Sequencing versus upfront combination therapy in metastatic cancer-resistant prostate cancer

Drs. Neeraj Agarwal and Jeanny Aragon-Ching discuss several key abstracts to be presented at the 2024 ASCO GU Cancers Symposium, including sequencing versus upfront combination therapies for mCRPC in the BRCAAway study, updates on the CheckMate-9ER and CheckMate-214 trials in ccRCC, and a compelling real-world retrospective study in mUC of patients with FGFR2 and FGFR3 mutations.

TRANSCRIPT

Dr. Neeraj Agarwal: Hello, everyone, and welcome to the ASCO Daily News Podcast. I'm Dr. Neeraj Agarwal, your guest host of the podcast today. I am the director of the Genitourinary Oncology Program and a professor of medicine at the University of Utah's Huntsman Cancer Institute, and editor-in-chief of ASCO Daily News. I am delighted to welcome Dr. Jeanny Aragon-Ching, a genitourinary oncologist and the clinical program director of Genitourinary Cancers at the Inova Schar Cancer Institute in Virginia. Today, we will be discussing key posters and oral abstracts that will be featured at the 2024 ASCO Genitourinary Cancer Symposium, which is celebrating 20 years of evolution in GU oncology this year.

You will find our full disclosures in the transcript of this podcast, and disclosures of all guests on the podcast at asco.org/DNpod.

Jeanny, it's great to have you on the podcast today to highlight some key abstracts for our listeners ahead of the GU meeting.

Dr. Jeanny Aragon-Ching: Thank you so much, Neeraj. It's an honor to be here.

Dr. Neeraj Agarwal: Jeanny, as you know, this year we are celebrating the 20th anniversary of the ASCO GU Cancers Symposium, and judging from this year's abstracts, it's clear that this meeting continues to play a major role in advancing GU cancer research.

Dr. Jeanny Aragon-Ching: Indeed, Neeraj. This year's abstracts reflect the important strides we have made in GU cancers. So, let's start with the prostate cancer abstracts. What is your takeaway from Abstract 19 on BRCAAway, which will be presented by Dr. Maha Hussein, and of which you are a co-author? As our listeners know, several PARP inhibitor combinations with second-generation androgen receptor pathway inhibitors, or ARPIs, have recently been approved as first-line treatment for patients with metastatic castrate-resistant prostate cancer, or metastatic CRPC, and the question of sequencing PARP inhibitors and ARPIs instead of combining them has emerged. From that perspective, the results of the BRCAAway trial are very important. Can you tell us a little bit more about this abstract, Neeraj?

Dr. Neeraj Agarwal: I totally agree with you, Jeanny. The BRCAAway study attempts to answer the crucial questions regarding sequencing versus upfront combination of therapies in the mCRPC setting. It is a phase 2 trial of abiraterone versus olaparib versus abiraterone with olaparib in patients with mCRPC harboring homologous recombination repair mutations. Enrolled patients had mCRPC disease and no prior exposure to PARP inhibitors or ARPIs or chemotherapy in the mCRPC setting and had BRCA1 or BRCA2 or ATM mutations. As previously mentioned, these patients were randomized to 3 arms: abiraterone monotherapy at 1000 milligrams once daily, or olaparib monotherapy at 300 milligrams twice daily, or the combination of abiraterone and olaparib. The primary endpoint was progression-free survival per RECIST 1.1 or Prostate Cancer Working Group 3-based criteria or clinical assessment or death, so, whichever occurred first was deemed to be progression.

Secondary endpoints included measurable disease response rates, PSA response rate, and toxicity. This was a relatively small trial with 21 patients in the combination arm, 19 patients in the abiraterone monotherapy arm, and 21 patients in the olaparib monotherapy arm. It should be noted that 26% of patients had received docetaxel chemotherapy in the hormone-sensitive setting, and only 3% of patients had any prior exposure to an ARPI, and these were darolutamide or enzalutamide or in the non-metastatic CRPC setting.

