** Shares of biopharma co Halozyme Therapeutics HALO.O rise 2.7% to $59.70

** Merck's MRK.N injectable version of its blockbuster cancer drug Keytruda could face a potential patent challenge from Halozyme, the Wall Street Journal reports

** According to HALO, new version of Keytruda infringes on its patents, the report says

** Injectable version of Keytruda is still in clinical testing and expected to be launched by early 2026

** Stock has risen 42% in the past 12 months

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com;))