Feb 24, 2022
Guest host, Dr. Neeraj Agarwal, editor-in-chief of ASCO Daily News and director of the Genitourinary Cancers Program at the University of Utah’s Huntsman Cancer Institute, and Dr. Jason Efstathiou, chair of the 2022 ASCO Genitourinary Cancers Symposium, discuss key abstracts and innovations in GU oncology featured at #GU22. Dr. Efstathiou is a professor at Harvard Medical School and director of the Genitourinary Division in Radiation Oncology at Massachusetts General Hospital.
Dr. Neeraj Agarwal: Hello, and welcome to the ASCO Daily News Podcast. I am Dr. Neeraj Agarwal, the director of the Genitourinary Program and professor of medicine at the University of Utah Huntsman Cancer Institute, and editor-in-chief of the ASCO Daily News. Today we'll be discussing key advances in GU oncology featured at the 2022 ASCO Genitourinary (GU) Cancers Symposium. I'm delighted to welcome Dr. Jason Efstathiou, who was the chair of this year's GU ASCO meeting. Dr. Efstathiou is the professor at Harvard Medical School and the director of Genitourinary Division in Radiation Oncology and clinical co-director of The Claire and John Bertucci Center for GU Cancers at the Massachusetts General Hospital. Our full disclosures are available in the show notes and the disclosure of all guests on the podcast can be found on our transcript at asco.org/podcast. Jason, thank you for coming on the podcast today.
Dr. Jason Efstathiou: Thank you very much, Neeraj. It's a real pleasure to be with you.
Dr. Neeraj Agarwal: So, Jason, the GU meeting showcased some fantastic advances across the spectrum of GU malignancies, can you please tell us about some of the hot topics that made the headlines this year?
Dr. Jason Efstathiou: Absolutely. This certainly was a dynamic and interactive hybrid ASCO GU meeting for all those attending in person, live streaming, or accessing the content on-demand. With over 5,200 registrants this year, that's an actual record for this meeting and over 70 countries represented. This meeting truly serves as the premier global event for all those who diagnose, treat and study GU cancers. The meeting highlighted novel scientific and clinical findings that were high impact. [And] in many cases will lead to practice-changing care. The meeting had a real focus on diversity, global perspectives, enhanced interactivity, networking, multidisciplinary, collaborative, and evidence-based care. As you know, this year's theme was “World Class Science, Patient-Centered Care,” and this theme was highlighted throughout the program. The meeting kicked off with a rich day focusing on prostate cancer, lots on PSMA imaging, such as Abstract 9 and a very, very excellent session on PSMA targeting and beyond which explored opportunities and challenges with PSMA novel therapeutics, including biomarkers of response and mechanisms of resistance.
Then Abstract 10 looked at PSMA PET and FDG PET as predictors of response and prognosis in a randomized phase 2 trial of Lutetium PSMA (177Lu-PSMA-617) vs cabazitaxel and metastatic castration-resistant prostate cancer (CRPC) progressing after docetaxel. And it suggested that Lutetium PSMA be prioritized in men with high PSMA expression. And this could actually be predictive. We had some awesome abstracts. Abstracts 222 and 223 suggested that a nozzle digital pathology-based biomarker developed using artificial intelligence is more effective than clinical prognostic markers for predicting long-term outcomes in patients with prostate cancer. And that this AI tool can actually successfully guide the use of androgen deprivation therapy in men with intermediate-risk localized prostate cancer. And then, of course, there were some very exciting results in discussion with the primary results of 3 potentially practice-changing phase 3 trials in the setting of metastatic prostate cancer that were presented in the oral prostate session. These were: PROpel (Abstract 11), MAGNITUDE (Abstract 12), and the ARASENS trials (Abstract 13). Neeraj, as a practicing medical oncologist, what did you think of these 3 abstracts?
