Key Abstracts in GU Cancers at ASCO24

ASCO Daily News

Dr. Neeraj Agarwal and Dr. Jeanny Aragon-Ching discuss promising combination therapies and other compelling advances in genitourinary cancers in advance of the 2024 ASCO Annual Meeting.

TRANSCRIPT

Dr. Neeraj Agarwal: Hello and welcome to the ASCO Daily News Podcast. I'm Dr. Neeraj Agarwal, your guest host of the ASCO Daily News Podcast today. I'm the director of the Genitourinary Oncology Program and a professor of medicine at the University of Utah Huntsman Cancer Institute, and editor-in-chief of the ASCO Daily News. I'm delighted to be joined by Dr. Jeanny Aragon-Ching, a GU medical oncologist and the clinical program director of genitourinary cancers at the Inova Schar Cancer Institute in Virginia. Today, we will be discussing some key abstracts in GU oncology that will be featured at the 2024 ASCO Annual Meeting.

Our full disclosures are available in the transcript of this episode.

Jeanny, it’s great to have you on the podcast.

Dr. Jeanny Aragon-Ching: Thank you so much, Dr. Agarwal. It's a pleasure to be here.

Dr. Neeraj Agarwal: So, Jeanny, let's start with some bladder cancer abstracts. Could you tell us about the Abstract 4509 titled, “Characterization of Complete Responders to Nivolumab plus Gemcitabine Cisplatin versus Gemcitabine Cisplatin Alone in Patients with Lymph Node Only Metastatic Urothelial Carcinoma from the CheckMate 901 Trial.”

Dr. Jeanny Aragon-Ching: Of course, Neeraj, I would be delighted to. First, I would like to remind our listeners that the CheckMate 901 trial was a randomized, open-label, phase 3 study, in which this particular sub-study looked at cisplatin-eligible patients with previously untreated, unresectable, or metastatic urothelial carcinoma who were assigned to receive the combination of gemcitabine and cisplatin, followed by up to 2 years of nivolumab or placebo. Based on the data presented at ESMO 2023 and subsequently published in the New England Journal of Medicine, which shows significantly improved progression-free survival and overall survival in patients receiving the combination of gemcitabine, cisplatin, and nivolumab, this regimen was approved in March 2024 as a first-line therapy for patients with unresectable or metastatic urothelial carcinoma.

In the abstract that will be featured at ASCO this year, Dr. Matt Galsky and colleagues present a post-hoc analysis that aims to characterize a subset of patients with complete response as well as those with lymph node-only metastatic disease. In patients receiving the experimental treatment, 21.7% achieved a complete response, while 11.8% of the patients in the control arm achieved a complete response. Among these complete responders, around 52% had lymph- node-only disease in both arms. Furthermore, when characterizing the subgroup of patients with lymph-node-only disease, those receiving the combination of gemcitabine-cisplatin plus nivolumab had a 62% reduction in the risk of progression or death and a 42% reduction in the risk of death compared to those treated with gemcitabine-cisplatin alone. The median overall survival in the experimental arm in this subgroup was around 46.3 months, while it was only 24.9 months in the control arm. The ORR in patients with lymph-node-only disease receiving gem-cis plus nivo was about 81.5% compared to 64.3% in those treated with gem-cis alone.

Dr. Neeraj Agarwal: Thank you, Jeanny, for the excellent summary of this abstract. We can say that nivolumab plus gemcitabine-cisplatin induced durable disease control and clinically meaningful improvements in OS and PFS compared to gem-cis alone in patients with lymph- node-only metastasis, and deserves to be considered as one of the options for these patients.

In a similar first-line metastatic urothelial carcinoma setting, Abstract 4502, also reported data on a recently approved combination of enfortumab vedotin and pembrolizumab. Can you tell us more about this abstract, Jeanny?

