Both Merck & Co. and Halozyme are holding their ground in a freshly unveiled patent dispute surrounding the New Jersey pharma’s under-the-skin version of its blockbuster cancer drug Keytruda.

Merck's injected version of its blockbuster cancer drug Keytruda could face a potential patent challenge from biotech Halozyme Therapeutics, the Wall Street Journal reported on Wednesday, citing people familiar with the matter.

The new formulation of Keytruda, currently under FDA review, is sparking conflict with Halozyme, which makes enzymes that convert intravenous drugs into injectable versions.

The company has asked the U.S. patent office to reconsider patents that could prevent it from selling a new version of its drug Keytruda.

Merck's newly developed injected version of its blockbuster cancer drug, Keytruda, may be at the center of a potential patent dispute, according to a report by The Wall Street Journal

Shares in pharmaceuticals giant Merck (MRK) weakened today on fears that a patent battle could jeopardize its plans to sell a new version of

Merck (MRK) stock trended lower as Halozyme (HALO) challenges the company over injectable Keytruda patents. Read more here.

Biotech Halozyme Therapeutics believes the new version of Merck's blockbuster cancer drug Keytruda infringes on its patents, the Wall Street Journal reported on Wednesday, citing people familiar with the matter.