Principal Scientist I, Medicinal Chemistry

Job overview

The Principal Scientist I, Medicinal Chemistry role is onsite in Watertown, MA, with an expected salary range of $108,500–$201,500 per year, plus a performance-based cash incentive. The scientist joins Mariana Oncology’s Discovery Chemistry team to advance radiopharmaceutical and precision-medicine programs focused on peptide-based therapeutics. The role provides technical and strategic leadership across medicinal chemistry programs, from hit identification through candidate nomination. Through peptide synthesis, data interpretation, mentoring, and cross-functional collaboration, the scientist helps guide discovery decisions and prepare methods for development studies.

What you'll do

• Lead medicinal chemistry design and synthesis from hit identification through candidate selection
• perform multi-step peptide synthesis
• provide scientific leadership for peptide synthesis laboratory activities
• advise project teams on synthetic strategy
• mentor junior scientists, co-ops, and interns
• manage external CRO relationships
• collaborate with biology, radiochemistry, DMPK, and pharmacology teams
• maintain laboratory records and safety compliance.

What we're looking for

Skills & competencies

principal scientist i

medicinal chemistry

watertown ma

mariana oncology

peptide synthesis

radiopharmaceuticals

drug discovery

precision medicine

discovery chemistry

cross-functional research

$108,500–$201,500/year

performance incentive

Work arrangement

• Weekend coverage required

Benefits & perks

• Performance-based cash incentive.

Why this role

Peptide medicinal chemistry and peptide synthesis expertise required; PhD with 0–3 years of relevant industry experience or BS/MS with 6+ years requested.

About the employer

Mariana Oncology is hiring for this role. Industry: Research and Development in Biotechnology (except Nanobiotechnology). Sector: 54.