Dr. Jeanny Aragon-Ching: Sure, Neeraj. So, as quick reminder to our audience, this regimen was tested in the EV-302 phase 3 trial, where patients with previously untreated, locally advanced or metastatic urothelial carcinoma were randomized to receive enfortumab vedotin, plus pembrolizumab or gemcitabine plus either cisplatin or carboplatin. These data were also first presented at ESMO 2023 and subsequently published in the New England Journal of Medicine. They showed that this immune based combination significantly improved both progression free survival and overall survival, which were the primary endpoints compared to chemotherapy. In this abstract, Dr. Shilpa Gupta from the Cleveland Clinic and colleagues present the results of patient reported outcomes based on quality-of-life questionnaires in this trial. Time to pain progression and time to confirm deterioration were numerically longer in patients treated with EV plus pembro, and patients with moderate to severe pain at baseline receiving this combination had a meaningful improvement in the Brief Pain Inventory Short-Form worst pain from week 3 through 26.

Dr. Neeraj Agarwal: Thank you, Jeanny. This means that patients treated with EV plus pembro did not only have improved survival compared with platinum-based chemotherapy, but also improvement in their quality-of-life and functioning, further supporting the value of this combination for patients with locally advanced or metastatic urothelial carcinoma. This is terrific news for all of our patients.

Before we wrap up the bladder cancer section, would you like to tell our listeners about Abstract 4565, which provides the data on the efficacy of trastuzumab deruxtecan in patients with bladder cancer?

Dr. Jeanny Aragon-Ching: Yes, Neeraj; this is timely given the recent FDA approval, which we will talk about. The abstract is titled, “Efficacy and Safety of Trastuzumab Deruxtecan in Patients with HER2 Expressing Solid Tumors: Results from the Bladder Cohort of the DESTINY-PanTumor02 Study.” And as a quick reminder, the DESTINY-PanTumor02 was a phase 2 open-label study where trastuzumab deruxtecan, an antibody-drug conjugate targeting HER2 expression on cancer cells, was evaluated in patients with HER2-expressing locally advanced or metastatic disease who previously received systemic treatment or who had no other treatment options. The expression of HER2 was evaluated on immunohistochemistry by local or central testing.

The primary endpoint was confirmed objective response rate by investigator assessment. Secondary endpoints included duration of response, progression free survival, disease control rate, and safety. The primary analysis, which was published in the Journal of Clinical Oncology, showed an ORR of 37.1% and responses across all cohorts and the median duration of response was 11.3 months. Based on these results, fam-trastuzumab deruxtecan-nxki was just granted accelerated FDA approval for unresectable or metastatic HER2-positive solid tumors in April 2024.

So, back to this abstract; Dr. Wysocki and colleagues report the results of the bladder cancer cohort. This study included 41 patients with urothelial cancer and at a median follow up of around 12.6 months, the objective response rate among these patients was 39%, the median PFS was 7 months, and the duration of response median was 8.7 months. The disease control rate at 12 weeks was around 71%. Regarding the safety profile, 41.5% of patients experienced grade ≥3 drug related adverse events and interstitial lung disease or pneumonitis did occur in about 4 patients. Although there was no statistical comparison between different groups, the ORR was numerically highest among the HER2 3+ group with 56.3%.

Dr. Neeraj Agarwal: Thank you, Jeanny. So, these data support consideration of trastuzumab deruxtecan as a salvage therapy option for pre-treated patients with HER2 expressing urothelial cancers and show that we are extending our treatment options to include therapies with novel mechanisms of action. This is definitely exciting news for patients with bladder cancer.

Dr. Jeanny Aragon-Ching: Yes, absolutely, Neeraj. Now, let's switch gears a bit to prostate cancer. Could you tell us about Abstract 5005 which is titled, “EMBARK Post Hoc Analysis of Impact of Treatment Suspension on Health Quality-of-Life?”

Dr. Neeraj Agarwal: Of course, I'd be happy to. So, enzalutamide was recently granted FDA approval for the treatment of patients with non-metastatic castration-sensitive prostate cancer with biochemical recurrence at high-risk of metastasis, based on the results of the EMBARK trial, which was a phase 3 study where patients with high-risk biochemical recurrence were randomized to receive either enzalutamide with leuprolide, enzalutamide monotherapy, or placebo plus leuprolide. The primary endpoint was metastasis-free survival with secondary endpoints including overall survival and safety. Results showed that patients receiving enzalutamide alone or enzalutamide plus leuprolide had significantly improved metastasis-free survival compared to those treated with leuprolide alone while preserving health-related quality-of-life.

