Character Biosciences has lined up $93 million to support clinical trials for two potential drugs that could provide much needed options for patients with common degenerative eye diseases. The firm’s series B fundraising was co-led by aMoon and Luma Group.
"We're on the precipice of something really special,” says Character CEO Cheng Zhang.
Character, initially called Clover Therapeutics, launched in 2018 to amass and analyze genetic data, clinical findings and eye imaging results to better understand the causes of dry age-related macular degeneration (dry AMD), a leading cause of vision loss. This approach led the biotech to the in-house discovery of two molecules — CTX203 and CTX114 — that are poised to be tested in people with dry AMD.
With CTX203, Character is targeting dysfunctional lipid biology that may drive the disease in some patients. Zhang says that the appearance of fatty lipid and protein deposits under the retina are a hallmark of dry AMD. Character’s data confirms that lipid transport machinery is associated with the disease, he says.
CTX203 is a helical peptide inspired by apolipoprotein A1 (ApoA1), a key component of "good cholesterol". When injected into the eye, this lipid regulator could help to clear these fatty deposits, both by mopping up the lipids and by stabilizing cholesterol transporters.
Character is planning a Phase I trial of CTX203 this year. A proof-of-principle study will then look for signs of efficacy in people with intermediate dry AMD, focused especially on individuals with genetic or image-based signatures of lipid dysfunction. If the peptide prevents retinal cell death and vision loss in these patients, it could become the first therapeutic for people with this intermediate-stage of the disease.
As dry AMD progresses, it can lead to a more severe form of disease called geographic atrophy. CTX114, an engineered version of Factor H-like protein 1 (FHL-1), is intended for people with this problem.
The protein complement Factor H and the related FHL-1 protein typically act to tamp down complement signaling and inflammation, Zhang says. But loss-of-function mutations in FHL-1 seem to exacerbate AMD progression. When injected into the eye, CTX114 could act as a new and improved version of the protein to keep complement signalling and inflammation in check. “What we're trying to do is not only replace that function, but augment it as well,” says Zhang.
A Phase I trial of CTX114 is planned for later this year, followed by a proof-of-concept trial in people with geographic atrophy and signatures of complement-related disease.
Two approved complement inhibitors — Apellis’s C3 inhibitor pegcetacoplan (Syfovre) and Astellas’s C5 inhibitor avacincaptad pegol (Izervay) — has validated the role of complement signalling in geographic atrophy. But Zhang says that Character’s preclinical data point to CTX114 having best-in-class potential. “We think this has the potential to be more effective in reducing the rate of geographic atrophy lesion growth, and we want to be able to show that it will preserve visual function as well,” he says.
Character is focused for now on dry AMD applications, says Zhang, and is on the lookout for molecules that act on other pathways to help more people with this disease. In January, the company partnered with Bausch + Lomb to progress these efforts. Other ophthalmological applications, such as glaucoma, are on the longer-term horizon.
“This could mark an inflection point in the way we think about the ophthalmology treatment paradigm,” says Zhang.
Chemical & Engineering News
ISSN 0009-2347
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