(UroToday.com) The 2024 European Society for Medical Oncology (ESMO) Annual Congress held in Barcelona, Spain between was host to a genitourinary cancers poster session. Professor Laurence Albiges presented the final results of CaboPoint, a phase II trial of cabozantinib after checkpoint inhibitor combinations in patients with advanced renal cell carcinoma (RCC).
The first line treatment landscape for patients with advanced RCC has rapidly evolved in recent years, with checkpoint inhibitor (CPI)-based combination therapy becoming an established standard of care.1,2 Current guidelines recommend dual CPI combinations (e.g. nivolumab plus ipilimumab) or CPI therapy in combination with vascular endothelial growth factor receptor (VEGFR)-targeting agents (e.g. pembrolizumab plus axitinib or nivolumab plus cabozantinib).3 However, since pivotal 2nd line therapies were established prior to the approval of 1st line CPI-based regimens, there is an emerging need to establish the safety and efficacy of these therapies in the post-CPI setting. The CaboPoint trial (NCT03945773) was designed to address the lack of prospective data for cabozantinib after 1st line CPI regimens. Cabozantinib, a multi-targeted tyrosine kinase inhibitor (TKI), was approved for the 2nd line treatment of advanced RCC following the phase 3 METEOR study, which demonstrated a significant improvement in survival and an objective response rate (ORR) of 17% with cabozantinib versus 3% with everolimus following VEGFR-targeted therapy.4
The objective of this study was to evaluate the efficacy and safety of cabozantinib in adults with unresectable, locally advanced, or metastatic RCC with a clear-cell component whose disease progressed after 1st line CPI-based therapy. In this report, Professor Albiges presented the final efficacy and safety results from CaboPoint, the 1st phase II trial to focus on 2nd line cabozantinib use after 1st line CPI combination therapy. The interim results were previously presented by Professor Albiges during ASCO GU 2023 and had demonstrated an overall ORR of 30%, including 32% in patients who had received 1st line CPI-CPI therapy and 25% in those who had received 1st line CPI-VEGF-targeted therapy.5
CaboPoint is a phase II, multicenter, open-label study that was conducted at 50 centers across Austria, France, Germany, Netherlands, Spain, Switzerland, and the UK. Eligible patients were adults with histologically confirmed, unresectable, locally advanced, or metastatic RCC with a clear cell component whose disease radiographically progressed following treatment with a 1st line CPI-based regimen. Prior treatment with cabozantinib was not permitted. Patients received cabozantinib (starting dose 60 mg/day) in two independent cohorts:
- Cohort A: patients with progression after dual CPI therapy (nivolumab plus ipilimumab)
- Cohort B: patients with progression after CPI plus VEGF-targeted therapy
Both cohorts received cabozantinib until study end (18 months after the last patient enrolled had started treatment), but could terminate earlier owing to disease progression, unacceptable toxicity, or withdrawal of consent.
The primary endpoint of the CaboPoint trial was ORR per RECIST v1.1 in Cohort A, evaluated by an independent central review. Secondary endpoints included:
- ORR in cohort B by independent central review
- ORR for both cohorts by local investigator review
- Time to response
- Duration of response
- Disease control rate
- Progression-free survival (all evaluated by independent central and local investigator review)
- Overall survival
- Safety
The sample size calculations are summarized below:
A total of 127 patients were enrolled (Cohort A: n=85; Cohort B: n=42). The median follow-up at the final analysis was 19.3 months. The mean patient age was 64 years (range: 41–86), 76% were male, 64% had a prior nephrectomy, 40% had ≥ 3 metastatic sites, 61% had metastatic disease at diagnosis, and 87% had International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) intermediate- or poor-risk disease at diagnosis. The baseline demographics and disease characteristics were similar across cohorts.
From an efficacy standpoint, the ORR by independent central review in Cohort A was 41% (95% CI: 30–52%; p<0.0001 against 10% threshold) and 28% (95% CI: 15–44%) in Cohort B. Only one complete response was observed, occurring in Cohort B. The disease control rates by independent central review were ≥83% in both cohorts and in the overall population.
The median best percentage reduction in baseline tumor size by independent central review is summarized in the figure below:
The median duration of response was not reached in Cohort A and was 8.3 months (IQR: 5.6–19.2) in Cohort B. The median progression-free survivals were 10.9 and 8.3 months, respectively.
Ad hoc analysis of median time-to-response by independent central review in patients who responded in the efficacy population was 2.8 (IQR: 2.7–5.5) months in Cohort A (n = 32) and 2.8 months (IQR: 2.8–2.9 months) in Cohort B (n = 11). The median overall survival was 24.3 months in (IQR: 18.5–31.8) in Cohort A and 24.1 months (IQR: 17.1–not calculable) in Cohort B.
From a safety standpoint, in Cohorts A and B, common (≥ 10% of patients) grade 3–4 treatment-emergent adverse events (TEAEs) were hypertension (38% and 21%, respectively) and diarrhea (12% and 10%, respectively). Treatment-related adverse events led to treatment interruption in 79% and 76% and dose reduction in 31% and 26% of patients in Cohorts A and B, respectively. Treatment-related serious adverse events occurred in 29% and 17% of patients in Cohorts A and B, respectively.
Professor Albiges concluded as follows:
- CaboPoint is the first European phase II, open-label, prospective trial to evaluate 2nd line cabozantinib in patients with locally advanced or metastatic RCC after disease progression on 1st line checkpoint inhibitor-based combination therapy and demonstrated both the efficacy and safety of cabozantinib in this setting.
- No new safety signals were reported.
- These findings support the continued use of cabozantinib monotherapy as a valuable 2nd line therapy option for patients who progress on recommended 1st line checkpoint inhibitor-based therapies, particularly ipilimumab plus nivolumab.
Written by: Rashid Sayyid, MD, MSc – Robotic Urologic Oncology Fellow at The University of Southern California, @rksayyid on Twitter during the 2024 European Society of Medical Oncology (ESMO) Annual Meeting, Barcelona, Spain, Fri, Sept 13 – Tues, Sept 17, 2024.
References:
- Lalani AA, Heng DYC, Basappa NS, et al. Evolving landscape of first-line combination therapy in advanced renal cancer: a systematic review. Ther Adv Med Oncol. 2022; 14:17588359221108685.
- Deleuze A, Saout J, Dugay F, et al. Immunotherapy in Renal Cell Carcinoma: The Future Is Now. Int J Mol Sci. 2020; 21(7):2532.
- Rathmell WK, Rumble RB, Van Veldhuizen PJ, et al. Management of Metastatic Clear Cell Renal Cell Carcinoma: ASCO Guideline. J Clin Oncol. 2022; 40(25):2957-2995.
- Choueiri TK, Escudier B, Powles T, et al. Cabozantinib versus everolimus in advanced renal cell carcinoma (METEOR): final results from a randomised, open-label, phase 3 trial. Lancet Oncol. 2016; 17(7):917-927.
- Albiges L, Powles T, Sharma A, et al. CaboPoint: Interim results from a phase 2 study of cabozantinib after checkpoint inhibitor (CPI) therapy in patients with advanced renal cell carcinoma (RCC). J Clin Oncol. 2023; 41:Number 6_suppl.