Dr. Neeraj Agarwal: I agree with you, Jason. These are indeed practice-impacting, practice-changing abstracts, which was a record for a prostate oral session, all 3 abstracts. In fact, the results of the phase 3 trials are [likely] going to influence or impact our practice in coming months. I would like to start with Abstract 11 on the results of the PROpel trial. So, PROpel is a randomized phase 3 trial evaluating the efficacy and safety of olaparib plus abiraterone vs placebo plus abiraterone. In the first-line metastatic cast of resistant cluster cancer, docetaxel therapy was allowed for these patients if given in the metastatic castration sensitive prostate cancer setting. Enrollment in the study was independent of the defects in the homologous recombination repair gene pathway. The primary endpoint was investigator assessed radiographic progression-free survival with multiple secondary endpoints, including overall survival and safety. A total of 796 patients were randomly assigned to olaparib plus abiraterone or placebo plus abiraterone at the pre-plant interim analysis.
Results show that with a significant improvement in the radiographic progression-free survival for all patients receiving the combination therapy, regardless of the presence of homologous recombination repair gene mutations. Overall survival analysis is still immature with only 29% event having occurred thus far. It is interesting that even patients deemed a negative for homologous recombination repair gene mutations showed significant improvement in video graphic progression-free survival when treated with the combination of olaparib plus abiraterone versus placebo plus abiraterone. I would like to mention the MAGNITUDE trial, which is Abstract 12, in the same context, as these have very similar populations and combination regimens.
So, MAGNITUDE is a randomized phase 3 trial evaluating the efficacy and safety of niraparib plus abiraterone vs placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer setting. The eligible patient population was slightly different from that in the PROpel trial—prior attacks in therapy or novel hormonal therapy in the metastatic castration sensitive prostate cancer or non-metastatic castration-resistant prostate cancer were allowed. Also, patients were eligible if they had received up to 4 months of abiraterone in the first-line metastatic CRPC setting. Prospective selection of the patients with, and without homologous recombination repair gene mutations was required.
So, the primary endpoint was radiographic progression-free survival by central with multiple secondary endpoints, including overall survival and safety. A pre-specified early fragility analysis was planned after enrolling 200 patients who are [homologous recombination repair] (HRR) negative and who were randomly assigned to receive either niraparib plus abiraterone or placebo plus abiraterone. The pre-planned fertility analysis showed no benefit in the biomarker negative cohort. Four hundred and twenty-three patients who were HRR positive were randomly assigned to receive either the combination of niraparib plus abiraterone or placebo plus niraparib at the pre-planned interim analysis. The results show that trial method—primary endpoint with a significant improvement in the radiographic progression-free survival for BRCA1 and 2 patients—and all patients who are homologous recombination repair mutation-positive [were] receiving the combination of niraparib plus abiraterone versus placebo plus niraparib. Overall survival reserve is still immature.
My combined take on the PROpel and the MAGNITUDE trial, based on the data presented so far or available in the public domain so far, is that both trials establish that combination of a PARP inhibitor plus abiraterone on in the first-line settings for me, for [patients with] HRR mutation-positive metastatic castration-resistant prostate cancer [will] improve radiographic progression-free survival. Even though overall survival data is immature for both trials, I expect both combinations will be approved by the U.S. Food and Drug Administration in the near future and will be available to our patients. The HRR negative in the PROpel trial also seemed to benefit with the combination of abiraterone plus olaparib.
I'm looking forward to data on confirmation of HRR negative status by tissue-based genomic profiling results in the full-length publication, which we expect to be published soon. If indeed confirmed, I see the combination of abiraterone plus olaparib to be a reasonable option for patients who are HRR negative in the first metastatic castration prostate cancer set. The last practice-changing abstract in the oral prostate session was Abstract 13 on the results of the ARASENS trial. ARASENS is a randomized phase 3 trial evaluating the efficacy and safety of darolutamide plus ADT or androgen deprivation therapy plus docetaxel versus placebo plus ADT plus docetaxel in patients with metastatic castration sensitive prostate cancer or mCSPC.
It is important to note that this study only included patients that were eligible for ADT plus docetaxel chemotherapy. The primary endpoint was overall survival with multiple secondary endpoints, including time to casted resistance, time to pain progression, time to first symptomatic skeletal event, and time to start of next antineoplastic therapy and of course, safety. A total of 1,300 patients were randomly assigned to the darolutamide plus ADT plus docetaxel vs placebo plus ADT plus docetaxel.
