The mar­ket­ing ef­fort for the MS drug Zin­bry­ta (da­clizum­ab) im­plod­ed to­day af­ter Eu­ro­pean reg­u­la­tors flagged a lethal safe­ty warn­ing over cas­es of in­flam­ma­to­ry en­cephali­tis and menin­goen­cephali­tis. Bio­gen $BI­IB and Ab­b­Vie $AB­BV, which had been look­ing to spend this year build­ing sales of the MS treat­ment, are now yank­ing it off the mar­ket in the EU and the US.

“Giv­en the na­ture and com­plex­i­ty of ad­verse events be­ing re­port­ed, char­ac­ter­iz­ing the evolv­ing ben­e­fit/risk pro­file of Zin­bry­ta will not be pos­si­ble go­ing for­ward giv­en the lim­it­ed num­ber of pa­tients be­ing treat­ed,” the com­pa­nies said in a state­ment. “There­fore, Bio­gen and Ab­b­Vie be­lieve it is in the best in­ter­est of pa­tients to vol­un­tar­i­ly with­draw world­wide mar­ket­ing au­tho­riza­tions for Zin­bry­ta.”

En­cephali­tis is char­ac­ter­ized by brain in­flam­ma­tion, usu­al­ly caused by a vi­ral in­fec­tion, which is rare and po­ten­tial­ly dead­ly.

Al San­drock, Bio­gen

The drug hit the US mar­ket in 2016 with a black box warn­ing over the threat of liv­er tox­i­c­i­ty af­ter the FDA ap­proved it for third-line MS cas­es. Reg­u­la­tors, though, have been will­ing to put up with con­sid­er­able safe­ty prob­lems with MS drugs so long as the dam­age to pa­tients is rare and the ben­e­fits con­sid­er­able. In this case, Bio­gen and Ab­b­Vie have yet to gain much trac­tion for a drug that an­a­lysts had felt would be lim­it­ed to peak sales of $500 mil­lion a year.

The with­draw­al won’t have much im­pact on Ab­b­Vie longterm, where the R&D group is in hot pur­suit of sev­er­al po­ten­tial block­busters to bol­ster its work around Hu­mi­ra. Bio­gen, though, won’t get off so easy. The big biotech made its rep in MS and has a thin pipeline dom­i­nat­ed by a high-risk Alzheimer’s ther­a­py. Bio­gen CMO Al San­drock man­aged to rat­tle the mar­ket re­cent­ly with news that they were adding pa­tients to their piv­otal tri­al for the Alzheimer’s drug to ac­count for some vari­abil­i­ty in the da­ta — which in turn trig­gered fresh jit­ters over its fu­ture.

“Bio­gen be­lieves the vol­un­tary world­wide with­draw­al of ZIN­BRY­TA, a treat­ment for re­laps­ing mul­ti­ple scle­ro­sis, is in the best in­ter­est of pa­tients,” said San­drock in a state­ment. “Bio­gen and Ab­b­Vie con­tin­ue to pri­or­i­tize pa­tient safe­ty and the care of mul­ti­ple scle­ro­sis pa­tients world­wide.”

89bio said its drug was better than placebo at lessening fibrosis without worsening nonalcoholic steatohepatitis, or NASH, in two of three dose groups.

The San Francisco biotech said it thinks the Phase IIb data pave the way for a potential Phase III, following in the footsteps of another biotech in its drug class, Akero Therapeutics. To fund a late-stage study, CEO Rohan Palekar told Endpoints News 89bio “would need to raise additional capital,” with the company having about $188 million at the end of last year.