck's blockbuster cancer therapy Keytruda that can be administered under the skin, offering a more convenient version of the widely used cancer immunotherapy.

The move marks a significant shift in how one of the world's top-selling cancer immunotherapies can be delivered, potentially improving patient experience and clinic efficiency.

It is also seen as part of Merck's strategy to defend Keytruda's market share as biosimilar competition looms.

The new version, branded as Keytruda Qlex, can be administered in as little as a minute or two depending on dosage, said Nancy Ibach, associate vice president of US Oncology at Merck, compared to IV infusion that typically takes about 30 minutes.

The recommended dosage of the injection is either 395 mg every three weeks or 790 mg every six weeks.

Keytruda, first approved in 2014, is used to treat multiple types of cancer. It generated nearly $30 billion in global sales last year.

Merck said it expects the injectable version to be available in the United States in late September, aiming to drive adoption ahead of the drug's expected patent expiry in 2028.

In clinical trials, the new version of the cancer drug was shown to be no less effective than its intravenous formulation.

The drugmaker said earlier this year it expects peak adoption of the injectable version to reach 30% to 40% of patients on Keytruda within two years.

Merck is the third drugmaker to bring a subcutaneous cancer therapy to market, following Roche's Tecentriq Hybryza and Bristol Myers Squibb's Opdivo Qvantig.

Despite being the third to enter the market, Merck believes its faster injection time and flexible dosing options offer a differentiated profile.

(Reporting by Kamal Choudhury and Sriparna Roy in Bengaluru; Editing by Maju Samuel and Shinjini Ganguli)