** Drugmaker BioCryst Pharmaceuticals' BCRX.O shares fall 11% to $8.20

** Co posts Q4 net loss of 13 cents per share, compared with analysts' estimates of a loss of 6 cents per share, according to data compiled by LSEG

** Separately in a filing, co discloses it received a notice from India's Annora Pharma in January regarding Annora's submission of an application to the FDA seeking approval to manufacture, use or sell a generic version of BCRX's Orladeyo before the expiration of patents

** The letter alleges that the patents, which expire in 2039, are invalid

** Orladeyo is used to prevent attacks of hereditary angioedema, a rare genetic disorder that causes severe swelling in the body

** BCRX intends to vigorously defend its intellectual property rights protecting Orladeyo, it said

** Co posts Q4 revenue of $131.5 million on strong sales for Orladeyo, compared with analysts' estimates of $130.2 million

** Expects 2025 total revenue between $560 million and $575 million vs analysts' estimates $545 million

** BCRX rose 63% in the last 12 months

(Reporting by Siddhi Mahatole)

((Siddhiprabhanjan.mahatole@thomsonreuters.com))