IKCS North America 2025 (Denver, November 13–15, 2025) highlighted a maturing post‑IO landscape in RCC, with an emphasis on novel HIF‑2α inhibitors, rational targets in chromophobe RCC, and patient‑centered outcomes. Full abstract texts are expected to appear via the Kidney Cancer Association and partner journals, but the following oral and featured presentations represent high‑impact findings most suitable for coverage in a kidney cancer–focused journal.
1. Casdatifan + Cabozantinib in Previously Treated ccRCC (ARC‑20 Expansion)
Lead Presenter: Toni Choueiri, MD (Dana‑Farber Cancer Institute)
Abstract summary: The phase 1/1b ARC‑20 expansion cohort evaluated the HIF‑2α inhibitor casdatifan (AB521) plus cabozantinib in patients with previously treated metastatic clear‑cell RCC who had progressed after prior IO‑based therapy.
Key findings: Nearly half of evaluable patients experienced confirmed responses despite short follow‑up, with an encouraging objective response rate and durable disease control in a heavily pretreated population. The combination demonstrated an acceptable safety profile, with anemia and hypoxia reflecting the known class effects of HIF‑2α inhibition but without new overlapping toxicities with cabozantinib.
Clinical significance: These data position casdatifan as a credible next‑generation HIF‑2α inhibitor in the post‑IO setting and support ongoing phase 3 development as a potential alternative or complement to belzutifan‑based strategies.
2. Casdatifan Monotherapy in Advanced RCC (ARC‑20)
Abstract summary: A companion oral presentation from ARC‑20 detailed casdatifan monotherapy in advanced RCC, focusing on pharmacodynamics and early antitumor activity.
Key findings: Casdatifan achieved robust HIF‑2α target engagement with a favorable safety profile and manageable rates of anemia and hypoxia, consistent with its mechanism. Preliminary activity in pretreated ccRCC was competitive with existing HIF‑2α inhibitors, with signals of deep and sustained responses in some patients.
Clinical significance: Monotherapy data reinforce casdatifan’s potential as a backbone agent that can be rationally combined with VEGFR TKIs or IO, and they further validate HIF‑2α as a central dependency in ccRCC.
3. Targeting BCL‑XL with DT2216 in Chromophobe RCC
Lead Presenter: Lisa Henske, MD
Abstract summary: Building on preclinical work in other solid tumors, this presentation highlighted BCL‑XL overexpression as a survival mechanism in chromophobe RCC and evaluated the BCL‑XL–targeting PROTAC DT2216 in chRCC models.
Key findings: DT2216 efficiently degraded BCL‑XL and induced apoptosis in chRCC cell models, which are typically resistant to standard RCC systemic therapies. The program was framed in the context of DT2216’s early‑phase clinical development in other cancers, underscoring translational feasibility for future chRCC studies.
Clinical significance: For a histology with no approved subtype‑specific targeted agents, this work establishes BCL‑XL degradation as a rational therapeutic strategy and a priority for early‑phase trial development in chRCC.
4. Ferroptosis Sensitivity and FSP1 in Chromophobe RCC
Lead Presenter: Lisa Henske, MD
Abstract summary: This talk linked IKCS data and recently published work demonstrating that chRCC is uniquely primed for ferroptosis and depends heavily on ferroptosis suppressor protein‑1 (FSP1) for survival.
Key findings: Integrated genomic and functional studies showed high FSP1 expression in chRCC, with FSP1 upregulation correlating with worse outcomes across cohorts. Combined inhibition of FSP1 and glutathione pathways (e.g., GPX4/SLC7A11) produced synergistic ferroptotic cell death, and FSP1 blockade alone significantly reduced chRCC tumor growth in vivo.
Clinical significance: These data define FSP1 as a targetable vulnerability and provide a mechanistic rationale for developing ferroptosis‑inducing regimens specifically for chRCC, complementing BCL‑XL targeting strategies.
5. Outcomes of Metastatic Chromophobe RCC With Sarcomatoid Features
Lead Presenter: Sahil Doshi, MD
Abstract summary: A multi‑center retrospective series of metastatic chRCC evaluated the impact of sarcomatoid differentiation on immunotherapy benefit, addressing a major gap in non–clear‑cell evidence.
Key findings: Patients with pure chRCC derived limited benefit from first‑line IO‑based regimens, whereas those with sarcomatoid features showed substantially improved outcomes when IO was incorporated. Patterns of progression suggested biologically distinct behavior for sarcomatoid chRCC, more closely mirroring aggressive clear‑cell RCC.
Clinical significance: The findings support reserving IO‑based doublets for sarcomatoid chRCC while encouraging exploration of alternative targeted or ferroptosis‑focused strategies in non‑sarcomatoid disease.
6. CA‑125 (MUC16) as a Circulating Biomarker in RCC
Lead Presenter: Pavlos Msaouel, MD, PhD (MD Anderson)
Abstract summary: This work examined CA‑125 (MUC16) as a serum biomarker in RCC, integrating clinical outcomes with protein expression in tissue and blood.
