PD-L1 tumour expression is predictive of pazopanib response in soft tissue sarcoma

Background Pazopanib, a multitargeted tyrosine kinase inhibitor, is recommended as the standard treatment for refractory soft tissue sarcoma (STS). However, there are comparatively few molecular determinants for predicting pazopanib efficacy. Based on correlative studies regarding the predictive impact of PD-L1, we investigated the clinical relevance of PD-L1 expression and evaluated its value for predicting pazopanib efficacy. Methods Tumour tissues from patients with advanced STS who went on to receive pazopanib were assessed for PD-L1 expression. Immunohistochemistry was performed using an anti-PD-L1 antibody, and the PD-L1 tumour proportion score (TPS) was calculated as the percentage of at least 100 viable cells with positive expression, defined as TPS ≥ 1%. Results Among the 67 patients, 8 (11.9%) achieved partial response and a median progression-free survival (PFS) of 4.8 months (95% CI 3.8–5.7). PD-L1 expression in tumour cells was detected in 13 (19.4%) cases and the TPS scores ranged from 1 to 100%, as follows: 0 (n = 54, 80.6%), 1–9% (n = 3, 4.5%), 10–49% (n = 9, 13.4%), and ≥ 50% (n = 1, 1.5%). PD-L1 positive tumours exhibited a poorer response to pazopanib treatment than the PD-L1 negative tumours (0% vs 14.8%, P = 0.07). PD-L1-positive tumours had significantly shorter PFS than the PD-L1-negative tumours (median PFS 2.8 vs 5.1 months, P = 0.003), and PD-L1 positivity was an independent predictor of poor response to pazopanib treatment (HR 2.77, 95% CI; 1.45–5.56, P = 0.006). Conclusion We identified that PD-L1 expression can help predict the clinical outcome of patients with advanced STS treated with pazopanib. Based on our study, stratification should be actively considered in order to identify patients who will benefit from pazopanib or further therapeutic strategies for future clinical trials.

PD-L1 Tumour Expression is Predictive of Pazopanib Response in Soft Tissue Sarcoma

Background Pazopanib, a multitargeted tyrosine kinase inhibitor, is recommended as the standard treatment for refractory soft tissue sarcoma (STS). However, there are comparatively few molecular determinants for predicting pazopanib efficacy. Based on correlative studies regarding the predictive impact of PD-L1, we investigated the clinical relevance of PD-L1 expression and evaluated its value for predicting pazopanib efficacy. Methods Tumour tissues from patients with advanced STS who went on to receive pazopanib were assessed for PD-L1 expression. Immunohistochemistry was performed using an anti-PD-L1 antibody, and the PD-L1 tumour proportion score (TPS) was calculated as the percentage of at least 100 viable cells with positive expression, defined as TPS ≥ 1%. ResultsAmong the 67 patients, 8 (11.9%) achieved partial response and a median progression-free survival (PFS) of 4.8 months (95% CI 3.8-5.7). PD-L1 expression in tumour cells was detected in 13 (19.4%) cases and the TPS scores ranged from 1‒100%, as follows: 0 (n=54, 80.6%), 1‒9% (n=3, 4.5%), 10‒49% (n=9, 13.4%), and ≥50% (n=1, 1.5%). PD-L1 positive tumours exhibited a poorer response to pazopanib treatment than the PD-L1 negative tumours (0% vs 14.8%, P=0.07). PD-L1-positive tumours had significantly shorter PFS than the PD-L1-negative tumours (median PFS 2.8 vs 5.1 months, P=0.003), and PD-L1 positivity was an independent predictor of poor response to pazopanib treatment (HR 2.77, 95% CI; 1.45-5.56, P=0.006). ConclusionWe identified that PD-L1 expression can help predict the clinical outcome of patients with advanced STS treated with pazopanib. Based on our study, stratification should be actively considered in order to identify patients who will benefit from pazopanib or further therapeutic strategies for future clinical trials.

Catfish egg lectin affects influx and efflux rates of sunitinib in human cervical carcinoma HeLa cells

New treatment protocols are aiming to reduce the dose of the multitargeted tyrosine kinase inhibitor sunitinib, as sunitinib elicits many adverse effects depending on its dosage. Silurus asotus egg lectin (SAL) has been reported to enhance the incorporation of propidium iodide as well as doxorubicin into Burkitt’s lymphoma Raji cells through binding to globotriaosylceramide (Gb3) on the cell surface. The objective of this study was to examine whether SAL enhances the cytotoxic effect of sunitinib in Gb3-expressing HeLa cells. Although the treatment with SAL delayed the cell growth and enhanced the propidium iodide uptake, cell death accompanied by membrane collapse was not observed. The viability of sunitinib-treated HeLa cells was significantly reduced when the treatment occurred in combination with SAL compared to their separate usage. Sunitinib uptake significantly increased for 30 min in SAL-treated cells, and this increment was almost completely abolished by the addition of L-rhamnose, a hapten sugar of SAL, but not by D-glucose. After removal of SU from the medium, the intracellular sunitinib level in SAL-treated cells was higher than in untreated cells for 24 h, which was not observed in Gb3-deficient HeLa cells. Furthermore, we observed that SAL promoted the formation of lysosome-like structures, which are LAMP1 positive but not acidic in HeLa cells, which can trap sunitinib. Interestingly, SAL-induced vacuolation in HeLa cells was not observed in another Gb3 positive Raji cells. Our findings suggest that SAL/Gb3 interaction promoted sunitinib uptake and suppressed sunitinib excretion and that sunitinib efficiently exerted cytotoxicity against HeLa cells.

Real-world evidence of cabozantinib in metastatic renal-cell carcinoma (mRCC): Results from the Canadian Kidney Cancer Information System (CKCis).

682 Background: Cabozantinib is a multitargeted tyrosine kinase inhibitor (TKI) that has demonstrated efficacy in mRCC randomized trials. Less is known about the activity of cabozantinib in patients (pts) exposed to immuno-oncology (IO) agents. We explored the real-world effectiveness of cabozantinib, including in pts who had progressed on IO therapy. Methods: Using CKCis, a prospective Canadian database, pts treated with cabozantinib monotherapy as second-line or later were identified. Baseline clinical and treatment characteristics were collected. Rates of partial response (PR), stable disease (SD), progressive disease (PD) and disease control (DCR, PR+SD) were determined along with median time to treatment failure (mTTF) and median overall survival (mOS). Results: A total of 156 pts were identified. Median age was 62 years (range 21-84), 74% of pts had clear-cell histology, and 54% had > 3 sites of metastases (12% in CNS, 47% in bone). At time of cabozantinib start, 34% had KPS score < 80. Outcomes are described below. Conclusions: The effectiveness of cabozantinib observed in this real-world population was consistent with results from clinical trials. Cabozantinib also appears to provide benefit to mRCC pts who have progressed on prior IO therapy, and should be incorporated into contemporary treatment algorithms. Further follow up is ongoing.[Table: see text]