NeoRad(Low): A phase 2 trial of neoadjuvant (NA) ipilimumab + nivolumab (ipi+nivo) with low dose stereotactic body radiation therapy (SBRT) as an immune stimulant in patients with resectable stage IB-III non-small cell lung cancer (NSCLC).
Authors: Thomas A. DiPetrillo, Maria Garcia-Moliner, Paul Koffer, Jaroslaw T. Hepel, Hina Khan, Humera Khurshid, Abbas Abbas, Ariel E. Birnbaum, Adam J. Olszewski, Cheyenne Ferreira, Faith Hassinger, Michele Carlin McCormick, Hannah Giesing, Nuno Rodrigues, Vallerie Rosati, Roxanne Wood, Amy Webber, Sara Maleki, Christopher G. Azzoli
Journal: Journal of Clinical Oncology (2024)

e20081 Background: Standard NA immune checkpoint blockade for patients with resectable NSCLC targets PD1 only and must be combined with platinum-based chemotherapy. In a randomized phase 2 NA study, ipi + nivo demonstrated greater immune-mediated efficacy compared to nivo alone with major pathologic response (MPR) 50% vs. 24%, Cascone T, et al. Nat Med. 2021;27(3):504-14). Preclinical and clinical studies have demonstrated that low doses of radiation enhance immune response by multiple mechanisms (dsDNA breaks, induction of STING, transcription of pro-inflammatory proteins, increased expression of neoantigens while sparing effector T cells). An approach incorporating low dose radiation as an immune stimulant potentially may improve immune-mediated efficacy and shorten the duration of NA treatment compared to approaches that use combined cytotoxic chemotherapy. Methods: This single-arm trial tested NA ipi (1 mg/kg d1) + nivo (3mg/kg d1, 15, 29) plus low-dose SBRT delivered as 2 fractions (4Gy x 2) to the gross primary tumor and nodal disease immediately following day 1 infusion and completed by day 3 in patients with medically operable stage IB-III NSCLC Patients went on to surgical resection between days 49 -63. The primary efficacy outcome measure was pathologic response (including MPR, and complete PR (CPR)). Secondary outcome measures included safety, and exploratory biomarkers of immune response in pre- and post-operative blood and tissue. A two-stage design was employed to stop the study for lack of efficacy if fewer than 3 of the first 9 evaluable patients achieved MPR or experienced undue toxicity. Results: Patients were treated on study: 4 men, 5 women, aged 40-71, stage IB (2), IIB (5), IIIA (1), IIIB (1); adenocarcinoma 7 (all EGFR,ALK -), squamous 2; ECOG PS 0-1 (9); all were former smokers. There were no dose limiting toxicities. Study-related toxicities were ≤ grade 2 including rash (2) and abdominal pain (1). There were no study-related surgical complications. One patient (IIIA, T1N2) experienced clinical and radiologic progression during study treatment and was confirmed to have pleural metastases at surgery. Of 7 patients resected to date, there was 1 CPR, 0 further MPR and 1 patient with surgery pending. All resected patients had some treatment effect, 3 were down staged and these elected not to receive adjuvant cytotoxic chemotherapy. The only patient to progress in 8 months med f/u was the patient progressing during NA therapy. Conclusions: Low-dose radiation with concurrent NA ipi + nivo was safe and well tolerated in this small cohort but did not improve MPR compared to historical phase 2 data of ipi + nivo alone. Standard and exploratory biomarkers of immune response will be presented to determine if patient selection played a role in these results. Clinical trial information: NCT04933903 .