Telix Pharmaceuticals Limited announced the publication of results from the ProstACT SELECT study in Cancers, a peer-reviewed journal. The Phase 1 study evaluated TLX591-Tx (lutetium-177 rosopatamab tetraxetan), a prostate-specific membrane antigen (PSMA) targeting radio antibody-drug conjugate therapy candidate. The publication confirms the utility of gallium-68 PSMA-PET imaging to select patients for TLX591-Tx therapy using a theranostic approach.

The study highlights TLX591-Tx’s differentiated clinical profile, characterized by an intensified dosing schedule, prolonged tumor retention, and low exocrine gland irradiation. In a heterogeneous population representative of a real-world setting, TLX591-Tx therapy in combination with standard of care demonstrated a manageable and predictable safety profile. Indicative efficacy was observed, with a median radiographic progression-free survival (rPFS) of 8.8 months reported in evaluable patients.

Key Findings from ProstACT SELECT

Nat Lenzo, MD, Nuclear Medicine Oncologist and Principal Investigator on the ProstACT SELECT study, commented on the results. "A key objective of ProstACT SELECT was to determine whether PSMA-PET imaging could reliably identify patients suitable for TLX591-Tx therapy, and the results clearly support this approach," Lenzo stated. The findings provide evidence that the PSMA-PET imaging agent and TLX591-Tx target the same disease sites, supporting the ongoing ProstACT Global trial for metastatic castration-resistant prostate cancer (mCRPC).

Ongoing Clinical Development

David N. Cade, MD, Group Chief Medical Officer at Telix, emphasized the significance of the publication. "The peer-reviewed results support our patient-selection strategy and demonstrate a differentiated pharmacologic profile characterized by durable tumor targeting, hepatobiliary clearance, and a manageable safety profile," Cade said. Telix is currently evaluating TLX591-Tx in the international multi-center Phase 3 ProstACT Global study for advanced metastatic prostate cancer.

The primary objectives of the ProstACT SELECT trial were to determine whole body biodistribution and organ radiation dosimetry and assess the safety and tolerability of TLX591-Tx in patients with advanced mCRPC. rPFS was a secondary study objective. TLX591-Tx has not received a marketing authorization in any jurisdiction.

Telix Pharmaceuticals Limited reported group revenue of US$247 million for the quarter ended June 30, 2026 (Q2 2026), representing a 21% increase year-over-year and a 7% rise quarter-over-quarter. The company anticipates FY 2026 revenue and other income will exceed US$1 billion, with revenue tracking in line with the upper end of its guidance range of US$950 million to US$970 million, plus US$40 million in non-refundable other income received from Regeneron. Precision Medicine revenue drove the growth, reaching US$202 million, up 30% year-over-year.

Financial Performance

The strong commercial performance enabled Telix to update its FY 2026 research and development expenditure guidance to a range of US$230 million to US$270 million. This increase is supported by the US$40 million non-refundable payment from Regeneron and aims to accelerate high-value clinical programs. Telix Manufacturing Solutions (TMS) revenue for the quarter was US$45 million.

Operational and Strategic Milestones

Telix achieved key regulatory advancements, including alignment with the United States Food and Drug Administration (FDA) for the ProstACT Global Phase 3 study of TLX591-Tx to advance to Part 2 in the U.S. The company also progressed its strategic collaboration with Regeneron to jointly develop and commercialize next-generation radiopharmaceutical therapies, initially focused on lung cancer. Additionally, Telix completed a refinancing of its convertible bond structure, issuing US$600 million of new convertible bonds due 2031 and repurchasing all outstanding 2029 convertible bonds.

Corporate Governance

Three new Non-Executive Directors were appointed to the Board effective May 11, 2026. David Gill, Maria Rivas, MD, and William Jellison joined the Board, enhancing the company's clinical, commercial, financial, and governance expertise.