Stock of the pharma firm settled with a gain of 1.63 per cent at Rs 805.20 on the BSE. During the day, it climbed 2.78 per cent to Rs 814.40.
At the NSE, the stock rose by 1.46 per cent to settle at Rs 804.
In terms of volume, 2.66 lakh shares of the company changed hands at the BSE, while more than 29 lakh shares were traded at the NSE during the day.
Tildrakizumab is being evaluated in Phase III registration trials for the treatment of chronic plaque psoriasis, a skin ailment.
"Merck will continue all clinical development and regulatory activities, which will be funded by Sun Pharma. Upon product approval, Sun Pharma will be responsible for regulatory activities, including subsequent submissions, pharmacovigilance, post approval studies, manufacturing and commercialisation of the approved product," it had said.