Telix Pharmaceuticals has announced the first patient dosing in its Phase I clinical trial of TLX090 (¹⁵³Samarium-DOTMP), a therapeutic radiopharmaceutical designed to target and relieve pain caused by metastatic bone disease.

The trial (NCT07197645), known as SOLACE (Samarium Optimized for Long-lasting Analgesia in Cancerous End-stage bone pain), will enroll up to 33 patients with advanced cancers that have spread to the bone.

Bone metastases are among the most common and painful complications of advanced cancer, affecting approximately 400,000 new patients each year. In prostate cancer alone, up to 90% of patients with advanced disease experience bone pain.

Traditional options such as opioids and external beam radiation therapy (EBRT) offer limited relief and carry substantial drawbacks. Opioids can lead to dependency, sedation, and regulatory scrutiny, while EBRT is localized, time-intensive, and unsuitable for patients with multiple sites of pain.

A Non-Opioid, Targeted Approach

Telix’s TLX090 aims to fill this gap by providing targeted radiation therapy that delivers pain relief directly to bone tumors while minimizing damage to healthy tissue. The company hopes TLX090 will offer systemic, long-lasting pain palliation—potentially up to four months from a single administration—with the option for repeat dosing.

According to Telix, early data from prior studies have shown a favorable safety profile and encouraging efficacy, suggesting TLX090 could represent a new non-opioid standard of care. The candidate’s cold-kit formulation also enables convenient pharmacy-based preparation, addressing cost and supply chain barriers that have limited the use of older samarium-based products.

Dr. Julio A. Peguero, Medical Director of Research at Oncology Consultants in Houston, emphasized the potential clinical impact of TLX090, stating: “Existing treatments often fall short—whether through limited effectiveness, incomplete pain relief, or burdensome side effects. TLX090 offers the potential for a better tolerated and more effective approach to pain management, with the goal of meaningfully improving patients’ quality of life.”

Telix’s Group Chief Medical Officer, Dr. David N. Cade, echoed this sentiment, highlighting the therapy’s alignment with the company’s mission: “TLX090 has the potential to bridge cancer treatment and quality-of-life care by offering a single-dose, systemic option for patients with metastatic bone pain. This represents a major clinical and commercial opportunity aligned with our broader oncology strategy.”

Data from the SOLACE trial will assess pharmacokinetics, dosimetry, safety, and pain relief. The findings are expected to determine TLX090’s comparability to legacy samarium treatments, potentially supporting a streamlined regulatory pathway for registration as an analgesic.

Another radiopharmaceutical in Telix portfolio is TLX101-CDx, an experimental imaging agent for glioma. Last month, the company announced that it had reached an agreement with the US Food and Drug Administration (FDA) to resubmit the therapy for approval, which is expected in the fourth quarter (Q4) of 2025. 

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