About Lei Li, Ph.D.
Lei Li, Ph.D., is a biostatistician and former FDA/CDRH primary statistical reviewer who now provides independent expert-witness and statistical consulting services to both plaintiff and defense counsel. His background combines an inside-the-agency regulatory perspective with hands-on statistical depth across the medical-device and pharmaceutical industries.
Professional background
From September 2020 to April 2022, Dr. Li served as a Mathematical Statistician and Primary Statistical Reviewer at the U.S. Food and Drug Administration, Center for Devices and Radiological Health (FDA/CDRH). In that role he reviewed premarket approval (PMA), De Novo, 510(k), investigational device exemption (IDE), pre-submission, and real-world-evidence (RWE) submissions; applied propensity-score methodology in RWE matters, including breast reconstruction and cervical artificial-disc devices; and authored statistical memoranda for therapeutic and diagnostic devices spanning general surgical, orthopedic, and in vivo and in vitro diagnostic areas. He is a former FDA reviewer and is no longer affiliated with the agency.
Following his agency tenure, Dr. Li was a Principal Biostatistician at Edwards Lifesciences (April 2022 – April 2023), where he supported cardiovascular early-feasibility studies, developed statistical analysis plans (SAPs), and applied mixed-modeling and win-ratio methods. He co-led the publication "Left Atrial to Coronary Sinus Shunting for Treatment of Symptomatic Heart Failure" in JACC: Cardiovascular Interventions and mentored junior staff. He subsequently served as a Statistical Project Leader at Sanofi (June 2023 – April 2025), leading vaccine programs from translational and phase I/II through phase III. That work included two phase I/II acne-vaccine studies using MCPMod for dose-finding and sample size, Bayesian Decision-by-Design Go/No-Go methodology, a phase III rabies-vaccine program with FDA and EMA activities (pre-BLA, BIMO, ISE, ISS), a phase III E. coli vaccine using a Bayesian group-sequential design with efficacy and futility monitoring, and co-leadership of phase III hemophilia (rare-disease) studies.
Since August 2025, Dr. Li has provided expert-witness and statistical consulting services through LunarAI LLC. He maintains an active research program in statistical methodology, with peer-reviewed publications and working manuscripts addressing permutation testing, sample-size re-estimation, win-ratio methods, group-sequential and anytime-valid trial design, and divergence-based inference. Engagements are conducted through LunarAI LLC and are available to both plaintiff and defense counsel, subject in every case to a conflicts-of-interest check.
Experience
A summary of Dr. Li's professional roles in regulatory review, industry biostatistics, and consulting.
- Sep 2020 – Apr 2022 Mathematical Statistician & Primary Statistical Reviewer — FDA, Center for Devices and Radiological Health (CDRH). Reviewed PMA, De Novo, 510(k), IDE, pre-submission, and real-world-evidence submissions; authored statistical memoranda for therapeutic and diagnostic devices.
- Apr 2022 – Apr 2023 Principal Biostatistician — Edwards Lifesciences. Cardiovascular early-feasibility studies, SAP development, and mixed-modeling and win-ratio methods; co-led a JACC: Cardiovascular Interventions publication.
- Jun 2023 – Apr 2025 Statistical Project Leader — Sanofi. Led vaccine programs across translational and phase I/II through phase III, including dose-finding, Bayesian Go/No-Go, group-sequential, and rare-disease studies.
- Aug 2025 – present Expert Witness & Statistical Consultant — LunarAI LLC. Independent statistical consulting and expert-witness services for plaintiff and defense counsel.
- 2018 – 2020 Graduate Teaching Assistant — George Mason University. Supported instruction in statistics during doctoral studies.
Education
- 2020 Ph.D., Statistics — George Mason University. Thesis: "Divergence Minimization Algorithm with Application to Healthcare Data."
- 2015 M.S., Statistics — George Washington University.
- 2013 B.S., Mathematics & B.S., Finance (dual degree) — Shandong University, China.
Areas of expertise
Dr. Li's work spans regulatory and litigation support, clinical-trial design, medical-device evaluation, and applied statistical methodology.
Litigation & Regulatory Support
- Expert reports and declarations
- Critique of opposing statistical analyses
- FDA regulatory considerations
- Adverse-event incidence analysis
Clinical Trials & Trial Design
- Clinical-trial design and SAPs
- Bayesian and adaptive designs
- Group-sequential design
- Sample-size re-estimation
Medical Devices
- PMA, De Novo, 510(k), IDE review
- Medical-device evaluation
- Real-world evidence
- Diagnostic device methodology
Statistical Methods
- Causal inference & propensity scores
- Win-ratio & probabilistic win-ratio
- MMRM and mixed modeling
- Permutation & studentized permutation tests
- Survival / time-to-event analysis
Therapeutic & Product Areas
- Cardiovascular devices
- Orthopedic & general surgical devices
- In vivo and in vitro diagnostics
- Vaccines and rare-disease programs
Tools
- SAS
- R
- Python
Selected publications & presentations
A selection of Dr. Li's peer-reviewed publications, working manuscripts, and invited presentations.
Peer-reviewed publications
- Dong, Y.X., & Li, L. (2026). "On Marginal Coordinate Test with Multivariate Responses." Journal of Systems Science & Complexity.
- Li, L., Vidyashankar, A.N., Diao, G., & Ahmad, E. (2019). "Robust Inference after Random Projections via Hellinger Distance for Location-scale Family." Entropy, 21, 348.
- Vidyashankar, A.N., & Li, L. (2019). "Ancestral Inference for Branching Processes in Random Environments and an Application to Polymerase Chain Reaction." Stochastic Models.
Selected presentations
- DSSV, Italy (Jul 2026, scheduled)
- ICSA Applied Statistics Symposium (Jun 2026)
- George Mason University (Feb 2026)
- Temple University (Oct 2025)
- University of Delaware (Oct 2025)
- Joint Statistical Meetings, Nashville (Aug 2025)
- FDA/ASA Conference (Sep 2021): "Propensity Score Methodology Applied to Clinical Study"
- Auburn University (Apr 2021)
Working research & preprints
- "A Sequential Studentized Permutation Test for Vaccine Efficacy" (2026)
- "EM Algorithm for Blinded Sample Size Re-estimation" (2026)
- "Probabilistic Win Ratio Method" (2026)
- "Anytime-valid Clinical Trial Design" (2025)
- "A Unified Framework for Group Sequential Design" (2025)
- "Divergence Methods for Models with Latent Structure" (submitted to JASA, under review)
Awards
- 2023 Edwards Lifesciences — Herculean Team Award Finalist, Innovative Study Design Award Finalist, and Operational Excellence Award Finalist.
- 2017 Outstanding Graduate Student, Washington Statistical Society.
A full curriculum vitae is available to qualified counsel on request.
Dr. Li is a former mathematical statistician with the U.S. Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), and is no longer affiliated with the FDA. This site is not affiliated with, endorsed by, or sponsored by the FDA or any government agency.
Discuss a potential engagement
Considering a biostatistics expert for a regulatory, clinical-trial, or medical-device matter? Reach out to discuss the issues in your case. Every engagement is subject to a conflicts-of-interest check.