Job: 62-21BA

Ambrx is a biopharmaceutical company enabling a new field of protein medicinal chemistry, using an innovative technology that directs incorporation of amino acids beyond nature’s conserved set into biosynthetic proteins to produce high value biologics products.

Ambrx is seeking a highly motivated, senior-level scientist to be a key member of the Translational Sciences (TS) team. The successful candidate will be primarily responsible for development of LC-MS/MS and ligand-binding assay pharmacokinetic (PK), anti-drug antibody (ADA), and cell-based neutralizing antibody (nAb) assays, in addition to managing GLP CROs for methods validation and non-clinical/clinical sample testing.

Job Responsibilities:

  • Independently develop small molecule LC-MS/MS and hybrid LC-MS/MS PK assays to support Ambrx’s programs from discovery to the clinic.
  • Work with TS team members to assess novel ligand bindings assay and immunogenicity assay formats and successfully develop PK, ADA, and cell-based nAb assays to support IND-enabling studies and clinical trials.
  • Request proposals, audit, and negotiate bioanalytical contracts with GLP CROs.
  • Work with TS team members to efficiently transfer and validate PK/immunogenicity methods to CROs within aggressive timelines.
  • Manage outsourced generation of antibodies for use as critical reagents in PK/ADA assays.
  • Author PK/TK/ADA study reports and nonclinical summaries for regulatory filings.
  • Provide technical guidance to junior scientists on the TS team.
  • Effectively communicate study results and timeline updates at internal project team meetings and collaborator meetings.
  • Perform PK parameter analysis using Phoenix WinNonlin software and interpret data.
  • Manage time and workload to meet project deliverables within aggressive deadlines.


Required Experience:

  • PhD with 5+ years experience (or MS with 10+ years experience) in the protein and small molecule bioanalytical field.
  • Demonstrated hands-on experience developing and validating small molecule LC-MS/MS and hybrid LC-MS/MS assays for quantification of PK samples; expertise in triple quad mass spectrometer systems.
  • Prior experience developing, transferring, and validating ligand binding PK assays and ADA assays for protein therapeutics using the MesoScaleDiscovery (MSD) platform.
  • Skilled in tissue culture techniques, developing cell-based nAb assays, and performing statistical analyses using JMP software (ex. outlier identification, cutpoint determination).
  • Knowledgeable in PK and immunogenicity regulatory guidances (USP, EP), bioanalytical white papers, and industry best practices.
  • Experience interviewing GLP CRO’s, conducting technical audits, negotiating quotes, and actively managing CROs to stay within the budget of quoted work.
  • Demonstrated capability to quickly troubleshoot data and identify solutions.
  • Prior experience working with ADCs, bispecific molecules, and PEGylated proteins.
  • Experience developing biomarker assays is a plus.
  • Previous supervisory experience.
  • Ability to work collaboratively in a goal-oriented, fast-paced, matrixed team environment.
  • Attention-to-detail, organizational skills, and strong written and oral communication skills are required.


To be considered as an applicant, please submit your resume/CV referencing the specific position of interest to   Applicants whose qualifications and experience most closely match the requirements of the position will be reviewed. Candidates will only be contacted for evaluative discussions. Ambrx offers competitive compensation & benefits.      EOE