Dr. Mary-Ellen Taplin joins the podcast to discuss the latest changes to the living guideline on metastatic castration-resistant prostate cancer (mCRPC). She reviews new treatment options for patients treated with ADT alone, ADT and an ARPI, ADT and docetaxel, and ADT, an ARPI, and docetaxel whose disease has progressed to mCRPC and the evidence that underpins these changes. Dr. Taplin highlights the updated algorithms within the guideline and the living format which will provide rapid, up-to-date, evidence-based information for clinicians and patients. Read the full living guideline update, "Systemic Therapy in Patients With Metastatic Castration-Resistant Prostate Cancer: ASCO Living Guideline, Version 2026.1." at www.asco.org/genitourinary-cancer-guidelines TRANSCRIPT This guideline, clinical tools and resources are available at www.asco.org/genitourinary-cancer-guidelines. Read the full text of the guideline and review authors' disclosures of potential conflicts of interest in the Journal of Clinical Oncology, https://ascopubs.org/doi/10.1200/JCO-25-02693 Brittany Harvey: Hello and welcome to the ASCO Guidelines podcast, one of ASCO's podcasts delivering timely information to keep you up to date on the latest changes, challenges, and advances in oncology. You can find all the shows, including this one, at asco.org/podcasts. My name is Brittany Harvey, and today I am interviewing Dr. Mary-Ellen Taplin from Dana-Farber Cancer Institute, lead author on "Systemic Therapy in Patients With Metastatic Castration-Resistant Prostate Cancer: ASCO Living Guideline, Version 2026.1." Thank you for being here today, Dr. Taplin. Dr. Mary-Ellen Taplin: Thank you, Brittany. It is a pleasure. Brittany Harvey: Before we discuss this guideline, I would like to note that ASCO takes great care in the development of its guidelines and ensuring that the ASCO Conflict of Interest Policy is followed for each guideline. The disclosures of potential conflicts of interest for the guideline panel, including Dr. Taplin who has joined us here today, are available online with the publication of the guideline in the Journal of Clinical Oncology, which is linked in the show notes. To dive into the content here and what we are here today to talk about, this living clinical practice guideline for systemic therapy for patients with metastatic castration-resistant prostate cancer is updated on an ongoing basis. Dr. Taplin, what prompted this latest update to the recommendations? Dr. Mary-Ellen Taplin: Thank you, Brittany. Several things prompted the latest update. There have been several phase III trials that have been practice-changing that have resulted in the last several years that needed to be added to the guidelines to inform clinicians of comprehensive treatment options. Brittany Harvey: Great, and it is great to have this updated guideline for readers. I would like to review the changes to the recommendations in this latest iteration across the patient populations that are outlined in the guideline. So, starting with: What are the updated recommendations for patients previously treated with androgen deprivation therapy alone whose disease has progressed to metastatic castration-resistant prostate cancer? Dr. Mary-Ellen Taplin: A nice feature of this guideline is that in addition to the tables, which provide detailed options, is at the end of the guidelines, our readers will find very clear algorithms that describe past treatment scenarios that patients could have had and then outline their treatment options. So it is very clear. Our clinicians will love these algorithms. And one of the changes for the disease state that you mentioned, which is the least treated castration-resistant state of prostate cancer which is previously treated with ADT alone, is that we recommend testing for mutations in the HRR, homologous recombination repair, genes. And the ones that are specifically known and applicable to prostate cancer are the BRCA genes. So there is clear recommendation of testing to remind us, as treating physicians, that now is the time, if it hasn't been done before, to institute both germline and somatic testing. And somatic testing, if it can be done on tissue, is preferable, but if not, the liquid biopsy approaches, the ctDNA approaches, have now advanced to the point that most patients with metastatic prostate cancer will be able to successfully have testing on the liquid biopsies. So that is number one, testing. And then the new treatment options include, if a patient does have an HRR gene alteration, and maybe about 20-25 percent of patients will be in that category, the combinations of an androgen pathway inhibitor and a PARP inhibitor are now treatment options. So for instance, talazoparib and enzalutamide; olaparib and abiraterone; or niraparib and abiraterone are some of the newer treatment options if the patient is HRR-positive. So, Brittany, in regard to patients treated with ADT