Agentic biomedical machine learning (ML) draws on complementary advances in biomedical evidence acquisition and executable program search. Existing systems connect aspects of these capabilities, but coordinating them throughout program search remains challenging. New evidence must guide candidate construction, execution outcomes must inform subsequent discovery and reuse, and validation demands must fit the search budget. We introduce BioDyad, which couples biomedical discovery and ML engineering through two hierarchies within Monte Carlo graph search. Its scientific hierarchy combines prior biomedical guidance with iterative discovery, then links biomedical plans to execution outcomes in memory for reuse across candidates. Its engineering hierarchy moves candidate programs from smoke execution, through train/validation evaluation, to full-data retraining. We evaluate BioDyad on the 76-task BioXArena benchmark under a two-hour per-task budget with three matched LLM backends. It achieves the highest penalized all-task score and task success rate among four agent methods and a one-shot baseline under each backend. These results support coordinating biomedical discovery and ML engineering to integrate external knowledge into executable programs across heterogeneous biomedical tasks.
Figures & tables
Type
Method
Scientific hierarchy
Search and engineering
Bio. discovery
Bio. memory
Program search
Staged eval.
Budget adapt.
Harness
BioXArena harness ( Li et al., 2026 )
✗
✗
✗
✗
✗
Bio. agents
Biomni ( Huang et al., 2025 )
✓
✗
✗
✗
✗
STELLA ( Jin et al., 2025 )
✓
✗
✗
✗
✗
VCHarness ∗ ( Cheng et al., 2026 )
△
△
✓
✗
✗
MLE agents
MLEvolve ( Du et al., 2026 )
✗
✗
✓
✗
✓
Table 1: Capabilities of representative agentic systems for biomedical ML program discovery.
Figure 1: BioDyad couples biomedical discovery and ML engineering within MCGS. The scientific hierarchy combines prior guidance, node-level discovery, and biomedical memory; the engineering hierarchy advances programs through smoke execution, train/validation evaluation, and full-data runs. Biomedical evidence guides candidate expansion, while execution feedback updates the search graph and memory within the wall-clock budget. The hERG Binding Affinity task from BioXArena ( Li et al., 2026 ) provides an illustrative example.
Figure 2: ReAct-based prior biomedical guidance. A plan-only agent alternates reasoning with read-only probes to compile verified data findings and biomedical insights.
Figure 3: Success rate (x-axis) and penalized all-task score (y-axis) under three LLM backends. Each panel compares four agent methods with a two-hour per-task budget and a one-shot baseline retaining only the first attempt, evaluated on the same 76 tasks.
LLM backend
Method
Seq
SC
Str
Net
Chem
Pert
Phen
Img
Text
Avg.
GPT-5.6-sol
One-shot
0.416
0.288
0.727
0.458
0.576
0.291
0.508
0.500
0.546
0.472
BioXArena Harness
0.663
0.786
0.834
0.458
0.928
0.517
0.606
0.714
0.637
0.685
Biomni
0.773
0.652
0.591
0.490
0.690
0.404
0.431
0.702
0.656
0.605
MLEvolve
0.790
0.798
0.794
0.527
0.922
0.597
0.575
0.673
0.720
0.715
BioDyad (ours)
0.776
0.861
0.815
0.521
0.926
0.776
0.594
0.666
0.671
0.738
GLM-5.1
One-shot
0.187
0.102
0.236
0.062
0.556
0.121
0.374
0.139
0.030
0.198
Table 2: Domain breakdowns of four agent methods and a one-shot baseline under three matched LLM backends on the 76 BioXArena tasks. Scores are penalized average scores; higher is better. Avg. is weighted by task count across all 76 tasks. Bold and underlining indicate the highest and second-highest distinct displayed scores, respectively, within each backend and column.
Method
Penalized score
Success rate
BioXArena Harn.
0.699±0.005
0.944±0.000
Biomni
0.647±0.012
0.889±0.000
MLEvolve
0.688±0.019
0.907±0.032
BioDyad
0.711±0.002
0.944±0.000
Table 3: Repeated-run robustness on the fixed 18-task subset with GPT-5.6-sol. Values are mean ± sample standard deviation (SD) across three independent runs.
Hierarchy
Mechanism
MLEvolve
MLEvolve
BioDyad
BioDyad
BioDyad
BioDyad
w/ discovery
w/o memory
w/o Sci.
w/o Eng.
(full)
Sci. hierarchy
Bio. discovery
✗
✓
✓
✗
✓
✓
Bio. memory
✗
✗
✗
✗
✓
✓
Eng. hierarchy
Staged evaluation
✗
✗
✓
✓
✗
✓
Performance ↑
Chemical biology
0.898
0.795
0.913
0.861
0.896
0.919
Phenotype-disease
0.538
0.599
0.560
0.468
0.570
0.606
Table 4: Component ablations with the GPT-5.4 backend. Scores are penalized task averages. Avg. is the task-weighted mean across all 16 tasks in the two domains; higher is better.
Figure 4: Biomedical feature integration in BioDyad: (a) predictive gain, (b) smoke-guided execution repair, and (c) no predictive gain despite successful execution. Scores are task-specific validation metrics; full execution denotes candidate train/validation evaluation.
Domain
Best-so-far test score
Score gain
2 h
4 h
6 h
8 h
10 h
12 h
2-4 h
4-12 h
2-12 h
Chemical biology
0.927
0.932
0.936
0.936
0.936
0.937
+0.006
+0.004
+0.010
Phenotype-disease
0.640
0.663
0.688
0.690
0.690
0.690
+0.022
+0.027
+0.050
Table 5: Retrospective best-so-far normalized test scores during 12-hour BioDyad runs with GPT-5.6-sol. Each checkpoint averages task-level maxima over all eight tasks in a domain, using the same runs as Appdx. D . Gain columns report absolute differences computed before rounding.
