In short
Clinical trials investigating 3,3-Diphosphono-1,2-Propanedicarboxylic Acid, Tetrasodium Salt (Dpd) are studying prostate cancer in Phase 2 pilot studies. The trials look at treatment response, safety, toxicity, imaging, and pathology in men with recurrent or oligometastatic disease. They focus on patients treated with PSMA-based radioligand therapy and, in one study, radical prostatectomy.
Key points
- Clinical trials of 3,3-Diphosphono-1,2-Propanedicarboxylic Acid, Tetrasodium Salt (Dpd) are focused on prostate cancer. The data describe two authorised Phase 2 pilot studies in small patient groups. One study looks at men with biochemical local recurrence after curative treatment, and the other studies men with oligometastatic disease planned for radical prostatectomy. The trials measure PSA response, imaging response, pathology, and safety or toxicity. Overall, the research is aimed at learning how well the treatment approach works and how safe it is in these specific prostate cancer settings.
Trial overview
The available trial data for 3,3-Diphosphono-1,2-Propanedicarboxylic Acid, Tetrasodium Salt (Dpd) describe two authorised Phase 2 interventional studies in prostate cancer. Both studies are pilot trials, which means they are small early studies designed to learn more about treatment effects and safety before larger research is done.
In both trials, the treatment approach is based on PSMA-RLT, which stands for prostate-specific membrane antigen radioligand therapy. The studies focus on men with prostate carcinoma in different clinical situations: one with local recurrence after prior curative treatment, and one with oligometastatic disease planned for surgery.
Study 1: biochemical recurrence without visible disease
The first study is titled [177Lu]Lu-PSMAI&T radioligand therapy for patients with prostate cancer and biochemical but not radio-morphological local recurrence after primary therapy with curative intent. This means the cancer has shown signs of return through PSA testing, but no clear tumor is seen on imaging scans.
This trial is authorised, Phase 2, and planned to enroll 26 patients. The brief summary says the study aims to evaluate the PSA response to [177Lu]Lu-PSMAI&T-RLT and to assess therapy toxicity of systemic treatment.
The primary outcomes are a PSA decline of at least 50% from baseline and toxicity related to blood counts, kidney function, and liver function, measured using CTCAE version 5.0. CTCAE is a standard system for grading treatment-related problems in clinical trials.
Study 2: neoadjuvant treatment before surgery
The second study is titled Neoadjuvant [177Lu]Lu-PSMAI&T radioligand therapy for patients with oligometastatic prostate cancer diagnosed using [68Ga]Ga-PSMA-11 PET imaging followed by radical prostatectomy. Neoadjuvant means treatment given before surgery, and radical prostatectomy means removal of the prostate gland.
This study is also authorised and in Phase 2, with an enrollment of 10 patients. The brief summary says the trial will evaluate PSA, imaging, and pathological response, as well as oncological outcomes in patients planned for radical prostatectomy after PSMA-RLT.
The primary outcome is to assess the safety and toxicity of neoadjuvant PSMA-RLT and radical prostatectomy. This makes safety a key part of the study because the treatment is given before major surgery.
What the trials measure
Across the two studies, the main research questions are whether treatment can lower PSA, whether cancer can be seen or measured better on imaging, and whether tissue findings after treatment or surgery show a response. These are common trial endpoints, which are the specific results researchers plan to measure.
- PSA response: The first study looks for a PSA drop of 50% or more, while the second study also tracks PSA response as part of the overall evaluation.
- Imaging response: The second study includes imaging response, meaning changes seen on scans after treatment.
- Pathological response: The second study checks tissue changes, usually from surgery, to see how the cancer looks under the microscope after treatment.
- Toxicity and safety: Both studies measure treatment-related harm, including changes in blood counts and organ function, and the second study also evaluates safety with surgery.
- Oncological outcomes: The second study also mentions cancer-related outcomes after treatment and surgery.
Who the trials are for
These trials are for patients with prostate carcinoma, but the exact patient groups are different. The first study is for patients with biochemical local recurrence after curative primary therapy, while the second study is for patients with oligometastatic prostate cancer identified by [68Ga]Ga-PSMA-11 PET imaging and then scheduled for radical prostatectomy.
Because these are pilot studies, they include only a small number of participants, 26 in one trial and 10 in the other. The trial data do not provide more detailed eligibility rules, so the main known requirements are the disease type and clinical setting described in each study.