alone, another new treatment option is the combination of radium-223 with enzalutamide. This is data based on the PEACE-3 trial which did show both an rPFS and OS benefit. For the patient who is HRR-negative and has previously not had an ARPI, just ADT alone, the combination of radium and enzalutamide is a new recommendation added to the algorithm. Brittany Harvey: Great. Thank you for reviewing those options for that patient population. And as you mentioned, I think those algorithms are very helpful as figures in the document. They are clear and can be used as at-a-glance tools for clinicians in their busy clinics. So then the next patient population that the guideline addresses: What is new for patients previously treated with androgen deprivation therapy and an androgen receptor pathway inhibitor whose disease has now progressed to metastatic castration-resistant prostate cancer? Dr. Mary-Ellen Taplin: Right, so there are several new treatment options. So one is lutetium-PSMA-617, the trade name of which is Pluvicto. So that has now been FDA approved to use after progression on an AR pathway inhibitor and prior to the use of docetaxel chemotherapy. Brittany Harvey: Thank you for reviewing that new option for patients treated with androgen deprivation therapy and an ARPI whose disease has progressed. So then moving into the next set of recommendations, what does the panel now recommend for patients previously treated with androgen deprivation therapy and docetaxel whose disease has progressed to metastatic castration-resistant prostate cancer? Dr. Mary-Ellen Taplin: The next group of patients is those treated with ADT and docetaxel but haven't had an AR pathway inhibitor. Treatment options, again the HRR testing is important. So all patients with metastatic castration-resistant prostate cancer should be considered for both germline and somatic testing. I will repeat that. And if they are BRCA mutation positive, then the option of talazoparib and enzalutamide; olaparib and abiraterone; and niraparib and abiraterone. So the AR pathway inhibitors plus the PARPs. There are three choices, so that can be somewhat complicated to think through, but most practitioners will get familiar with one of those combinations and be their go-to. So those are for BRCA-positive or HRR-positive. The talazoparib/enzalutamide trial also included non-BRCA HRR-positive gene mutations. And if they are HRR-negative, the option that we discussed above of radium and enzalutamide is new to the guideline. Brittany Harvey: Great. And then the last category of patients that is addressed in this update: What has changed for patients previously treated with androgen deprivation therapy, an androgen receptor pathway inhibitor, and docetaxel whose disease has now progressed to metastatic castration-resistant prostate cancer? Dr. Mary-Ellen Taplin: Well, in this space, patients who are heavily pretreated with ADT and ARPI, one or even two, and chemotherapy, generally with docetaxel, the recommendations are not new within the last year or two. And they include Pluvicto; a PARP inhibitor if HRR-positive and they have not had one; second-line chemotherapy such as cabazitaxel. And if they are a very rare group and they have been sequenced and they are MSI-high, then considering a PD-1 inhibitor such as pembrolizumab can be considered. I will note that this is a very small percentage of mCRPC patients, probably in the order of 5 percent or less. Brittany Harvey: Understood. And I appreciate you reviewing the recommendations across all of these patient populations. It sounds like some of the key points is that HRR testing is very important for this patient population, and that the algorithms and the tables in the manuscript provide the full list of options that clinicians and patients can refer to. Dr. Mary-Ellen Taplin: Those are the highlights. And I will note in the tables, all the sections have "Special Considerations" sections because patients never fall into the black and white of one category. And those practical information or special situations sections of each of the recommendations can also help clinicians think about the individual patient in front of them and how they might choose one therapy over another since there are generally choices in all of these treatment situations. Brittany Harvey: Absolutely. That information for the individualized patient-clinician decision-making is really key when, as you said, there is a list of options to choose from. So in your view, what should clinicians know as they implement this living guideline update, and how do these changes impact patients? Dr. Mary-Ellen Taplin: I am so excited about this living document. ASCO has invested to developing the software to, in real time and iteratively, assess the new data that is published in prostate cancer and other diseases. So now we don't have to wait many years for the next guideline to come out. The guidelines will