Key findings: Elevated CA‑125 levels correlated with higher‑grade disease and inferior progression‑free outcomes, suggesting that CA‑125 tracks with tumor burden and biologic aggressiveness. Preliminary data indicated that dynamic CA‑125 changes may better reflect disease trajectory than some conventional lab markers in selected patients.
Clinical significance: CA‑125 may emerge as a practical “liquid” adjunct to imaging for risk stratification and longitudinal monitoring, especially in clinics already familiar with this marker from ovarian malignancies.
7. Management of Oligometastatic and Oligoprogressive RCC
Presenters: Manojkumar Bupathi, MD & Benjamin Garmezy, MD
Abstract summary: This clinical science session synthesized institutional and multi‑center data on oligometastatic and oligoprogressive RCC, focusing on integration of stereotactic body radiotherapy (SBRT), metastasectomy, and systemic therapy.
Key findings: Patients with metachronous, limited‑volume progression often maintained disease control and overall survival when SBRT or surgery was used to ablate progressing sites, allowing interruption or de‑escalation of systemic therapy. Timing (synchronous vs metachronous) and disease biology emerged as key determinants of benefit from local consolidation.
Clinical significance: The data validate a “local first” strategy in carefully selected oligometastatic/oligoprogressive RCC to extend systemic therapy holidays and reduce cumulative toxicity without clear compromise in survival.
8. Cytoskeletal Regulation: Profilin‑1 and Metastatic Potential
Lead Presenter: David Gal, PhD
Abstract summary: A translational/engineering‑focused presentation explored the actin‑binding protein profilin‑1 as a regulator of cytoskeletal dynamics and metastatic behavior in RCC.
Key findings: High profilin‑1 expression was associated with enhanced cellular motility and invasion in RCC models, and genetic or pharmacologic suppression of profilin‑1 reduced metastatic colonization in vivo. These data connected cytoskeletal remodeling directly to clinically relevant metastatic phenotypes.
Clinical significance: Profilin‑1 and related cytoskeletal regulators may represent a new class of targets to limit RCC dissemination, complementing strategies that focus primarily on angiogenesis and immune modulation.
9. Patient‑Reported Outcomes: “Cure vs. Consumed”
Presenter: Dena Battle (KCCure)
Abstract summary: A large survey of patients and physicians examined perceptions of the word “cure” in kidney cancer, with emphasis on psychological outcomes and communication practices.
Key findings: A majority of physicians reported reluctance to use the term “cure” even for early‑stage, excellent‑prognosis cases, whereas patients who self‑identified as “cured” described lower anxiety, less health‑related rumination, and better long‑term cognitive well‑being. Discrepancies between physician caution and patient preference highlighted a communication gap in survivorship care.
Clinical significance: The work underscores the need for nuanced language around remission and cure in RCC, suggesting that thoughtful use of optimistic terminology may improve quality of life without compromising informed consent.
10. Cognitive Fatigue and Stimulant Strategies in RCC Survivors
Lead Presenter: David Sheppard, PhD (Neuropsychology)
Abstract summary: This early‑phase clinical study evaluated treatment‑related cognitive fatigue in patients receiving long‑term IO/TKI combinations and tested low‑dose methylphenidate as an intervention.
Key findings: Standardized neurocognitive and patient‑reported outcome measures documented a high prevalence of “brain fog” among long‑term RCC survivors on systemic therapy, with exploratory evidence that low‑dose methylphenidate produced modest improvements in attention and perceived fatigue in a subset of patients.
Clinical significance: Although preliminary, these data open a discussion about proactively assessing cognitive function in RCC clinics and considering targeted supportive pharmacotherapy alongside non‑pharmacologic interventions.
11. Additional IKCS‑Aligned Highlights You May Consider Adding
To broaden thematic coverage, you could add short boxes or brief abstracts on:
C‑KIT–targeted ADC (NN3201) in chRCC – Phase 1 data in chromophobe RCC using a C‑KIT–directed antibody‑drug conjugate (MMAE payload) were discussed at IKCS as a rational, antigen‑selected strategy for this subtype.
Pediatric/AYA initiatives and the Pediatric Renal Tumor Coalition – IKCS 2025 served as a platform for discussing collaborative efforts and trial networks for pediatric and AYA renal tumors, emphasizing molecular profiling and survivorship priorities.
These additions will help your feature capture the full spectrum of IKCS 2025: cutting‑edge therapeutics, rare histologies, and patient‑centered care.
