Dr. Sumit Subudhi Answers Questions on Prostate Cancer and Immunotherapy from the CRI Virtual Immunotherapy Patient Summit

At the CRI Virtual Immunotherapy Patient Summit in October, patients and caregivers were eager to further their understanding of immunotherapy for prostate cancer.

Sumit K. Subudhi, MD, PhD, a medical oncologist and immunologist at the University of Texas MD Anderson Cancer Center, led the Prostate Cancer and Immunotherapy Breakout Session.

We followed up with Dr. Subudhi after the event to discuss several more questions from attendees.

When conventional therapies don’t work, is immunotherapy still effective for prostate cancer?

Dr. Subudhi: Sipuleucel-T (PROVENGE®) is a cancer vaccine (a form of immunotherapy) that is considered to be a standard-of-care (conventional) therapy for asymptomatic or minimally symptomatic patients with metastatic castration-resistant prostate cancer. All other types of immunotherapies are considered to experimental for prostate cancer. We have found that other immunotherapies (e.g., immune checkpoint therapies) can be effective in a subset of patients with metastatic castration-resistant prostate cancer.

At what point would you introduce immunotherapy versus other standard therapy for a patient? Some oncologists seem to be reluctant to prescribe immunotherapy over other therapies.

Dr. Subudhi: I would consider it at any point as we do not know when exactly the optimal time is to introduce immunotherapies. Standard therapies can be used in the future in case the immunotherapy does not work. The only time I would hesitate considering an immunotherapy is if a patient has a rapidly progressing cancer that is causing significant symptoms (e.g., bone pain requiring high doses of narcotics). This is because it often takes immunotherapy more than one month to be effective; whereas many of the standard therapies can improve symptoms faster.

If immunotherapy works, but a few years later the cancer returns, can you begin immunotherapy treatment again?

Dr. Subudhi: There is evidence in melanoma that this approach can be effective for immune checkpoint therapies, which are only improved for prostate cancer patients with tumors harboring DNA mismatch repair defects (dMMR) or high tumor mutational burden (TMB-H).

What are common questions your patients have? What questions do you suggest patients and caregivers bring to their treating oncologists? 

Dr. Subudhi: The two most common questions I receive from my patients and caregivers are:

1. What immunotherapy options are available for me?
2. How long do I have to live?

I recommend that patients and caregivers ask their treating oncologists:

1. How often do you treat my type of cancer?
2. Why are you choosing this particular treatment option for my cancer?
3. What are other possible options for treating my cancer?
4. Are there any clinical trials available for treating my cancer?

How has immunotherapy changed your outlook as an oncologist? Do you think that immunotherapy will one day become standard of care for all prostate cancer patients?

Dr. Subudhi: As an oncologist, immunotherapy has given me hope that we can cure cancers that were thought to be incurable. I realize we have a long way to go to make that a reality for prostate cancer, but we and others (including our patients) are taking the right steps to get there.

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