In prior testing, teverelix achieved rapid testosterone suppression with a 97.5% probability of castration shortly after dosing in a 50-patient Phase 2a study, but durability fell to 82.5% by Day 42. Separately, an exploratory interim look from Medicus’s SkinJect Phase 2 program in basal cell carcinoma suggested greater than 60% clinical clearance, with full topline expected in Q1 2026.
Medicus Pharma received FDA “study may proceed” clearance to initiate a 40-patient, open-label Phase 2b dose-optimization study of teverelix, a long-acting GnRH antagonist, in advanced prostate cancer patients appropriate for ADT and enriched for cardiovascular risk. The regimen includes an initial 540 mg load split across intramuscular and subcutaneous injections, followed by 360 mg subcutaneous every six weeks for about 22 weeks. The primary endpoint is medical castration by Day 29 sustained through Day 155 with a target probability above 90%. Secondary objectives include the depth and consistency of FSH suppression and cardiovascular safety. The study is positioned to refine dose and schedule to close the durability gap seen in Phase 2a and to support a registrational path the company says is aligned with prior FDA feedback focused on APC patients with increased cardiovascular risk.
The strategy is a targeted labeling play. GnRH antagonists already differentiate by avoiding flare and, in some analyses, show a more favorable cardiovascular signal than agonists. Medicus is attempting to formalize that clinical logic into a CV-risk–anchored indication, rather than competing head-to-head across the full ADT market that is dominated by entrenched agonist depots and an approved oral antagonist. Achieving this requires two proofs: sustained testosterone and FSH suppression that is operationally simple for sites and patients, and credible cardiovascular outcomes evidence in a risk-enriched population. The Phase 2b focuses on the former while building exposure and safety context for the latter, with a stated intent to move into a pivotal program that pairs castration durability with cardiovascular endpoints.
For sites and CROs, the operational footprint is non-trivial despite the small N. Screening will likely incorporate objective CV metrics such as CAC scoring and ASCVD risk assessment, potentially pulling in cardiology for baseline and event adjudication. The depot’s mixed IM/SC loading and six-week maintenance cadence favors oncology clinics accustomed to injectable ADT workflows but adds complexity on Day 1. Laboratory cadence for testosterone and FSH will drive visit schedules; the cardiovascular component will necessitate consistent capture of MACE and concomitant medications, tightening data quality requirements and pushing demand for central adjudication. Regulators will scrutinize whether a CV-risk–defined population and biomarker suppression translate into clinically meaningful MACE reduction, a bar that typically requires larger, longer trials than efficacy-focused ADT studies. Payers may welcome clearer risk stratification if it simplifies utilization management, but any cardiovascular claim will need robust prospective data beyond historical comparisons.
What to watch next is whether the Phase 2b can demonstrate sustained castration above the 90% threshold through Day 155 and show tighter, more durable FSH suppression than earlier dosing explored by Antev prior to acquisition. Early signals on injection-site tolerability, depot pharmacokinetics, and adherence to the six-week interval will inform Phase 3 design and commercial practicality versus monthly injectables and daily oral therapy. Clarity on the pivotal trial’s cardiovascular statistical plan, event rates in a risk-enriched cohort, and adjudication framework will determine how credible a differentiated label could be. On the portfolio front, SkinJect’s imminent Phase 2 readout will test Medicus’s partner-first model and capital efficiency claims. The core risk remains that a small, open-label Phase 2b can optimize dose but cannot de-risk the cardiovascular thesis; without a well-powered outcomes program, the CV-focused positioning may not translate into regulatory or market separation.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
