Outcomes of Patients with Metastatic Renal Cell Carcinoma Treated with Targeted Therapy After Immuno-oncology Checkpoint Inhibitors

Abstract

Background: Immuno-oncology (IO) therapies have changed the treatment standards of metastatic renal cell carcinoma (mRCC). However, the effectiveness of targeted therapy following discontinuation of IO therapy in real-world settings has not been well studied.

Objective: To describe treatment sequence and assess clinical effectiveness of targeted therapy for mRCC patients who received prior IO therapy.

Design, setting, and participants: A retrospective, longitudinal cohort study using data from eight international cancer centers was conducted. Patients with mRCC were ≥18yr old, received IO therapy in any line, and initiated targeted therapy following IO therapy discontinuation.

Intervention: Patients were treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) or mammalian target of rapamycin inhibitors (mTORIs).

Outcome measurements and statistical analysis: Outcomes were time to treatment discontinuation (TTD), overall survival (OS), and objective response rate (ORR). Crude and adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazard models. Models were adjusted for age, sex, therapy line, and International Metastatic RCC Database Consortium risk group.

Results and limitations: Among 314 patients, 276 (87.9%) and 38 (12.1%) were treated with VEGFR-TKI and mTORI therapy, respectively. The most common tyrosine kinase inhibitor treatments were axitinib, cabozantinib, and sunitinib following IO therapy. In adjusted models, patients treated with VEGFR-TKI versus mTORI therapy had lower hazard of TTD after IO treatment (aHR=0.46; 95% CI: 0.30-0.71; p < 0.01). One-year OS probability (65% vs 47%, p < 0.01) and proportion of ORR (29.8% vs 3.6%, p < 0.01) were significantly greater for patients treated with VEGFR-TKIs versus those treated with mTORIs.

Conclusions: Targeted therapy has clinical activity following IO treatment. Patients who received VEGFR-TKIs versus mTORIs following IO therapy had improved clinical outcomes. These findings may help inform treatment guidelines and clinical practice for patients post-IO therapy.

Patient summary: Patients may continue to experience clinical benefits from targeted therapies after progression on immuno-oncology treatment.

Keywords: Immuno-oncology; Mammalian target of rapamycin inhibitors; Metastatic renal cell carcinoma; Real-world effectiveness; Sequential therapies; Targeted therapy; Vascular endothelial growth factor receptor tyrosine kinase inhibitors.