Telix Pharmaceuticals' Trial Dispute Gives Way to a Powerful Relief Rally

A short-seller-fuelled dispute over clinical trial completion hit the stock hard, before positive safety data and an FDA resubmission cleared the overhang.

31 Jul 2026 · 3 min read

Telix Pharmaceuticals sank to around $10.48 by January after being sold down aggressively on delays to product approvals and a disputed claim about whether a key clinical trial had actually completed enrolment, before a March relief rally of more than 35 percent arrived once ProstACT Global Phase 3 safety data and an FDA resubmission removed the overhangs weighing on the stock.

Disputed trial claims and delayed approvals sink the stock

Greencape Capital said Telix delivered results that disappointed the market in December, and while remaining confident in the stock, expected a reversal in fortunes to take longer than hoped. Equity Trustees Asset Management said concerns around the immediacy of earnings continued to weigh on sentiment despite a solid third-quarter update with upgraded revenue guidance, as the market remained focused on rising operating expenditure and delays to the ProstACT safety study. Ellerston Capital said shares came under pressure in mid-December after an undisclosed party communicated that Telix's TLX591 ProsACT Global Part 1 trial had not been completed, a claim the company officially disputed, stating the trial had in fact completed enrolment, noting that given the high level of open short positions in the stock, the facts can sometimes get distorted.

Company management attributed pressure on shares to an undisclosed party communicating that its TLX591 ProsACT Global Part 1 trial had not been completed. TLX officially disputed the claim, stating that ProsACT Global Part 1 had in fact completed enrolment.

— Ellerston Capital, Monthly Report, December 2025

A strong result gets lost in the noise

Selector Funds Management said Telix delivered its fourth-quarter update in January, with revenue of US$208 million, up 46 percent on the prior corresponding period, and full-year revenue of US$804 million, up 56 percent, in line with upgraded guidance of US$800 million to US$820 million, with Precision Medicine revenue from Illuccix and Gozellix growing 16 percent over the year to US$161 million. Perennial Partners said the stock still fell 5.8 percent on no particular news, though it continued to see significant upside.

Overhangs clear, and a powerful relief rally follows

Pendal Group said the stock rose 5.0 percent after Telix finally released safety data for TLX591, which appeared good, with the company planning to file for FDA approval to move into phase three. Equity Trustees Asset Management, a top contributor, said that after being aggressively sold down the prior year on delays to product approvals, the company started delivering on milestone catalysts, driven by clinical trial results including Part 1 of the ProstACT Global Phase 3 study. Ellerston Capital said Part 1 of the trial met its primary objectives, confirming acceptable safety, tolerability and dosimetry for TLX591, removing a key overhang and driving a powerful relief rally, with Telix also resubmitting a new drug application with additional data to the FDA a week later. Perennial Partners confirmed the 36.6 percent gain, with Telix also resubmitting its application for the Pixclara brain cancer imaging agent. Glennon Small Companies said Telix reported unaudited first-quarter 2026 group revenue of US$230 million, up 11 percent quarter on quarter, with Precision Medicine revenue up 16 percent, reflecting strong growth across both Illuccix and Gozellix.

After being sold down aggressively last year on delays to product approvals and associated earnings growth, the company exhibited large valuation upside and started to deliver on milestone catalysts during the quarter.

— Equity Trustees Asset Management, Quarterly Report, March 2026

Mint Asset Management said the stock rallied 22 percent as delayed milestones began being delivered, taking some profits following the strong performance. Australian Eagle Asset Management, holding a short position that cost it 2.7 percent, remained skeptical, citing ongoing regulatory uncertainty, leadership changes and rising cost pressures weighing on earnings visibility, seeing a downside skew to the risk-reward despite solid revenue growth, pending further clinical and regulatory clarity.

What fund managers say they are watching next is the FDA's decision on the TLX591 phase three filing following the positive safety data, the outcome of the Pixclara resubmission for brain cancer imaging, continued growth in Precision Medicine revenue from Illuccix and Gozellix, and whether the remaining skepticism about regulatory and leadership uncertainty proves warranted.