Senior Scientist, Protein & Peptide/Chemical-Protein Conjugate Formulation

Company: JLSa2
Location: South San Francisco
Posted on: March 7, 2026

Job Description:

JLSa2, founded in 2024, is a well-resourced, seed-stage venture backed company located in South San Francisco currently developing a robust pipeline of novel protein-drug conjugate therapies to better address human metabolic diseases and other non-oncology related diseases. The Senior Protein & Peptide/Chemical-Protein Conjugate Formulation Scientist is a technical leader responsible for the development, optimization, and characterization of stable formulations for protein- and peptide/chemical conjugates-based therapeutics. This role provides deep subject-matter expertise in biophysical characterization, formulation design, and stability strategy, supporting programs from late discovery through clinical development. The position combines hands-on experimental work with technical leadership, cross-functional influence, and strategic input into developability and CMC decisions. Key Responsibilities Formulation Development & Strategy Design and optimize formulations for proteins and peptide/chemical-protein conjugates (liquid, long-acting, oral and high-concentration) Develop formulation strategies that address stability, aggregation, degradation, and delivery challenges Support route of administration and dosage form selection for subcutaneous and oral routes Lead formulation risk assessments and mitigation strategies Biophysical & Analytical Characterization Apply biophysical techniques to assess stability and developability (e.g., DSC, DLS, CD, SEC, HIC, rheology, subvisible particles) Interpret stress and forced degradation data to guide formulation decisions Collaborate with analytical teams on method development and comparability Program & Cross-Functional Leadership Serve as formulation lead on cross-functional project teams Provide formulation input to candidate selection and early CMC strategy Support tech transfer to development, manufacturing, and external partners Contribute to IND-enabling and regulatory documentation (CMC sections) Mentorship & Scientific Leadership Mentor junior formulation and analytical scientists Establish best practices, workflows, and technical standards Act as a subject-matter expert in internal reviews and governance forums External Collaboration Manage and oversee formulation activities with CROs and CDMOs Evaluate new formulation technologies and excipient strategies Stay current with advances in protein and peptide formulation science Required Qualifications Education & Experience PhD in pharmaceutical sciences, chemical engineering, biochemistry, or related discipline 5–10 years of industry experience in protein and/or peptide formulation Deep expertise in biologics and drug-conjugates formulation and stability science Experience with high-concentration formulations and/or long-acting injectables Experience with oral delivery formulations Proven track record supporting clinical candidates Strong experimental design, data interpretation, and problem-solving skills Preferred Qualifications Familiarity with device compatibility and combination products Familiarity with Auntie and Big Tuna and other Unchained analytical tools Experience with global regulatory filings (IND/IMPD) Prior experience in biotech or fast-paced development environments Key Competencies Scientific rigor and technical depth Cross-functional leadership without direct authority Strategic thinking with hands-on execution Clear scientific communication and documentation Mentorship and team development Reporting Structure Reports to: VP of Protein Engineering Role level: Senior individual contributor with project leadership responsibilities Salary Range: $175,000 to $200,000 (Compensation will be commensurate with experience/expertise/level and could fall outside of the stated range)

Keywords: JLSa2, Concord , Senior Scientist, Protein & Peptide/Chemical-Protein Conjugate Formulation, Science, Research & Development , South San Francisco, California