One important aspect in the design of the trial was that patients who achieved undetectable PSA at week 37 underwent treatment suspension. The treatment was resumed if PSA rose to more than 2 ng/ml for patients who underwent radical proctectomy or when PSA rose to more than 5 ng/ml for those who did not undergo surgery.

In this abstract, Dr. Stephen Freedland and colleagues present a post-hoc analysis of health-related quality-of-life outcomes after treatment suspension between weeks 37 and 205. They found that treatment was suspended in 90.9% of patients receiving enzalutamide plus leuprolide, 85.9% of those receiving enzalutamide monotherapy, and 67.8% of those receiving leuprolide monotherapy. Among those patients who stayed on treatment suspension, a trend toward numerical improvement in health-related quality-of-life after week 37 was seen in all 3 arms and this reached clinically meaningful threshold at week 205 in pain questionnaires, physical well-being, urinary and bowel symptoms. For hormonal treatment side effects, all arms reached clinically meaningful improvement at the subsequent assessments of week 49 to week 97. However, patients slowly deteriorated, with clinically meaningful deterioration at week 205 relative to week 37 in patients receiving the combination of enzalutamide and leuprolide and those treated with leuprolide.

Concerning sexual activity, a clinically meaningful improvement was reported only in patients receiving enzalutamide plus leuprolide, possibly because sexual function was better preserved prior to suspension in the enzalutamide monotherapy arm and thus there was less opportunity for “improvement” while on suspension.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj, for this great summary. This analysis confirms that treatment suspension in good responders might lead to a clinically meaningful improvements in health-related quality-of-life.

Now, moving on to patients with metastatic castration-resistant prostate cancer, what can you tell us, about Abstract 5008 titled, “Baseline ctDNA analyses and associations with outcomes in taxane-naive patients with mCRPC treated with 177Lu-PSMA-617 versus change of ARPI in PSMAfore”?

Dr. Neeraj Agarwal: Sure, Jeanny. The PSMAfore trial was a phase 3 study that compared the efficacy of 177Lu-PSMA-617 versus an ARPI switch in patients with mCRPC and prior progression on a first ARPI, and not previously exposed to docetaxel chemotherapy. The primary endpoint was rPFS and OS was an important secondary endpoint. The primary analysis presented at ESMO 2023 showed a significantly prolonged rPFS in patients receiving lutetium. In the abstract that will be featured at the 2024 ASCO Annual Meeting, Dr. Johann De Bono and colleagues present an exploratory analysis regarding the associations between baseline circulating tumor DNA and outcomes.

ctDNA fraction was evaluated in all samples as well as alterations in key prostate cancer drivers prevalent in more than 10% of participants. The investigators sought to interrogate the association of ctDNA fraction or alterations with rPFS, PSA response, and RECIST response at data cutoff. They showed that median rPFS was significantly shorter in patients with a ctDNA fraction >1% compared to those with a fraction < 1% regardless of the treatment arm. Furthermore, ctDNA fraction >1% was also associated with worst RECIST response and PSA50 response. Regarding prostate cancer drivers, median rPFS was significantly shorter in patients with alterations in the AR, TP53 or PTEN in both treatment arms. There was no significant association between ctDNA alterations and PSA or objective responses.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So, these results show that the presence of a ctDNA fraction >1% or alterations in AR, P53 and PTEN were all associated with worse outcomes regardless of treatment with lutetium or change in the ARPI. These data are definitely important for counseling and prognostication of patients in the clinic and may guide the design of future clinical trials. Let's move on to kidney cancer. Neeraj, do you have any updates for us?

Dr. Neeraj Agarwal: Sure. In Abstract 4512 titled, “A Multi-institution Analysis of Outcomes with First-Line Therapy for 99 Patients with Metastatic Chromophobe Renal Cell Carcinoma,” Dr. Sahil Doshi and colleagues present a retrospective, multi-institutional study comparing survival outcomes, including time-to-treatment failure and overall survival, between different first-line treatment options in patients with metastatic chromophobe renal cell carcinoma, where limited clinical trial data exists to guide systemic therapy. They categorized patients into 4 treatment groups: and immune checkpoint inhibitors + targeted therapy doublets (such as ICI VEGF TKI); pure immune checkpoint inhibitor monotherapy and doublets (such as ipilimumab plus nivolumab); targeted therapy doublets (such as lenvatinib plus everolimus), and targeted monotherapy (such as sunitinib).

