Conference Preview: Late-Breaking Abstracts at ASCO GU 2026

The late-breaking abstracts (LBAs) at this year’s American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium offer an early look at data that may meaningfully shift clinical decision-making across urologic oncology. As the treatment landscape continues to evolve, particularly with the expansion of targeted therapies, antibody-drug conjugates, and perioperative immunotherapy strategies, this year’s LBA slate reflects a growing emphasis on biomarker-driven care and treatment intensification across disease states.

From novel combinations in advanced renal cell carcinoma (RCC) to perioperative approaches in muscle-invasive bladder cancer (MIBC) and risk-adapted strategies informed by circulating tumor DNA (ctDNA), several anticipated presentations at this year’s meeting are poised to inform how urologists and urologic oncologists think about sequencing, de-escalation, and bladder preservation.

Below, we highlight all of the LBAs set to be presented at this year’s conference. You can keep up with Urology Times’® full meeting coverage here.

LBA417: Belzutifan (bel) plus lenvatinib (lenva) versus cabozantinib (cabo) for advanced renal cell carcinoma (RCC) after anti–PD-(L)1 therapy: Open-label phase 3 LITESPARK-011 study

Presenter: Robert J. Motzer, MD

Summary: Robert J. Motzer, MD, will present initial findings from the phase 3 LITESPARK-011 trial (NCT04586231), evaluating the combination of belzutifan (Welireg) and levatinib (Lenvima) in patients with locally advanced or metastatic clear cell renal cell carcinoma (ccRCC) whose disease progressed on or after treatment with an anti-PD-1/L1 therapy. Topline data from the trial, shared by Merck and Eisai in October 2025,¹ showed that the combination led to statistically significant improvements in progression-free survival and objective response rate vs cabozantinib (Cabometyx).

According to the companies, “LITESPARK-011 marks the first positive phase 3 study of a HIF-2 alpha inhibitor in combination with a multi-targeted VEGF tyrosine kinase inhibitor.”

LBA418: Adjuvant pembrolizumab plus belzutifan versus pembrolizumab for clear cell renal cell carcinoma (ccRCC): The randomized phase 3 LITESPARK-022 study

Presenter: Toni Choueiri, MD

Summary: Toni Choueiri, MD, will present additional data on belzutifan from the LITESPARK-022 study, this time in combination with adjuvant pembrolizumab (Keytruda) for patients with ccRCC following nephrectomy. An interim analysis of the data, shared in October 2025,² found that the trial met its primary end point, showing that the addition of belzutifan to pembrolizumab in the adjuvant setting achieved a statistically significant and clinically meaningful improvement in disease-free survival compared with pembrolizumab plus placebo.

LBA630: Neoadjuvant and adjuvant enfortumab vedotin (EV) plus pembrolizumab (pembro) for participants with muscle-invasive bladder cancer (MIBC) who are eligible for cisplatin: Randomized, open-label, phase 3 KEYNOTE-B15 study

Presenter: Matthew D. Galsky, MD

Summary: Matthew D. Galsky, MD, is set to share the anticipated results of the phase 3 KEYNOTE-B15 trial (NCT04700124). Merck and Astellas shared topline results from the trial in December 2025,³ reporting that perioperative enfortumab vedotin-ejfv (EV; Padcev) plus pembrolizumab yielded significant improvements in event-free survival, overall survival, and pathologic complete response rates vs neoadjuvant chemotherapy in patients with MIBC who are eligible for cisplatin-based chemotherapy.

These findings build on results from the KEYNOTE-905 trial (NCT03924895), presented at ESMO 2025,⁴ which found that the combination extended event-free and overall survival in patients with MIBC who are ineligible for cisplatin-based chemotherapy. These findings led to FDA approval of EV/pembrolizumab in this population in November 2025.

