Cellectis is halting work on its allogeneic CAR-T cell therapies to instead focus on early-stage in vivo editing programmes, the company announced Monday. The strategic shift, which will also see the company pivot from oncology to chronic disease, triggered a 41% drop in its shares. The biotech is now looking for partnership opportunities for lasme-cel and eti-cel, which it was developing for B-cell acute lymphoblastic leukaemia (B-ALL) and non-Hodgkin lymphoma (NHL)."Despite our continued conviction in the promise of allogeneic CAR-T cell therapies and strong physician interest in lasme-cel and eti-cel, the commercial and clinical landscape for B-ALL and NHL changed materially. Continued and recently accelerated advances in frontline treatment regimens have lowered relapse rates, reducing the number of patients progressing to later lines of therapy," the company said. "Concurrently, the rapid emergence of bispecific antibodies and in vivo CAR-T approaches has intensified competition in second and third-line treatment settings. Together, these dynamics have reduced the addressable patient population for lasme-cel and eti-cel, resulting in slower enrollment, a potentially longer and more costly development pathway, and therefore a delayed timeline to potential registration."Instead, Cellectis will concentrate on a pair of preclinical candidates that use distinct methods of in vivo gene editing: base editing and epigenetic editing, both of which are designed to avoid double-strand DNA breaks. The first, .HEAL-101, is designed to treat severe hypertriglyceridaemia (sHTG) by targeting APOC3 with a TALE-base editor formulated in lipid nanoparticles (LNP). In a hypertriglyceridaemic humanised APOC3 transgenic mouse model, .HEAL-101 led to a mean 70% decrease in plasmatic APOC3 levels and a mean 76% decrease in triglyceride levels, both from baseline.Cellectis plans to start a Phase I investigator-initiated trial (IIT) in China, with preliminary data due in the second half of 2027. The second programme, .HEAL-201, uses in vivo editing to target PCSK9 in the hopes of treating severe hypercholesterolaemia. Formulated in LNP, the candidate comprises a TALE-epigenetic modulator specific to the promoter of PCSK9.A humanised liver mouse model study showed that an intravenous injection of the candidate decreased plasmatic levels of PCSK9 by an average of roughly 90%. Similar to .HEAL-101, Cellectis is planning to launch a Chinese Phase I IIT of .HEAL-201. Early findings from that study are expected in the first half of 2028. "Our decision to focus Cellectis on in vivo gene editing reflects the progress we have made with .HEAL-101 and .HEAL-201 and our assessment of where our gene editing capabilities can be most effectively deployed," said CEO André Choulika. "They have generated encouraging preclinical proof-of-concept and our priority is now to advance both programs toward the clinic and generate first-in-human data."Cellectis' pivot to abandon ex vivo cell therapies in favour of in vivo modalities mirrors similar strategic shifts from TScan Therapeutics and Arsenal Biosciences, which also announced layoffs (see – Spotlight On: In vivo CAR-Ts gain momentum with early clinical wins).