He walked out of a quantum physics lecture because the green leaves outside were more interesting. Two decades later he is building antibodies that switch biology back on.
For thirty years, the antibody business has mostly been a business of saying no. Find the protein driving a disease, design a molecule that clamps onto it, and shut it down. Alexey Lugovskoy spent two decades inside that world and came out convinced that the more interesting medicine was waiting on the opposite side of the equation: the diseases caused not by a signal that is too loud, but by one that has gone silent.
That is the premise of Diagonal Therapeutics, the Watertown, Massachusetts company he co-founded in January 2022 and runs as president and CEO. Diagonal builds what it calls clustering antibodies, agonists that gather receptors together and reactivate the cellular signaling a genetic defect has switched off. The goal is not to dampen disease. It is to restore the conversation a cell was supposed to be having all along.
The market is paying attention. In April 2024 Diagonal came out of stealth with a $128M Series A from Atlas Venture, Lightspeed Venture Partners and Velosity Capital, with BVF, RA Capital and Viking Global along for the ride. Then in January 2026 it closed an oversubscribed $125M Series B co-led by Sanofi Ventures and Janus Henderson Investors, bringing in Deep Track, EcoR1, Logos and others. Roughly a quarter of a billion dollars, raised on the idea that antibodies can be taught to activate.
The hard part is geometry. An activating antibody cannot simply grab its target; it has to find multiple binding sites and hold them in precise configurations, so that receptors cluster the way a healthy cell would cluster them. Diagonal built a computational platform to search that space, because, as Lugovskoy puts it, nature offers no blueprint. "There are a lot of human diseases that require reactivation of signaling for a curative effect," he has said. The company's wager is that a whole category of medicine has been sitting unbuilt because the tools to design it did not exist.
Its lead program, DIAG723, is a first-in-class clustering antibody aimed at the ALK1-BMPRII receptor axis, designed to correct the root cause of hereditary hemorrhagic telangiectasia (HHT), a rare bleeding disorder affecting more than 150,000 people across the U.S. and Europe, with a path toward pulmonary arterial hypertension as well. Diagonal expects to dose its first human patients in the first half of 2026. After a career spent shepherding other people's molecules into the clinic, Lugovskoy is finally about to do it with his own.
Picture a switch. Conventional antibody drugs are excellent at flipping switches off - clamp the target, silence it, done. Diagonal works the harder direction: flipping the switch back on. To do that, an antibody has to cluster receptors into the exact arrangement a healthy cell uses to fire a signal.
It is the difference between a brake and an ignition. Far more of biology than you would think is waiting on the ignition.
The crowded approach. Antibody binds, target goes quiet. Most drugs live here.
Diagonal's lane. Antibody clusters receptors, signaling switches back on.
Work on challenging problems of strong pharmaceutical relevance, surrounded by a good group of people.
Grows up an avid reader, drawn to physics, devouring Feynman in junior high. Earns a B.Sc. in mathematics and physics at the Moscow Institute of Physics and Technology.
Mid-lecture on quantum physics, he admits to himself he is far more passionate about biology than particles. He turns toward immunology - and earns a Ph.D. in biophysics at Harvard.
Roughly nine years as Associate Director of Drug Discovery. Co-invents the pan-RAF inhibitor tovorafenib (2006-07), later FDA-approved in 2023 for pediatric glioma.
About six years as Vice President of Therapeutics, advancing oncology programs.
Chief Development Officer for roughly five years, taking programs into first-in-human studies. Adds an MIT Sloan executive certificate.
Chief Operating Officer, building out a leadership team and pipeline.
Co-founds the company and becomes CEO, also serving as Entrepreneur-in-Residence at Atlas Venture. $128M Series A in 2024, $125M Series B in 2026, with DIAG723 entering the clinic.
Two colleges, one pivotHe enrolled in two physics colleges before deciding biology was the thing that, in his words, tickled his imagination.
Failure, reframedHis long-running work on alpha-v-beta-6 integrin across companies he calls "uncomfortable" - a learning experience, not a haunting.
Small on purposeHe likes lean teams because "all spectrum of corporate activity is just more transparent to people."
Sixteen-year overnight successThe first drug he co-invented took about sixteen years from lab bench to FDA approval.
The inner voiceHe credits weekend science reading and "this inner voice" for steering a career across four companies.
Editor on the sideWhile running a venture-backed biotech, he serves as an associate editor of the antibody journal mAbs.