Diagonal Therapeutics – a company pioneering a new approach to discover and develop agonist antibodies – has launched with $128 million in financing. BVF Partners and Atlas Venture co-led the Series A funding round, with participation from Lightspeed Venture Partners, RA Capital Management, Frazier Life Sciences, Viking Global Investors, Velosity Capital, and Checkpoint Capital. The company was co-founded by CEO Alex Lugovskoy, Ph.D., and Atlas and was previously seeded by Atlas, Lightspeed Venture Partners, and Velosity Capital.
The funding will support the advancement of the company’s proprietary DIAGONAL platform and pipeline of novel therapeutics to value-creating milestones, including its lead program for the treatment of hereditary hemorrhagic telangiectasia (HHT), a debilitating bleeding disorder with limited therapeutic options, via clinical proof-of-concept. And Diagonal’s agonist antibody activates a receptor complex in the TGF-β superfamily genetically impaired in HHT patients. In the preclinical models of HHT, Diagonal’s agonist antibodies prevent and reverse the formation of pathological vascular malformations.
Unlike most approved antibodies (which inhibit a cellular function), agonist antibodies activate a signaling cascade by binding two receptors and bringing them together in a particular conformation that enables their activation. And given the many potential binding sites between each receptor and an antibody, nearly infinite binding configurations exist – of which only a small subset will result in the optimal agonistic activity. This has made identifying or rationally designing agonist antibodies difficult.
The DIAGONAL platform solves this issue, combining proprietary computational and experimental techniques that enable Diagonal scientists to sift through billions of combinations at unprecedented speeds and with high fidelity. With the platform, Diagonal discovered antibody candidates against 4 complex targets, providing a new path to treating severe diseases, including:
1.) Hereditary hemorrhagic telangiectasia (HHT) – also known as Osler–Weber–Rendu syndrome. HHT is a monogenic and orphan disease that affects over 150,000 patients in the US and EU, and for which no approved therapies are currently available. In HHT, mutations in the TGF-β receptor superfamily complex create two types of abnormal blood vessels—telangiectasias and arteriovenous malformations (AVMs)—that are fragile and susceptible to rupture and bleeding. These bleeding events lead to chronic anemia, necessitating frequent iron infusions or red blood cell transfusions. AVMs, if left untreated, may result in lung and brain hemorrhage, stroke, heart failure, and death. And Diagonal’s agonist antibody candidates reactivate dormant signaling, addressing the root cause of the disease.
2.) Pulmonary arterial hypertension (PAH)—PAH is an orphan disease that causes high blood pressure and affects the arteries in the lungs and the right side of the heart. In patients with PAH, the vasculature narrows due to an imbalance in the antiproliferative and hyperproliferative pathways. Diagonal’s agonist antibody corrects signaling and restores vascular wall homeostasis.
KEY QUOTES:
“We are fundamentally changing how agonist antibody therapies are developed. The DIAGONAL platform allows us to overcome technical limitations that hindered agonist antibody discovery in the past, and we have demonstrated that we can efficiently advance novel drug candidates for diseases where patients have limited or no treatment options. Our approach enables us to treat a wide range of disorders where signaling pathways have been disrupted with agonist antibodies that have superior potency and selectivity, tunable and sustained pharmacology, excellent developability, and low immunogenicity.”
– Alex Lugovskoy
“The biopharmaceutical industry has a robust, growing toolkit of approaches to inhibit disease-associated pathways. However, we still lack systematic pharmacologic approaches to activate biological pathways to treat diseases caused by deficient signaling. Diagonal’s platform addresses this unmet need by rapidly identifying antibodies that activate key pathways. I am excited to support them as they advance their therapeutic candidates for patients in need.”
– Michael Gladstone, Partner at Atlas Venture and Board Chair of Diagonal
