Blue Earth Therapeutics Shares Phase 1 Trial Results for Lutetium (177Lu) rhPSMA-10.1 Injection

Blue Earth Therapeutics has reported promising advancements in its investigational radioligand therapy, which is being trialed for treating metastatic castrate-resistant prostate cancer. The recent findings come from a Phase 1 trial involving 13 patients and indicate potential for highly optimized pharmacokinetics. The study involves the use of Lutetium (177Lu) rhPSMA-10.1 Injection, a radioactive compound designed to target prostate-specific membrane antigens (PSMA). The results, which focus on dosimetry and pharmacokinetics, reveal that the compound delivers a significantly higher dose of radiation to tumors compared to healthy tissues like the kidneys. This therapeutic approach shows promise compared to first-generation PSMA-targeted radioligand treatments.

The data from this Phase 1 trial are impressive, showing high ratios of absorbed radiation dose to tumors versus healthy tissue. For instance, the mean tumor to salivary gland ratio was 73, while the tumor to kidney ratio was 32. Specific imaging techniques defined a median absorbed radiation dose to tumors of 8.9 Gy per GBq of administered radioactivity. Conversely, the mean absorbed radiation doses to the kidneys and salivary glands were only 0.27 Gy/GBq and 0.13 Gy/GBq, respectively.

A critical factor underlying these results is the biological half-life of the injection in tumors, averaging 338 hours. When combined with the physical half-life of Lutetium-177, which is 6.7 days, the effective mean half-life stands at 91.4 hours. This extended retention period allows the therapy to deliver radiation to tumors over an extended time frame, enhancing its effectiveness. The ability to maintain prolonged drug retention in tumors without increasing retention in healthy tissues underscores the positive dosimetry data reported.

Following consultations with regulatory authorities and a review of preliminary data, the pathway is now clear for Blue Earth Therapeutics to advance to the Phase 2 portion of the trial. This phase will experiment with innovative dosing regimens aimed at optimizing patient outcomes. The focus will be on maximizing radiation doses to tumors while extending the duration of therapy. The first patients are expected to enroll in this phase within the current quarter.

David Gauden, CEO of Blue Earth Therapeutics, emphasized the significance of the Phase 1 data in validating the innovative approach to optimizing radioligand therapy. He noted the importance of the ratios of tumor to healthy organ absorbed radiation doses as key metrics for assessing the risk and benefit profile of these therapies. Gauden highlighted that controlling normal organ toxicity is crucial since it limits the total amount of radioactivity that can be administered. Therefore, increasing the radioactivity concentrated in tumors is vital. This approach holds the potential to significantly benefit prostate cancer patients compared to existing radioligand therapies, and the completion of this study marks a substantial step toward realizing this goal.

Prostate cancer remains a major health issue, with an estimated 50,055 new cases of metastatic forms diagnosed in the United States in 2025 alone. Although the mortality rate for prostate cancer has been declining over the past three decades, the five-year survival rate for newly diagnosed metastatic cases is still only 36.6%. There is a considerable need for improved treatment options and patient outcomes in this area.

Blue Earth Therapeutics is developing next-generation targeted radiotherapeutics, with a focus initially on prostate cancer. The company aims to innovate and enhance existing technologies, advancing new targeted therapies for serious diseases.