Merck said on Tuesday a study showed its injectable version of cancer drug Keytruda was not inferior to the currently approved intravenous formulation of its treatment, likely making it even more accessible and easier to administer.
Shares of Merck were up 1.8% in premarket trading following the news.
The pharmaceutical company was testing the injectable version of the world's biggest-selling drug in a late-stage trial of patients with a type of lung cancer.
The injectable version could potentially protect the drug, which had sales of about $25 billion last year, from competition that is expected when the IV version loses exclusivity later in the decade.
Merck plans to discuss the results with regulators globally as soon as possible, said Marjorie Green, head of oncology, global clinical development at the company's research unit.
Keytruda was injected under the skin in about 2-3 minutes in the trial, compared with the current delivery method in which patients are put on an intravenous drip for about 30 minutes in a health office once every three or six weeks.
Despite the short time of administration, the injectable version was also non-inferior in terms of exposure in the patients' bodies as well as its concentration immediately before the next dose was administered, Merck said.
The injection is a fixed-dose combination of Keytruda with berahyaluronidase alfa, an enzyme that allows large volume of subcutaneous, or under the skin, administration of drugs that are typically given as an IV infusion.
Several pharmaceutical companies are developing injectable versions of their IV drugs using variants of hyaluronidase to offer quick alternatives.
South Korea-based biopharmaceutical company Alteogen is developing and manufacturing the enzyme used with Keytruda. It is also developing an injectable version of Daiichi Sankyo's cancer drug Enhertu.
Alteogen's rival Halozyme is also developing injectable versions of various drugs from Roche, Johnson & Johnson, Pfizer and others.