Figure 5: Candidate test scores during 12-hour searches: (a) BACE1 binding affinity, (b) CYP inhibition, (c) Alzheimer’s disease staging, (d) breast-cancer subtype. Gray points show candidate scores; blue lines show retrospective maxima; orange dashed lines show linear fits against time.
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Agent
Seq
SC
Str
Net
Chem
Pert
Phen
Img
Text
Avg.
BioDyad (GPT-5.6-sol)
0.776
0.861
0.815
0.521
0.926
0.776
0.594
0.666
0.671
0.738
BioDyad (GLM-5.1)
0.776
0.771
0.729
0.509
0.932
0.737
0.600
0.700
0.552
0.705
BioDyad (DeepSeek-V4)
0.717
0.791
0.789
0.510
0.909
0.717
0.600
0.646
0.608
0.701
MLEvolve ( Du et al., 2026 )
0.765
0.798
0.750
0.510
0.869
0.601
0.502
0.606
0.534
0.666
STELLA ( Jin et al., 2025 )
0.677
0.559
0.481
0.497
0.878
0.555
0.574
0.651
0.641
0.613
Biomni ( Huang et al., 2025 )
0.526
0.646
0.569
0.497
0.723
0.628
0.547
0.659
0.415
0.579
Appendix
Table 6: Comparison with the penalized score presented on BioXArena’s leaderboard across all 76 tasks. Avg. is task-weighted across all tasks. Baseline scores are reported by BioXArena ( Li et al., 2026 ) ; BioDyad scores use the same evaluation protocol. Bold marks the highest score in each column. Backends differ across systems (Appdx. E.2 ).
Hierarchy
Mechanism
MLEvolve
MLEvolve
BioDyad
BioDyad
BioDyad
BioDyad
w/ discovery
w/o memory
w/o Sci.
w/o Eng.
(full)
Sci. hierarchy
Bio. discovery
✗
✓
✓
✗
✓
✓
Bio. memory
✗
✗
✗
✗
✓
✓
Eng. hierarchy
Staged evaluation
✗
✗
✓
✓
✗
✓
Outcomes
Full runs
552
672
639
446
668
566
Valid
304 (55.1%)
314 (46.7%)
425 (66.5%)
319 (71.5%)
411 (61.5%)
458 (80.9%)
Appendix
Table 7: Candidate outcomes in the component ablations. Each entry gives a count and its percentage of that configuration’s full-execution runs.
Domain
Task
Test 2 h
Test 4 h
Test 12 h
Δ 2-4 h
Δ 4-12 h
CB
BACE1 Binding Affinity
0.934
0.936
0.939
+0.002
+0.003
CB
Cell Painting Perturbation
0.982
1.000
1.000
+0.018
+0.000
CB
CYP Inhibition (Multi-label)
0.940
0.941
0.944
+0.001
+0.003
CB
EGFR Binding Affinity
0.925
0.927
0.927
+0.003
+0.000
CB
GPCR Binding (Multi-class)
0.948
0.953
0.970
+0.005
+0.017
CB
hERG Binding Affinity
0.898
0.908
0.909
+0.010
+0.001
Appendix
Table 8: Normalized test-score checkpoints and gains in the 12-hour traces. CB denotes chemical biology and PD denotes phenotype-disease. Each checkpoint is a retrospective maximum over completed candidates. Gains are absolute differences computed before rounding.
Figure 6: Cumulative best normalized test scores for all 16 tasks, using the same runs as Table 8 . The upper two rows show chemical-biology tasks and the lower two show phenotype-disease tasks. Each task has its own vertical scale. Steps occur at logged candidate completion; dashed guides mark 2 and 4 hours. No score is shown before the first completed candidate, and the last observed best is carried forward to 12 hours.
Domain
First task
Second task
Sequence
gene-tissue-expression
isoform-expression
Single-cell
batch-integration
cell-type-from-expression
Structure
complex-structure-evaluation
enzyme-commission-prediction
Network biology
gene-disease-association
go-function-multi-label
Chemical biology
bace1-binding-affinity
cell-painting-perturbation
Perturbation dynamics
cancer-drug-sensitivity
crispr-perturbation-prediction
Appendix
Table 9: Fixed repeated-run subset: the first two tasks per domain in BioXArena Table A4, preserving its within-domain order.
Method
Metric
Run 1
Run 2
Run 3
Mean ± SD
BioXArena Harness
Score
0.695
0.705
0.699
0.699±0.005
Success rate
0.944
0.944
0.944
0.944±0.000
Biomni
Score
0.637
0.660
0.644
0.647±0.012
Success rate
0.889
0.889
0.889
0.889±0.000
MLEvolve
Score
0.709
0.683
0.672
0.688±0.019
Success rate
0.944
0.889
0.889
0.907±0.032
Appendix
Table 10: Per-run results on the fixed 18-task subset with GPT-5.6-sol. Score is the penalized mean over all 18 tasks; success rate is the successful task count divided by 18. Summary entries report mean ± sample standard deviation (SD) across three independent runs.
Method
LLM backend
Biomni
Claude Sonnet 4 ( Anthropic, 2025 )
STELLA
Dev/Tool-Creation: Claude Sonnet 4.6 ( Anthropic, 2026b ) ;
Manager/Critic: Gemini 3.1 Pro ( The Gemini Team, 2026 )
MLEvolve
Gemini 3.1 Pro ( The Gemini Team, 2026 )
ML-Master 2.0
DeepSeek-V4-Pro ( Xu et al., 2026 )
Appendix
Table 11: Original backends of BioXArena’s reported agent systems, retained for the overall reference experiment.