Editas Medicine on Friday announced that the FDA has approved the launch of a Phase I/II trial for EDIT-101, an experimental CRISPR genome-editing drug being developed to treat Leber's congenital amaurosis type 10 (LCA10). According to Editas, EDIT-101 is set to be "the first in vivo CRISPR medicine administered to people anywhere in the world." 

The clearance triggers a $25-million milestone payment to Editas from partner Allergan as part of their 2017 agreement to develop genome-editing medicines to treat ocular diseases. Editas, which did not specify when the trial would start, said the companies expect to enrol 10 to 20 patients in the dose-escalation study of EDIT-101. The therapy is administered via a subretinal injection to reach and deliver the gene-editing machinery directly to photoreceptor cells, Editas said. 

"The FDA's acceptance of our [investigational new drug application] for EDIT-101 is a significant moment in the field of genome editing, and importantly, a critical milestone for patients, as we are now one step closer to a treatment for LCA10," said Katrine Bosley, chief executive officer at Editas. 

Earlier this year, CRISPR Therapeutics and Vertex Pharmaceuticals began clinical testing on CTX001, an autologous gene-edited haematopoietic stem cell therapy for patients with sickle-cell disease. In October, the FDA lifted a clinical hold it had placed on a study of CTX001 in May. 

Meanwhile, ProQR recently reported Phase I/II results showing that six of 10 patients with LCA10 being treated with its intravitreal antisense oligonucleotide therapy QR-110 every three months achieved a "clinically meaningful" response in visual acuity and mobility course endpoints. The company expects to advance QR-110 into a Phase II/III trial in the first half of 2019. According to ProQR, the first-in-class investigational RNA-based oligonucleotide is designed to address the underlying cause of LCA10 due to the p.Cys998X mutation in the CEP290 gene.