In the subgroup of patients with IMDC favorable-risk disease (269 individuals), rates of 1-year OS (95% vs 94%; hazard ratio [HR], 0.64; 95% CI, 0.24-1.68), 1-year PFS (68% vs 60%; HR, 0.81; 95% CI, 0.53-1.24), and overall response (OR; 66.7% vs 49.6%) favored patients in the immunotherapy-based arm. However, these differences were more pronounced in the 592 patients with IMDC intermediate- or poor-risk disease, with respective rates of 1-year OS (87% vs 71%; HR, 0.52; 95% CI, 0.37-0.74), 1-year PFS (56% vs 40%; HR, 0.67; 95% CI, 0.53-0.85) and OR (55.8% vs 29.5%) for those receiving pembrolizumab/axitinib versus sunitinib.

Regarding the subgroup of patients with disease characterized by sarcomatoid features, approximately 50 patients were identified in each study arm. In comparison with the intention-to-treat population, the percentage of patients with IMDC intermediate/high risk disease was higher in this subgroup. 

The depth of tumor response for patients with measurable disease characterized by sarcomatoid features,  with respective rates for those with tumor shrinkage by 60% or higher (54% vs 16%), 80% or higher (33% vs 8%) and 100% (ie, complete response [CR]; 13% vs 2%) again favoring patients receiving pembrolizumab plus axitinib.  


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In the sarcomatoid subgroup, 1-year PFS rates were 57% [combination] and 26% [sunitinib). While median PFS was not reached in the combination arm, it was 8.4 months for patients receiving sunitinib (HR, 0.54; 95% CI, 0.29-1.00). The ORR rates were 58.8% [combination therapy] and 31.5% [sunitinib] in this subgroup. Median OS was not reached in either arm (HR, 0.58, 95% CI, 0.21-1.59). 

In his concluding remarks, Brian Rini, department of hematology and medical oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio, who was the study presenter, stated that “pembrolizumab plus axitinib is a new standard of care for first-line treatment of advanced clear cell RCC with OS, PFF, and ORR benefit in all IMDCC risk categories and substantial activity in participants with sarcomatoid RCC.”

References

  1. Rini BI, Plimack ER, Stus V, et al. Pembrolizumab (pembro) plus axitinib (axi) versus sunitinib as first-line therapy for metastatic renal cell carcinoma (mRCC): Outcomes in the combined IMDC intermediate/poor risk and sarcomatoid subgroups of the phase 3 KEYNOTE-426 study. Presented at: 2019 American Society of Clinical Oncology (ASCO) Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract 4500.
  2. Rini BI, Plimack ER, Stus V, et al. Pembrolizumab plus axitinib versus sunitinib for advanced renal-cell carcinoma. N Engl J Med. 2019;380:1116-1127. 
  3. Pembrolizumab (Keytruda®) [package insert]. Whitehorse Station, NJ: Merck & Co., Inc.; 2019. 

This article originally appeared on Cancer Therapy Advisor