Allergan plc. (NYSE:AGN), based in Dublin, Ireland, has announced the acquisition of Michigan-based gene therapy company RetroSense Therapeutics in an upfront all-cash based transaction for $60M. As part of the transaction, Allergan has additionally agreed to the payment of further potential regulatory and commercialization milestone payments related to a lead development program, “RST-001”, an experimental gene therapy treatment for retinitis pigmentosa (RP). The deal comes on the back of increased intensity in recent years in the field of coular gene therapy as several new biotech and larger pharmaceutical companies invest increased resources in the market potential for these novel technologies.
Less than a year prior to the acquisition announcement, RetroSense itself announced receipt of clearance from the FDA to initiate a first-in-human study of an optogenetic strategy for the treatment of RP. Completion of a low dose cohort of RP patients had been safely achieved by August 2016 with a mid-dose cohort to come. The company is aiming to deliver a “channelrhodopsin 2” gene, originally isolated from green algae, and transfect the gene into cells of the inner retina. The experimental treatment will use adeno-associated viral (AAV) vectors as the delivery tool and the trial is expected to recruit approximately 15 patients in total.
Optogenetics aims to use light sensitive molecules from a variety of biological sources to boost or assist residual activity in a medically relevant context. One of the most regularly used light-activated molecules is the channelrhodopsin-2 light-gated cation channels, derived from the green alga, Chlamydomonas reinhardtii. However, other groups have engineered novel optogenetic proteins that are customised to natural light intensities exploited by the human retina. The current optogenetic tool from RetroSense, termed RST-001, received Orphan Drug designation from the FDA in late 2014 and, according to the company, was the first-in-class gene therapy application of optogenetic technology.
The technology was originally pioneered by Dr. Zhuo-Hua Pan at Wayne State University and Dr. Alex Dizhoor at Salus University. Research in animal models, showed that a channelrhodopsin-2 (ChR2) gene delivered to the inner retinal neurons of the common marmoset, resulted in retinal gene expression of the transgene. In addition, the research demonstrated that the intravitreal AAV-2 delivered transcripts were capable of mediating light responses recordable by electrophysiological testing. The potential of the field to treat retinal disorders in which the primary photoreceptors are reduced in number was clearly attractive to RetroSense and then to Allergan. Commenting on the acquisition, Brent Saunders, CEO and President of Allergan stated, “the acquisition of RetroSense and its RST-001 program builds on Allergan’s deep commitment to eye care, and our focus on investing in game-changing innovation for retinal conditions, including Retinitis Pigmentosa, where patients desperately need treatment options.” On the RetroSense side, CEO Sean Ainsworth, stated, “with its deep commitment to eye care, strong eye care professional community network, and its commitment to advancing innovation across retinal conditions, Allergan was the most compelling partner and the best strategic fit to advance the development of RST-001 and maximize the potential for this technology platform. The addition of RST-001 to Allergan’s world-class eye care development and commercialization organization will position this potentially revolutionary technology to be used by ophthalmology professionals to improve the treatment of patients with retinal diseases around the world.”