ASCO GU 2022: Tivozanib As First-Line Treatment of Metastatic Renal Cell Carcinoma: A Real-World Outcome Review in North-West of England, UK

(UroToday.com) The Poster Session C on the third day of the American Society for Clinical Oncology (ASCO) Genitourinary Cancer Symposium 2022, focused on Renal Cell Cancer; Adrenal, Penile, Urethral, and Testicular Cancers. In this session, Dr. Heseltine presented a real-world analysis of tivozanib as first-line therapy of metastatic renal cell carcinoma (mRCC).

In the randomized TIVO-1 study, patients with mRCC treated with first-line tivozanib had improved PFS compared to those treated with sorafenib. However, it is important to understand treatment outcomes for patients treated outside the confines of a randomized controlled trial.

The authors therefore performed a multi-center retrospective analysis of patients with mRCC who began tivozanib as first-line therapy between March 2017 and May 2019. The authors assessed overall response rate (ORR), survival (OS, PFS) and toxicity until a data cut off of November 30, 2020.

The authors identified 113 patients, of whom 22% had IMDC favorable-risk disease, 52% had intermediate risk disease, and 26% had poor risk disease. With a median follow-up of 25.9 months (18.3 to 44.7 months), 18% pts remain on treatment at data cut-off. 88.5% commenced tivozanib at full dose, of which 67% maintained dose intensity. 11.5% commenced tizovanib with dose reduction due to prior TKI toxicities or comorbidities. The median number of cycles was 7 (1-33).

In terms of efficacy, ORR was 29% (complete response 0%, partial response 29%, stable disease 39%, progressive disease 26%, and not estimable 6%). The median PFS was 9.0 months (95% C.I. 6.0-12.1 months). Stratified by IMDC risk group, the median PFS 23.0 months (95% C.I. 7.6-38.4 months) among patients with favorable-risk disease, 10.0 months (95% C.I. 6.3-13.7 months) among patients with intermediate-risk disease, and 3.0 months (95% C.I. 1.5.- 4.5 months) among those with poor-risk disease (p<0.0001).

The median OS was 25.0 months (95% C.I. 15.4-34.6 months). Adverse events (AEs) of any grade occurred in 77% (≥G3 13%) including fatigue 42% (≥G3 0%), diarrhoea 19% (≥G3 < 1%), mucositis 24% ( ≥G3 2%), anorexia 12% (≥G3 < 1%); and hypertension 7% (≥G3 2%). Notable ≥G3 events included abnormal liver function 3%; vascular events 2% and seizure < 1%. 18% of patients discontinued treatment due to toxicity with no treatment-related deaths.

The authors conclude that these real-world data suggest a comparable efficacy of tivozanib to randomized data.