About Us…

Obsidian Therapeutics is pioneering engineered cell and gene therapies to deliver transformative outcomes for patients. Obsidian’s programs apply our cytoDRiVE® technology in Cell and Gene therapy products to control expression of proteins for enhanced therapeutic efficacy and safety. Obsidian’s lead program is currently in clinical development for the treatment of patients with metastatic melanoma and non-small cell lung cancer.

We’re proud of our diverse talented team and committed to cultivating an environment of inclusion where each person feels a strong sense of belonging and is supported to continuously learn and contribute their best work. Our Research team is based in the heart of Cambridge, MA, and Technical Operations team is based in our purpose built facility in Bedford, MA. Obsidianites enjoy a highly collaborative culture, competitive salary and benefits, and potential for ownership through stock options.

Our Opportunity...

We’re looking for a highly motivated Director, Medical Writing with BLA/NDA experience to lead the strategic planning, development, and execution of regulatory and clinical documents supporting the advancement of Obsidian’s clinical development programs.

This individual will serve as the company's medical writing leader and subject matter expert, responsible for ensuring the delivery of high-quality, scientifically rigorous, regulatory-compliant documents that effectively communicate the clinical evidence supporting the product. The role combines strategic leadership with hands-on execution and will partner closely with Clinical Science, Regulatory Affairs, Biometrics, Clinical Operations, Clinical Safety, CMC, and external vendors.

This is a unique opportunity to establish a phase-appropriate medical writing capability within a clinical-stage biotechnology company preparing for its first product submission. You will be a vital part of a highly collaborative team working to unlock the promise of precision cell therapy for patients, starting with our lead program amsoki-cel (OBX-115), a novel engineered tumor-infiltrating lymphocyte (TIL) cell therapy that uses our proprietary cytoDRiVE® platform. This is a unique opportunity to be a valuable contributor in a well-funded clinical company with field-leading advisors, best-in-class partners, and an experienced team.

This is a remote role; travel to support job duties may be occasionally required.

You Will...

Core responsibilities

• Develop and execute the company's medical writing strategy in support of clinical development, regulatory submissions, and launch readiness.
• Partner with Regulatory Affairs to ensure strategic alignment, submission readiness, consistency of messaging, and compliance with applicable regulatory guidance.
• Translate complex clinical, statistical, safety, translational, and manufacturing information into clear, scientifically accurate narratives.
• Lead the authoring, review, and finalization of major regulatory documents, including: BLA submission documents, Module 2 clinical summaries, Clinical Study Protocols, Investigator Brochures, Clinical Study Reports (CSRs), Statistical Analysis Plan summaries, Integrated Summaries of Safety (ISS), Integrated Summaries of Efficacy (ISE), responses to health authority questions.
• Collaborate with Clinical Development and Biometrics to construct compelling evidence packages.
• Serve as the primary medical writing representative on cross-functional program and submission teams; drive alignment on scientific messaging, timelines, and review processes.
• Establish document planning, governance, standards, templates, and quality systems.
• Ensure consistency across protocols, SAPs, CSRs, safety documents, and regulatory summaries.
• Contribute to inspection readiness and document traceability activities.
• Establish document development processes that support rapid execution without compromising quality.
• Build a scalable medical writing operating model that effectively leverages external partners; oversee contract medical writers, editors and document publishing vendors as needed.
• Identify risks, resource constraints, and submission-critical dependencies early and proactively in order to implement mitigation plans to ensure critical path deliverables are met.
• Implement best practices for content reuse, document standards, authoring technologies, and quality control.
• Develop and maintain writing templates, style guides, and document repositories.
• Ensure compliance with ICH, GCP, FDA, EMA, and company quality requirements.

You Bring...

Core Qualifications

• Advanced scientific degree preferred (PhD, PharmD, MD, or equivalent); Master's degree with significant relevant experience will be considered.
• 10+ years of biotechnology or pharmaceutical medical writing experience.
• Demonstrated experience authoring and leading major regulatory submission documents, including experience supporting BLA/NDA.
• Cell therapy experience highly preferred; oncology, gene therapy, or advanced therapeutics experience may be considered.
• Strong understanding of ICH guidelines and global regulatory requirements.
• Experience managing external medical writing vendors and consulting resources.
• Excellent scientific communication and project management skills.
• Ability to synthesize complex clinical and statistical information into clear, persuasive scientific narratives.
• Thrives in highly cross-functional small to mid-sized biotech environments, where adaptability and a high degree of collaboration are required.
• Strategic Agility - balances long-term submission planning with near-term execution demands.
• Has built and led lean teams with strong external consultants; comfortable operating within lean infrastructure.
• Execution Excellence - Creates and leads disciplined approach that consistently produces high-quality deliverables at the pace required by the business.

Bonus Qualifications

• Experience supporting a first product approval.
• Experience with autologous cell therapy or similarly complex clinical study.
• Participation in/leadership of at least one successful BLA approval.

Cultural Competencies

• Inspires confidence, credibility, and trust internally and externally; recognized for high integrity.
• Operates with Urgency, adept at building buy-in and driving alignment within and across teams, senior leadership, and external partners.
• Exceptional communication skills in verbal, written, and visual formats, and adapted to the audience.
• Tenacious and resilient – has navigated significant challenges (scientific and business) and is not easily daunted.
• Excellent organizational skills; able to manage multiple tasks of varying degrees of complexity in parallel.
• Remains calm under pressure and leads others through complex situations.
• Builds followership by being transparent, persuasive, excited about the work, and willing to work hard together to get the job done.
• Continuous learner – actively follows innovations in area of expertise, fosters innovative thinking, and adopts novel approaches that are fit for purpose.
• Reflective and self-aware; leads by example with a growth mindset.

Obsidian is committed to equitable and transparent pay practices.

The anticipated base salary range for this role is below. The actual base salary offered will be determined based on a combination of factors, including applicable qualifications, level of education, the depth of experience, unique skills, geographic location, internal equity, and/or business needs. The actual base salary offered will be in accordance with federal, state, and/or local wage requirements for the role’s location.

Our competitive compensation package includes an annual incentive bonus as a percentage of actual base salary and long-term incentives in the form of employee stock options, both of which are commensurate with the role’s level. We also offer a generous benefits package which includes comprehensive medical, dental, and vision coverage; company contributions to health savings and retirement accounts; ample paid time off; access to wellness programs; and rich career growth opportunities.

Anticipated Base Salary Range

$220,500—$269,500 USD

Obsidian is proud to be an equal opportunity employer, cultivating a welcoming and diverse environment. All applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, veteran status or any other applicable legally protected characteristics.