Institutes
Refine
Document Type
- Article (2) (remove)
Language
- English (2)
Has Fulltext
- yes (2)
Is part of the Bibliography
- no (2)
Keywords
- Cabozantinib (1)
- Immune checkpoint inhibitor (1)
- Immune refractory (1)
- Metastatic renal cell carcinoma (1)
- Previously treated patients (1)
- biomarker (1)
- everolimus (1)
- metastatic renal cell carcinoma (1)
- phase IV (1)
- second-line (1)
Institute
- Medizin (2)
Background: Efficacy of treatment after failure of check point inhibitors (ICI) therapy remains ill-defined in metastatic renal cell carcinoma (mRCC).
Objective: To evaluate the safety and effectiveness of cabozantinib after failure of ICI-based therapies.
Design, setting and participants: Patients with mRCC who concluded cabozantinib treatment directly after an ICI-based therapy were eligible. Data was collected retrospectively from participating sites in Germany.
Interventions: Cabozantinib was administered as a standard of care.
Outcome measurements and statistical analysis
Adverse events (AE) were reported according to CTCAE v5.0. Objective response rate according to RECIST 1.1 and Progression Free Survival (PFS) were collected from medical records. Descriptive statistics and Kaplan-Meyer-plots were utilized.
Results and limitations: About 56 eligible patients (71.4% male) with median age of 66 years and clear cell histology in 66.1% (n = 37) were analyzed. 87.5% (n = 49) had ≥ 2 previous lines. IMDC risk was intermediate or poor in 17 patients (30.4%) and missing in 66.1%. 20 patients (35.7%) started with 60 mg. 55.4% (n = 31) required dose reductions, 26.8% (n = 15) treatment delays and 1.8% (n = 1) treatment discontinuation. Partial response was reported in 10.7% (n = 6), stable and progressive disease were reported in 19.6% (n = 11) and in 12.5% (n = 7). 32 patients were not evaluable (57.1%). Median treatment duration was 6.1 months. Treatment related AE were reported in 76.8% (n = 43) and 19.6% (n = 11) had grade 3-5. Fatigue (26.8%), diarrhea (26.8%) and hand-foot-syndrome (25.0%) were the 3 most frequent AEs of any grade and causality. SAE were reported in 21.4% (n = 12), 2 were fatal. Major limitation was the retrospective data capture in our study.
Conclusions: Cabozantinib followed directly after ICI-based therapy was safe and feasible. No new safety signals were reported. A lower starting dose was frequently utilized in this real-world cohort, which was associated with a favorable tolerability profile. Our data supports the use of cabozantinib after ICI treatment.
Simple Summary: Treatment of metastatic renal cell carcinoma (mRCC) remains a challenge due to the lack of biomarkers indicating the optimal drug for each patient. This study analyzed blood samples of patients with predominant clear cell mRCC who were treated with the mTOR inhibitor everolimus after failure of one prior tumor therapy. In an exploratory approach, predictive blood biomarkers were searched. We found lower levels of the protein thrombospondin-2 (TSP-2) at the start of the therapy and higher lactate dehydrogenase (LDH) levels in serum two weeks after therapy initiation to be associated with therapy response. Of note, these blood biomarkers had a higher predictive value than baseline patient parameters or risk classifications. Polymorphisms in the mTOR gene appeared to be associated with therapy response, but were not significant. To conclude, it seems feasible to identify patients showing longtime responses to everolimus and possible to increase tumor therapy response rates based on biomarkers for individual therapy selection.
Abstract: There is an unmet need for predictive biomarkers in metastatic renal cell carcinoma (mRCC) therapy. The phase IV MARC-2 trial searched for predictive blood biomarkers in patients with predominant clear cell mRCC who benefit from second-line treatment with everolimus. In an exploratory approach, potential biomarkers were assessed employing proteomics, ELISA, and polymorphism analyses. Lower levels of angiogenesis-related protein thrombospondin-2 (TSP-2) at baseline (≤665 parts per billion, ppb) identified therapy responders with longer median progression-free survival (PFS; ≤665 ppb at baseline: 6.9 months vs. 1.8, p = 0.005). Responders had higher lactate dehydrogenase (LDH) levels in serum two weeks after therapy initiation (>27.14 nmol/L), associated with a longer median PFS (3.8 months vs. 2.2, p = 0.013) and improved overall survival (OS; 31.0 months vs. 14.0 months, p < 0.001). Baseline TSP-2 levels had a stronger relation to PFS (HR 0.36, p = 0.008) than baseline patient parameters, including IMDC score. Increased serum LDH levels two weeks after therapy initiation were the best predictor for OS (HR 0.21, p < 0.001). mTOR polymorphisms appeared to be associated with therapy response but were not significant. Hence, we identified TSP-2 and LDH as promising predictive biomarkers for therapy response on everolimus after failure of one VEGF-targeted therapy in patients with clear cell mRCC.