Abstract CT076: A Phase 1, first-in-human study of IB-T101, an OUTLAST™ CAR-T product for the treatment of CD70-positive clear cell renal carcinoma

Abstract Relapsed/refractory clear cell renal cell carcinoma (ccRCC) presents an unmet medical need for patients faced with limited treatment options and poor clinical outcomes. CD70 is commonly expressed in ccRCC and is an attractive target for chimeric antigen receptor T cell (CAR-T) therapy. IB-T101 is an autologous anti-CD70 CAR-T for the treatment of ccRCC that has been expanded under OUTLAST™ conditioning. OUTLAST™ conditioning is a proprietary platform that expands T cells in conditions emulating the tumor microenvironment (TME) thereby imbuing them with the ability to thrive and perform in the TME once administered to the patient. OUTLAST™ conditioning is easy to implement during ex vivo cell expansion and generates a CAR-T product that exhibits an early memory T cell phenotype, is resistant to suppressive TME cues, and exhibits increased persistence. These attributes are expected to lead to superior clinical outcomes for IB-T101 CAR-T cells in ccRCC solid tumors. Here we present an in-progress phase 1, first-in-human, open label, single center investigator-initiated clinical trial aimed at evaluating the safety and efficacy of IB-T101 in ccRCC in patients that have relapsed on prior VEGF targeting therapies alone or in combination with checkpoint blockade. Autologous patient T cells are transduced with a lentiviral vector encoding a CD70-targeting CAR and are CRISPR Cas9 gene edited to knock out endogenous CD70, followed by expansion under OUTLAST™ conditioning. Escalating doses of IB-T101 CAR-T cells (150 - 500 x 106) will be infused following lymphodepletion. Primary endpoints of the study will assess the safety and tolerability of IB-T101. Additional objectives of the study are to assess the anti-tumor activity and the pharmacokinetics of IB-T101. Correlative assessments will include pre-treatment biopsies to assess the level of CD70 expression in the tumor. Citation Format: Warren Anderson, Bo Liu, Yuning Lei, Jun Cui, Yarong Liu, Kevin Carbajal, Matthias Schroff, Maximilian Richter. A Phase 1, first-in-human study of IB-T101, an OUTLAST™ CAR-T product for the treatment of CD70-positive clear cell renal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT076.