Phase I/II study of BMS-986156 with ipilimumab or nivolumab with or without stereotactic ablative radiotherapy in patients with advanced solid malignancies

Background BMS-986156 is an agonist of the glucocorticoid-induced tumor necrosis factor receptor (TNFR)-related protein (GITR) and promotes increased effector T-cell activation. Combined anti-GITR, anti-programmed death-1, anti-cytotoxic T-lymphocyte-associated protein 4 antibodies and radiotherapy improve tumor control in preclinical studies. Herein we describe the results of the safety and efficacy of BMS-986156+ipilimumab or nivolumab with/without stereotactic ablative radiotherapy (SABR) in patients with advanced solid cancers (NCT04021043). Methods This open-label, multigroup, single-center phase I/II study enrolled patients with histologically-confirmed stage IV solid cancers resistant to standard treatments. Group 1 (G1, n=20) received four cycles of ipilimumab (3 mg/kg) plus BMS-986156 (30 mg as dose level 1 (L1) or 100 mg as dose level 2 (L2)), every 3 weeks (Q3W). Group 2 (G2, n=10) received four cycles of ipilimumab (3 mg/kg) plus BMS-986156 (dose as determined in G1, Q3W) with SABR (50 Gy/4 fx or 60-70 Gy/10 fx to liver/lung lesions. Group 3 (G3, n=20) received four cycles of nivolumab (480 mg) plus BMS-986156 (30 mg), every 4 weeks with SABR. Maintenance nivolumab could be given up to 2 years. Tumor responses were assessed every 1-3 months until progression, using immune-related response criteria. Results 50 patients were enrolled between 10/2019 and 12/2021. Patients received a median of 3 (IQR 2-4.25) initial treatment cycles. 100 mg BMS-986156 with ipilimumab was tolerated well. Five discontinued BMS-986156 with ipilimumab due to treatment-related adverse events (TRAEs), with three in G1/L1, one in G1/L2 and one in G2, respectively. 22 patients (44%) experienced Grade 1-3 TRAEs (6, 4, 5, 7 patients for G1/L1, G1/L2, G2, G3). Six (12%) had Grade 3 TRAEs (2, 2, 1, 1 for G1/L1, G1/L2, G2, G3), with elevated alanine aminotransferase (n=3, in G1/L2, G2 and G3) and aspartate aminotransferase (n=2, in G2 and G3) being the most common. There was no Grade 4-5 TRAEs. Overall, 19/39 (48.7%) patients eligible for efficacy analysis had stable disease and 3 (7.7%) achieved a partial response. Out-of-field (abscopal) disease control rate (ACR) and out-of-field (abscopal) response rate (ARR) were 38.5% and 7.7%, respectively, with the highest ACR (50%, 9/18) and ARR (11.1%, 2/18) in G3. Conclusions BMS-986156 was well-tolerated with ipilimumab, nivolumab, with or without SABR. Outcomes were encouraging in this population, as more than half of patients had stable disease/partial response.