The U.S. Food and Drug Administration (FDA) announced on Friday that it has approved a new subcutaneous injection formulation of Merck's blockbuster cancer treatment Keytruda, providing a more convenient delivery method for this widely used cancer immunotherapy.

This development marks a significant transformation in the delivery method for the world's best-selling cancer immunotherapy, potentially enhancing patient experience and treatment efficiency. The move is also viewed as part of Merck's strategy to defend Keytruda's market share as biosimilar competition approaches.

Nancy Ibach, Vice President of Merck's U.S. Oncology Division, stated that the new formulation, branded as Keytruda Qlex, requires only one to two minutes for administration depending on the dose, compared to approximately 30 minutes typically needed for intravenous infusion.

The recommended dosage for the injection is 395 milligrams every three weeks or 790 milligrams every six weeks.

Keytruda was first approved in 2014 for treating various cancer types and generated nearly $30 billion in global sales last year.

Merck indicated that it expects the subcutaneous injection formulation to launch in the U.S. in late September, aiming to drive market adoption of the drug before its patent expires in 2028.

Clinical trials demonstrated that the new subcutaneous injection formulation is not inferior in efficacy to the intravenous infusion formulation.

The pharmaceutical giant stated earlier this year that it expects the subcutaneous injection formulation to achieve a penetration rate of up to 30% to 40% of Keytruda's patient population within two years.

Merck becomes the third pharmaceutical company to launch a subcutaneous injection cancer therapy, following Roche's Tecentriq Hybryza and Bristol Myers Squibb's Opdivo Qvantig.

Despite being the third company to enter this market, Merck believes its faster injection speed and flexible dosing regimen provide differentiated advantages.