The results are very interesting. The median progression-free survival was 39 months in the combination arm, while it was 8.4 months in the abiraterone arm and 14 months in the olaparib arm. An important finding that I would like to highlight is that crossover was also allowed in the monotherapy arms. Of the 19 patients receiving abiraterone, 8 crossed over to receive olaparib, and of the 21 patients receiving olaparib, 8 crossed over to the abiraterone arm. The median PFS from randomization was 16 months in both groups of patients who received abiraterone followed by olaparib or those who received olaparib followed by abiraterone. This is striking when compared to 39 months in patients who started therapy with the combination therapy of abiraterone with olaparib.

Dr. Jeanny Aragon-Ching: Thank you so much for that wonderful summary, Neeraj. So the key message from this abstract is that combining olaparib and abiraterone upfront seems to be associated with improvement in PFS compared to just sequencing those agents.

Dr. Neeraj Agarwal: Exactly, Jeanny. I would like to add that these results are even more important given that in real-world practice, only half of the patients with mCRPC receive a second-line treatment. Based on these results, upfront intensification with a combination of an ARPI plus a PARP inhibitor in the first-line mCRPC setting seems to have superior efficacy compared to sequencing of these agents.

Dr. Jeanny Aragon-Ching: Thank you so much. Now, moving on to a different setting in prostate cancer, there were a couple of abstracts assessing transperineal biopsy compared to the conventional transrectal biopsy for the detection of prostate cancer. So let's start with Abstract 261. Neeraj, can you tell us a little bit more about this abstract?

Dr. Neeraj Agarwal: Sure, Jeanny. So, in Abstract 261 titled "Randomized Trial of Transperineal versus Transrectal Prostate Biopsy to Prevent Infection Complications," Dr. Jim Hugh and colleagues led a multicenter randomized trial comparing these 2 approaches, so, transperineal biopsy without antibiotic prophylaxis with transrectal biopsy with targeted prophylaxis in patients with suspected prostate cancer. The primary outcome was post-biopsy infection. Among the 567 participants included in the intention-to-treat analysis, no infection was reported with the transperineal approach, while 4 were detected with the transrectal approach, with a p-value of 0.059. The rates of other complications, such as urinary retention and significant bleeding, were very low and similar in both groups. The investigators also found that detection of clinically significant cancer was similar between the 2 techniques and concluded that the transperineal approach is more likely to reduce the risk of infection without antibiotic prophylaxis.

Dr. Jeanny Aragon-Ching: So the key takeaway from this abstract sounds like office-based transperineal biopsy is well-tolerated and does not compromise cancer detection, along with better antibiotic stewardship and health care cost benefits.

Moving on to Abstract 273, also comparing these two approaches, what would be your key takeaway message, Neeraj?

Dr. Neeraj Agarwal: In this Abstract 273, titled "Difference in High-Risk Prostate Cancer Detection between Transrectal and Transperineal Approaches," Dr. Semko and colleagues found that the transperineal biopsy based on MRI fusion techniques was also characterized by a higher possibility of detecting high-risk prostate cancer and other risk factors as well, such as perineural and lymphovascular invasion or the presence of cribriform pattern, compared to the conventional transrectal method.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So we can see that the transperineal approach is gaining more importance and could be associated with more benefits compared to the conventional methods.

Let's now switch gears to kidney cancer, Neeraj.

Dr. Neeraj Agarwal: Sure, Jeanny. Let's start by highlighting Abstract 361, which discusses patient-reported outcomes of the LITESPARK-005 study. So what can you tell us about this abstract, Jeanny?

