Scientist I, Discovery Chemistry

Arrowhead Pharmaceuticals, Inc. (Nasdaq: ARWR) is a commercial-stage biopharmaceutical company developing medicines that treat intractable diseases by silencing the genes that cause them. Using a broad portfolio of RNA chemistries and efficient modes of delivery, Arrowhead therapies trigger the RNA interference (RNAi) mechanism to induce rapid, deep, and durable knockdown of target genes. The company focuses on developing innovative drugs for diseases with a genetic basis, typically characterized by the overproduction of one or more proteins involved in disease. Arrowhead’s RNAi-based therapeutics leverage the natural pathway of gene silencing, enabling the pursuit of disease targets not addressable by small molecules and biologics. The company’s clinical pipeline includes targets in the liver and lung, with a promising preclinical pipeline.

Arrowhead’s corporate headquarters is in Pasadena, CA, with research and development teams in Madison, WI, and San Diego, CA, and a state-of-the-art manufacturing facility in Verona, WI.

About the role

Arrowhead Pharmaceuticals is seeking a highly motivated Scientist I to join the Discovery Chemistry team in San Diego. This role will focus on the design, synthesis, purification, and characterization of peptides that support the discovery and optimization of next-generation RNAi therapeutics. The position is onsite 5 days a week in San Diego.

Responsibilities

• Design, execute, optimize, and troubleshoot solid-phase peptide synthesis (SPPS) workflows using both automated and manual synthesis techniques.
• Purify and characterize peptides using chromatographic and mass spectrometry techniques, including HPLC and LC-MS.
• Analyze experimental data, interpret results, and propose next steps to support discovery programs.
• Contribute to the design and optimization of novel peptide constructs that support RNAi therapeutic development.
• Maintain accurate and well-organized experimental records using electronic laboratory notebooks (ELNs).
• Present scientific findings and participate in project team discussions.
• Maintain laboratory equipment and ensure compliance with laboratory safety procedures and company policies.
• Stay current with emerging technologies and scientific literature in peptide chemistry and drug discovery.

Requirements

• Bachelor's or Master's degree in Chemistry, Biochemistry, or a related scientific discipline.
• 8+ years of relevant industry laboratory experience or demonstrated scientific leadership within peptide chemistry.
• Strong background in organic chemistry and analytical chemistry.
• Hands-on experience with solid-phase peptide synthesis (SPPS).
• Experience operating automated peptide synthesizers.
• Proficiency in analytical characterization using HPLC, UPLC, and LC-MS.
• Excellent experimental design, troubleshooting, and problem-solving skills.
• Strong written and verbal communication skills with the ability to effectively present scientific results.

Preferred Qualifications

• Experience supporting peptide discovery from hit identification through lead optimization.
• Experience with high-throughput peptide synthesis or screening technologies.
• Familiarity with biophysical assays used to characterize biomolecular interactions.
• Experience working on oligonucleotide, peptide, or RNA-based therapeutic discovery programs.
• Demonstrated ability to work independently while contributing effectively to cross-functional research teams.

Pay

California pay range: $105,000 USD - $115,000 USD.

Benefits

Arrowhead provides competitive salaries and an excellent benefit package.