New Trials in Prostate Cancer: Could Your Patient Benefit?

A number of late-phase clinical trials in prostate cancer have opened in recent months. Maybe one of your patients could benefit from being enrolled.

Patients for whom there is clinical suspicion of prostate cancer and who have not undergone biopsy. Adult men for whom there is clinical suspicion of prostate cancer based on positive prostate MRI findings or, in the absence of positive MRI findings, ongoing suspicion based on prostate-specific antigen (PSA) level, family history, or a positive digital rectal exam are sought for a phase 3 study of the performance of a new radioactive diagnostic agent (tracer).

The product, gallium-68 prostate-specific membrane antigen ([Ga-68]PSMA), was approved by the US Food and Drug Administration in December 2020. PSMA is expressed at high levels on prostate cancer cells; this product binds to it then emits positrons that can be detected by positron-emission tomography (PET). This new imaging modality, PSMA PET, is highly sensitive and has recently been incorporated into guidelines from the National Comprehensive Cancer Network.

In the trial that is currently recruiting, participants will receive one injection of [Ga-68]PSMA, after which they will undergo a 30-minute PET/CT scan. Follow-up biopsy will be performed to enable comparison of the [Ga-68]PSMA images with standard histopathology. The study opened in August and aims to recruit 100 participants at the University Hospitals Cleveland Medical Center, Cleveland, OH. Overall survival (OS) and quality of life (QoL) will not be tracked. More details are available at clinicaltrials.gov.

“Studies that further elucidate the value of PSMA PET scanning are of great value. Getting additional information that confirms histologically the PSMA findings with the actual biopsy material is critical as we expand our understanding of this new modality,” commented Marc Garnick, MD, Gorman Brothers Professor of Medicine, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts. He is not an investigator in the trial and was approached for comment.

Oligometastatic prostate cancer. Veterans with one to five lesions suspicious for nodal recurrence or metastasis that developed after local therapy for prostate cancer are invited to join a Veterans Affairs phase 2/3 trial comparing standard systemic therapy (SST) alone to SST plus PET-directed local therapy. Participants will receive SST for approximately 4 years until disease progression or death, whichever comes first. The treating physician and patient will jointly choose the local therapy on the basis of the location of the lesion(s); options include radiotherapy, surgery, cryotherapy, and others. The investigators plan to enroll 464 men. The trial began recruiting on July 1 in 14 states. The primary outcome is castration-resistant prostate cancer–free survival. OS and QoL are secondary outcomes. More details are available at clinicaltrials.gov.

The published trial description does not specify the PET/CT tracer that will be used. Garnick said that if PSMA is used, then “this study is very important. PSMA scanning will change the way in which we assess the degree of advancement in men with not only biochemical recurrent disease, but those found to have oligometastatic disease.” He said that if PSMA is not used, “the study is outdated before it begins.”

Metastatic castration-resistant prostate cancer (mCRPC) after failure of androgen receptor–directed therapy (ARDT). Patients with mCRPC in whom disease progression occurs, as evidenced by serum PSA level or the occurrence of new bone lesions, despite having received one or more ARDT agents can join a phase 3 study of an experimental small molecule called VERU-111 (sabizabulin). The drug acts as an oral cytoskeleton disruptor. Patients can have previously taken any ARDT, including abiraterone, enzalutamide, darolutamide, and apalutamide. Participants will receive either VERU-111 or an ARDT (one that they haven’t yet received) for up to 1 year. Investigators started recruiting on June 24 and hope to enroll 245 men in 26 states. Radiographic progression-free survival is the primary outcome. OS over approximately 1 year is a secondary outcome. QoL will not be tracked. More details are available at clinicaltrials.gov.

Taxane-naive mCRPC after failure of one ARDT. Men with mCRPC whose PSA level continues to rise or whose soft-tissue or bone lesions have progressed despite their taking an ARDT are eligible for a phase 3 trial of an experimental targeted radioligand therapy called [Lu-177]PSMA-617. Radioligand therapies combine a targeting molecule that binds to a tumor marker (in this case, PSMA) with a radioactive isotope that damages tumor-cell DNA and inhibits growth and replication. Patients will receive radioligand therapy for up to 36 weeks or ARDT for 43 months until radiographic progression or death. The multinational study started recruiting on June 15. The investigators hope to enroll 450 patients. US sites are in Louisiana, Nebraska, and Washington State. The primary outcome is radiographic progression-free survival. OS and QoL are secondary outcomes. More details are available at clinicaltrials.gov.

Garnick said, “Lu-177–directed therapy for PSMA-positive disease is a potentially major advance for our treatment options, and this study will help define its appropriate use.”

Metastatic hormone-sensitive prostate cancer (mHSPC). Another phase 3 study of [Lu-177]PSMA-617 seeks to enroll men with PSMA-positive mHSPC who are treatment naive or have been “minimally treated” with hormonal therapy. Participants will receive either [Lu-177]PSMA-617 for up to 36 weeks plus standard of care for up to 50 months or standard of care alone. The primary outcome is radiographic progression-free survival; OS and QoL are secondary outcomes. The study opened on June 9. The investigators hope to recruit 1126 men in Florida and Nebraska and five European countries. More details are available at clinicaltrials.gov.

Garnick commented: “The expansion of clinical studies using Lu-177 to include mHSPC is a welcome addition.”

Organ-confined nonmetastatic prostate cancer prior to surgery. Patients with organ-confined, nonmetastatic prostate cancer (stages cT1c–T2c) who are scheduled to undergo bilateral nerve-sparing radical prostatectomy are sought for a phase 2/3 trial of oral 4-aminopyridine (4-AP, fampridine, Ampyra) for mitigating the peripheral nerve damage so feared after this procedure. Patients will take the study drug or a placebo for 3 months following surgery. Incontinence and erectile dysfunction are the primary outcome measures. OS and QoL will not be tracked. The trial is centered at the University of Rochester, in Rochester, New York. The investigators seek to enroll 70 men. More details are available at clinicaltrials.gov.

Garnick is editor-in-chief of the Harvard Medical School Annual Report on Prostate Diseases, for which he receives an honorarium. He has disclosed no financial relationships relevant to the trials discussed in this article.

All trial information is from the US National Library of Medicine, National Institutes of Health (online at clinicaltrials.gov).

Source: Read Full Article