Principal Scientist I, Medicinal Chemistry

Mariana Oncology • Watertown, MA

2d • $108,500 - $201,500

About The Position

Mariana Oncology is seeking a Principal Scientist I, Medicinal Chemistry to join our Discovery Chemistry team. The successful candidate will play a key role in advancing innovative radiopharmaceutical and precision medicine programs, with a focus on peptide-based therapeutics. This individual will contribute both as a technical and strategic leader to medicinal chemistry efforts from hit identification through candidate nomination.

Requirements

• PhD in Organic Chemistry, Medicinal Chemistry, or a related discipline with 0-3 years of relevant industry experience; or BS/MS in Chemistry or a related discipline with 6+ years of relevant industry experience.
• Demonstrated expertise in peptide medicinal chemistry and peptide synthesis is required; experience in small-molecule medicinal chemistry is a plus.
• Strong understanding of drug discovery principles, medicinal chemistry, structure-based drug design, and synthetic organic chemistry.
• Proven ability to independently solve complex scientific challenges and develop creative, practical solutions.
• Experience managing external CROs and scientific collaborations.
• Demonstrated ability to influence project direction, build productive cross-functional relationships, and thrive in a collaborative, matrixed environment.
• Excellent communication, organizational, and scientific writing skills with strong attention to detail.

Nice To Haves

• experience in small-molecule medicinal chemistry is a plus.

Responsibilities

• Lead medicinal chemistry design and synthesis activities from hit identification through lead optimization and candidate selection.
• Serve as a hands-on contributor, executing multi-step peptide syntheses to support radiopharmaceutical discovery programs.
• Provide scientific leadership and operational oversight for peptide synthesis laboratory activities.
• Serve as an internal subject matter expert in peptide chemistry, driving problem-solving efforts, improving workflows, and advising project teams on synthetic strategy.
• Mentor and provide technical guidance to junior scientists, co-ops, and interns.
• Manage external CRO relationships to ensure timely execution of chemistry objectives.
• Collaborate with cross-functional teams, including biology, radiochemistry, DMPK, and pharmacology, to advance discovery programs.
• Derive insights from chemistry, affinity, pharmacology, and DMPK datasets to inform molecular design, project strategy, and candidate selection.
• Present project updates and scientific findings to project teams, departmental audiences, and leadership through clear oral and written communications.
• Maintain accurate electronic laboratory notebook records and ensure compliance with laboratory safety and HSE requirements.
• Partner with Development colleagues to transfer synthetic methods and analytical procedures supporting regulatory-enabling studies.
• Deliver high-quality results while effectively managing priorities and timelines in a fast-paced environment.

Benefits

• performance-based cash incentive

What This Job Offers

• Job Type: Full-time
• Career Level: Principal