Director, ADC & DAC (Contract-to-Hire)

Location: Cambridge, MA (on-site) Employment Type: Full-time, contract-to-hire (12 months), with conversion to a permanent position based on performance and business needs Reports To: Executive Director, Translational Research & Corporate Development Start Date: Immediate About PineTree Therapeutics PineTree Therapeutics is a Cambridge, MA–based biotechnology company developing novel antibody- based therapeutics, including antibody-drug conjugate (ADC) and degrader-antibody conjugate (DAC) programs. We are a small, hands‑on team that values scientific rigor, speed, and ownership. Position Summary The Director, ADC & DAC will provide scientific and technical leadership for PineTree’s antibody‑drug and degrader‑antibody conjugate programs, serving as the owner and single point of accountability for the end‑to‑end conjugate effort; from linker, payload, and conjugation strategy through candidate selection and IND‑enabling development. This is an active technical leadership role. You will set the scientific direction for the conjugate effort and stay deep in the science—driving design decisions and troubleshooting the most challenging linker‑payload and bioconjugation problems, rather than executing routine bench work. Payloads of interest span targeted small‑molecule and classical cytotoxic modalities. Key Responsibilities Own the overall ADC/DAC effort and serve as the single point of accountability for PineTree's conjugate programs. Define and drive the integrated linker‑payload and conjugation strategy from feasibility and proof‑of‑concept through candidate selection and IND‑enabling development. Contribute to program prioritization, timelines, and go/no‑go decisions. Linker, Payload & Conjugation Strategy (Design & Optimization) Guide selection and optimization of linkers, conjugation chemistries, attachment sites, and drug‑to‑antibody ratio (DAR). Apply deep medicinal‑ and bioconjugation‑chemistry expertise to match payloads with appropriate linker‑payload designs. Lead the design, structure‑activity analysis, and troubleshooting of complex linker‑payload constructs. Advise on payload‑class selection, physicochemical properties, conjugate stability, and release mechanisms. Intellectual Property & Platform Innovation Help PineTree build proprietary IP around linkers and conjugation approaches for future ADC and DAC programs. Identify novel linker/conjugation concepts that enhance intracellular payload delivery and release. Contribute to invention disclosures, patent filings, and freedom‑to‑operate assessments in collaboration with internal leadership and IP counsel. CMC, Analytical & Translational Interface Partner with CMC, analytical, DMPK/toxicology, and translational colleagues to ensure conjugate designs are developable and support IND‑enabling and downstream activities. Advise on ADC/DAC analytics (e.g., DAR and drug‑load distribution, aggregation, free payload, LC‑MS, HIC), conjugate stability, and the PK/tox implications of linker‑payload choices. Contribute conjugate‑related content to scientific reports and regulatory documentation as programs advance. Qualifications Required Ph.D. in synthetic organic chemistry, medicinal chemistry, bioconjugation/chemical biology, or a related discipline (or equivalent experience). 10+ years of biotech/pharmaceutical experience in ADC or bioconjugate drug development, with demonstrated depth in linker‑payload design and antibody conjugation. Proven track record advancing ADC/conjugate programs — from linker‑payload design and optimization through candidate selection and/or IND‑enabling development. Hands‑on expertise in linker chemistry and conjugation methods (e.g., cysteine/lysine and site‑specific conjugation, DAR control and characterization) across multiple payload classes. Working knowledge of payload classes, including cytotoxics and, ideally, small‑molecule inhibitors, targeted degraders, or molecular glues. Solid understanding of ADC/DAC analytics, conjugate stability, and the PK/tox and developability implications of linker‑payload design. Ability to operate independently and lead complex, cross‑functional programs to concrete deliverables. Preferred Experience conjugating small‑molecule inhibitors, targeted degraders (e.g., PROTAC or molecular glue), beyond classical cytotoxics. Experience with multispecific antibodies and/or targeted protein degradation. Track record of generating linker/conjugation intellectual property (issued patents, invention disclosures). Prior experience establishing conjugation capabilities, platforms, or IP at a biotech. Experience supporting IND‑enabling development and early clinical (Phase I) programs, particularly in oncology. We offer a highly competitive compensation package, including equity participation that reflects the strategic importance of this role. The engagement begins as a contract with the potential for conversion to a permanent (full‑time) position based on performance and business needs. As a permanent employee, PineTree offers comprehensive benefits, including medical and dental insurance, paid time off, and a 401(k) with a company match. Physical Requirements Prolonged periods of sitting at a desk and working on a computer. Periods of standing and working in a laboratory environment may be required. Must be able to lift up to 20 pounds at times. An individual in this position may be exposed to laboratory and chemical hazards, including the handling of cytotoxic and other potent compounds under appropriate safety controls. #J-18808-Ljbffr Pinetree Therapeutics, Inc