Editas Medicine announces that it will discontinue internal investments in EDIT-101 for Leber Congenital Amaurosis 10 (LCA10) and other programs on inherited retinal diseases - including EDIT-103 for rhodopsin-associated autosomal dominant retinitis pigmentosa. The move is part of a strategic reprioritisation to narrow the R&D efforts to focus on hemoglobinopathies and in vivo discovery to pursue and develop programs the company believes have maximum probabilities of technical, regulatory, and commercial success. As a result, resources will be allocated towards EDIT-301 for treating severe sickle cell disease and transfusion-dependent beta-thalassemia. In addition, investments in the company's wholly-owned multiplexed edited induced pluripotent stem cell (iPSC) derived natural killer (iNK) cell programs, including EDIT-202 for solid tumours, will also be discontinued.
Recent Nobel Prize laureate Svante Pääbo is co-authoring a paper that describes a method to detect unintended on-target effects in CRISPR genome editing by DNA donors carrying diagnostic substitutions. The so-called ‘sequence-ascertained favourable editing' (SAFE) donor approach allows unintended events affecting editing target sites to be easily detected when the target site is sequenced to determine the genome editing outcome in cellular clones. The authors analysed more than 850 human embryonic stem cell clones edited with 'SAFE' donors and detected all copy number changes and almost all clones with gene conversion.
Polymerase-free targeted long-read sequencing is superior to PCR-based nanopore sequencing for capturing CRISPR editing and AAV integration outcomes, according to work by scientists in the US. They compared the technique after in vivo single- and dual-gRNA AAV-CRISPR editing of human ATXN2 in transgenic mouse models of spinocerebellar ataxia type 2 (SCA2). PCR-based nanopore sequencing showed a bias for partial AAV fragments and inverted terminal repeats (ITRs) and failed to detect full-length AAV. At the same time, the polymerase-free method found AAV integration, 1-2% of which contained the entire AAV genome, and greater than 150 kb deletions at target loci and rearrangements of the transgenic allele (1%).