Prescient Therapeutics Ltd has received Fast Track Designation from the United States Food and Drug Administration (FDA) for its lead candidate PTX-100, marking a significant advancement in the company's commercialization strategy for this novel oncology treatment.
The designation specifically applies to PTX-100 for the treatment of adults with relapsed or refractory (r/r) mycosis fungoides, the most common subtype of Cutaneous T-Cell Lymphoma (CTCL). This regulatory milestone provides Prescient with several advantages, including enhanced access to FDA officials and the ability to submit New Drug Applications (NDAs) on a rolling basis, potentially expediting the review process.
"Getting Fast-Track designation is a critical milestone towards our goal of advancing PTX-100 into a registration-enabling trial designed to support potential accelerated approval and, from there, commercialization," said Prescient Therapeutics CEO James McDonnell. "As we progress our Phase 2 trials, we will be engaging closely with the FDA to ensure alignment on endpoints and study scope."
Novel Mechanism of Action Targets Cancer Cell Growth
PTX-100 represents a first-in-class compound designed to inhibit geranylgeranyl transferase-1 (GGT-1), a critical enzyme involved in cancer cell proliferation. By blocking GGT-1, the drug disrupts oncogenic Ras signaling pathways, specifically inhibiting the activation of Rho, Rac, and Ral circuits within cancer cells, ultimately triggering apoptosis (programmed cell death) in malignant cells.
Currently, PTX-100 is believed to be the only GGT-1 inhibitor in clinical development worldwide, positioning Prescient at the forefront of this novel therapeutic approach. The compound has already received Orphan Drug Designation from the FDA for all T-cell lymphomas, further highlighting its potential significance in addressing these challenging hematological malignancies.
Promising Clinical Data Supports Development
The FDA's decision to grant Fast Track status follows encouraging results from PTX-100's clinical development program. A Phase 1b study enrolled 19 T-cell lymphoma patients and demonstrated a favorable safety profile at various doses up to 2,000 milligrams per square meter.
Notably, the trial reported a 42% overall response rate among all evaluable T-cell lymphoma patients, with six out of seven CTCL patients receiving clinical benefit. Responders demonstrated a median progression-free survival (PFS) rate exceeding 10 months, significantly outperforming the typical median PFS of approximately 3.1 months associated with vorinostat, a standard care treatment for this condition.
One patient from the Phase 1 study achieved complete response and continues to receive PTX-100 under Australia's compassionate access scheme, underscoring the drug's potential for durable clinical benefit in some patients.
Phase 2 Clinical Trial Now Underway
Prescient has already initiated a Phase 2a clinical study of PTX-100, with the first site activation completed at the Epworth Freemasons hematology unit in Melbourne, Australia. This open-label trial will evaluate two dosage levels in approximately 40 patients with relapsed/refractory CTCL.
Professor Miles Prince, a world-leading expert in CTCL treatment, will serve as the principal investigator for this trial—the first of multiple Phase 2a studies Prescient plans to initiate across Australia, the United States, and Europe.
Addressing an Unmet Medical Need
Mycosis fungoides, as the most common form of CTCL, represents a serious condition with significant unmet medical needs despite existing treatment options. The FDA's Fast Track Designation acknowledges that PTX-100 shows potential to address these gaps in care.
Fast Track status is part of the FDA's broader initiative to accelerate the development and review of drugs for serious conditions, enabling earlier patient access to promising new therapies. For patients with limited treatment options, this regulatory pathway can be crucial in bringing innovative medicines to market more efficiently.
As Prescient continues to build momentum with PTX-100, the company remains focused on its strategic vision of developing personalized cancer treatments that can make a meaningful difference for patients with difficult-to-treat malignancies.
