A RECENT Phase I clinical trial has provided promising results for a novel immunotherapy approach to treat early-stage ERBB2-positive breast cancer. The study, conducted at Moffitt Cancer Center in Tampa, Florida, explored the combination of intratumoral (IT) delivery of conventional type 1 dendritic cells (cDC1) and anti-ERBB2 antibodies, including trastuzumab and pertuzumab.
Twelve patients with ERBB2-positive breast cancer participated in the trial, which aimed to evaluate the safety, immunogenicity, and preliminary efficacy of this treatment. Patients received six weekly injections of IT cDC1, followed by chemotherapy. The trial tested two different doses of cDC1—50 million (DL1) and 100 million (DL2) cells. Results revealed that the therapy was well tolerated, with minimal adverse events, including chills, fatigue, and injection site reactions. Importantly, no severe safety concerns were raised.
The higher dose of cDC1 (DL2) showed particularly promising results, with enhanced immune responses and significant tumor regression before the start of chemotherapy. Imaging results indicated that nine patients achieved objective responses, including six partial and three complete responses. Additionally, seven patients achieved a pathologic complete response after surgery, indicating the potential for long-term remission.
These findings suggest that the combination of IT cDC1 and anti-ERBB2 antibodies may offer a safer, more effective treatment for early-stage ERBB2-positive breast cancer, reducing the need for aggressive chemotherapy. Based on the results, DL2 will be further evaluated in a Phase II trial.
Helena Bradbury | AMJ
Reference
Han HS et al. Alteration of the tumor microenvironment with intratumoral dendritic cells before chemotherapy in ERBB2 breast cancer: A nonrandomized clinical trial. JAMA Oncol. 2024. doi:10.1001/jamaoncol.2024.5371
