J591 in Patients With Advanced Prostate Cancer and Unfavorable Circulating Tumor Cell Counts

Prostate Cancer Clinical Trial

Official title: Anti-Prostate-Specific Membrane Antigen Monoclonal Antibody J591 in Patients With Advanced Prostate Cancer and Unfavorable Circulating Tumor Cell Counts

Status Completed

Clinical Trial Summary

This clinical trial is for men with advanced prostate cancer that may have spread to other parts of the body.

Currently, once prostate cancer cells have spread from the prostate to other organs it is not treatable by surgery. The purpose of this study is to treat patients with an experimental antibody (i.e. that has not been FDA approved) called J591 that attaches itself to a special protein on cancer cells called PSMA to try to eliminate these cancer cells (called circulating tumor cells) from the circulation.

In the initial phase of the study, 6 participants will receive the experimental J591 treatment. Routine blood tests, research blood tests, physical exam will be performed at each visit. Participants will also be asked to complete a questionnaire about how they are feeling. Participants will have a radiographic scan every 3 months to check the status of their disease.

Participants who tolerate the treatment well may be re-treated at the same level every 3 months, and may continue on treatment as long as they are responding to therapy and not experiencing unacceptable side effects.

Clinical Trial Description

J591 is a de-immunized monoclonal antibody against the extracellular domain of prostate-specific membrane antigen (PSMA). Background data demonstrate that mAb Hu-J591 doses as low as 20 mg may lead to a decrease in CTCs and that doses up to 300 mg are safe. With a goal of establishing less frequent, potentially more convenient and cost-effective future therapy, the investigators propose a single-center, open-label, dose de-escalation study to determine the effect of mAb Hu-J591 on circulating tumor cells in subjects with metastatic PC. Four dose levels are planned with a minimum of 6 and maximum of 24 subject enrollment starting with a single infusion of 300 mg of mAb Hu-J591.

In the initial phase of the study a cohort of 6 subjects will receive 300 mg of mAb Hu-J591 and blood samples will be collected pre and post-infusion for the detection of CTCs, PSA and to assess hematological toxicity at screening, baseline, week 1, week 4, week 8, and week 12. In addition, patients will receive a dose of 89Zr-DFO-huJ591 (5 mCi) 2-4 weeks prior to treatment and will undergo 89Zr-DFO-huJ591 PET imaging 1-3 weeks pre-treatment (optional) as well as repeat 89Zr-DFO-huJ591 infusion (5 mCi) at 11 weeks and PET/CT imaging at 12 weeks (optional).

If less than four subjects respond by dropping their CTC counts from more than or equal to 5 CTCs/7.5 mL whole blood to less than 5 CTCs/7.5 mL whole blood in the initial cohort, the trial will be ended at this dose. If four or more subjects respond, an additional 6 subjects will be accrued to the second dose level (200 mg). The same decision rule will be applied to evaluate two additional lower dose levels (100 mg, 50 mg) with 6 subjects enrolled in each cohort. Imaging studies will be performed prior to treatment at screening and at 3 months or as clinically indicated to assess disease response.

Subjects who tolerate the initial infusion well (< grade 2 toxicities) may be re-treated every 3 months (12 weeks) at the same dose-level until progression. ;

Related Conditions & MeSH terms

• Neoplastic Cells, Circulating
• Prostate Cancer
• Prostatic Neoplasms

• NCT number: NCT02552394
• Study type: Interventional
• Source: Weill Medical College of Cornell University
• Status: Completed
• Phase: Phase 1
• Start date: July 2015
• Completion date: January 3, 2021