An At­las-found­ed biotech qui­et­ly shut down this week, with the CEO post­ing on­ly a short state­ment on LinkedIn to an­nounce the move.

Triplet Ther­a­peu­tics is no longer op­er­a­tional, chief ex­ec Nes­san Berming­ham said on the so­cial me­dia site Tues­day, less than three years af­ter it launched. In De­cem­ber 2019, Triplet de­buted with a $59 mil­lion Se­ries A, nab­bing cash from At­las, MPM Cap­i­tal and Pfiz­er Ven­tures in an ef­fort to de­vel­op an­ti­sense drugs for Hunt­ing­ton’s dis­ease.

“It is with great sad­ness we an­nounce the clo­sure of Triplet Ther­a­peu­tics,” Berming­ham’s state­ment read in part. “We want to thank all the em­ploy­ees, ad­vi­sors and in­vestors that sup­port­ed the com­pa­ny in ad­di­tion to CH­DI who not on­ly was a great part­ner and pa­tient ad­vo­cate but al­so stepped in to con­tin­ue the Nat­ur­al His­to­ry Study (Shield-HD) that we had ini­ti­at­ed.”

At­las de­clined to com­ment, point­ing to Berming­ham’s LinkedIn post. The news was first re­port­ed by STAT.

Triplet had been at­tempt­ing to in­ves­ti­gate the DNA dam­age re­sponse path­way and how it could be tar­get­ed with an­ti­sense oligonu­cleotides to treat Hunt­ing­ton’s and oth­er sim­i­lar dis­eases, known as re­peat ex­pan­sion dis­or­ders. At the time of launch, Triplet said it had found a few key dri­vers (out of 100) that showed the po­ten­tial to stop the in­ser­tion of ge­net­ic re­peats.

But ear­ly last year, Roche shut­tered a Phase III tri­al look­ing at an an­ti­sense Hunt­ing­ton’s treat­ment known as tomin­ersen. Just one week lat­er, the biotech Wave Life Sci­ences al­so scrapped an an­ti­sense drug for Hunt­ing­ton’s, cit­ing a fail­ure to sep­a­rate from place­bo in im­pact­ing the mu­tant Hunt­ingtin pro­tein at any of the dosage lev­els.

Those fail­ures prompt­ed Triplet’s in­vestors to back out right around the time the biotech sought to put to­geth­er a Se­ries B round, STAT re­port­ed.

Hunt­ing­ton’s con­tin­ues to thwart every­thing re­searchers throw at it, and Triplet is just the lat­est com­pa­ny to wave the white flag in this space. But by shut­ting down com­plete­ly rather than piv­ot­ing, the biotech took a more dras­tic step in the wake of its de­feat. Berming­ham al­so point­ed to tox­i­c­i­ty is­sues in his state­ment emerg­ing from the an­ti­sense tech, mak­ing a path for­ward dif­fi­cult.

“Suf­fice to say the un­der­ly­ing sci­ence of tar­get­ing re­peat ex­pan­sion dis­or­ders through MSH3 knock­down re­mains a vi­able ap­proach from our van­tage point,” the CEO wrote, “how­ev­er the da­ta with our lead com­pound re­flect­ed pri­or ex­pe­ri­ences with ASO tox in the CNS.”