LBA632: Circulating tumor DNA (ctDNA) to guide response-adapted bladder preservation in muscle invasive bladder cancer (MIBC): Integrated analysis of the RETAIN trials

Presenter: Pooja Ghatalia, MD

Summary: Pooja Ghatalia, MD, will present ctDNA results from an integrated analysis of the RETAIN trials, which evaluated a response-adapted bladder preservation strategy in patients with MIBC. RETAIN-1 was a phase 1 single-arm study that established the feasibility of risk-enabled therapy by demonstrating a 73% metastasis-free survival (MFS) at 2 years among patients treated with AMVAC followed by a risk-adapted approach to local consolidation.⁵ RETAIN-2, which employed a similar approach but added neoadjuvant chemoimmunotherapy, further demonstrated encouraging MFS rates in those allocated to active surveillance. ⁶

LBA631: RC48G001: A phase 2 study of disitamab vedotin in HER2-expressing previously treated advanced UC

Presenter: Thomas Powles, MBBS, MRCP, MD

Summary: Data from the phase 2 RC48G001 trial NCT04879329) will be shared by Tom Powles, MBBS, MRCP, MD. Overall, the study assessed the safety and efficacy of disitamab vedotin alone or with pembrolizumab in treating patients with HER2-expressing locally advanced or metastatic urothelial carcinoma.⁷

LBA307: Androgen deprivation therapy and radiotherapy with or without cabazitaxel in very-high risk localized prostate cancer: First results of the PEACE-2 randomized phase III trial

Presenter: Karim Fizazi, MD, PhD

Summary: Karim Fizazi, MD, PhD, will present the first results from the phase 3 PEACE-2 study (NCT01952223) exploring androgen deprivation therapy and radiotherapy with or without cabazitaxel (Jevtana) in very high-risk localized prostate cancer. According to María Teresa Bourlon, MD, MS, FASCO, who outlined several trials ahead of ASCO GU, these findings will help clarify whether chemotherapy adds meaningful benefit before metastatic progression.

LBA639: Updated clinical results and associated biomarkers from an ongoing phase 1 study of FX-909, a first-in-class peroxisome proliferator-activated receptor gamma (PPARG) inhibitor, in patients (pts) with advanced urothelial carcinoma (adv UC)

Presenter: Matthew D. Galsky, MD

Summary: Matthew D. Galsky, MD, will again take the stage to present results from a phase 1b trial (NCT05929235) of FX-909 in patients with locally advanced or metastatic urothelial carcinoma. According to Flare Therapeutics, FX-909 is a small molecule inhibitor of PPARG, which is a “master regulator of the luminal lineage.”⁸

LBA629: SWOG S1602: A phase III randomized trial to evaluate BCG strain differences and priming with intradermal BCG before intravesical therapy for BCG-naïve high-grade non-muscle invasive bladder cancer (NCT #03091660)

Presenter: Robert S. Svatek, MD

Summary: Robert S. Svatek, MD, will share results from the randomized phase 3 SWOG S1602 trial (NCT03091660), which is evaluating whether the Tokyo-172 BCG strain is non-inferior to TICE BCG for preventing high-grade recurrence in patients with BCG-naïve, high-risk non–muscle invasive bladder cancer.⁹ The study is also assessing whether intradermal priming with Tokyo-172 BCG prior to standard intravesical instillation improves time to high-grade recurrence compared with intravesical therapy alone. Secondary and exploratory end points include progression-free survival, complete response in patients with carcinoma in situ, and potential immunologic predictors of treatment response.

LBA637: Induction ipilimumab plus nivolumab followed by consolidating chemoradiotherapy as bladder-sparing treatment in stage II/III urothelial carcinoma of the bladder: The phase 2 Indi-Blade trial

Presenter: Jan-Jaap Jelmer Mellema, MD

Summary: Phase 2 results from the Indi-Blade trial (NCT05200988) will be presented by Jan-Jaap Jelmer Mellema, MD. Overall, the single-arm study is evaluating the efficacy of induction immunotherapy with ipilimumab plus nivolumab followed by chemoradiation as a bladder-sparing strategy for patients with cT2–4aN0-2 urothelial bladder cancer. The primary end point is bladder-intact event-free survival, with secondary outcomes including overall survival, recurrence-free survival, safety, quality of life, and bladder function.¹⁰

