FDA Grants Fast Track Designation to Batiraxcept for Kidney Cancer Subset

The FDA’s decision to grant fast track designation to batiraxcept for treating patients with advanced or metastatic clear cell renal cell carcinoma — a type of kidney cancer — was supported by data from a phase 1b trial.

The FDA has granted fast track designation to batiraxcept for the treatment of patients with clear cell renal cell carcinoma (RCC) — a type of kidney cancer — that progressed following 1 or 2 previous lines of systemic therapy such as prior vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI)-based treatment, according to a press release from Aravive.

The FDA’s fast track designation was based on data from the phase 1b portion of the phase 1/2 AVB500-RCC-003 trial (NCT04300140). Results from the trial indicated that patients treated with batiraxcept plus cabozantinib (Cabometyx) achieved an objective response rate (ORR) of 57% and a median progression-free survival (PFS) of 11.4 months.

These findings, according to the manufacturer, demonstrate the potential of adding batiraxcept to increase the clinical activity of cabozantinib among patients with metastatic clear cell RCC. Additionally, the use of batiraxcept yielded no dose limiting toxicities at either studied dose.

“Since preclinical data published…in 2019 observed that batiraxcept may restore TKI sensitivity, it makes sense that the combination of batiraxcept and cabozantinib may exhibit its greatest impact in those patients who have failed prior VEGF-TKI therapies,” Gail McIntyre, PhD, DABT, CEO of Aravive, said in the release. “Understanding the [phase 1b clear cell] RCC data has allowed us to identify the most appropriate patient population in which to evaluate batiraxcept in combination with cabozantinib and potentially the quickest path to approval in this population with an unmet medical need.”

Batiraxcept is a novel decoy protein that binds to GAS6, the sole ligand that activates the AXL receptor, thereby inhibiting metastasis and tumor growth while restoring sensitivity to anti-cancer agents.

As of September 2022, investigators of AVB500-RCC-003 enrolled 26 previously treated patients with clear cell RCC who received batiraxcept treatment during the phase 1b portion of the trial. In this portion of the trial, 16 patients received 15 mg/kg of batiraxcept with 60 mg of cabozantinib daily, and 10 received 20 mg/kg of batiraxcept with cabozantinib daily.

Key primary end points of the trial included the incidence of adverse effects, ORR, duration of response, clinical benefit rate, PFS, and overall survival. Secondary end points included the pharmacokinetics of the study agents and changes from baseline in anti-drug antibody titers.

Patients 18 years and older with histologically confirmed advanced or metastatic clear cell RCC based on imaging were eligible to enroll on the trial. Additional inclusion criteria included having radiologic imaging with a CT scan or MRI within 28 days of enrollment; at least 1 measurable lesion per RECIST v1.1 criteria; an ECOG performance status of 0 or 1; adequate bone marrow, liver, and kidney function; and a life expectancy of more than 12 weeks.

Patients were unable to enroll on the trial if they had received prior treatment with cabozantinib or nivolumab (Opdivo). Patients were also unsuitable for enrollment if they were receiving concurrent anti-cancer therapy, had a history of prior malignancy within the past 3 years, symptomatic central nervous system metastases, active gastrointestinal disease that would affect cabozantinib treatment, and nephrotic range proteinuria at screening.


Aravive announces fast track designation of batiraxcept for treatment of ccRCC. News release. Aravive. November 29, 2022. Accessed November 29, 2022. bit.ly/3gJuUxZ