Deciding without the key variable
Exposure is inferred from blood, animal models, or bulk tissue, but delivery inside the patient's tumor cells is rarely measured and never experimentally controlled.
When a program misses, plasma levels, animal studies, and biopsy markers can suggest why, but they rarely settle whether the drug hit the wrong biology or never reached its target inside the patient's tumor cells. We test it directly, so you fix the right thing before your next trial.
The Physicality Gap
A molecule that works in a dish meets tissue, stroma, and membranes in a patient. Development teams track exposure carefully: plasma pharmacokinetics, tissue levels in animals, target expression and pharmacodynamic markers in biopsies. But these measure delivery indirectly, and they show what happened alongside response, not what caused it. When a drug fails, they rarely say for certain whether the biology was wrong or the drug never reached the inside of the tumor cells at a working dose.
The fixes are opposite. Guess wrong, and you shelve a drug that works or fund another trial that fails for the same reason.
Exposure is inferred from blood, animal models, or bulk tissue, but delivery inside the patient's tumor cells is rarely measured and never experimentally controlled.
Boards and partners want to know why a program missed. "The biomarker didn't hold up" isn't an answer anyone can act on.
A drug that never got in and a drug that failed once inside need opposite fixes. Confusing them wastes the next trial.
Why it matters
Clinical trials are the most expensive experiments in medicine, and most of them fail. When a drug fails for lack of efficacy, the next move depends entirely on why. Guessing is costly in both directions.
The biology works. Re-engineer the delivery (linker, payload, formulation, dose) or enroll the patients the drug can reach, instead of writing off years of work.
No delivery fix will help. Stop before the next trial and move the budget to programs that can win.
Knowing whose tumors a drug actually reaches turns a broad trial into an enriched one: smaller, faster, and more likely to succeed.
A failed program is mispriced until someone knows why it failed. Causal evidence changes what a shelved asset, an in-licensing deal, or a board decision is worth.
1. Sun et al., Acta Pharmaceutica Sinica B, 2022 (analysis of 2010–2017 clinical data). 2. Hsiue, Moore & Alexander, Clinical Trials, 2020 (pivotal trials for FDA-approved cancer drugs, 2015–2017). 3. DiMasi, Grabowski & Hansen, Journal of Health Economics, 2016.
Try it
Clinical data can't change how much drug gets into a cell. Our experiments can. We use sonoporation, a brief pulse of ultrasound with microbubbles that temporarily opens cell membranes, to push more drug inside tumor cells while the drug itself stays exactly the same. If response rises with delivery, the drug was delivery-limited. If it doesn't, the mechanism is the problem.
Without sonoporation, neither kills many cells, just as in the clinic. Turn up sonoporation to find out why.
Illustrative simulation. Sonoporation is used only as an in vitro laboratory tool.
The experiment behind it
Every program runs through the same four-arm design in patient-derived tumor organoids. The only thing sonoporation changes is how much drug gets into the cells, not the drug and not the cells. That makes it an instrumental variable: a controlled lever that separates the effect of delivery from the effect of the drug's mechanism, something observational data can't do.
In the sonoporation arms, ultrasound (left) makes microbubbles at the tumor’s surface oscillate, briefly opening cell membranes so the drug can get in.
Sonoporation is used only as an in vitro laboratory tool, with low-energy settings that open membranes briefly without damaging cells.
Lab in the loop
scDEFT's predictions aren't taken on faith. Each one is tested in the four-arm experiment, and every result, confirmed or not, goes back into training. Over time the model learns what no public dataset contains: how drug response changes when delivery is controlled.
The engine
Our AI reads a patient's cells before treatment, predicts how they'll change under a drug, and traces the prediction back to named gene programs. It was trained and tested on matched before-and-after biopsies from nine clinical trials and cohorts, in five solid tumor types and in inflammatory bowel disease, not on cell lines. For patients held out from training, its predictions closely track what actually happened.
Predicting response before treatment (AUROC, IBD cohorts)
0.50 is chance. scDEFT was the only method whose confidence interval excluded it.
Working with us
A molecule in development, or one that missed its endpoint. We scope the question with your team in one working session.
scDEFT screens the drug across patient cell states. We confirm key predictions in patient-derived organoids, with and without controlled delivery.
Delivery or mechanism, which patients respond, and what to change: advance, redesign delivery, re-select patients, or stop.
Why we're different
Typical AI drug discovery platform
Causal Data AI
Where teams start
Checkpoint inhibitors, chemotherapy, and targeted and endocrine therapies: the drug classes scDEFT has already been trained on in solid tumors.
Separate a salvageable drug from a failed hypothesis, and find the subgroup where it works.
Antibody-drug conjugates, bispecifics, and RNA therapeutics, where getting the payload into the right cell is often the whole problem.
Beyond oncology
Nothing in scDEFT or the four-arm design is specific to cancer. Any tissue that stands between a drug and its target, whether a tumor's stroma, an inflamed gut lining, or scar tissue, raises the same question and gets the same test.
Antibodies and small molecules, with antibody-drug conjugates next. scDEFT tested across six trials in five tumor types, with seven more qualifying trials queued.
scDEFT was first tested in inflammatory bowel disease, where it predicted anti-TNF response before treatment better than published signatures.
Dense scar tissue is a physical barrier to drugs, making delivery a leading suspect whenever a promising antifibrotic falls short.
The Causal MoA Atlas
Every four-arm experiment adds measurements that exist nowhere else: how a drug changes a patient's cells when it reaches them, and when it doesn't. Across drugs, tissues, and diseases, those results build into an atlas that makes every new prediction better than the last. It grows with each program we run.
Illustrative. The atlas is being built program by program.
The team
If you're deciding whether to advance, redesign, or stop a program, a causal answer is the right next step. We're taking on a small number of solid tumor programs this year.