** Shares of biotech co Immunome IMNM.O down 3.5% premarket at $22.65 after $400 mln follow-on priced

** Bothell, Washington-based IMNM late Tues announced selling ~18.6 mln shares at $21.50, an 8.4% discount to last sale

** IMNM shares jumped nearly 16% on Mon after co said its experimental drug, varegacestat, met main goal in late-stage study for patients with desmoid tumors

** After the bell Mon, co launched $400 mln offering. IMNM shares added another 3.7% on Tues

** Co plans to use net offering proceeds to fund potential commercial launch of varegacestat, continued commercial development and manufacturing scale-up for varegacestat, continued clinical and preclinical development of other pipeline assets, among other uses, per the offering prospectus

** Leerink, JP Morgan, TD Cowen, Goldman and Guggenheim are joint bookrunners

** Stephens analyst Melissa Roberts says in note that IMNM's capital raise qualifies for "immediate adjustment in market indexes", and estimates passive demand for 1.6 mln shares, or about one day of buying demand, in the Q4 rebalance after the close on Fri, Dec 19

** Through Tues close, shares have more than doubled YTD

** All 13 analysts are bullish and median PT is $33, per LSEG data

(Lance Tupper is a Reuters market analyst. The views expressed are his own)

((lance.tupper@tr.com 1-646-279-6380))