Designing molecules that score high on the DRD2 oracle
Find molecules that a dopamine-D2 activity model scores highly, within 10,000 oracle calls.
State the problem, from PMO (Practical Molecular Optimization)
Browse files+58 −0 README.md added View file
| @@ -0,0 +1,58 @@ | ||
| 1 | +# Designing molecules that score high on the DRD2 oracle | |
| 2 | + | |
| 3 | +Dopamine receptor D2 is the target of most antipsychotics, and a support vector machine trained on measured activities is a standard stand-in for the assay. This task asks a design algorithm to find molecules that score highly on that model while calling it at most 10,000 times. | |
| 4 | + | |
| 5 | +## Task | |
| 6 | + | |
| 7 | +Propose molecules as SMILES strings and maximise the DRD2 oracle, a support vector machine with a Gaussian kernel over ECFP6 fingerprints, fitted to ExCAPE-DB activity data and returning a score in $[0, 1]$. The run is scored by AUC top-10 over a 10,000-call budget, so both the final quality and how quickly it was reached count. | |
| 8 | + | |
| 9 | +## Background | |
| 10 | + | |
| 11 | +The oracle was introduced with REINVENT in 2017 and became one of the most-used targets in generative chemistry. PMO put it in a budgeted setting after observing that most reported comparisons ignore how many oracle calls a method spends, which is the one resource that matters when the oracle is an assay rather than a model. DRD2 is the easy end of the benchmark: several methods already reach above 0.9, so the interesting question is how few calls suffice. | |
| 12 | + | |
| 13 | +## Data and evaluation | |
| 14 | + | |
| 15 | +- Data: there is no training set to fit. Any database a method needs is restricted to ZINC 250k, which ships | |
| 16 | + with the repository, so no method gets an advantage from a richer corpus. | |
| 17 | +- Budget and seeds: 10,000 oracle calls per run, and five independent runs with different random seeds | |
| 18 | + (`python run.py METHOD --task production --n_runs 5 --oracles drd2`). Report the mean and standard deviation | |
| 19 | + over the runs. The budget counts distinct valid canonical SMILES: a molecule queried twice is served from the | |
| 20 | + cache for free, and an invalid SMILES scores 0. | |
| 21 | +- Metric: AUC top-10. The mean score of the ten best molecules found so far is recorded every 100 calls, the | |
| 22 | + curve against the number of calls is integrated by the trapezoid rule and divided by the 10,000-call budget, so | |
| 23 | + the value lands in $[0, 1]$ and higher is better. A run that stops early keeps its final top-10 value for the | |
| 24 | + rest of the budget. Unlike a plain top-10 average, the metric rewards reaching a good score early. | |
| 25 | +- Official evaluation code: <https://github.com/wenhao-gao/mol_opt> (MIT), where `main/optimizer.py` holds the | |
| 26 | + budget accounting and the AUC. Oracles come from the Therapeutics Data Commons via PyTDC (MIT); the ZINC | |
| 27 | + database is free to use. | |
| 28 | + | |
| 29 | +## What is known | |
| 30 | + | |
| 31 | +- Best in the PMO paper's table: SynNet at 0.969 ± 0.004, then Graph GA at 0.964 ± 0.012 and DoG-Gen at 0.948 ± 0.001. REINVENT, the best method overall across the 23 oracles, reaches 0.945 ± 0.007 here. | |
| 32 | +- Later work on the same protocol reports higher: Genetic GFN at 0.974 ± 0.006 and Mol GA at 0.950 ± 0.004 (five runs, 10,000 calls). | |
| 33 | +- A random screen of ZINC 250k scores 0.545, so the oracle is easy to satisfy but not trivially so. | |
| 34 | +- This oracle is close to saturated, and the headroom left is in sample efficiency rather than in the final score. | |
| 35 | + | |
| 36 | +## What would count as progress | |
| 37 | + | |
| 38 | +- A mean AUC top-10 above 0.969 on `drd2` from five runs under the official protocol, reported | |
| 39 | + with the per-run values and the standard deviation. To beat the field rather than the 2022 table, the number to | |
| 40 | + pass is 0.974 (Genetic GFN). | |
| 41 | +- The run logs, which record every scored molecule in order, so the AUC and the oracle-call count can be | |
| 42 | + recomputed rather than trusted. | |
| 43 | +- Code in the repository's method layout, so the result can be re-run on the other 22 oracles: a method that wins | |
| 44 | + on one oracle and loses elsewhere is the pattern PMO was built to expose. | |
| 45 | + | |
| 46 | +## References | |
| 47 | + | |
| 48 | +1. W. Gao, T. Fu, J. Sun and C. W. Coley, "Sample Efficiency Matters: A Benchmark for Practical Molecular Optimization", *NeurIPS 2022 Datasets and Benchmarks* (2022). <https://arxiv.org/abs/2206.12411> | |
| 49 | +2. M. Olivecrona, T. Blaschke, O. Engkvist and H. Chen, "Molecular de-novo design through deep reinforcement learning", *Journal of Cheminformatics* **9**, 48 (2017). <https://doi.org/10.1186/s13321-017-0235-x> | |
| 50 | +3. W. Gao, R. Mercado and C. W. Coley, "Amortized Tree Generation for Bottom-up Synthesis Planning and Synthesizable Molecular Design", *ICLR 2022* (2021). <https://arxiv.org/abs/2110.06389> | |
| 51 | +4. H. Kim, M. Kim, S. Choi and J. Park, "Genetic-guided GFlowNets for Sample Efficient Molecular Optimization", *NeurIPS 2024* (2024). <https://arxiv.org/abs/2402.05961> | |
| 52 | +5. A. Tripp and J. M. Hernández-Lobato, "Genetic algorithms are strong baselines for molecule generation" (2023). <https://arxiv.org/abs/2310.09267> | |
| 53 | + | |
| 54 | +## Source | |
| 55 | + | |
| 56 | +Imported from [PMO (mol_opt), the `drd2` oracle](https://github.com/wenhao-gao/mol_opt), curated by Wenhao Gao, Tianfan Fu, Jimeng Sun | |
| 57 | +and Connor W. Coley. Open according to the source as of 2026-10-20. The statement above is written in our own | |
| 58 | +words; see the source for the original wording, history and discussion. | |