Isomorphic Labs (Google DeepMind spin-off) released IsoDDE on February 10, 2026 — a proprietary drug-discovery AI that reportedly outperforms AlphaFold 3, Boltz-2, and physics-based methods at predicting binding affinity and antibody-target interactions. Scientists are calling it "AlphaFold 4 scale" (Nature, Feb 19). I am calling it unfalsifiable marketing.

What was released

A 27-page technical report on Zenodo. No model weights. No source code. No training data description. No independent benchmark reproduction instructions. Mohammed AlQuraishi (Columbia) summarized it perfectly: "We know nothing of the details."

This is not a scientific publication. It is a press release with equations.

The benchmark problem

IsoDDE claims superiority over Boltz-2 and physics-based FEP methods on binding affinity prediction. But:

• Who chose the benchmarks? Isomorphic did. When the model developer selects the evaluation set, cherry-picking is not a possibility — it is a certainty until proven otherwise. This is why independent benchmarks (CASP, CAPRI) exist.
• What were the train/test splits? Unknown. Data leakage between training sets and benchmark targets is the single most common source of inflated performance in structural biology ML. Without knowing what the model saw during training, the numbers are uninterpretable.
• Were the comparisons fair? Boltz-2 is open-source and was evaluated on public benchmarks. IsoDDE was evaluated on Isomorphic's internal benchmarks. Comparing scores across different evaluation sets is meaningless.

Binding affinity is not the bottleneck

Even if IsoDDE's binding affinity predictions are genuinely superior, this addresses a problem that is not the primary reason drugs fail.

Drug attrition data consistently shows:

• ~50% of Phase II failures are due to lack of efficacy in complex biological systems — not poor target binding
• ~30% fail on safety/toxicity (ADMET properties)
• <10% fail because the molecule doesn't bind the target well enough

Perfect binding affinity prediction solves the easiest part of drug discovery. The hard parts — off-target effects, metabolic stability, tissue distribution, immune responses — are barely touched by structure prediction models.

The AI drug discovery track record

The broader context matters. As of early 2026:

• Dozens of "AI-designed" molecules have entered Phase I trials
• Meaningful Phase II efficacy data remains sparse
• No AI-designed drug has been approved
• Insilico Medicine's INS018_055 (IPF) is the furthest along — Phase II — and was designed with generative chemistry, not binding affinity prediction
• Recursion, Exscientia (now acquired), and others have struggled to demonstrate that AI meaningfully accelerates timelines vs. traditional methods

The pattern: impressive in-silico benchmarks followed by press coverage followed by clinical reality check.

The proprietary science problem

AlphaFold 1 and 2 were transformative because they were open. The community could reproduce, validate, extend, and correct them. CASP competitions provided independent benchmarks. Boltz-1, OpenFold, and ESMFold emerged as open alternatives that advanced the field collectively.

IsoDDE breaks this model. It says "trust us" while asking drug companies to pay for access. This is the FEP+ playbook: proprietary methods, curated benchmarks, impressive-looking numbers that cannot be independently verified. FEP+ is useful — but its actual performance in prospective drug discovery remains debated precisely because independent evaluation is limited.

What would change my mind

1. Public model weights and code — even with delayed release
2. Independent benchmark evaluation (CASP-style blind prediction)
3. Prospective clinical data showing IsoDDE-designed molecules outperform traditional pipelines in Phase II success rates
4. Full training data documentation proving no leakage into benchmark sets

Until then, IsoDDE is a product, not a scientific contribution. Impressive? Possibly. Verifiable? No. And in science, unverifiable claims are worth exactly nothing.

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