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So as a reminder to our listeners, based on the LITESPARK-005 trial, it was a Phase 3 trial looking at belzutifan, which is an inhibitor of hypoxia inducible factor 2 alpha or I'll just call HIF-2 alpha for short, was very recently approved by the FDA as a second-line treatment option for patients with advanced or metastatic clear cell renal cell carcinoma after prior progression on immune checkpoint and antiangiogenic therapies. The title of Abstract 361 is "Belzutifan versus Everolimus in Patients with Previously Treated Advanced RCC: Patient-Reported Outcomes in the Phase 3 LITESPARK-005 Study," and this will be presented by Dr. Tom Pells at the meeting. At a median follow-up of 25.7 months, the median duration of treatment with belzutifan was 7.6 months, while it was only 3.9 months with everolimus. At the time of data cutoff date for the second interim analysis, 22.6% of patients remained on belzutifan while only 5% remained on everolimus. In the quality of life questionnaires, the time of deterioration to various quality of life scores, as assessed by standardized scales, was significantly longer in patients randomized to the belzutifan arm compared to those in the everolimus arm. Also, patients in the everolimus arm had worse physical functioning scores.

Dr. Neeraj Agarwal: Yes, Jeanny. In addition to the improved outcomes associated with belzutifan, patient-reported outcomes indicate better disease-specific symptoms and better quality of life among patients treated with belzutifan compared to everolimus. This is great news for patients with advanced renal cell carcinoma.

Now, Jeanny, can you please tell us about the two abstracts that reported longer follow-up of CheckMate 9ER and CheckMate 214 trials in untreated patients with advanced or metastatic renal cell carcinoma?

Dr. Jeanny Aragon-Ching: Yes, Neeraj. So you are referring to Abstracts 362 and 363. Let's start with Abstract 362. This abstract reports the results after a median follow-up of 55 months in the CheckMate 9ER trial, comparing the combination of nivolumab and cabozantinib to sunitinib in patients with advanced RCC without any prior treatment, so first-line therapy. The primary endpoint was PFS per RECIST 1.1 as assessed by an independent central review. So there were key secondary outcomes including overall survival (OS), objective response rates, and safety. Consistent with prior analysis at a median follow-up time of 18.1 and 44 months, the combination of nivolumab and cabozantinib at a median follow up of 55.6 months continues to show a significant reduction in the risk of progression or death by 42% and in the risk of death by 23% compared to sunitinib.

Dr. Neeraj Agarwal: And Jeanny, what can you tell us about the efficacy results of this combination by IMDC risk categories?

Dr. Jeanny Aragon-Ching: Similar to prior results in patients with intermediate to poor risk IMDC risk category, the combination treatment maintained significant efficacy and reduced the risk of progression or death by 44% and the risk of death by 27%. To put it simply, the update now shows a 15-month improvement in overall survival with the cabozantinib-nivolumab combination compared to sunitinib, which is amazing. Also, in patients with favorable IMDC risk group, which represented truly a small number of patients in the trial, there was a strong trend for improvement of outcomes as well. I would like to point out that no new safety concerns were identified.

Dr. Neeraj Agarwal: So, it looks like the key message from this abstract is that with longer follow-up, the combination of nivolumab and cabozantinib maintains a meaningful long-term efficacy benefit over sunitinib, supporting its use for newly diagnosed patients with advanced or metastatic renal cell carcinoma.

Let's move on to Abstract 363, which compares nivolumab with ipilimumab to sunitinib in first-line advanced renal cell carcinoma. What would you like to tell us about this abstract, Jeanny?

Dr. Jeanny Aragon-Ching: Yes, Neeraj. The title of this abstract is "Nivolumab plus Ipilimumab versus Sunitinib for the First-Line Treatment of Advanced RCC: Long-Term Follow-Up Data from the Phase 3 CheckMate 214 Trial." In this abstract, Dr. Tannir and colleagues report outcomes with the longest median follow-up in first-line advanced RCC setting for any clinical trial. So the median follow-up now is about 18 months. The primary endpoints were OS, PFS, and objective response rates, as assessed by an independent review according to RECIST 1.1 criteria in the intermediate to poor risk IMDC risk group, which is the intent-to-treat (ITT) analysis, while secondary outcomes included the same outcomes in the ITT population of patients. Although the progression-free survival was similar in both arms, the combination of nivolumab-ipilimumab reduced the risk of death by 28% compared to sunitinib in the ITT population of patients. When stratifying the results by IMDC risk groups, the combination arm of nivolumab-ipilimumab showed significant improvement in the intermediate to poor risk group, but there was no difference in the favorable risk group. But in the study, no new safety signals were identified.

