Piper Sandler analyst Edward Tenthoff raised the firm's price target on Argenx (ARGX) to $258 from $198 and reiterates an Overweight rating on the shares.

The Phase III ADAPT trial of efgartigimod in generalized myasthenia gravis met the primary endpoint of Myasthenia Gravis Activities of Daily Living score response at 67.7% versus 29.7% on placebo, Tenthoff tells investors in a research note.

The stock in morning trading is up 28%, or $44.54, to $202.50. Based on the top-line data, the analyst is confident in FDA approval and U.S. launch next year.