I build and evaluate large language models for healthcare. At M42 in Abu Dhabi I lead work on the Med42 family of open-weight clinical LLMs, covering the full pipeline — continuous pretraining, instruction tuning, preference alignment — and the evaluation and safety frameworks used to decide whether any of it is fit for clinical use.
Much of my recent work argues the same point from different angles: benchmark scores are a poor proxy for clinical reliability. That has led to research on evaluation-framework variability, dataset transparency and bias, sycophancy under authoritative pressure, and multilingual clinical care in Arabic.
Before healthcare I spent six years at EDF R&D, where I also completed a PhD on detecting novelty in textual data streams as early as possible.
Selected work
Med42 — open-weight clinical LLMs
A suite of clinical LLMs built on Llama 2 and Llama 3, adapted with specialised clinical data and multi-stage preference alignment. The v2 models outperform their Llama 3 base counterparts and GPT-4 across standard medical benchmarks.
Med42 paper
Med42-v2 paper
Llama3-Med42-70B
Llama3-Med42-8B
med42-70b
MEDIC — evaluating LLMs in clinical applications
A framework that assesses clinical LLMs across five dimensions — reasoning, ethics and bias, data and language understanding, in-context learning, and clinical safety — rather than collapsing everything into a single benchmark score.
Paper
Leaderboard
BioToken & BioFM — genomic foundation models
A tokenization framework that encodes genetic variants and structural annotations — coding regions, transcript boundaries — directly into genomic representations, instead of treating DNA as plain linear text. The resulting 265M-parameter model stays competitive with genomic foundation models an order of magnitude larger.
Paper
BioFM-265M
Selected publications
Full list on Google Scholar.
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2026
Overalignment in Frontier LLMs: An Empirical Study of Sycophantic Behaviour in Healthcare
C. Christophe, W. M. Abdul, P. Munjal, T. Raha, R. Rajan, P. Kanithi
arXiv:2601.18334
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2026
Cross-Examination Framework: A Task-Agnostic Diagnostic for Information Fidelity in Text-to-Text Generation
T. Raha, C. Christophe, N. Saadi, H. A. Javed, M. A. F. Pimentel, R. Rajan, et al.
arXiv:2601.19350
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2025
Building Trust in Clinical LLMs: Bias Analysis and Dataset Transparency
S. Maslenkova, C. Christophe, M. A. F. Pimentel, T. Raha, M. U. Salman, et al.
arXiv:2510.18556
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2025
BioToken and BioFM: Biologically-Informed Tokenization Enables Accurate and Efficient Genomic Foundation Models
A. Medvedev, K. Viswanathan, P. Kanithi, K. Vishniakov, P. Munjal, C. Christophe, et al.
bioRxiv 2025.03.27.645711
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2025
Bridging Language Barriers in Healthcare: A Study on Arabic LLMs
N. Saadi, T. Raha, C. Christophe, M. A. F. Pimentel, R. Rajan, P. K. Kanithi
arXiv:2501.09825
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2024
Beyond Fine-tuning: Unleashing the Potential of Continuous Pretraining for Clinical LLMs
C. Christophe, T. Raha, S. Maslenkova, M. U. Salman, P. Kanithi, M. A. F. Pimentel, S. Khan
Findings of EMNLP 2024
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2024
Named Clinical Entity Recognition Benchmark
W. M. Abdul, M. A. F. Pimentel, M. U. Salman, T. Raha, C. Christophe, P. K. Kanithi, et al.
arXiv:2410.05046
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2024
MEDIC: Towards a Comprehensive Framework for Evaluating LLMs in Clinical Applications
P. K. Kanithi, C. Christophe, M. A. F. Pimentel, T. Raha, N. Saadi, H. Javed, et al.
arXiv:2409.07314
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2024
Med42-v2: A Suite of Clinical LLMs
C. Christophe, P. K. Kanithi, T. Raha, S. Khan, M. A. F. Pimentel
arXiv:2408.06142
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2024
Beyond Metrics: A Critical Analysis of the Variability in Large Language Model Evaluation Frameworks
M. A. F. Pimentel, C. Christophe, T. Raha, P. Munjal, P. K. Kanithi, S. Khan
arXiv:2407.21072
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2024
Med42 — Evaluating Fine-Tuning Strategies for Medical LLMs: Full-Parameter vs. Parameter-Efficient Approaches
C. Christophe, P. K. Kanithi, P. Munjal, T. Raha, N. Hayat, R. Rajan, et al.
arXiv:2404.14779
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2021
Monitoring Geometrical Properties of Word Embeddings for Detecting the Emergence of New Topics
C. Christophe, J. Velcin, J. Cugliari, M. Boumghar, P. Suignard
EMNLP 2021
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2021
Change Detection in Textual Classification with Unexpected Dynamics
C. Christophe, J. Velcin, J. Cugliari, P. Suignard, M. Boumghar
Expert Systems with Applications, vol. 176
Experience
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2023 – now
Senior Applied Scientist, NLP
M42 (formerly G42 Healthcare) · Abu Dhabi, UAE
Clinical LLMs end to end: continuous pretraining, instruction tuning and alignment, plus the evaluation and safety work that decides what ships. Also clinical information extraction — NER and entity linking — over large-scale patient data.
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2017 – 2023
Research Engineer / Data Scientist
EDF R&D · France
NLP for customer-feedback analysis and anomaly detection on electricity-production time series. Completed a PhD in parallel under a CIFRE arrangement with ERIC Lab.
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2017
Assistant Researcher
ERIC Lab, Université Lyon 2 · France
Weak-signal detection in text streams using topic modelling — comparing topics learned from different corpora to surface genuinely novel documents.
Education