He named the company after an area code, then went looking for the part of a cancer cell that fixes its own DNA - and broke it.
In late May 2026, on a poster board at the world's largest cancer meeting, a single number did the talking. Fifty-seven percent of patients with BRCA-mutated, platinum-resistant ovarian cancer responded to ETX-19477, the lead drug from a roughly 21-person company in San Diego. Five months earlier the FDA had handed that same molecule a Fast Track designation. The company is 858 Therapeutics, and the chemist who built it is Jeffrey Stafford.
Stafford's job title is CEO and co-founder, but the more accurate description is the one he has carried since 1991: someone who turns molecules into medicine. ETX-19477 is an inhibitor of PARG, an enzyme buried inside the cellular machinery that repairs damaged DNA. Block it in the right tumor and the cancer cell loses its ability to patch itself together. It is the kind of target other drug hunters spent years calling intractable.
"Turning molecules into medicine is the whole job. Everything else is logistics."
858 Therapeutics does not chase the obvious targets. Its portfolio reads like a list of biology's hard problems: PARG and the DNA-repair pathway, ADAR1 and innate immune signaling, METTL3 and the chemistry of RNA itself. Each is a node where cancer cells are quietly vulnerable, and each demands a chemist's patience to hit cleanly with a small molecule.
The strategy has a logic Stafford has run before. Find a biological switch that tumors depend on. Build a precise molecule to flip it. Prove it in the clinic. In September 2024 the company raised a $50 million Series B led by Avidity Partners to push that thesis forward, on top of the $60 million Series A it launched with in 2021.
In 2025 it signed a small-molecule discovery collaboration with OpenBench, leaning on computational methods to widen the funnel of candidate molecules. For a company of two dozen people running a trial that drew a crowd at ASCO, the leverage matters.
Most drug hunters spend a career without a single approval. Stafford's discovery teams have a hand in three - across kidney cancer, diabetes, and the operating room.
A tyrosine kinase inhibitor used in advanced renal cell carcinoma and certain soft-tissue sarcomas.
A DPP-4 inhibitor prescribed to help control blood sugar in type 2 diabetes.
A fast-acting sedative used for procedural sedation - chemistry that buys minutes, not months.
Cancer cells survive because they are good at fixing their own broken DNA. A whole class of drugs - PARP inhibitors - exploits that by jamming one repair enzyme, and they reshaped treatment for BRCA-mutated cancers. The catch is resistance: tumors learn to route around the block.
PARG sits one step further along the same pathway. Where PARP builds the repair scaffolding, PARG tears it down so the cell can recycle and move on. ETX-19477 is designed to inhibit that glycohydrolase, attacking DNA repair from a different angle - the kind of move that can matter most in tumors that have already shrugged off the first drug. That is the bet behind 858's lead program, and the early ovarian-cancer numbers are the first real evidence it might pay off.
Behind ETX-19477 sits a deliberately varied bench: ADAR1, an enzyme tied to innate immune signaling; METTL3, which writes chemical marks onto RNA; and QPCT/L. Different biology, same discipline - precise small molecules aimed at nodes most companies avoid.
858 Therapeutics runs out of Merryfield Row in Torrey Pines, the dense San Diego mesa where a generation of small molecule discovery companies have clustered within walking distance of each other. It is not an accident of geography. Stafford built his career in this corridor, and the company's name - lifted straight from the local area code - reads like a flag planted in the ground.
The model is lean on purpose. Roughly two dozen people, a sharp pipeline, and outside collaborators like OpenBench to extend the chemistry reach without ballooning headcount. It is the operating philosophy of a founder who has done this twice before and knows that a focused team with one convincing molecule can outrun a crowded one. With $110 million raised and a drug already drawing crowds at ASCO, the third act is the one that gets to finish the sentence the first two started.
Two companies bought. Three drugs approved. One area code on the door. — The short version of a long career
Stafford's training is pure chemistry. A B.S. in Chemistry from UCLA, a Ph.D. in Organic Chemistry from Cornell, and an NIH postdoctoral fellowship at UC Berkeley. In 1991 he walked into the Glaxo Research Institute and started doing the work he has never really stopped doing.
The pattern of his career is build-and-hand-off. He was the founding CSO of Quanticel Pharmaceuticals, which pioneered a single-cell genomics platform aimed at cancer stem cells; Celgene acquired it in 2015 for its epigenetics pipeline. He then ran Jecure Therapeutics as CEO, a company built around inhibiting the NLRP3 inflammasome; Genentech acquired it in 2018.
858 Therapeutics, founded in 2019, is the third act. Same instinct, harder targets, and this time the molecule is already in patients. He is also a co-author of numerous peer-reviewed papers in organic and medicinal chemistry - the academic paper trail of someone who never left the lab in spirit.
The company is named for San Diego's area code - identity planted squarely in the city's biotech corridor before the first molecule was made.
His approved drugs span kidney cancer, type 2 diabetes, and procedural sedation. The chemistry travels.
The headcount running a clinical trial that drew attention at the largest oncology conference on earth.
Undergrad, doctorate, and NIH fellowship - a resume that reads like a chemistry syllabus before the first company.