Phio Pharmaceuticals (PHIO) investor relations material

Disease and market opportunity

• cSCC accounts for ~1.8 million annual cases and 25% of solid tumors; incidence is rising with aging, UV exposure and weakened immunity.

• High-risk lesions represent ~1.1 million cases; estimated neoadjuvant market was $2B-$3B in the presentation and $2.2B-$3.3B in the Q&A.

• Surgery is the standard of care, but lesion size, location and patient comorbidities can increase risks including disfigurement, impaired function and reconstructive surgery.

• PH-762 is positioned to complement, not replace, dermatologic surgery; physician interviews described it as an advancement, while market share estimates remain premature.

Phase Ib clinical results

• Phase Ib involved four injections over three weeks across five escalating dose cohorts; the highest-dose cohort had an 85% response rate, with 6 of 7 patients responding.

• In the highest-dose cohort, 4 responders had 100% pathological clearance, 1 had >90% clearance and 1 had >50%; overall response across cohorts was 65%.

• No immune or dose-limiting toxicities were seen across a 20-fold dose escalation, supporting a favorable safety and tolerability profile.

• Results covered tumors of different sizes and locations; management cited a modest dose response and said Phase Ib learnings will inform a more effective next-trial design.

INTASYL platform and intellectual property

• INTASYL is a self-delivering siRNA platform designed to temporarily silence PD-1 in T cells, reactivating immune cells to attack tumors and release interferon gamma.

• Local tumor delivery is intended to reduce systemic exposure and related toxicity risks compared with systemically infused monoclonal antibodies.

• Administration can take 1-2 minutes in a physician's office; the drug is refrigeration stable for two years and allows flexible dosing.

• The IP portfolio includes 54 issued patents extending through 2044, covering the platform, gene sequences, compounds, methods of use and combinations with monoclonal antibodies.

• API and finished drug product are manufactured in the U.S., reducing exposure to tariff variability.