Principal Scientist

3 weeks ago


San Diego, United States Expedition Therapeutics Full time

Principal Scientist / Director, Medicinal Chemistry We are an innovative, science-driven biotechnology company developing novel therapeutics for COPD and other serious neutrophilic inflammatory diseases. Our team combines deep discovery and development expertise with a nimble, collaborative culture to advance cutting‑edge programs from concept through clinical proof‑of‑mechanism. Position Summary We are seeking an accomplished Principal Scientist or Director-level Medicinal Chemist to lead small molecule drug discovery programs through lead optimization and pre‑IND candidate selection. This individual will guide compound design, SAR interpretation, and synthetic strategy while managing CRO‑based chemistry execution to ensure high-quality data and timely delivery. Working closely with biology, DMPK, and translational teams, the candidate will drive data‑driven decision‑making and contribute scientific expertise to business development diligence and external collaborations. Key Responsibilities Lead medicinal chemistry efforts for small molecule programs targeting respiratory and inflammatory pathways. Drive structure–activity relationship (SAR) optimization to improve potency, selectivity, ADME, and other properties. Collaborate with cross‑functional team to design experiments that inform mechanism, PK/PD relationships, and compound differentiation. Support preclinical candidate nomination, IND‑enabling studies, and regulatory documentation. CRO & External Management Manage and guide CRO partners conducting synthesis, purification, and analytical characterization of small molecules. Ensure scientific rigor, quality, and reproducibility in all external chemistry deliverables. Identify, qualify, and manage CROs to expand synthetic and analytical capabilities as needed. Review and approve study plans, reports, and data packages from external partners. Cross‑functional Collaboration, IP & Diligence Support Work closely with biology, DMPK, and translational teams to integrate chemical and biological data into program strategies. Provide scientific input during business development diligence, including evaluation of external assets, chemical IP, and compound data packages. Monitor competitive landscapes and evolving IP positions, help define compound series strategy and contribute to patent applications. Represent medicinal chemistry in internal governance, partner meetings, and external diligence interactions. Qualifications Ph.D. in Organic or Medicinal Chemistry, with 8–15+ years of biotech/pharma experience (title commensurate with experience). Proven track record in lead optimization and pre‑IND candidate advancement. Strong command of synthetic chemistry, SAR interpretation, and drug design principles. Experience collaborating with cross‑functional teams and translating preclinical data into actionable chemistry insights. Demonstrated success managing CRO‑based chemistry operations and ensuring high-quality deliverables. Excellent communication and presentation skills, with the ability to engage both scientific and business audiences. Proactive, solution‑oriented mindset; thrives in a small, entrepreneurial biotech environment. Preferred Experience Background in respiratory, inflammation, or immunology‑related drug discovery is preferred but not required. Familiarity with structure‑based design, computational chemistry, or cheminformatics tools. Exposure to IP strategy, patent drafting, and licensing or partnership diligence. Why Join Us High‑impact, visible role with direct influence on discovery strategy and program advancement. Collaborative, science‑first culture where innovative thinking is encouraged and recognized. Competitive salary, equity participation, and comprehensive benefits package. Seniority level: Director Employment type: Full‑time Job function: Science #J-18808-Ljbffr



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