Senior Manager, Process Development and Manufacturing

Assembly Biosciences, Inc.; South San Francisco (CA); Hybrid; USD 199,000 - 204,000; Full time

Job summary

Assembly Bio is seeking a Senior Manager to lead process development and manufacturing for small molecule drug substances in a hybrid South San Francisco role. You will oversee development, scale‑up, and tech transfers, ensuring cGMP compliance and robust manufacturing strategies across CMOs.

The role requires advanced degree plus substantial hands‑on experience in process chemistry, CRO/CMO interaction, and regulatory support for submissions. Strong collaboration and leadership are essential.

Qualifications

• PhD with 3+ years, MS with 6+ years, or BS with 8+ years of small molecule drug substance development experience.
• Strong hands‑on process chemistry experience and familiarity with drug substance manufacturing equipment.
• Knowledge of global regulatory requirements (cGMP, ICH, USP).
• Experience coordinating CROs/CMOs for drug substance development and testing.

Responsibilities

• Support drug substance development and manufacturing activities at CMOs to ensure timely delivery.
• Collaborate with CMOs to design, develop, and implement robust chemical synthesis processes.
• Support technical transfer of processes between sites as needed.
• Contribute to phase-appropriate route design and control strategy implementation.
• Coordinate with cross-functional teams to align drug substance and drug product programs.
• Provide technical reviews of batch records, deviations, and investigations.
• Design and execute experiments for robustness, scale‑up, transfer, and validation.
• Review regulatory submissions and provide technical justifications for questions.

Skills

Process chemistry expertise

CRO/CMO coordination

cGMP knowledge

Regulatory knowledge (ICH, USP)

Communication & collaboration

Project management

Education

PhD

MS

BS

Job description

POSITION SUMMARY

Position Title: Senior Manager, Process Development and Manufacturing

Reports to: Executive Director, Process Development and Manufacturing

Status: Regular, Full-time, Exempt

Location: South San Francisco, CA/Hybrid

Summary: The Senior Manager of Process Development and Manufacturing will be responsible for supporting process chemistry activities for Assembly Biosciences’ small molecule compounds, including development of drug substance manufacturing routes, process scale‑up, technology transfers and CMO coordination.

Specific responsibilities include, but are not limited to:

• Supporting drug substance development and manufacturing activities at CMOs to ensure timely delivery of drug substance meeting quality standards.
• Collaborating with CMOs to design, develop, and implement robust chemical synthesis processes for starting materials, intermediates, and APIs.
• Supporting technical transfer of starting material, intermediates, and API processes between sites as needed.
• Contributing to phase-appropriate synthetic route design and control strategy implementation (including fate and purge studies and mutagenic impurity evaluation) for starting materials, intermediates, and APIs across early- and late-stage programs.
• Collaborating cross-functionally to ensure seamless transitions between drug substance and drug product programs and CMOs.
• Providing technical support in ensuring that CMO manufacturing facilities are compliant with cGMPs.
• Providing technical review and approval of batch records, deviations, investigations, and technical reports.
• Designing and executing experiments for process robustness, optimization, scale‑up, transfer, and validation.
• Reviewing and summarizing process development results and analytical data from CROs/CMOs.
• Supporting authoring and reviewing drug substance sections in regulatory submissions, including technical justifications for regulatory questions.
• Functioning as a highly effective communicator, discussion leader, and team player in a dynamic team culture.

This job description outlines the primary duties and responsibilities of the role; however, it is not intended to be all-inclusive. The scope of responsibilities may be modified, expanded, or adjusted at the discretion of the organization to meet evolving business needs.

Qualifications Include:

• Ph.D. with 3+ years, MS with 6+ years, or BS with 8+ years of small molecule drug substance development experience in the pharmaceutical or biotech industry.
• Strong technical skills and hands‑on experience in process chemistry, including in‑depth knowledge of drug substance manufacturing equipment.
• Knowledge of global pharmaceutical regulatory requirements (e.g., cGMP, ICH, USP).
• Experience working with CROs/CMOs for drug substance development, manufacturing, and testing.
• Effective communicator with strong interpersonal, collaboration, and time‑management skills.
• Self‑motivated and adaptable in a fast‑paced environment, able to manage multiple projects and shifting

Pay Range: $199,400 - $203,700 annualized

The stated pay range for this position reflects the San Francisco Bay Area job market. Assembly Bio establishes pay ranges based on geographic work locations. Additional factors such as academic credentials and relevant experience will influence the actual salary offered.

About Assembly Bio

Assembly Bio (NASDAQ: ASMB) is an ambitious biopharmaceutical company with cutting‑edge therapeutic candidates capable of improving the lives of millions living with devastating viral and liver diseases. We have multiple ongoing clinical programs focused on the development of novel treatments for herpesviruses, hepatitis delta virus (HDV), cholestatic liver diseases and hepatitis B virus (HBV). Further, our research organization is dedicated to the discovery of new therapies to change the treatment paradigm for individuals living with serious viral and liver diseases.

We pride ourselves on creating a culture and work environment that is scientifically driven, ambitious, and collaborative. We encourage diversity of thought that leads to great innovation and are looking to add great people to our dynamic team who are driven to transform the lives of patients. We set our sights high—and pursue our goals with determination. Our unique organization stands ready to welcome talented, motivated individuals, who share our ambitions.

As an equal opportunity employer, we are committed to diversity and inclusion and will

not tolerate discrimination and harassment of any kind. All employment decisions are based on business needs, job requirements and individual qualifications, without regard to race, color, religion or belief, national, social or ethnic origin, sex (including pregnancy), age, physical, mental or sensory disability, HIV status, sexual orientation, gender identity and/or expression, marital, civil union or domestic partnership status, past or present military service, family medical history or genetic information, family or parental status, or any other status protected by the laws or regulations in the locations where we operate.

Information for Recruitment Agencies

Assembly Bio does not accept from recruiters/agencies any unsolicited resumes, or any candidate information including blinded resumes and will not be responsible for any fees related to resumes or candidate information that is unsolicited. Please do not contact hiring managers or Assembly Bio employees directly with any information related to a resume or a candidate. We handle all recruiting through our internal Human Resources team, and we will reach out to you directly should we wish to engage in a search. Your willingness to comply with this will significantly impact any decision we may make about doing business with you.