Prescient Therapeutics Ltd (ASX:PTX, OTC:PSTTF) has received Orphan Drug Designation (ODD) from the European Medicines Agency (EMA) for its lead candidate PTX-100 for the treatment of cutaneous T-cell lymphoma (CTCL), covering both mycosis fungoides and Sézary syndrome subtypes.
The designation provides a range of regulatory and commercial advantages in Europe, including 10 years of market exclusivity upon approval, protocol assistance, reduced regulatory fees and access to centralised marketing authorisation. It also complements PTX-100’s existing Orphan Drug and Fast Track status with the US Food and Drug Administration (FDA).
Disrupting cancer growth pathways
PTX-100 is a first-in-class therapy designed to disrupt cancer growth pathways and is currently being evaluated in a Phase 2a trial in patients with relapsed or refractory CTCL.
Prescient CEO James McDonnell said the EMA decision was an important step in the company’s development and commercial plans.
“Securing EMA Orphan Drug Designation is a major milestone in our mission to bring innovative therapies to patients with limited options,” McDonnell said. “This recognition validates our science and strengthens our commercial pathway in key markets.”
The company is advancing PTX-100 through clinical development and preparing for further discussions with the EMA to progress the pathway towards marketing authorisation.
Targeted therapy – PTX-100
PTX-100 is a first-in-class targeted therapy that blocks geranylgeranyl transferase-1 (GGT-1), an enzyme involved in cancer cell growth. By inhibiting GGT-1, PTX-100 disrupts oncogenic Ras signalling pathways through effects on Rho, Rac and Ral circuits, triggering apoptosis (cell death) in cancer cells. It is believed to be the only GGT-1 inhibitor in clinical development worldwide.
The drug has previously shown a favourable safety profile and early signs of clinical activity in a Phase 1 study and a recent pharmacokinetic/pharmacodynamic basket study in both haematological and solid malignancies. PTX-100 recently completed a Phase 1b expansion cohort in T-cell lymphomas, demonstrating encouraging efficacy and safety.
The US FDA has granted PTX-100 Orphan Drug Designation for all T-cell lymphomas and Fast Track Designation for adults with relapsed or refractory mycosis fungoides, the most common form of cutaneous T-cell lymphoma (CTCL). A global Phase 2 study in CTCL is now under way, with the Phase 2a portion expected to enrol up to 40 patients.
Investor briefing
McDonnell will host a live online investor briefing on Tuesday, November 25, 2025, at 3:00 pm (AEDT).
Registration: https://prescienttherapeutics.investorportal.com.au/investor-briefing/