Director, Medicinal Chemistry

About the role

Assembly Biosciences, a clinical-stage biotechnology company developing small molecule antivirals and liver disease treatments, is hiring a Director, Medicinal Chemistry in South San Francisco (on-site / hybrid). The Director reports to the Vice President, Medicinal Chemistry and co-leads a full-phase small molecule antiviral discovery program from lead optimization through candidate nomination, while also contributing design ideas and scientific judgment across the rest of the portfolio. Wet chemistry is run through CRO partners.

Key responsibilities

• Co-lead a full-phase discovery program: own the MedChem strategy, drive the design-synthesis-test-analysis cycle and advance it to development candidate nomination
• Design new target molecules and chemical series using property-based and structure-based design, working with computational chemistry and structural biology scientists
• Manage external synthetic chemistry at CROs: set priorities, review and troubleshoot routes, safeguard data quality and compound integrity, and deliver on timelines across time zones
• Integrate virology, biochemistry, DMPK and safety data into design, and resolve DMPK liabilities such as metabolic stability, permeability, efflux, transporters, protein binding and CYP inhibition/induction
• Contribute to early-phase discovery, including target and hit triage, hit-to-lead progression and evaluation of new starting points and modalities
• Give scientific input and feedback to other discovery programs and participate in multidisciplinary teams with virology, DMPK, informatics, pharmacology, toxicology and CMC colleagues
• Make data-driven go/no-go decisions on series progression and resource allocation
• Help acquire the computational, biophysical, structural, analytical or synthetic tools a program needs
• Review patent literature and work with the patent attorney on invention disclosures and filings
• Mentor colleagues and CRO partner scientists

Required profile

• PhD in synthetic organic or medicinal chemistry
• At least 8 years of drug discovery experience in pharma or biotech
• Demonstrated experience leading or co-leading a program from hit-to-lead through lead optimization to development candidate nomination
• Experience directing synthetic chemistry carried out by domestic or international CRO partners
• Excellent written and oral communication, teamwork and ability to work with minimal supervision in a fast-paced, small company
• Knowledge of antiviral drug discovery is desirable but not required

Required skills

• Structure-based drug design and use of protein structures and computational tools
• Diagnosing and solving DMPK issues in lead optimization
• Working knowledge of PK and PK/PD concepts applied to compound design