Dr. Rahul Aggarwal is an Associate Clinical Professor of Medicine in the University of California, San Francisco Genitourinary Oncology and Developmental Therapeutics programs. He’s keenly interested in developing novel therapeutics and imaging strategies for men with advanced prostate cancer.
Dr. Aggarwal is a Co-Investigator in the ongoing Prostate Cancer Foundation’s Stand Up To Cancer-funded West Coast Dream Team prostate cancer consortium.
Prostatepedia spoke with him about his clinical trial on hormonal annihilation in men with high-risk biochemically recurrent prostate cancer.
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What is the thinking behind your clinical trial on hormonal annihilation in men with high-risk biochemically recurrent prostate cancer?
Dr. Aggarwal: This trial is for patients with prostate cancer who previously had what we call a radical prostatectomy, or the prostate was removed, as their primary treatment and then subsequently had evidence of cancer recurrence as indicated by a rising PSA. We’re specifically looking at patients with a PSA that is rising quickly with a PSA doubling time of nine months or less.
We know that this group of patients is at risk for subsequent development of metastases as well as at risk for prostate cancer-related mortality. One standard treatment approach is to use intermittent hormone therapy, which can suppress the cancer for a period of time. Inevitably, though, the cancer becomes hormone or castration-resistant.
Once that happens, patients have fewer treatment options remaining and a shorter prognosis.
The main goal of the study is to use some of the more potent hormonal therapies that have been developed, including Zytiga (abiraterone) and Erleada (apalutamide). and apply them to this situation to see if we can durably suppress the patients’ prostate cancer in a finite period of treatment. Rather than treating indefinitely, we treat everyone on the study for 12 months, and then we stop and let their testosterone levels recover and any side effects related to hormone therapy stop or lessen. Hopefully, we can see long-term control of patients’ PSA levels or maybe for some prevent the need for future treatment.
In this way you would also lessen some of the side effects associated with these treatments?
Dr. Aggarwal: Exactly. Then the total duration, or percent time, spent on hormone therapy would be shorter. Even though we’re giving more potent hormone therapy, this would actually translate into less overall treatment and less medical burden from a side effect perspective. Some of the other studies that have come out using medicines like Zytiga (abiraterone) and Erleada (apalutamide) in the hormone sensitive or castration resistant settings do seem to suggest there is a benefit to giving these medicines earlier in the treatment course. I think it fits with what we’re seeing in terms of the general trends in the use of these medicines and the management of prostate cancer.
What can a patient expect to happen step by step if he ends up participating?
Dr. Aggarwal: The treatment phase of the study consists of monthly visits for a year in which patients are getting hormone injections. Then it is a randomized study, so in the standard of care arm men would be getting the hormone injections alone once a month for a year. Then there are two experimental, or investigational, arms with added hormonal therapy. One arm has added Erleada (apalutamide). The third arm adds Erleada (apalutimide) plus Zytiga (abiraterone).
Patients have a two in three chance of being on one of the added hormonal treatment arms.
This is an open label trial, meaning there is no placebo. Everyone will get active treatment, so there’s no risk that their PSA levels won’t go down. Every patient responds initially to hormone therapy, or nearly everyone. We see patients monthly for hormone treatments. We evaluate them for side effects. At four or five time points throughout the study, we have patients fill out questionnaires regarding their symptoms. We do want to understand from a patient perspective what quality of life and symptoms are like during the course of treatment.
After one year of treatment, assuming the PSA is not rising, patients will then enter a follow-up phase which we try to make easy. We check patients’ PSA and testosterone levels once a month, but we don’t require any mandated in-person visits to allow more flexibility for those who live far away from the study center where they were treated.
At the time that the PSA rises to above 0.2, that’s the cut off for what we call PSA progression, which is the primary endpoint of the study. After that treatment is per the discretion of the patient and treating doctor. We still follow patients long term for metastases free and overall survival. The treatment options at that point are completely up to whatever is decided upon between the patient and his doctor. It’s flexible on the backend too if his PSA were to rise.