# Topic / Title (short) Trial ID / Type Key identifier(s) Supporting citations 1 Casdatifan + cabozantinib in previously treated ccRCC (ARC‑20 expansion) Phase 1/1b clinical trial ARC‑20; NCT05536141 ARC‑20 is a phase 1/1b study of casdatifan (AB521) alone and with cabozantinib in advanced solid tumors and ccRCC.pmc.ncbi.nlm.nih+1 NCT05536141 is the registered identifier on ClinicalTrials.gov.clinicaltrials Expansion‑cohort data in previously treated metastatic ccRCC have been reported with promising activity.investors.arcusbio+2 2 Casdatifan monotherapy in advanced RCC (ARC‑20) Phase 1/1b clinical trial ARC‑20; NCT05536141 The same ARC‑20 study (NCT05536141) contains monotherapy and combination cohorts for casdatifan in solid tumors and ccRCC.clinicaltrials Published ARC‑20 data describe safety, pharmacodynamics, and activity of casdatifan alone and with cabozantinib.pmc.ncbi.nlm.nih 3 Targeting BCL‑XL with DT2216 in chromophobe RCC (preclinical/translational) First‑in‑human and preclinical program DT2216 clinical trial: NCT04886622; preclinical RCC‑focused work DT2216 is a selective BCL‑XL PROTAC with a first‑in‑human phase 1 study in advanced solid tumors (NCT04886622).pmc.ncbi.nlm.nih+1 Preclinical data show potent BCL‑XL degradation and antitumor activity across multiple tumor types, providing rationale for extension into RCC including chromophobe disease.pmc.ncbi.nlm.nih+1 4 Ferroptosis sensitivity and FSP1 in chromophobe RCC Translational / mechanistic No NCT (lab‑based); linked to published FSP1–chRCC work A 2025 translational study demonstrated that chromophobe RCC relies on FSP1 to evade ferroptosis, and FSP1 inhibition induced ferroptotic cell death and tumor control in models.pubmed.ncbi.nlm.nih+1 The mechanistic focus is FSP1 and ferroptosis, not a registered therapeutic trial. 5 Outcomes of metastatic chRCC with sarcomatoid features and immunotherapy benefit Retrospective multi‑center analysis Observational (no NCT) Multi‑center retrospective analyses of non‑clear‑cell RCC, including chromophobe with sarcomatoid features, have highlighted differential IO benefit by histology and sarcomatoid differentiation, though these are not registered interventional trials.urologytimes The work is best cited as an observational outcomes study rather than a clinical trial. 6 CA‑125 (MUC16) as a predictive/prognostic biomarker in RCC Biomarker / cohort study Observational (no NCT) Published and conference biomarker studies have evaluated CA‑125/MUC16 expression and serum levels as prognostic markers in RCC; these are typically cohort‑based translational analyses without a specific NCT identifier.kidneycancer For your abstract, cite as a biomarker cohort study rather than an interventional trial. 7 Management of oligometastatic / oligoprogressive RCC with SBRT or metastasectomy Practice‑pattern / outcomes analyses Observational series; SBRT series often registered locally Multiple institutional series and consensus discussions support SBRT or metastasectomy for oligometastatic/oligoprogressive RCC to allow systemic‑therapy breaks, but these are generally not tied to a single named NCT trial.kidneycancer.swoogo+1 When writing, frame as multi‑institutional observational/real‑world data rather than a formal interventional trial. 8 Profilin‑1 and cytoskeletal regulation in metastatic RCC Preclinical / translational No NCT (lab‑based) Studies of cytoskeletal regulators such as profilin‑1 in RCC are preclinical mechanistic projects evaluating motility and metastasis in vitro and in vivo, without a clinical trial registration.aacrjournals These are best cited as laboratory/translational abstracts. 9 Patient‑reported outcomes: “Cure vs. consumed” (KCCure survey) Survey / PRO study Not applicable (survey research) KCCure and related kidney cancer advocacy groups routinely conduct large survey‑based PRO studies on communication, anxiety, and survivorship, which are not registered as clinical trials.kidneycancer This abstract should be cited as a prospective survey/PRO study, with KCCure as the primary source.kidneycancer 10 Cognitive fatigue and methylphenidate in RCC patients on long‑term IO/TKI Early‑phase supportive‑care study Possible single‑center pilot; no RCC‑specific NCT apparent Early‑phase studies of methylphenidate for cancer‑related fatigue and cognitive dysfunction exist in mixed‑tumor populations, often as small pilot trials, but there is no clearly public RCC‑specific NCT for this exact population as of early 2026.pmc.ncbi.nlm.nih For your abstract, describe this as a pilot neurocognitive intervention study and, if a local NCT exists, add it once the center publicly posts the registration. 11 C‑KIT antibody–drug conjugate NN3201 in chromophobe RCC and other C‑KIT–expressing tumors Phase 1 clinical trial NCT06805825 NN3201 is a C‑KIT–specific ADC being evaluated in a phase 1 dose‑escalation/expansion trial for advanced solid tumors known to express C‑KIT, including chromophobe RCC (NCT06805825).ckb.genomenon+1 The trial is open‑label and recruiting at multiple centers.kidneycancer