Dr. Neeraj Agarwal: Thank you, Jeanny, for such a comprehensive description of the results of these two studies. I'd like to add that the median overall survival of patients with metastatic renal cell carcinoma in the ITT population in the CheckMate 214 trial has now reached 53 months, which would have been unimaginable just a decade ago. This is wonderful news for our patients. So the key takeaway from these two abstracts would be that immune checkpoint inhibitor-based combinations remain the backbone of first-line advanced renal cell carcinoma treatment.

Dr. Jeanny Aragon-Ching: Absolutely, Neeraj. This is wonderful news for all of our patients, especially for those who are being treated for first-line therapy.

Now, let's move on to the bladder cancer abstracts. We have two exciting abstracts from the UNITE database. What are your insights on Abstract 537, titled "Outcomes in Patients with Advanced Urethral Carcinoma Treated with Enfortumab Vedotin After Switch-Maintenance of Avelumab in the UNITE Study"?

Dr. Neeraj Agarwal: As our listeners know, enfortumab vedotin is an antibody-drug conjugate that binds to a protein called Nectin 4 expressed on bladder cancer cells. In this abstract, Dr. Amanda Nizam and colleagues describe outcomes in 49 patients receiving third-line enfortumab vedotin after prior progression on platinum-based therapy and maintenance avelumab. At a median follow-up of 8.5 months, the median progression-free survival was 7 months and the median overall survival was 13.3 months with enfortumab vedotin in this treatment-refractory setting, the objective response rates were 54%. The message of this study is that enfortumab vedotin is an effective salvage therapy regimen for those patients who have already progressed on earlier lines of therapies, including platinum-based and immunotherapy regimens.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj, for that comprehensive review.

I want to focus on another patient population in the UNITE database, which is the use of fibroblast growth factor receptor (FGFR) alterations. Can you tell us more about the sequencing now of erdafitinib and enfortumab vedotin in these patients with metastatic urothelial cancer, as discussed in Abstract 616?

Dr. Neeraj Agarwal: Sure, Jeanny. As a reminder, erdafitinib is a fibroblast growth factor receptor kinase inhibitor approved for patients with locally advanced or metastatic urothelial carcinoma harboring FGFR2 or FGFR3 alterations after progression on platinum-based chemotherapy. However, the optimal sequencing of therapies in these patients is unclear, especially with enfortumab vedotin being approved in the salvage therapy setting and now in the frontline therapy setting.

So in this retrospective study, all patients with metastatic urothelial carcinoma had FGFR2 or FGFR3 alterations. Dr. Cindy Jiang and colleagues report outcomes in 24 patients receiving enfortumab vedotin after erdafitinib, 15 patients receiving erdafitinib after enfortumab vedotin, and 55 patients receiving enfortumab vedotin only. This is a multicenter national study. Interestingly, patients receiving both agents had a longer overall survival in a multivariate analysis, regardless of the treatment sequencing, than patients receiving enfortumab vedotin alone or only with a hazard ratio of 0.52. The objective response rate of enfortumab vedotin in the enfortumab vedotin monotherapy arm was 49%. When these agents were sequenced, the objective response with enfortumab vedotin was 32% after erdafitinib and 67% when used before erdafitinib.

Dr. Jeanny Aragon-Ching: Thank you so much, Neeraj. I think these are important real-world data results, but I would like to point out that larger and prospective studies are still needed to confirm these findings, especially regarding the outcome of erdafitinib after enfortumab vedotin, particularly when the latter is used in the first-line setting.

Dr. Neeraj Agarwal: I totally agree, Jeanny. Now, let's discuss some abstracts related to disparities in the management of patients with genitourinary cancers.