They identified 99 patients, of whom 54 patients received targeted monotherapy, 17 received ICI VEGF-TKI, 14 received targeted doublet, and 14 patients received only ICI therapies. So the patients treated with any doublet containing a targeted agent had a 52% decrease in the risk of treatment failure and a 44% decrease in the risk of death compared to those treated with targeted monotherapy. The median time to treatment failure was 15 months with IO-targeted doublet, and the median overall survival was 56 months.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So, these results show that targeted doublet regimens resulted in a longer time to treatment failure and overall survival compared to any monotherapy in patients with chromophobe metastatic RCC and definitely provides valuable insights on treatment selection, albeit I would say there's still a small number of patients that were included in this retrospective analysis.

Dr. Neeraj Agarwal: I completely agree this is a relatively small number of patients, but I decided to highlight the abstract given how rare the cancer is, and it is highly unlikely that we'll see large randomized clinical trials in patients with metastatic chromophobe renal cell carcinoma.

So, before we wrap up the podcast, what would you like to tell us about Abstract 5009 which is titled, “A Phase II Trial of Pembrolizumab Platinum Based Chemotherapy as First Line Systemic Therapy in Advanced Penile Cancer: HERCULES (LACOG 0218) Trial.”

Dr. Jeanny Aragon-Ching: I'm glad you brought this up, Neeraj. As our listeners may know, advanced penile squamous cell carcinoma has a poor prognosis with limited treatment options. From this perspective, the results of the LACOG 0218 trial are very important. As you mentioned, this was a phase 2 single-arm study evaluating the addition of pembrolizumab to platinum-based chemotherapy as first-line treatment in patients with metastatic or locally advanced penile squamous cell carcinoma not amenable to curative therapy. Patients enrolled received chemotherapy, namely 5-Fluorouracil with cisplatin or carboplatin and pembrolizumab 200 mg IV every 3 weeks for 6 cycles, followed by pembrolizumab 200 mg IV every 3 weeks up to 34 cycles. The primary endpoint was confirmed overall response rate by investigator assessment.

In the 33 patients eligible for the efficacy analysis, the confirmed ORR by investigator assessment was 39.4% and included one complete response and 12 partial responses. The confirmed ORR was 75% in patients with high TMB and 55.6% in patients positive for HPV16, making TMB and HPV16 potential predictive biomarkers for efficacy in this study. Concerning the toxicity profile, any grade treatment-related adverse events were reported in around 92% of patients, and grade 3 or more treatment-related adverse events occurred in 51% of patients. 10.8% of patients discontinued treatment due to adverse events.

Dr. Neeraj Agarwal: Thank you, Jeanny. I would like to add that HERCULES is the first trial to demonstrate the efficacy of an immune checkpoint inhibitor in advanced penile squamous cell carcinoma with a manageable safety profile. Thus, the combination of ICI with platinum-based chemotherapy is a promising treatment for advanced penile squamous cell carcinoma and warrants further investigation.

Dr. Jeanny Aragon-Ching: I agree, Neeraj. Any final remarks before we conclude today's podcast?

Dr. Neeraj Agarwal: Jeanny, I really want to thank you for your participation and valuable insights. Your contributions are always appreciated, and I sincerely thank you for taking the time to join us today.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. It was a pleasure.

Dr. Neeraj Agarwal: As we bring this podcast to an end, I would like to acknowledge the significant advances happening in the treatment of patients with genitourinary cancers. During our upcoming 2024 ASCO Annual Meeting, there will be an array of different studies featuring practice-changing data presented by researchers and physicians from around the globe. I urge our listeners to not only participate in this event to celebrate these achievements, but to also play a role in sharing these cutting-edge data with healthcare professionals worldwide. Through our collective efforts, we can surely optimize the benefits of patients on a global scale.

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 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 podcast. Thank you very much.

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions.

Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

Find out more about today’s speakers:

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.