Testing Interruption of Hormonal Medications in Patients Responding Exceptionally to Therapy for Metastatic Prostate Cancer, (A-DREAM)

Inclusion Criteria:

Histologic or clinical diagnosis of metastatic prostate cancer

Must have had evidence of metastatic disease by bone scan, or nodal or visceral lesions on computed tomography (CT) or magnetic resonance imaging (MRI) prior to starting on intense antiandrogen therapy (ADT)

Radiographic evidence of disease is not required at the time of enrollment
No metastases to liver or to brain, as these represent aggressive variant disease biology for which intermittent treatment may not be favored

Must currently be receiving intense ADT for metastatic hormone sensitive prostate cancer (mHSPC)

Testosterone suppression (TS) with luteinizing hormone releasing hormone (LHRH)-agonist or LHRH-antagonist AND
An approved secondary androgen receptor pathway inhibitor (ARPI) abiraterone, enzalutamide, or apalutamide (or darolutamide if approved for this indication)
Must have remained on testosterone suppression for metastatic disease continuously (without treatment breaks) for 540-750 days (approximately 18 to 24 months) from time of first dose of LHRH agonist or antagonist by time of registration. A period of anti-androgen treatment prior to LHRH agonist or antagonist initiation is not included in the 540 - 750 days (approximately 18 to 24 months)
Must have received treatment with ARPI for at least 360 days in total by time of A032101 registration. Treatment breaks from ARPI of up to 28 days are permitted (for example peri-procedural or for management of a temporary adverse event) as long as PSA did not rise while holding therapy
Prior TS in the context of neoadjuvant/concurrent/adjuvant treatment with local therapy is permitted. Prior course(s) of intermittent TS for biochemical-only recurrence is permitted. However, if the patient previously received TS, metastatic progression for which intense ADT was initiated must have occurred during an off-treatment interval and with testosterone >= 150 ng/dL
Prior local therapy for prostate cancer (either before or after diagnosis of metastatic disease) is permitted. Prior treatment with docetaxel chemotherapy for up to 6 cycles is permitted. Prior radiation therapy to metastatic sites (either for symptom palliation or for ablation of oligometastatic disease) is permitted

Exclusion Criteria:

No history of surgical castration
No history of ARPI use prior to diagnosis of mHSPC for which the patient is currently receiving intense ADT (such as in the neoadjuvant setting with prior local therapy)
No current or prior treatment with experimental agents for metastatic hormone-sensitive prostate cancer
Eastern Cooperative Oncology Group (ECOG) performance status 0-2

Prior to initiating intense ADT

Prostate specific antigen (PSA) >= 5 ng/ml
Testosterone >= 150 ng/dl. Patients are permitted to enroll if testosterone was not measured prior to initiating intense ADT for mHSPC if they did not previously receive TS and were not known or suspected to be hypogonadal at the time

At time of enrollment to A032101

PSA < 0.2 ng/ml

** PSA values (measured in the same laboratory) must be stable or falling for 3 consecutive measurements - i.e. any PSA rise must be followed by a decrease in PSA that is further decreased or stable on a 3rd measurement. Any patient with 2 consecutive rises in PSA values since achieving castrate level of testosterone is not eligible

Testosterone < 50 ng/dl
No current participation in a clinical study that does not allow for TS or ARPI interruption
No patients with a "currently active" second malignancy * Patients with non-melanomatous skin cancer, superficial bladder cancer, cancer not needing active therapy for at least 2 years, cancer for which the treating investigator deems the subject