Telix surges on Phase 3 prostate cancer trial success
PSMA-targeted therapy shows safety profile in 36 patients, paves way for global 490-patient expansion
Telix Pharmaceuticals shares surged as much as 14 percent in Australian trading after the company announced positive results from the first stage of its global Phase 3 prostate cancer trial, marking a significant milestone for the radiopharmaceutical developer.
The stock advanced to A$11.62 on the ASX, while its NASDAQ-listed shares climbed 5.5 percent to $7.52, following news that the ProstACT study achieved its primary safety and dosimetry objectives. The trial evaluates TLX591-Tx, a prostate-specific membrane antigen (PSMA)-targeted therapy for patients with metastatic castration-resistant prostate cancer.
"These results reinforce the feasibility of integrating TLX591-Tx with current standard of care therapies," the company said, noting that the data supports advancing to a global expansion targeting approximately 490 patients.
The Phase 3 study's first part enrolled 36 patients across three cohorts, each receiving TLX591-Tx in combination with standard therapies: enzalutamide, abiraterone, or docetaxel. All patients completed both doses as planned, with the trial demonstrating an acceptable safety profile consistent with previous studies of the lutetium radio antibody-drug conjugate therapy.
Treatment-related side effects were primarily low-grade, with fatigue affecting 53 percent of patients, nausea in 28 percent, and dry mouth in 25 percent. Hematologic events were described as transient and manageable, with higher-grade blood cell decreases occurring at rates expected for this class of therapy.
A key differentiator emerged in the safety data: TLX591-Tx showed no significant acute or delayed kidney toxicity in long-term follow-up, a notable advantage over other PSMA-targeted small molecule radioligand therapies. The therapy's larger molecular weight enables clearance through the liver rather than kidneys, potentially reducing common side effects such as dry mouth and dry eyes.
Radiation exposure to critical organs remained well below established safety limits, according to the study results.
The company has already initiated Part 2 of the study, a randomized treatment expansion, in jurisdictions where regulatory approval has been secured. Patient enrollment is underway in Australia, New Zealand, and Canada, with additional regulatory clearances obtained for China, Singapore, South Korea, Türkiye, and the United Kingdom. Telix plans to submit the Part 1 data to the U.S. Food and Drug Administration to amend its Investigational New Drug application, enabling U.S. participation in the expansion phase.
The clinical milestone comes as Telix strengthens its commercial position, having reported group revenue of US$803.8 million for fiscal year 2025, representing a 56 percent increase year-over-year. The commercial performance was driven primarily by Illucix, the company's diagnostic product, with the recent launch of Gozellix contributing to accelerated growth.
Analysts maintain a positive outlook on the stock, with a consensus rating of "Moderate Buy" and an average target price of $20.89, significantly above the current trading level. The company's market capitalization stands at approximately $3.3 billion, with revenue reaching $664.2 million over the trailing twelve months.
The ProstACT study represents Telix's push to expand beyond its diagnostic portfolio into therapeutic applications. Success in the Phase 3 program would position TLX591-Tx as a potential first-line treatment option for aggressive prostate cancer, addressing a significant unmet medical need in metastatic castration-resistant disease.
Radiopharmaceuticals have emerged as a promising modality in oncology, combining targeted delivery with radiation therapy. Telix's approach leverages PSMA, a protein highly expressed on prostate cancer cells, to deliver radioactive lutetium-177 directly to tumors while sparing healthy tissue.
The company will host a conference call to discuss the results on Tuesday at 9:30 a.m. Australian Eastern Daylight Time (Monday 6:30 p.m. Eastern Daylight Time), providing investors with an opportunity to hear management discuss the clinical and commercial implications of the Phase 3 data.