Volastra Therapeutics' VLS-1488, a novel KIF18A inhibitor, has received Fast Track designation from the FDA for the treatment of patients with platinum-resistant high-grade serous ovarian cancer (HGSOC). This designation is intended to accelerate the development and review of drugs that treat serious conditions and fill unmet medical needs. The drug is currently being evaluated in a Phase I/II clinical trial (NCT05902988).
Mechanism of Action
VLS-1488 is designed to inhibit KIF18A, a protein involved in chromosome alignment during mitosis. By inhibiting KIF18A, VLS-1488 traps chromosomally unstable tumor cells in mitosis, preventing their proliferation and leading to cell death. The selective action of VLS-1488 is expected to minimize toxic effects on normal, healthy cells.
Clinical Trial Details
The ongoing Phase I/II trial is a first-in-human study evaluating the safety, tolerability, and preliminary efficacy of VLS-1488 in patients with advanced cancers, including HGSOC. The trial consists of two parts: dose escalation and dose expansion. The dose escalation phase aims to determine the maximum tolerated dose (MTD) and identify suitable dose levels for the expansion phase. The dose expansion phase will further examine the safety, tolerability, drug-drug interaction risk, food effect, and preliminary efficacy of VLS-1488 in various tumor types and dose levels.
Patients enrolled in the trial are administered oral VLS-1488 tablets once daily in 28-day cycles. Key inclusion criteria include age of 18 years or older, an ECOG performance status of 1 or below, and at least one measurable disease site. Eligible tumor types include HGSOC, squamous non-small cell lung cancer, triple-negative breast cancer, gastric adenocarcinoma, and several other advanced cancers. The dose escalation phase requires patients to have exhausted all available therapeutic options providing clinically meaningful benefits.
Endpoints and Assessments
In the dose escalation phase, primary endpoints include the incidence of dose-limiting toxicities, MTD, frequency of serious adverse events, and treatment-related adverse events, all assessed up to 12 months. The dose expansion phase focuses on objective response rate and frequency of trigger events, evaluated up to 18 months. Secondary endpoints in both phases include duration of response, disease control rate, and progression-free survival, assessed up to 32 months.
Significance of Fast Track Designation
"Platinum-resistant high-grade serous ovarian cancer is marked by poor prognosis, highlighting the urgent need for new therapies for this devastating disease," said Scott Drutman, MD, PhD, CMO, and Head of Research and Development at Volastra Therapeutics. "Fast Track designation for VLS-1488 reaffirms the clear potential of KIF18A inhibition to address this unmet medical need and represents a critical step towards bringing these novel therapeutics to patients."
