Associate Scientist, CMC (Gene Therapy)

Application deadline: 12 Sep 2026 
Location: San Diego 92121, California, United States 
Contract type: Permanent 
Job ID: 4836 

Bring your scientific curiosity to the bench and help shape the future of gene therapy CMC.

In this hands-on role, you will turn complex science into robust processes, meaningful data, and practical solutions that help move an HSV-1 gene therapy program forward.

About Replay, now part of LEO Pharma

Replay Holdings, Inc. ("Replay"), now part of LEO Pharma, is advancing the future of gene therapy for patients with rare disease. A gene therapy company focused on HSV-based vectors for topical dermatology applications, Replay combines the agility of a small, high-impact team with the global reach and patient commitment of LEO Pharma.

In CMC, Process & Analytical Development, we share a “challenge accepted” mindset and are guided by simplification, collaboration, and accountability to achieve our goals.

Your role

As Associate Scientist, CMC, you will be an independent bench scientist supporting upstream, downstream, formulation, and analytical workstreams for our gene therapy program. You will design and execute experiments, troubleshoot technical challenges, interpret data, and help build phase-appropriate methods and processes.

This is a role for a scientist who enjoys hands-on laboratory work, scientific problem solving, and contributing in a fast-paced, cross-functional environment.

You will:

• Independently design, execute, and troubleshoot experiments across cell culture, viral production, purification, formulation, and analytical workflows.
• Develop, optimize, and support qualification of assays and process steps for an HSV-1 gene therapy program.
• Run vector characterization and release-relevant assays, including viral titer, genome quantitation, potency, and impurity/residual testing.
• Author and revise protocols, SOPs, technical reports, and development summaries in line with data integrity and Good Documentation Practices.
• Support analytical method and process transfer to CDMOs, including review of data packages and resolution of technical questions.

The role also offers the opportunity to contribute to control strategy, specification setting, stability programs, and the day-to-day technical guidance of research associates.

This is a highly visible opportunity to work close to the science in a collaborative, resource-conscious team where your work can directly influence development decisions. You will gain exposure across CMC disciplines, contribute to external partner interactions, and help build rigorous processes in a dynamic gene therapy setting.

Your qualifications

To succeed in this role, we imagine that you have deep scientific training and hands-on experience in biologics, viral vectors, or related CMC development. You are comfortable working independently at the bench and can translate experimental results into clear conclusions and next steps.

• Hands-on experience in at least one CMC area: cell culture/upstream, purification/downstream, formulation, or analytical development is a requirement for this role.
• Bachelor's degree in biology, biochemistry, virology, microbiology, biomedical engineering, or chemical engineering with 4+ years of relevant laboratory experience OR Master's degree with 2+ years of related experience.
• Experience developing, optimizing or troubleshooting process steps.
• Viral vector CMC experience, preferably HSV; experience with AAV, lentivirus, or adenovirus is also relevant.
• Familiarity with qPCR/ddPCR, viral titer or potency assays, GMP expectations, ICH/FDA guidance, and method or process transfer to CDMOs.

You will bring competent technical writing, sound data interpretation skills, and basic statistical understanding. You communicate clearly, work well across functions, and thrive in a hands-on, safety-first laboratory environment.

Your new team

You will join CMC – Process & Analytical Development in San Diego, working on-site five days per week in a BSL-2 laboratory. The team works cross-functionally across process, analytical, formulation, quality, and external partner activities. You will be part of a small, ambitious group where collaboration, scientific rigor, and practical problem solving are essential.

Compensation

The base salary range for this position is $100,000 - $110,000. The base salary range represents the anticipated low and tier of the range for this position. Salary will vary depending on several factors such as the candidates’ qualifications, skills, competencies and proficiency for the role. In addition, some positions may include eligibility to earn commission/bonus based on company and/or individual performance.

Your Application

You do not need to upload a cover letter, but feel free to add a few sentences in your resume on why this position sparked your interest. Please refrain from including a photograph.

Beyond the skin

Become part of Replay and the LEO Pharma partnership, as we go beyond the skin to make a lasting impact. We are the legacy-builders of the future – enabling people to have a better today and tomorrow. Through collaboration and partnerships, we can do much more. 

For certain positions, you may be required to complete a background check conducted by a third party.

Join us and make an impact - Together, we reach far beyond the skin