An­oth­er day, an­oth­er AAV-de­liv­ered gene ther­a­py run­ning in­to road­blocks with the FDA.

The agency has placed a clin­i­cal hold on Log­icBio’s AAV-de­liv­ered gene edit­ing ther­a­py LB-001 af­ter two ado­les­cent pa­tients in an ear­ly tri­al for the drug were di­ag­nosed with throm­bot­ic mi­croan­giopa­thy (TMA), a clin­i­cal syn­drome de­fined by the for­ma­tion of tiny clots in blood ves­sels, the com­pa­ny said Wednes­day.

The biotech is try­ing LB-001 in a Phase I/II tri­al dubbed SUN­RISE to treat chil­dren with the rare meta­bol­ic dis­ease methyl­malonic acidemia, which re­sults in pa­tients not be­ing able to break down cer­tain fats and pro­teins.

In that study, two of four pa­tients re­port­ed cas­es of TMA, nei­ther of which proved fa­tal. In the first case, Log­icBio in­sti­tut­ed new safe­ty pro­to­cols in the SUN­RISE tri­al fol­low­ing the pa­tient’s di­ag­no­sis. That case was re­solved as of De­cem­ber 2021.

In the sec­ond case, the pa­tient was di­ag­nosed with TMA in Jan­u­ary of this year and is cur­rent­ly be­ing mon­i­tored.

With now two cas­es re­port­ed, the FDA opt­ed to halt de­vel­op­ment un­til more in­fo on what ex­act­ly caused those side ef­fects is picked out. In the mean­time, Log­icBio has said it’s putting tri­al da­ta up­dates on pause and work­ing with the agency to get the study back up and run­ning.

TMA has been a com­mon stum­bling block be­fore in gene ther­a­py stud­ies, a fact which Log­icBio ad­mit­ted in its re­lease. But it’s still not a wel­come re­sult for the com­pa­ny or its lead drug. LB-001 pur­ports to work by in­sert­ing a cor­rec­tive copy of the methyl­malonyl-CoA mu­tase gene in­to hu­man cells, dri­ving ther­a­peu­tic pro­duc­tion of that en­zyme in the liv­er.

Shares in $LOGC were trad­ing down 34% be­fore the bell Wednes­day.

Though Decibel Therapeutics has largely pivoted toward gene therapies for the inner ear, its lead clinical candidate simply aims to protect cancer patients from chemotherapy-induced hearing loss. On Tuesday, the biotech presented its first efficacy data for the program, and execs like what they see.

Decibel reported interim results from a Phase Ib study showing the experimental drug, dubbed DB-020, largely protected a small group of patients from losing their hearing. Researchers used a particularly unique study design, administering the compound in one of each patients’ ears before they received cisplatin chemotherapy and placebo in the other.

In November, Pfizer disclosed it’s spun out the Phase II dual JAK1/TYK2 inhibitor to a startup formed in collaboration with an unnamed, experienced partner.

We now know who the partner is. And as Pfizer and Roivant officially take the wraps off Priovant Therapeutics, the companies reveal that they have started two registrational trials of the drug, brepocitinib, as part of a broader plan to develop a big, first-in-class franchise spanning multiple orphan and specialty autoimmune diseases.

The FDA’s adcomm of outside vaccine experts will meet tomorrow to discuss how to protect the US from a likely coming wave of Omicron cases in the fall and winter, and whether to deploy vaccines that specifically target the Omicron variant.

While the data so far are limited, the FDA sounded an upbeat tone in the briefing documents on Pfizer/BioNTech’s candidates, released this weekend ahead of the VRBPAC meeting.