Stannous oxide

Stannous oxide is a chemical substance that serves as an auxiliary component in radiopharmaceutical preparation kits. In the clinical trial records presented here, it appears under the full registry name stannous oxide, 3,3-diphosphono-1,2-propanedicarboxylic acid, tetrasodium salt (DPD). It is not the main therapeutic agent in the trials; instead, it is part of the kit system used to prepare imaging agents for prostate cancer.

What is stannous oxide?

Stannous oxide is a chemical substance classified in the therapeutic area of neoplasms (diseases [C] - neoplasms [C04]). It is authorised as a medicine under the product name TECEOS Trockenstechampullen, with authorisation record AT 4-00026 held by CIS BIO INTERNATIONAL. In the two trials described on this page, stannous oxide is listed as an auxiliary substance in two product records, meaning it supports the preparation or administration of the main investigational therapy rather than being the tested treatment itself.

How does stannous oxide work?

Stannous oxide functions as a reducing agent in radiopharmaceutical kits. In the preparation of technetium-99m labelled compounds, stannous ions reduce the technetium from a higher oxidation state to a lower one, allowing it to bind to the targeting molecule. This chemical step is essential for creating a stable imaging agent that can be injected into the patient. The trial records do not describe the mechanism of action in further detail, as stannous oxide is an auxiliary component rather than the active pharmaceutical ingredient under investigation.

Which conditions is stannous oxide used or studied for?

• Prostate carcinoma — both trials involve patients with prostate cancer. One trial focuses on patients with biochemical recurrence after primary therapy, while the other includes patients with oligometastatic prostate cancer planned for radical prostatectomy.

How is stannous oxide given?

Stannous oxide is provided as a solution for injection. The route of administration is intravenous, including intravenous bolus use. In the trials, the product TECEOS Trockenstechampullen containing stannous oxide is administered intravenously. The substance is part of a fixed combination in two product records, meaning it is supplied together with other components needed for the radiopharmaceutical preparation.

What do the clinical trials show?

Two clinical trials involving stannous oxide as an auxiliary substance are registered. Both are Phase 2 pilot studies in prostate carcinoma and both are currently authorised. The first trial (2024-519348-34-00) plans to enrol 26 participants with prostate cancer and biochemical but not radio-morphological local recurrence after primary therapy with curative intent.^[1] The second trial (2024-519377-18-00) plans to enrol 10 participants with oligometastatic prostate cancer diagnosed using [68Ga]Ga-PSMA-11 PET imaging and scheduled for radical prostatectomy.^[2]

Both trials investigate [177Lu]Lu-PSMAI&T radioligand therapy (PSMA-RLT). Stannous oxide, as part of the TECEOS kit, is used in the preparation of the imaging component. The primary outcomes measured include PSA response, defined as a PSA decline of at least 50% from baseline, and therapy toxicity assessed by CTCAE version 5.0.^[1] The second trial additionally assesses safety and toxicity of neoadjuvant PSMA-RLT followed by radical prostatectomy.^[2]

Both trials are interventional in design. The participants receive intravenous administration of the radiopharmaceutical preparations. The trials are pilot studies, meaning they are early-phase investigations designed to gather initial safety and efficacy data before larger studies may be conducted.

What side effects are known?

The trial records do not provide a dedicated list of side effects specifically attributed to stannous oxide. As an auxiliary component of a radiopharmaceutical kit, its safety profile is considered within the overall assessment of the imaging procedure. The trials monitor therapy toxicity, including changes in blood count, kidney and liver function, assessed by CTCAE version 5.0.^[1]