Pentixapharm: positive Phase II data on Pentixafor PET diagnostics pave way also for therapeutics

New clinical Phase II data on [68Ga]Ga-Pentixafor released by Pentixapharm in February confirm the potential of Pentixafor PET/CT as a non-invasive alternative to adrenal venous sampling (AVS) for the subtyping of primary aldosteronism.

In the prospective study, the radiodiagnostic agent demonstrated high specificity and moderate sensitivity in identifying unilateral aldosterone-producing adenomas when compared with AVS as well as postoperative biochemical outcomes. The procedure was well tolerated and preferred by almost all study participants over the invasive AVS.

The study was conducted in Australia and initiated by the investigator. Funding was provided by the CASS Foundation and the Australian Medical Research Future Fund. Adult patients with primary aldosteronism and an adrenal adenoma visible on CT were included. The aim was to assess the diagnostic performance of Pentixafor PET/CT as a possible alternative to the current gold standard AVS, which is invasive, requires a high level of expertise and infrastructure, and is available only in specialised centres.

Basis for Phase III development

According to the company, the results support the further clinical development of [68Ga]Ga-Pentixafor into a Phase III study. Precise subtyping of primary aldosteronism is clinically relevant, as only patients with unilateral disease benefit from potentially curative adrenalectomy, while bilateral forms are generally treated medically.

Pentixapharm notes that the newly published data are consistent with earlier investigator-initiated studies, including the CASTUS Step 1 study. This demonstrates a reproducible diagnostic performance across different studies and geographical regions.

Radiopharmacy and theranostics on the rise

Pentixapharm’s advance comes at a time of rapidly growing interest in radiopharmaceutical approaches. Radiopharmacy combines molecular targets with radioactively labelled compounds, enabling both highly precise diagnostics and targeted therapies. Particularly dynamic is the development of so-called theranostics, in which the same molecular target is first visualised diagnostically and subsequently addressed therapeutically.

This field is being driven by the clinical success of radioligand-based therapies, particularly in oncology, as well as by advances in radionuclide production and molecular imaging. The added value lies in individualised treatment decisions: imaging not only provides anatomical information but also reveals functional and molecular properties of tissue in vivo.

This approach is gaining importance beyond oncology. In the case of primary aldosteronism, precise molecular imaging could help reduce invasive diagnostics, improve patient selection and make treatment pathways more efficient – particularly in light of new pharmacological treatment options such as aldosterone synthase inhibitors.

CXCR4 as a diagnostic target

[68Ga]Ga-Pentixafor is a gallium-68-labelled radiodiagnostic agent for visualising the chemokine receptor CXCR4 using PET/CT. Studies show pronounced CXCR4 overexpression in aldosterone-producing adrenal tumours, a hallmark of unilateral primary aldosteronism. According to the company, clinical experience from around 1,600 applications across various indications is available.

In Pentixapharm’s assessment, the Phase II data now presented strengthen the clinical and regulatory foundation of the programme and underline the potential of molecular imaging as a decision-making tool in the personalised treatment of endocrine diseases. The parallel strategy of also delivering a cancer-destroying radioligand to the site of action via this molecular target is therefore gaining further momentum. Pentixapharm went public in 2024. Until then, there had been no initial public offering of a German biotech company on the Frankfurt Stock Exchange for several years.