Telix Pharmaceuticals Limited and St Vincent’s Hospital have dosed the first patients with TLX597-Tx in the OPTIMAL-e trial for metastatic hormone-sensitive prostate cancer (mHSPC). The Phase 2 study, led by Professor Louise Emmett at St Vincent’s Hospital in Sydney, Australia, evaluates an adaptive-dosed radioligand therapy aimed at improving efficacy and quality of life in earlier-stage disease. The trial builds upon the OPTIMAL-PSMA study, which recently completed patient enrollment.

OPTIMAL-e is a single-arm, open-label trial assessing TLX597-Tx in combination with androgen deprivation therapy (ADT) and an androgen receptor pathway inhibitor (ARPI). The study focuses on the therapy's impact on prostate-specific antigen (PSA) response rates, evaluating its potential to deepen and sustain responses while monitoring the safety of dose intensification. The adaptive approach involves continuing treatment when the PSMA target persists and pausing it upon significant tumor burden reduction, guided by PSMA-PET imaging and PSA measurements.

TLX597-Tx is a next-generation small molecule radioligand therapy targeting PSMA. It has demonstrated favorable biodistribution and dosimetry in prior studies, including OPTIMAL-PSMA, with low exposure to salivary glands and kidneys and high uptake in PSMA-expressing tumors. The therapy is designed to address earlier-stage metastatic prostate cancer, where maintaining quality of life is a critical treatment goal.

Louise Emmett, MD, Director of Theranostics and Nuclear Medicine at St Vincent’s Hospital and Lead Investigator, emphasized the trial's individualized strategy. "By using PSMA-PET imaging and PSA measurements to monitor disease burden, treatment can be continued when the PSMA target persists, and paused when there is a significant reduction in tumor burden," Emmett said. "This approach aims to maintain disease control while minimizing unnecessary treatment exposure."

David N. Cade, MD, Group Chief Medical Officer at Telix, highlighted the significance of earlier intervention. "While the currently approved radioligand therapy has demonstrated a modest improvement in overall survival in advanced-stage disease, we believe earlier intervention may offer the potential to further improve outcomes and prolong quality of life for patients," Cade stated.

TLX597-Tx is part of Telix’s broader prostate cancer portfolio, which includes TLX591-Tx, currently in Phase 3 trials for metastatic castration-resistant prostate cancer (mCRPC). The two therapies exhibit complementary modes of action, targeting different stages of the disease. TLX597-Tx has not received marketing authorization in any jurisdiction.

Citigroup analyst Laura Sutcliffe has maintained a Buy rating on Telix Pharmaceuticals (NASDAQ: TLX) while lowering the price target to $22. The revision adjusts the previous target of $22.5, reflecting updated valuation expectations.

Analyst Rating and Price Target

The research firm's continued endorsement supports the company's market position despite the reduced price objective.

The adjustment follows a previous endorsement by HC Wainwright & Co., where analyst Robert Burns reiterated a Buy rating with a price target of $20.