Tackling Rare Genetic Diseases with Diagonal Therapeutics

What It Covers

Diagonal Therapeutics SVP Eric Duhaime explains how the 24-person private biotech uses clustering bispecific antibodies to target root-cause receptor mutations in rare genetic diseases, with lead program DIAC723 entering clinical trials in 2026 for HHT.

Key Questions Answered

• •Root-cause targeting: Diagonal's bispecific antibodies act as molecular glue, forcing four cell-surface receptors into a specific confirmation to restore normal intracellular signaling — directly fixing the loss-of-function mutation rather than addressing downstream effects competitors target with anti-angiogenic approaches.
• •Market-building strategy: Before seeking investors, Diagonal invested heavily in Komodo Health claims data post-Series A to quantify commercial opportunity for HHT — a disease with 250,000 patients across the US and EU and zero approved therapies — then published findings in the American Journal of Hematology.
• •Pipeline scope at lean scale: With 24 full-time employees, Diagonal runs five programs: one lead asset (HHT and pulmonary arterial hypertension) entering the clinic in 2026, plus three preclinical programs in lead optimization, demonstrating that a small team wearing multiple hats can sustain a multi-indication platform.
• •Investor validation signal: Diagonal closed a Series B with 17 biotech-specific investors, and additional investors beyond that syndicate expressed interest in HHT — a signal that publishing disease-awareness data with leading KOLs and patient advocacy groups materially accelerates fundraising for uncharted rare disease indications.