# Hybrid Quantum Approach for Sampling Molecular Fragment Libraries to Discover Novel Therapeutics for Ebola

### Introduction

- Fragment-based drug design (FBDD) uses molecular fragments to identify potential drug candidates, formulated as a combinatorial optimization problem. Finding the optimal solution in such a vast search space is challenging, particularly for generating a Pareto front of solutions, which classical samplers struggle to achieve.
- To address these challenges, we propose a novel method that leverages quantum techniques, offering more efficient navigation of the solution space and a broader set of promising candidates for evaluation.

### Method

- Generate fragment library
- Translate constraints to QAOA
- Prepare Ansatz
- Sample library via QAOA
- Apply subgraph mining to reduce quantum errors

### Conclusions

- We compared our hybrid QAOA sampler to the classical greedy steepest descent (CGSD) sampler:
  - Figure A: QAOA sampler returns over 5x more samples on average.
  - Figure B: QAOA yields a broader range of pharmacophore scores, including higher scores than CGSD.
  - Figure C: After 10 rounds, QAOA steadily discovers unique optimal molecules, while CGSD struggles to find new ones.
  - This work is a part of a [DARPA IMPAQT contract.  More details here.](https://polarisqb.com/polaris-news/polarisqb-receives-darpa-impaqt-funding-to-advance-quantum-computing-for-drug-design/)

[TO DOWNLOAD THE ONE PAGER AS A PDF CLICK HERE](https://polarisqb.com/wp-content/uploads/2025/02/Copy-of-Darpa_quantum_onepager-FINAL-1124.pdf "TO DOWNLOAD THE ONE PAGER AS A PDF CLICK HERE")

Authors: Benson, Maurice; Byler, Kendall; Petroff, Anna B.; Ingman, Victoria; Villar, Santiago; Hendrix, Paul; Simpson, William C.; Goldhagen, Guy; Shipman, William J.; Keinan, Shahar

Published On: November 24th, 2024  
Categories: [News](https://polarisqb.com/category/polaris-news/)  
Tags: [White Paper](https://polarisqb.com/tag/white-paper/)