Results show the primary endpoint of the study was met with a significant improvement in overall survival and a 32% reduction in risk of death for patients on the triplet therapy with thalidomide plus ADT plus docetaxel. While this study offers an additional excellent option for our patients with metastatic castration-sensitive prostate cancer, in an older patient population [the] use of docetaxel may be a significant limitation to this combination. In addition, this study did not answer the question [of] if adding docetaxel to ADT plus a novel hormonal therapy backbone will also improve survival with the advent of multiple doublets and triplet combinations. In recent years, it is very important to find biomarkers that may predict response to these treatments and personalized therapy.
Dr. Jason Efstathiou: Well, Neeraj, it certainly is a mic drop moment. Isn't it? When you can announce that the New England Journal of Medicine has just released the publication of your ARASENS trial, as you're presenting it at ASCO GU don't you think (DOI: 10.1056/NEJMoa2119115)?
Dr. Neeraj Agarwal: Indeed, I think this is one of the most exciting ASCO GU meetings I've seen ever from GU ASCO. This is not an exaggeration.
Dr. Jason Efstathiou: I totally agree. It was a phenomenal meeting and a very dynamic rich prostate day.
Dr. Neeraj Agarwal: So, let's move on to bladder cancer. Jason, what are your key takeaways from the studies of bladder cancer presented in this meet?
Dr. Jason Efstathiou: Thanks, Neeraj. Yeah, the sessions on urothelial cancer were phenomenal and there were great sessions on novel therapies, such as antibody-drug conjugates in advanced urothelial cancer and management of toxicities. There were abstracts such as [Abstract] 440 suggesting that neoadjuvant gemcitabine and cisplatin produced a favorable pathologic response rate and was well tolerated in patients with high-grade upper tract urothelial carcinoma, and thus should be potentially deemed a new standard. Abstract 442 was a phase 2 trial that suggested that maintenance treatment with niraparib plus best supportive care did not improve outcomes compared to best supportive care alone, in patients with advanced urothelial carcinoma that did not progress after first-line chemotherapy.
There was Abstract 435, which was an earlier face study suggesting that neoadjuvant treatment with enfortumab demonstrated promising activity among patients who are cisplatin-ineligible with muscle-invasive bladder cancer. And then there was a lot of focus in the meeting on trimodality therapy and optimizing bladder preservation. Dr. Alexandre R. Zlotta presented Abstract 433, which was a large multi-institutional match comparison of radical cystectomy to trimodality therapy for patients with muscle-invasive bladder cancer. And it suggested equivalent oncologic outcomes for select patients, and that trimodality therapy should be offered as an effective alternative for these patients. So Neeraj, moving on to kidney cancer, what were your key takeaways from these studies on kidney cancer presented in this meeting?
Dr. Neeraj Agarwal: Yes, Jason, thank you. There were exciting results presented from multiple studies in kidney cancer as well. For example, Abstract 290 presented by Dr. Toni K. Choueiri from the Dana-Farber Cancer Institute on the 30-month follow-up of the KEYNOTE-564, which showed continued and strong disease-free survival benefit with adjuvant pembrolizumab in the context of localized or completely dissected renal cell carcinoma. I would like to highlight that highest benefit was seen in those patients who had oligometastatic disease, who on different surgery to remove those metastatic foresight and then were randomly assigned to receive pembrolizumab vs placebo in this trial. Abstract 291, presented by Dr. Matthew Zibelman from Fox Chase Cancer Center, showed the combination of axitinib with nivolumab was associated with close to 70% objective responses. Abstract 300 on kidney cancer on more than 1,000 patients—and on the International Metastatic Renal Cell Carcinoma Consortium, or IMDC Consortium—show that in the context of first-line immunotherapy regimens, presence of lung metastasis, CT nephrectomy and better MDC risk scores correlated with improved objective responses on this novel immunotherapy regimens.
