CounterX Therapeutics

About CounterX Therapeutics

CounterX Therapeutics is a clinical-stage biotechnology company developing first-in-class monoclonal antibody therapies designed to prevent fentanyl overdose and eliminate overdose-related deaths.

CounterX is pioneering a new biological approach to overdose prevention. Rather than reversing overdose after it occurs or managing opioid dependence, CounterX’s lead program, CTRX-101, is designed to bind fentanyl in circulation, prevent it from reaching the brain, and blunt life-threatening respiratory and cardiovascular effects.

CTRX-101 is a once-monthly, subcutaneous monoclonal antibody intended for patients with moderate to severe opioid use disorder, including those presenting after non-lethal overdose. The therapy is not an opioid, not a controlled substance, and does not induce withdrawal, making it compatible with existing medications for opioid use disorder.

CounterX is supported by substantial non-dilutive NIH funding and is advancing toward IND submission in 2026.

Founders & Leadership

CounterX Therapeutics is led by a team operating at the intersection of addiction neuroscience, clinical medicine, and disciplined biopharmaceutical execution.

Marco Pravetoni, PhD – Founder & Chief Scientific Officer

Dr. Pravetoni is a globally recognized leader in substance use disorder and addiction immunopharmacology. He holds the Rick L. Seaver Endowed Professorship in Brain Wellness and serves as Professor of Psychiatry and Behavioral Sciences. His NIH-funded research forms the scientific foundation of CounterX’s antibody-based overdose prevention platform.

Shawn Iadonato, PhD – Chief Executive Officer

Dr. Iadonato is an experienced biopharmaceutical executive with a strong track record of translating novel science into clinical-stage programs. He brings deep expertise in drug development strategy, regulatory execution, capital formation, and company building across the biotech lifecycle.

Craig Philips – Chief Financial Officer

Craig Philips is a seasoned life sciences finance leader with extensive experience in biotech financial strategy, capital planning, and investor operations. He has supported early- and growth-stage biotechnology companies through financing rounds, operational scaling, and long-term value creation.

The leadership team is further supported by experienced business development executives and a Scientific Advisory Board of leading clinicians and addiction specialists.

Why Now?

• Public Health Urgency
• Illicit fentanyl is the leading cause of death for Americans aged 18–45 and now accounts for ~70% of all overdose deaths.
• First-in-Class Biology
• CTRX-101 introduces a prevention-based mechanism that blocks fentanyl from penetrating the blood–brain barrier, offering protection for up to 30 days.
• Clear Clinical & Regulatory Pathway
• IND filing planned for Q2 2026, with Phase 1 clinical proof-of-concept targeted for 2027 and a potential FDA Emergency Use Authorization (EUA) pathway.
• Large, Reimbursable Market
• Approximately 2.4 million treated OUD patients in the U.S., ~740,000 non-lethal overdose ED visits annually, and strong payer precedent from long-acting injectable MOUDs.
• Capital-Efficient Execution
• Early research and portions of clinical development are funded through NIH grants, enabling disciplined advancement with limited dilution.

Advisory Board Role Overview

CounterX Therapeutics is inviting senior healthcare leaders to join its Board of Advisors to support the strategic development and scaling of a first-in-class overdose-prevention platform.

This role is designed for experienced healthcare executives, physician-leaders, payer strategists, public-sector leaders, and biopharmaceutical operators who have shaped clinical adoption, reimbursement strategy, or national healthcare expansion initiatives.

Advisors work closely with CounterX’s executive leadership and scientific team to provide strategic guidance while helping position the company for clinical, commercial, and public-sector success.

Areas of Advisory Contribution

Advisors may contribute across one or more of the following areas:

• Healthcare system adoption and market entry strategy
• Medicaid, Medicare, Medicare Advantage, and commercial reimbursement strategy
• Public health, state, and federal stakeholder engagement
• Clinical positioning across emergency medicine and addiction care
• Pricing, unit economics, and scalable deployment models
• Long-term platform and portfolio expansion strategy

Strategic Alignment & Investment Consideration

CounterX values strong alignment between its advisors and long-term mission.

As part of the advisory board discussion, candidates are asked to consider whether they would be open to exploring an investment in connection with advisory participation.

Any investment participation is entirely optional, independent of advisory responsibilities, and subject to review of company materials and terms.

Why Join CounterX?

• Meaningful Impact
• Contribute to a platform designed to prevent overdose deaths at scale.
• Category-Defining Innovation
• Help shape a new biological prevention category in addiction and public health.
• Exceptional Leadership & Science
• Work alongside world-class addiction scientists and experienced biotech executives.
• Critical Inflection Point
• CounterX is entering clinical development with clear near-term milestones and significant long-term upside.

Compensation & Participation

• Equity Participation
• Advisors receive equity in recognition of their strategic contributions.
• Optional Investment Opportunity
• Select advisors may choose to participate in the company’s current financing round. Participation is optional and separate from advisory responsibilities.

Commitment to Inclusion

CounterX Therapeutics is committed to building a diverse and inclusive advisory board. We believe diverse perspectives are essential to solving complex public health challenges and welcome advisors from all backgrounds.