** Brokerage Oppenheimer says there is an opportunity for competition given a cautious uptake of Merck's MRK.N therapy, Winrevair, for a rare lung condition

** Early trends of Merck's therapy indicate the sickest patients being prioritized - brokerage

** U.S. FDA approved the therapy for treating pulmonary arterial hypertension in March this year

** As of Sept. 30, FDA's adverse event reporting system lists 254 cases, with 103 serious, including 8 reported deaths, believed to be related to MRK's therapy

** Doctors exercise heightened caution when recommending it to patients with a history of bleeding risks

** As the safety profile continues to emerge, there is an opportunity for potentially safer treatments that could be used in earlier lines, says brokerage

** There is potential for Keros Therapeutics' KROS.O cibotercept for higher dosing compared to Winrevair, says Oppenheimer

** Gossamer Bio's GOSS.O seralutinib stands out with a clean long-term safety and efficacy profile

(Reporting by Sriparna Roy in Bengaluru)

((Sriparna.Roy@thomsonreuters.com;))