Abstract 350 on the update of the cabozantinib nivolumab was a sunitinib trial in metastatic renal cell carcinoma in the first-line setting. And it showed that the combination of cabozantinib nivolumab continues to be associated with improved survival with the 30% reduced risk of death, even after this longer follow up—approximately 3 years. So, indeed, multiple abstracts on kidney cancer with real impact on how we practice medicine. So, Jason, let me switch gears here and talk about the education session. For example, there was a compelling keynote address by Dr. Karen Knudsen, the CEO of the American Cancer Society, about disparities in GU cancers in the United States. Are there any key messages that you would like to highlight briefly before we wrap up the podcast today?
Dr. Jason Efstathiou: Thanks, Neeraj. Absolutely. The educational sessions were phenomenal. There was a must-see session, by the way, on management of rare variants in GU cancers. They made management of nuanced, rare variants and rare situations, very practical. And then there was an exciting prostate focus session called “Regulating the Wild West: PET-Based Imaging in Trials and the Clinic.” This session was planned with representatives from the U.S. Food and Drug Administration as we have done for the past 3 years. But this year it looked at how often PET-based imaging affects clinical decision making and prostate cancer and how the integration of novel molecular-based imaging like PET informs clinical trial design and endpoints, including regulatory considerations. And yes, of course, as you noted this year's program also focused on identifying and addressing disparities in cancer care and research with sessions each day, focused on this topic (Abstract 225, 446, 472, and 26).
There were great oral presentations and there was a phenomenal Virtual Poster Walk with Dr. Ahmedin Jemal from the American Cancer Society. He, by the way, is an author that we have all quoted. So, please check that out. But we were thrilled, absolutely thrilled to have Dr. Karen Knudsen, the CEO of the American Cancer Society (ACS) as our keynote speaker to address this important topic in her phenomenal and frankly, inspiring talk called “A Path Forward: Addressing Disparities in Genitourinary Cancers.” This talk was especially poignant because as you know, there is a new and robust collaboration between ASCO and the ACS that was announced earlier this month on February 1, regarding equity, diversity, and inclusion in cancer care. ASCO's work aims to address all of the important differences that can impact access to cancer care and outcomes, including age, gender, race, sexual orientation, and geography, both in the U.S. and internationally. ASCO has clearly aligned its equity, diversity, and inclusion (EDI) goals within the mission pillars of research, education, and quality.
Dr. Neeraj Agarwal: Thank you, Jason, for sharing your insights with us today. It is really an exciting time in GU oncology. Thank you.
Dr. Jason Efstathiou: Thank You, Neeraj. I totally agree.
Dr. Neeraj Agarwal: And thank you to our listeners for joining us today. You will find links to the abstracts discussed today on the transcript of this episode. Finally, if you like what you're hearing on the ASCO Daily News podcast, please take a moment to rate, review and subscribe wherever you get your podcast. Thank you so much.
Dr. Neeraj Agarwal:
Consulting or Advisory Role: Pfizer, Medivation/Astellas, Bristol-Myers Squibb, AstraZeneca, Nektar, Lilly, Bayer, Pharmacyclics, Foundation Medicine, Astellas Pharma, Lilly, Exelixis, AstraZeneca, Merck, Novartis, lily, Eisai, Seattle Genetics, EMD Serono, Janssen Oncology, AVEO, Calithera Biosciences, MEI Pharma, Genentech, Astellas Pharma, Foundation Medicine, and Gilead Sciences
Research Funding (Institution): Bayer, Bristol-Myers Squibb, Takeda, Pfizer, Exelixis, Amgen, AstraZeneca, Calithera Biosciences, Celldex, Eisai, Genentech, Immunomedics, Janssen, Merck, Lilly, Nektar, ORIC Pharmaceuticals, ORIC Pharmaceuticals, crispr therapeutics, and Arvinas
Dr. Jason Efstathiou:
Consulting or Advisory Role: Blue Earth Diagnostics, AstraZeneca, Boston Scientific, Roivant Pharma, Merck, and Myovant Sciences
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