Efficacy and safety of pembrolizumab in metastatic urothelial carcinoma: results from KEYNOTE-045 and KEYNOTE-052 after up to 5 years of follow-up.

BACKGROUND: Immune checkpoint inhibitors are a standard therapy in metastatic urothelial carcinoma (UC). Long-term follow-up is necessary to confirm durability of response and identify further safety concerns. PATIENTS AND METHODS: In KEYNOTE-045, patients with metastatic UC that progressed on platinum-containing chemotherapy were randomly assigned 1:1 to receive pembrolizumab or investigator's choice of paclitaxel, docetaxel, or vinflunine. Primary endpoints were progression-free survival per RECIST version 1.1 by blinded independent central review (BICR) and overall survival. In KEYNOTE-052, cisplatin-ineligible patients with metastatic UC received first-line pembrolizumab. The primary endpoint was objective response rate per RECIST version 1.1 by BICR. RESULTS: A total of 542 patients (pembrolizumab, n = 270; chemotherapy, n = 272) were randomly assigned in KEYNOTE-045. The median follow-up was 62.9 months (range 58.6-70.9 months; data cut-off 1 October 2020). At 48 months, overall survival rates were 16.7% for pembrolizumab and 10.1% for chemotherapy; progression-free survival rates were 9.5% and 2.7%, respectively. The median duration of response (DOR) was 29.7 months (range 1.6+ to 60.5+ months) for pembrolizumab and 4.4 months (range 1.4+ to 63.1+ months) for chemotherapy; 36-month DOR rates were 44.4% and 28.3%, respectively. A total of 370 patients were enrolled in KEYNOTE-052. The median follow-up was 56.3 months (range 51.2-65.3 months; data cut-off 26 September 2020). The confirmed objective response rate was 28.9% (95% confidence interval 24.3-33.8), and the median DOR was 33.4 months (range 1.4+ to 60.7+ months); the 36-month DOR rate was 44.8%. Most treatment-related adverse events for pembrolizumab in either study were grade 1 or 2 and manageable, which is consistent with prior reports. CONCLUSION: With ∼5 years of follow-up, pembrolizumab monotherapy continued to demonstrate durable efficacy with no new safety signals in patients with platinum-resistant metastatic UC and as first-line therapy in cisplatin-ineligible patients. CLINICAL TRIAL REGISTRY AND ID: With ClinicalTrials.gov NCT02256436 (KEYNOTE-045); https://clinicaltrials.gov/ct2/show/NCT02256436 and NCT02335424 (KEYNOTE-052); https://clinicaltrials.gov/ct2/show/NCT02335424.

Prospective study assessing hypoxia-related proteins as markers for the outcome of treatment with sunitinib in advanced clear-cell renal cell carcinoma.

BACKGROUND: Previous studies suggest that expression of hypoxia markers may be associated with response to antiangiogenic drugs. Thus, we aimed to identify predictors of sunitinib outcome in clear-cell renal cell carcinoma (ccRCC). PATIENTS AND METHODS: The expression of eight key proteins related to hypoxia (CAIX, HIF1A, HIF2A, VEGFA, VEGFR1, VEGFR2, VEGFR3 and PDGFRB) and P-glycoprotein were assessed by immunohistochemistry in 67 primary ccRCC samples from prospectively recruited patients treated with first-line sunitinib. The proteins expression, VHL inactivation and EGLN3 mRNA content were compared with the patients' response to sunitinib. RESULTS: High expression of HIF2A and PDGFRB was associated with better sunitinib RECIST objective response (P = 0.024 and P = 0.026; respectively) and increased VEGFR3 expression was associated with longer progression-free survival (P = 0.012). VEGFR3 overexpression showed a negative correlation with VEGFR3 polymorphism rs307826 (P = 0.002), a sunitinib resistance predictor. With respect to overall survival (OS), high VEGFA was associated with short (P = 0.009) and HIF2A with long (P = 0.048) survival times. High EGLN3 mRNA content was associated with shorter OS (P = 0.023). CONCLUSIONS: We found an association between several proteins involved in hypoxia and sunitinib efficacy. In addition, low VEGFR3 expression was associated with worse outcome and with VEGFR3 rs307826 variant allele, reinforcing VEGFR3 as a marker of sunitinib resistance.