REFERENCES

1. Merck and Eisai announce WELIREG® (belzutifan) plus LENVIMA® (lenvatinib) met primary endpoint of progression-free survival (PFS) in certain previously treated patients with advanced renal cell carcinoma. News release. Merck. October 28, 2025. Accessed February 23, 2026. https://www.businesswire.com/news/home/20251028392813/en/Merck-and-Eisai-Announce-WELIREG-belzutifan-Plus-LENVIMA-lenvatinib-Met-Primary-Endpoint-of-Progression-Free-Survival-PFS-in-Certain-Previously-Treated-Patients-With-Advanced-Renal-Cell-Carcinoma

2. Merck announces KEYTRUDA® (pembrolizumab) plus WELIREG® (belzutifan) met primary endpoint of disease-free survival (DFS) in certain patients with clear cell renal cell carcinoma (RCC) following nephrectomy. News release. Merck. October 28, 2025. Accessed February 23, 2026. https://www.businesswire.com/news/home/20251028020827/en/Merck-Announces-KEYTRUDA-pembrolizumab-Plus-WELIREG-belzutifan-Met-Primary-Endpoint-of-Disease-Free-Survival-DFS-in-Certain-Patients-With-Clear-Cell-Renal-Cell-Carcinoma-RCC-Following-Nephrectomy

3. First and only immunotherapy plus ADC regimen, used perioperatively, to extend survival for cisplatin-eligible patients with MIBC. News release. Merck. December 17, 2025. Accessed December 17, 2025. https://www.merck.com/news/keytruda-pembrolizumab-plus-padcev-enfortumab-vedotin-ejfv-significantly-improved-event-free-survival-overall-survival-and-pathologic-complete-response-rates-for-cisplatin-eligible-pa/

4. Perioperative (periop) enfortumab vedotin (EV) plus pembrolizumab (pembro) in participants (pts) with muscle-invasive bladder cancer (MIBC) who are cisplatin-ineligible: The phase III KEYNOTE-905 study. Presented at: 2025 European Society for Medical Oncology Congress. October 17-21, 2025. Berlin, Germany. Abstract LBA2. https://s3.eu-central-1.amazonaws.com/m-anage.com.storage.esmo/static/esmo2025_abstracts/LBA2.html.pdf

5. Geynisman DM, Abbosh PH, Ross E, et al. Phase II Trial of Risk-Enabled Therapy After Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer (RETAIN 1). J Clin Oncol. 2025;43(9):1113-1122. doi:10.1200/JCO-24-01214

6. Ghatalia P, Ross EA, Zibelman MR, et al. A phase 2 trial of risk enabled therapy after neoadjuvant chemo-immunotherapy for muscle-invasive bladder cancer (RETAIN-2). J Clin Oncol. 2025;43(5). doi:10.1200/JCO.2025.43.5_suppl.815

7. A Study of Disitamab Vedotin Alone or With Pembrolizumab in Urothelial Cancer That Expresses HER2. ClinicalTrials.gov. Last updated January 7, 2026. Accessed February 23, 2026. https://clinicaltrials.gov/study/NCT04879329

8. Flare Therapeutics announces initiation of phase 1B study of FX-909 for treatment of metastatic urothelial cancer. News release. Flare Therapeutics. August 5, 2025. Accessed February 23, 2026. https://www.flaretx.com/flare-therapeutics-announces-initiation-of-phase-1b-study-of-fx-909-for-treatment-of-metastatic-urothelial-cancer/

9. S1602: Different Strains of BCG With or Without Vaccine in High Grade Non- Muscle Invasive Bladder Cancer. ClinicalTrials.gov. Last updated April 2, 2025. Accessed February 23, 2026. https://clinicaltrials.gov/study/NCT03091660

10. Checkpoint Inhibition and Chemoradiotherapy as Bladder Sparing Treatment in UC (Indi-Blade). ClinicalTrials.gov. Last updated March 18, 2024. Accessed February 23, 2026. https://clinicaltrials.gov/study/NCT05200988