3,3-Diphosphono-1,2-Propanedicarboxylic Acid, Tetrasodium Salt (Dpd)

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.

Table of contents

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.[1][2] 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.[1][2]

In both trials, the treatment approach is based on PSMA-RLT, which stands for prostate-specific membrane antigen radioligand therapy.[1][2] 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.[1][2]

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.[1] This means the cancer has shown signs of return through PSA testing, but no clear tumor is seen on imaging scans.[1]

This trial is authorised, Phase 2, and planned to enroll 26 patients.[1] 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.[1]

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.[1] CTCAE is a standard system for grading treatment-related problems in clinical trials.[1]

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.[2] Neoadjuvant means treatment given before surgery, and radical prostatectomy means removal of the prostate gland.[2]

This study is also authorised and in Phase 2, with an enrollment of 10 patients.[2] 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.[2]

The primary outcome is to assess the safety and toxicity of neoadjuvant PSMA-RLT and radical prostatectomy.[2] This makes safety a key part of the study because the treatment is given before major surgery.[2]

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.[1][2] These are common trial endpoints, which are the specific results researchers plan to measure.[1][2]

  • 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.[1][2]

  • Imaging response: The second study includes imaging response, meaning changes seen on scans after treatment.[2]

  • Pathological response: The second study checks tissue changes, usually from surgery, to see how the cancer looks under the microscope after treatment.[2]

  • 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.[1][2]

  • Oncological outcomes: The second study also mentions cancer-related outcomes after treatment and surgery.[2]

Who the trials are for

These trials are for patients with prostate carcinoma, but the exact patient groups are different.[1][2] 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.[1][2]

Because these are pilot studies, they include only a small number of participants, 26 in one trial and 10 in the other.[1][2] 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.[1][2]

Trial ID Phase Condition studied Status Enrollment
2024-519348-34-00 Phase 2 Prostate carcinoma with biochemical but not radio-morphological local recurrence after curative primary therapy Authorised 26
2024-519377-18-00 Phase 2 Oligometastatic prostate carcinoma diagnosed using [68Ga]Ga-PSMA-11 PET imaging, followed by radical prostatectomy Authorised 10

Ongoing Clinical Trials on 3,3-Diphosphono-1,2-Propanedicarboxylic Acid, Tetrasodium Salt (Dpd)

  • Study of [177Lu]Lu-PSMA-I&T Therapy for Patients with Oligometastatic Prostate Cancer Using Gozetotide and Stannous Oxide Combination

    Recruiting

    2 1 1 1
    Austria
  • Study on Lutetium (177Lu) Zadavotide Guraxetan for Prostate Cancer Patients with Biochemical Recurrence After Initial Curative Treatment

    Recruiting

    2 1 1 1
    Austria

Glossary

  • Prostate carcinoma: Cancer that starts in the prostate gland, which is a male reproductive gland.
  • Biochemical recurrence: A rise in PSA after treatment that suggests cancer may have returned, even if scans do not show a tumor.
  • Radio-morphological recurrence: Cancer that can be seen on imaging scans. In one trial, patients had PSA evidence of recurrence but no visible lesion on scans.
  • Oligometastatic: A small number of cancer spread sites. This usually means the disease has spread, but only to a few places.
  • PET imaging: A scan that helps find cancer activity in the body. One trial used [68Ga]Ga-PSMA-11 PET imaging to diagnose disease.
  • Radical prostatectomy: An operation to remove the prostate gland.
  • PSA: Prostate-specific antigen, a blood test used to follow prostate cancer.
  • PSA response: A change in PSA level that shows whether treatment may be working.
  • Toxicity: Harmful effects of treatment. These trials measure changes in blood counts, kidney function, and liver function.
  • CTCAE: A standard system used in trials to grade side effects and lab changes.
  • Pathological response: Changes seen in tissue after treatment, often checked after surgery.
  • Pilot study: A small early study used to see if a treatment idea is worth testing further.

References

  1. https://clinicaltrials.gov/study/2024-519348-34-00
  2. https://clinicaltrials.gov/study/2024-519377-18-00