Scientist/Sr. Scientist: In vivo Pharmacology

About Firefly Bio:

Firefly specializes in Degrader Antibody Conjugates (DACs) which combine the unique strengths of ADCs with selective protein degraders. Our state-of-the-art platform results in highly specific delivery of degraders to target tissue. Our mission is to realize the full potential of ADCs by unlocking new classes of payloads. Our company culture is built on the values of Focus, Integrity, Respect and Energy.

Position Summary:

Firefly Biologics is seeking a highly motivated Scientist or Senior Scientist to join our in vivo pharmacology team with a focus on oncology drug discovery. This lab-based role will contribute to all phases of preclinical development, with a particular emphasis on antibody-drug conjugates (ADCs).

The ideal candidate will have deep, hands-on expertise in mouse oncology models, biologics or ADC pharmacology, and in vivo study design and execution. In vivo pharmacology will be the primary focus of this position, and strong proficiency in these skills is essential. Experience with in vitro cell-based assays is considered a plus and preferred but not required.

You will lead the design and execution of in vivo efficacy, safety, pharmacokinetic (PK), and pharmacodynamic (PD) studies. You may contribute to in vitro assays assessing target engagement, pathway modulation, cytotoxicity, and biomarker validation. Cross-functional collaboration with chemistry, biology, bioanalytical, and translational teams will be essential to align strategies and support data-driven decision-making.

Responsibilities:

• Lead the design and execution of in vivo studies in tumor models (CDX, PDX) including efficacy, PK/PD, MoA, combination studies, and biomarker evaluations.
• Manage and perform in vivo studies at internal vivarium facilities; coordinate with CROs as needed.
• Drive the development and characterization of preclinical tumor models, ensuring reproducibility and appropriate use of standard-of-care controls.
• Ensure ethical and regulatory compliance in animal studies and maintain rigorous, well-documented records to support IND-enabling studies.
• Synthesize complex in vivo pharmacology and biomarker data to provide strategic insights and recommendations for program advancement.
• Collaborate with multidisciplinary project teams to align pharmacology and translational strategies with program goals.
• Present data clearly to stakeholders and contribute to study reports, regulatory documents, and internal decision-making.
• Mentor junior scientists and help foster a culture of scientific excellence and innovation.
• (Preferred) Develop and execute in vitro pharmacology assays to support ADC mechanism of action and biomarker discovery.
• (Preferred) Implement and analyze biomarker assays such as ELISA, MSD, flow cytometry, qPCR, Western blotting, and IHC.

Requirements and Experience:

• PhD in Oncology, Biology, Pharmacology, or a related field, with 5 years of relevant industry experience; MS with 6+ years may also be considered.
• Extensive hands-on, must-have experience with in vivo pharmacology techniques, including tumor implantation, dosing (IV, IP, SC, PO), blood/tissue collection, necropsy, and PK/PD sample handling.
• Proven ability to independently design, execute, and interpret in vivo oncology studies.
• (Preferred) Experience with in vitro assays supporting drug MoA and biomarker assessment.
• Experience with ADC biology, antibody therapeutics, non-GLP tox, and mechanistic studies.
• Familiarity with regulatory documentation and contribution to IND-enabling studies is preferred.
• Proficiency in GraphPad Prism, Excel, PowerPoint, and standard data analysis tools.
• Strong communication, time management, and organizational skills.
• Demonstrated ability to lead and mentor junior staff.
• Comfortable working independently in a fast-paced, cross-functional team environment.
• Willingness to work flexible hours, including some weekends, to maintain study integrity.

Benefits:

Every team member is essential in shaping Firefly Bio's culture and science, and for our success. We offer competitive compensation packages including stock options and the opportunity to be part of ground-breaking research. Firefly Bio is an equal opportunity employer and will consider all applicants for employment. Firefly Bio does not discriminate based on race, sex, color, religion, age, national origin, marital status, disability, veteran status, genetic information, sexual orientation, gender identity or any other reason prohibited by law in provision of employment opportunities and benefits.