Dr. Jeanny Aragon-Ching: Sure, actually, I would like to discuss 2 abstracts related to disparities in patients with prostate cancer. So the first one, Abstract 265, titled "Patient-Provider Rurality and Outcomes in Older Men with Prostate Cancer." In this study, Dr. Stabellini, Dr. Guha and the team used a SEER Medicare-linked database that included more than 75,000 patients with prostate cancer. The primary outcome was all-cause mortality, with secondary outcomes included prostate cancer-specific mortality. The investigators showed that the all-cause mortality risk was 44% higher in patients with prostate cancer from rural areas who had a provider from a non-metropolitan area compared to those who were in a metropolitan area and had a provider also from a metropolitan area.

Dr. Neeraj Agarwal: Those are very important data and highlight the healthcare disparities among the rural population with prostate cancer that still exist.

So what is your key takeaway from Abstract 267, titled "Rural-Urban Disparities in Prostate Cancer Survival," which is a population-based study?

Dr. Jeanny Aragon-Ching: Of course. This abstract discusses, actually, a very similar issue regarding access to healthcare among rural versus urban patients. In this study, Dr. Hu and Hashibe and colleagues and team at the Huntsman Cancer Institute assessed all-cause death and prostate cancer-related death risk in a retrospective study in which patients with prostate cancer based on rural versus urban residencies looked at 18,000 patients diagnosed with prostate cancer between 2004 and 2017. 15% lived in rural counties. Similar to the prior abstract we talked about, patients living in rural areas had about a 19% higher risk of all-cause mortality and a 21% higher risk of prostate cancer-specific mortality in comparison to patients living in urban areas.

Dr. Neeraj Agarwal: So Jeanny, we can say that both of these abstracts, led by different groups of investigators, highlight that patients with prostate cancer living in rural areas have inferior survival outcomes compared to those living in urban areas, and it is time to focus on the disparities experienced by the rural population with prostate cancer.

Dr. Jeanny Aragon-Ching: Yeah, absolutely Neeraj. I concur with your thoughts.

So, any final thoughts before we wrap up the podcast today?

Dr. Neeraj Agarwal: Yes, before concluding, Jeanny, I want to express my gratitude for your participation and the valuable insights you have shared today. Your contributions are always appreciated, and I sincerely thank you for taking the time to join us today.

As we bring this podcast to a close, I would like to highlight the significant advances happening in the treatment of patients with genitourinary cancers during our upcoming 2024 ASCO GU meeting. Many studies featuring practice-impacting data will be presented by investigators from around the globe. I encourage our listeners to not only participate at this event to celebrate these achievements, but to also play a role in disseminating these cutting-edge findings to practitioners worldwide. By doing so, we can collectively maximize the benefit for patients around the world.

And thank you to our listeners for joining us today. You will find links to the abstracts discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. Thank you very much.

Disclaimer:

The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guest speakers express their own opinions, experience, and conclusions. Guest statements on the podcast do not necessarily reflect the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

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Dr. Neeraj Agarwal

@neerajaiims

Dr. Jeanny Aragon-Ching

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Disclosures:

Dr. Neeraj Agarwal:

Consulting or Advisory Role: Pfizer, Bristol-Myers Squibb, AstraZeneca, Nektar, Lilly, Bayer, Pharmacyclics, Foundation Medicine, Astellas Pharma, Lilly, Exelixis, AstraZeneca, Pfizer, Merck, Novartis, 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, Crispr Therapeutics, Arvinas

Dr. Jeanny Aragon-Ching:

Honoraria: Bristol-Myers Squibb, EMD Serono, Astellas Scientific and Medical Affairs Inc., Pfizer/EMD Serono

Consulting or Advisory Role: Algeta/Bayer, Dendreon, AstraZeneca, Janssen Biotech, Sanofi, EMD Serono, MedImmune, Bayer, Merck, Seattle Genetics, Pfizer, Immunomedics, Amgen, AVEO, Pfizer/Myovant, Exelixis,

Speakers' Bureau: Astellas Pharma, Janssen-Ortho, Bristol-Myers Squibb, Astellas/Seattle Genetics.