** Shares of Vertex Pharmaceuticals VRTX.O fall 5.04% to $475 premarket

** Co posted Q1 revenue of $2.77 billion, missing analyst estimates of $2.85 billion according to data compiled by LSEG

** Co raised the low end of its full-year 2025 revenue forecast range to $11.85 billion from $11.75, keeping the higher end at $12 billion

** Co saw a revenue decline in Russia where Vertex's intellectual property rights is being violated

** Street estimates may not have fully encompassed the previously disclosed impacts of an unauthorized copy of co's cystic fibrosis Trikafta in Russia - William Blair

** Reports quarterly adj profit of $4.06 per share, below estimates of $4.32

** Up to last close, stock down ~24% YTD

(Reporting by Sriparna Roy in Bengaluru)

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