Principal Scientist, Medicinal Chemistry

Psivant; Watertown (MA); On-site; USD 140,000 - 170,000; Full time

Benefits offered by this job

Competitive salary

401k match

Impactful therapeutics

Collaborative team

Job summary

PsiThera is seeking a talented medicinal chemist to advance peptide therapeutics and small molecules from hits to development candidates. You will lead synthesis, design, and data interpretation across computational and experimental teams to drive programs toward the clinic.

The ideal candidate has deep experience with macrocyclic peptides, oral delivery optimization, and leading CRO chemistry efforts in a fast-paced biotech environment. PsiThera offers a collaborative, cutting-edge setting.

Qualifications

• Bachelor's/Master's/PhD in organic or medicinal chemistry.
• 5–10 years in biotech/pharma with hit-to-development experience.
• Experience in peptide synthesis and small molecule optimization.
• Strong background in structure-based design and in silico methods.
• Leadership of CRO chemistry teams is preferred.

Responsibilities

• Advance peptide therapeutics and macrocyclic peptides to development candidates.
• Collaborate with CADD, biophysics, biology to meet timelines and goals.
• Apply structure- and computation-based design to optimize molecules.
• Oversee external chemists to ensure timely delivery of targets.
• Interpret analytical results to confirm compound quality.
• Lead or co-lead medicinal chemistry efforts across programs.

Skills

Organic chemistry

Medicinal chemistry

Peptide synthesis

Macrocyclic peptides

In silico design

Team leadership

CRO management

ADME/PK

Data analysis

Communication skills

Education

PhD in Organic/Medicinal Chemistry

MS in Medicinal Chemistry

BS in Chemistry

Tools

Solid-phase peptide synthesis

Solution-phase synthesis

Computational modeling

Peptide informatics

Spotfire

Job description

PsiThera is seeking a talented and creative medicinal chemist with a strong track record of advancing peptide therapeutics and small molecule drug discovery projects from initial hits through to development candidate selection to join our dynamic, multidisciplinary team. Our science and our team are focused on combining medicinal chemistry with our cutting-edge computational platform to rapidly identify and optimize molecules into innovative medicines for patients.

We are looking for a self-motivated individual who thrives in a fast-paced, highly collaborative environment that integrates computational and experimental data to drive our programs to the clinic. The ideal candidate will have direct experience optimizing and advancing novel peptide therapeutics into clinical development, integrating a deep knowledge of synthetic and medicinal chemistry with in silico drug discovery methods to perform multiparameter optimization, including ADME/PK considerations, and rapidly advance programs from hit identification to lead selection to development candidate nomination. A successful candidate will have a deep knowledge of design and synthesis of peptides and peptidomimetics with enhanced potency, stability, and pharmacokinetic properties, strong synthetic chemistry skills, expertise in creative and practical small molecule design, experience guiding teams of CRO chemists and excellent communication skills.

This individual will join our growing medicinal chemistry team and collaborate closely across functions including computational chemistry, biophysics, structural biology, and biology teams to provide actionable insights and strategic guidance.

Responsibilities

• Advance peptide therapeutics, especially macrocyclic peptides and small molecule programs from screening to development candidate selection
• Champion cross-functional collaboration, in collaboration with CADD, biophysics, structural biology, DMPK and biology design molecules to achieve program goals and meet timelines
• Implement structure-based and computational-based drug design to optimize peptide and small molecule therapeutics; Prioritize and implement synthesis
• Manage teams of external synthetic chemists to ensure timely delivery of complex target molecules for biological testing
• Ensure data integrity and project success by interpreting analytical results to confirm compound quality
• Stay current with chemistry, medicinal chemistry and project-relevant literature as well as with new patent application filings
• Lead research team or serve as medicinal chemistry lead from concept through lead optimization toward clinical development

Qualifications

• Education: BS, MS or PhD in organic chemistry, medicinal chemistry or a closely related field
• Experience: 5-10 years of experience in the biotechnology or pharmaceutical industry, with a proven track record of advancing molecules from hit to development candidate selection
• Demonstrated expertise in organic chemistry, including proficiencies in both automated solid-phase peptide synthesis, and solution-phase small molecule synthesis
• Demonstrated expertise in medicinal chemistry, analyzing data, designing molecules and implementing synthesis to optimize both peptides and small molecules for oral delivery
• Deep knowledge of macrocyclic peptides optimization, including properties required for oral administration
• Proficient instruction-based ligand design to guide peptide and small molecule optimization
• Experience with computational modeling and simulation for design and optimization of peptides and small molecules
• Experience utilizing peptide informatics tools for SAR
• Familiarity with machine learning and AI-driven platforms in drug discovery
• Experience leading and managing teams of external chemists
• Experience in a leadership role is preferred, as a project lead or co-lead, as well as functional area lead for medicinal chemistry
• Hands‑on and collaborative attitude with proven ability to work across drug discovery disciplines, including biology, structural biology, computational chemistry and biophysics
• Excellent communication skills, with the ability to inspire, collaborate and lead a multidisciplinary environment
• Excellent organizational skills and attention to detail, with a strong passion for learning new concepts and technologies
• Familiarity with library‑based screening technologies (DEL, mRNA display, phage display) and direct experience with screen follow‑up and fragment‑based drug discovery
• Experience with progressing programs through lead optimization for immunology targets
• Familiarity with molecular modeling tools
• Proficiency with data analysis tools such as Spotfire

Benefits

• Competitive salary and benefits package including 401k match
• Opportunity to make a significant impact on the development of novel therapeutics
• Work with a talented and passionate team of scientists
• Be a part of a cutting‑edge company that is revolutionizing drug discovery

About Us

PsiThera is creating better therapeutics through an integrated molecular design paradigm that leverages best‑in‑class physics‑based and AI technologies honed through decades of research and innovation. Our focus is first‑in‑class inflammation and immunology (I&I) small molecule therapeutics. We have assembled a diverse team with extensive experience across disciplines ranging from physics and computer science to chemistry, biology, biochemistry, and structural biology. This continuum of complementary skills drives our scientific vision to deliver meaningful therapeutics to patients in need. We are patient‑inspired, perseverant, synergistic, supportive, intrepid, and inclusive. If you’re passionate about advancing medicine in a fast‑paced, innovative environment, and eager to contribute to a team that blends advanced computation with drug discovery, PsiThera might be the perfect fit for you.

At PsiThera, we are a lean, high‑performing team dedicated to pushing boundaries and achieving growth—both personally and scientifically. We seek individuals who are smart, collaborative, and thrive in a dynamic, early‑stage biotech environment.

Our Story: https://psithera.com/company/

Team: https://psithera.com/company/team-and-leadership/

PsivantTherapeutics, Inc. (d/b/a PsiThera) is proud to be an Equal Opportunity Employer, committed to fostering an inclusive and diverse workplace.

We comply with all applicable laws and regulations, ensuring that all qualified applicants receive consideration for employment without regard to race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, disability, veteran status, genetic information, or any other legally protected status.