Chimeric antigen receptor (CAR)-T cell therapies have revolutionised the treatment of advanced haematologic malignancies, achieving durable complete remission in patients with refractory disease. CAR-T therapies targeting solid tumours are a rapidly developing field with an active early pipeline. Relapsed and refractory (R/R) renal cell carcinoma (RCC) presents a high unmet need, as there is a large patient population with a dismal prognosis and limited therapeutic options once the tumour becomes refractory to immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs).
Promising results from Allogene Therapeutics’s Phase I, dose-escalation, multicenter TRAVERSE trial of ALLO-316 were presented at the 2023 American Association for Cancer Research (AACR) Annual Meeting, held between 14 and 19 April. ALLO-316 is a novel, off-the-shelf (allogeneic), HLA-unmatched, CD70-targeting CAR-T cell product that is designed to reduce graft-versus-host-disease (GVHD) (a double TCR and CD52 knockout), to prevent the disruption of CD70 in the CAR-T cells (avoid fratricide), and to include a CD20 mimotope-based intra-CAR off switch to enable effective CAR-T elimination with the anti-CD20 antibody. The primary outcome measures of the study were ALLO-316’s safety and tolerability. The secondary outcome measures were the evaluation of the anti-tumour efficacy, pharmacokinetics, and pharmacodynamics of ALLO-316. The study enrolled 19 patients (median age 62 years, range 50–70 years, 16% female) with advanced or metastatic RCC who had received prior treatment with an ICI or TKI. ALLO-316’s safety profile was consistent with autologous CAR-T.
All-grade and grade 3 or higher adverse events (AEs) included infusion-related reactions (5% and 0%, respectively), cytokine release syndrome (58% and 5%), neurotoxicity (68% and 11%), infection (42% and 21%), and prolonged grade three or higher cytopenia (16%). Pharmacokinetic data showed high ALLO-316 expansion and elimination of CD70-positive host T cells, preventing GVHD. ALLO-316’s anti-tumour activity correlated with CD70 expression in RCC, with a 17% overall response rate and 89% disease control rate (DCR) across all subjects, as well as a 33% overall response rate and 100% disease control rate in subjects with CD70-positive tumours. Expansion cohorts are planned by the end of 2023, with the potential inclusion of additional CD70-positive subtypes.
In the eight major markets (US, France, Germany, Italy, Spain, UK, China, and Japan), the number of RCC prevalent cases is projected to reach 236,000 cases by 2028, with 95,000 cases having metastatic disease. Approximately 30% of advanced RCC patients treated with TKIs and ICIs in the first and second line develop R/R disease and will move on to an additional line of treatment. There is no current standard of care for these patients. If successful, allogeneic CAR-T could offer hope to R/R RCC patients, as it has the advantage over autologous CAR-T in terms of production time and availability to patients who are not eligible for autologous CAR-T. GlobalData estimates total RCC drug sales to reach $7.4bn by 2028, with a US market share of $4.3bn.