Akash Patnaik, MD, PhD
The role of immunotherapy may have had a slower uptick in patients with prostate cancer compared with other tumor types, but progress is being made, explains Akash Patnaik, MD, PhD, an assistant professor of Medicine at the University of Chicago Medicine.
Aside from the immuno-based agent sipuleucel-T (Provenge), Patnaik discussed the status with immunotherapy and personalized therapy in prostate cancer at the OncLive
State of the Science Summit on GU and Prostate Cancer.
In an interview with OncLive
during the meeting, Patnaik discussed immunotherapy and personalized medicine tactics in the field of prostate cancer, as well as the work that needs to be done with existing targeted therapies and biomarker development.
OncLive: What are the latest advancements with immunotherapy and personalized medicine in prostate cancer?
: It is a very exciting time in oncology right now, with advances in precision medicine and a framework for understanding how some of these therapies that target specific aberrations in the tumor can ultimately lead to clinical benefit. There is also tremendous excitement and momentum with immunotherapies in a range of cancers—both solid tumors and hematologic malignancies.
However, there is still a subset of patients across all of these cancers who do not respond to immunotherapy. The challenge, particularly in the context of prostate cancer—which is one of the cancers where immune-based therapies have not been home runs—is that there have been limited successes, but clearly, there is room for improvement.
It will be challenging to understand how we can think about combinatorial approaches to enhance the efficacy and immunoresponsiveness of these cancers.
Are there immunotherapy combinations that are being studied right now in prostate cancer that have potential?
The only FDA-approved agent presently is sipuleucel-T, which is a vaccine-based therapy that has been shown to have a survival benefit in a phase III clinical trial. One challenge that remains with sipuleucel-T is determining the patients who are likely to benefit from this therapy. We do not have a biomarker yet that can identify the subset of patients who will respond.
The T-cell checkpoint blockade strategies have shown responses as well, but not strong enough to see a survival benefit with ipilimumab (Yervoy), for example. We are presently pursuing several mechanistically oriented combinatorial strategies, where we can explore oncogenic signaling pathways in the cancer and decipher overcoming resistance to these immune-based therapies using drugs that target oncogenic signaling.
Looking at the therapies that we do have available for patients with prostate cancer, do you find that there are challenges with sequencing?
In the context of metastatic castration-resistant prostate cancer, there have been several agents that have been FDA-approved since 2009. Therefore, the landscape has clearly evolved significantly in the last 7 years. The jury is still out in terms of how best to sequence these therapies or even combine some of them. There are ongoing clinical trials that can answer some of those questions.