Administrative Assistant

Job Title: Administrative Assistant

Department: HR & Operations

Reporting to: Associate Director, Executive Administration & Operations

Location: San Diego, CA

About Sirius

Sirius is a clinical stage biotech company developing innovative siRNA therapies for global markets. We are dedicated to discovering and developing new treatment options for cardiovascular and cerebrovascular disease and translating siRNA technology into transformative medicine for the treatment of chronic diseases. Our most advanced products are SRSD107 for the treatment of thromboembolic disorders, SRSD216 for the treatment of hyperlipoproteinemia, and SRSD101 for the treatment of dyslipidemia.

Founded in 2021 by a world-class leadership team and investors, Sirius is dual headquartered in San Diego, where discovery center is located, and Shanghai, where translational medicine and clinical operation center is based. Sirius has raised nearly US$150 million funding to date from top global VC funds such as OrbiMed and Creacion Ventures.

Summary of Position

We are seeking a highly organized and proactive Administrative Assistant to support executive operations and daily office management. This role reports directly to the Associate Director of Executive Administration & Operations and serves as a key support in executing administrative and operational priorities.

This is a high-impact, hands-on role ideal for someone who thrives in a fast-paced biotech startup environment.

Employment Type : Full-Time, Temporary (3–6 months, with strong potential for conversion)

This role is structured as a temporary full-time position for an initial period of 3–6 months, with strong potential for conversion to a regular full-time role based on performance and business needs. The position is eligible for company benefits during the temporary period in accordance with company policies.

Key Responsibilities

1. Executive & Administrative Support

• Provide day-to-day administrative support to leadership (calendar scheduling, meeting coordination, travel arrangements)
• Coordinate internal and external meetings, including preparing agendas and tracking follow-ups
• Support company events, board meetings, and leadership visits (logistics, catering, on-site coordination)

2. Office & Operations Management

• Oversee office operations, including vendor coordination, supplies, and workspace organization
• Support facility-related tasks (maintenance requests, vendor scheduling, office setup for expansion)
• Ensure smooth day-to-day office experience for employees and visitors

3. HR & People Operations Support

• Assist with onboarding and offboarding logistics, including equipment setup, orientation scheduling, and documentation tracking
• Maintain employee records and internal HR documentation with accuracy and confidentiality
• Support core HR processes such as PTO tracking, payroll coordination, employee communications, and benefits enrollment, including expatriate support
• Assist with onboarding programs and ongoing employee training, including new hire orientation and preparation of performance-related documentation

4. Cross-functional Coordination

• Work closely with Finance, HR, and external vendors to support operational processes
• Track and follow up on key operational tasks and deadlines
• Support ad hoc projects as needed in a growing organization

Qualifications

• Bachelor’s degree preferred
• 2–5 years of administrative, operations, or office management experience
• Strong organizational and multitasking skills with high attention to detail
• Excellent communication skills and a proactive, problem-solving mindset
• Ability to handle sensitive and confidential information with discretion
• Comfortable working in a fast-paced, evolving startup environment

Nice to Have

• Experience in biotech, healthcare, or startup environment
• Exposure to HR processes or payroll systems (e.g., TriNet)
• Experience supporting senior executives