Tivozanib sustains PFS benefit over sorafenib in mRCC with long-term follow-up

Treatment with tivozanib (Fotivda) was associated with a fivefold increased likelihood of experiencing long-term progression-free survival (PFS) compared to treatment with sorafenib (Nexavar) among patients with pretreated relapsed/refractory renal cell carcinoma (RCC), according to the latest findings from the TIVO-3 trial presented during the 2022 ASCO Genitourinary Cancers Symposium.¹

TIVO-3 included 350 patients with relapsed/refractory RCC who received 2 or more prior lines of systemic therapy. Half were randomized to receive tivozanib, while the other half received sorafenib. Superior PFS findings for the tivozanib arm led to the TKI’s approval last March, while longer-term follow-up with a data cutoff of May 24, 2021, continued to show that, on average, tivozanib was superior.

“In this analysis, we assessed the proportion of TIVO-3 patients with relapsed/refractory mRCC who achieved a [long-term] PFS at regular intervals up to 4 years after initiation of [tivozanib] or [sorafenib],” the researchers wrote on their poster presentation, noting that they tracked survival data from the TIVO-3 trial at 6-, 12- 18-, 24-, 30-, 36, 42, and 48-month marks.

However, since there was a low number of patients at the 42- and 48-month marks at the time of the data cutoff, the researchers could not conduct any inferential statistical analyses.

At the 3-year mark, landmark long-term PFS rates, as assessed by the investigators, were 12.3% (95% CI, 8-18) and 2.4% (95% CI, 1-6) in the tivozanib and sorafenib arms, respectively. Tivozanib continued to best sorafenib at the 4-year mark, too, with PFS rates at 7.6% (95% CI, 4-13) and 0%, respectively.

“[Investigator assessed] PFS analyzed with extended follow-up was consistent with the [independent review committee] PFS in the primary analyses,” the researchers wrote in a poster of the findings. “OS continued to mature with longer follow-up, now demonstrating a nonsignificant trend in favor of [tivozanib].”

The patient population was well-balanced between the tivozanib and sorafenib arms, with 34, 109, and 32 patients in the favorable, intermediate and poor risk groups, respectively in the tivozanib arm. Meanwhile, on the sorafenib arm, there were 36 patients with favorable risk, 105 with intermediate risk, and 34 with poor risk disease. The majority of patients in each group (128 for tivozanib and 131 for sorafenib) had no prior immunotherapy, and 79 patients in the tivozanib group had treatment with 2 TKI therapies, compared with 80 patients in the sorafenib group. All patients included in the analysis had an ECOG score of 0 or 1.

Of note, subgroups with 15% long-term PFS at 3 years include IMDC favorable risk, female gender, ECOG performance score of 0, and an average age of 65 years old.

“A clinically relevant proportion of patients were alive and progression-free at 3 and 4 years after initiating [tivozanib] therapy compared with sorafenib, and this difference was consistent across all clinical and demographic subgroups evaluated,” the researchers concluded.

Reference

1. Atkins MB, Verzoni E, Escudier B, et al. Long-term PFS from TIVO-3: Tivozanib (TIVO) versus sorafenib (SOR) in relapsed/refractory (R/R) advanced RCC. Presented at: 2022 ASCO Genitourinary Cancers Symposium. Feb. 17-19, 2022. Virtual.