Scientist/Sr. Scientist, Oligo Chemistry (REMOTE)

Korsana Biosciences; Waltham (MA); Remote; USD 115,000 - 140,000; Full time

Job summary

Korsana Biosciences in Waltham, MA seeks a senior chemist to design and optimize chemically modified oligonucleotides, develop novel nucleoside analogs, and guide lead optimization through SAR campaigns.

Responsibilities include synthesizing oligonucleotides, interpreting SAR data, collaborating with biology and translational sciences, and overseeing external CROs to ensure timely project execution.

Qualifications

• Ph.D. or M.S. with oligonucleotide industry experience.
• Hands-on organic synthesis and nucleoside chemistry.
• Expertise in siRNA, ASO, PMO, or related modalities.
• Deep knowledge of oligonucleotide modification patterns.
• Experience with synthesis platforms and purification workflows.
• Strong analytical skills (LC-MS, RP-HPLC, IEX, CE, MALDI-TOF).
• Medicinal chemistry SAR campaigns for oligonucleotide therapeutics.
• Familiarity with delivery technologies for targeting and delivery.
• Experience supporting lead optimization and candidate selection.

Responsibilities

• Design and optimize chemically modified oligos to improve potency and delivery.
• Develop novel nucleoside analogs and backbone chemistries for oligos.
• Generate SAR data to guide lead optimization across chemistries.
• Design oligo libraries with bioinformatics and biology teams.
• Develop synthetic routes for oligonucleotide building blocks.
• Oversee synthesis, purification, and analytical characterization of oligos.
• Manage external CROs for experimental design and timelines.
• Apply analytical methods (RP-HPLC, IEX, LC-MS, CE, SEC) for characterization.
• Collaborate with biology and pharmacology to link chemistry and activity.
• Contribute to next-gen oligonucleotide platform technologies.
• Evaluate emerging technologies to enhance potency and safety.
• Maintain thorough technical documentation and communicate results.

Skills

Scientific creativity

Cross-disciplinary collaboration

Medicinal chemistry data integration

Independent yet collaborative

Strong communication skills

Problem-solving in pharma

Education

Ph.D. in Organic Chemistry/Medicinal Chemistry

M.S. with 2–5 years in oligonucleotide therapeutics

Hands-on organic synthesis & nucleoside chemistry

Therapeutic oligonucleotide chemistry expertise

Understanding of modification patterns & PK/PD

Oligonucleotide synthesis platforms & purification

Analytical skills: LC-MS, RP-HPLC, IEX, CE, MALDI-TOF

SAR campaign experience for oligonucleotides

Delivery technologies familiarity (GalNAc etc.)

Lead optimization & candidate selection experience

Tools

Automated solid-phase synthesis

Preparative HPLC

Job description

Responsibilities

• Design and optimize chemically modified oligonucleotides, including siRNAs, ASOs, PMOs, and other emerging modalities.
• Develop novel nucleoside analogs, phosphoramidites, backbone chemistries, and oligonucleotide architectures to improve potency, stability, durability, and tissue delivery.
• Generate and interpret structure-activity relationships (SAR) to guide lead optimization across oligonucleotide chemistries and modification patterns.
• Design oligonucleotide libraries in collaboration with bioinformatics and biology teams to support cellular and in vivo screening campaigns.
• Develop synthetic routes for novel oligonucleotide building blocks using modern organic and nucleoside chemistry approaches.
• Oversee the synthesis, purification, and analytical characterization of oligonucleotides and intermediates, leveraging both internal capabilities and external CRO partners.
• Manage external CROs, including experimental design, prioritization, technical oversight, data review, timeline management, and troubleshooting to ensure high‑quality and timely project execution.
• Develop and apply analytical methods, including RP‑HPLC, IEX, LC‑MS, CE, and SEC, to characterize oligonucleotides and support process development.
• Partner closely with biology, pharmacology, toxicology, and translational sciences teams to understand how chemical modifications impact biological activity and therapeutic performance.
• Contribute to next‑generation oligonucleotide platform technologies, including novel chemistries, delivery strategies, and manufacturability improvements.
• Evaluate emerging technologies and scientific literature to identify innovative approaches that enhance potency, extra‑hepatic delivery, durability, and safety.
• Maintain thorough technical documentation and effectively communicate experimental strategies, results, and recommendations to cross‑functional teams.

Education & Experience

• Ph.D. in Organic Chemistry, Medicinal Chemistry, or a related discipline with 0‑3 years of relevant industry experience, or M.S. with 2‑5 years of industry experience in oligonucleotide therapeutic development.
• Extensive hands‑on experience in organic synthesis and nucleoside chemistry, including the synthesis and characterization of phosphoramidites or related oligonucleotide building blocks.
• Demonstrated expertise in therapeutic oligonucleotide chemistry, including siRNA, antisense oligonucleotides, splice‑switching oligonucleotides, PMOs, or related modalities.
• Possess a deep understanding of contemporary oligonucleotide modification patterns, including 2′-O‑methyl, 2′-fluoro, LNA, cEt, constrained analogs, phosphorothioate stereochemistry, phosphodiester incorporation, glycol nucleic acids, morpholino chemistry, and other emerging chemistries and how individual modifications influence potency, nuclease resistance, pharmacokinetics, biodistribution, immunostimulation, and toxicity.
• Direct experience with oligonucleotide synthesis platforms and purification workflows, including automated solid‑phase synthesis and preparative HPLC.
• Strong analytical expertise with LC‑MS, RP‑HPLC, ion exchange chromatography, capillary electrophoresis, MALDI‑TOF, and related characterization techniques.
• Experience designing and interpreting medicinal chemistry SAR campaigns for oligonucleotide therapeutics.
• Familiarity with oligonucleotide delivery technologies, including GalNAc conjugates, lipid conjugates, peptide conjugates, antibody‑oligonucleotide conjugates, nanoparticles, or other targeted delivery systems is desirable.
• Experience supporting lead optimization and candidate selection within a drug discovery environment is preferred.

Skills & Attributes

• Exceptional scientific creativity and problem‑solving skills with the ability to design innovative chemical solutions to challenging therapeutic problems.
• Deep understanding of the evolving oligonucleotide therapeutics landscape and current state‑of‑the‑art chemistry across siRNA, ASO, PMO, and emerging RNA‑targeting platforms.
• Ability to integrate medicinal chemistry, synthetic chemistry, biology, and pharmacology data into coherent lead optimization strategies.
• Strong communication skills with the ability to present complex scientific concepts to multidisciplinary teams.
• Demonstrated ability to work independently while thriving in a collaborative, fast‑paced, and highly interdisciplinary research environment.
• Passion for advancing transformative nucleic acid medicines through innovative chemistry and rigorous scientific execution.

The anticipated base salary range for this position is $115,000 - $140,000. This role may also be eligible for a target annual bonus and equity‑based compensation, as well as participation in the company’s benefit programs. Actual compensation will depend on several factors, which may include, but are not limited to relevant years of experience, educational background, and geography.

Korsana Biosciences is an Equal Opportunity Employer. We are committed to fostering a diverse, inclusive, and equitable workplace where all individuals are valued and respected. Employment decisions are based on qualifications, merit, and business needs, without regard to race, color, religion, gender, sexual orientation, national origin, disability, veteran status, or any other protected status.