Local Sustained Dinutuximab Delivery and Release From Methacrylated Chondroitin Sulfate.

Neuroblastoma (NB) is the most common pediatric extracranial solid tumor. High-risk NB is a subset of the disease that has poor prognosis and requires multimodal treatment regimens, with a 50% rate of recurrence despite intervention. There is a need for improved treatment strategies to reduce high-risk patient mortality. Dinutuximab is an anti-GD2 antibody ideal for targeting GD2 expressing NB cells, but binding of the antibody to peripheral nerve fibers leads to severe pain during systemic administration. Intratumoral delivery of the anti-GD2 antibody would allow for increased local antibody concentration, without increasing systemic toxicity. Chondroitin Sulfate (CS) is a biocompatible glycosaminoglycan that can be methacrylated to form CSMA, a photocrosslinkable hydrogel that can be loaded with therapeutic agents. The methacrylation reaction time can be varied to achieve different degrees of substitution, resulting in different release and degradation profiles. In this work, 4 and 24 h reacted CSMA was used to create hydrogels at 10% and 20% CSMA. Sustained in vitro release of dinutuximab from these formulations was observed over a 24-day period, and 4 h reacted 10% CSMA hydrogels had the highest overall dinutuximab release over time. An orthotropic mouse model was used to evaluate in vivo response to dinutuximab loaded 4 h methacrylated 10% CSMA hydrogels as compared to bolus tail vein injections. Tumor growth was monitored, and there was a statistically significant increase in the days to reach specific tumor size for tumors treated with intratumoral dinutuximab-loaded hydrogel compared to those treated with dinutuximab solution through tail vein injection. This supports the concept that locally delivering dinutuximab within the hydrogel formulation slowed tumor growth. The CSMA hydrogel-only treatment slowed tumor growth as well, an interesting effect that may indicate interactions between the CSMA and cell adhesion molecules in the tumor microenvironment. These findings demonstrate a potential avenue for local sustained delivery of dinutuximab for improved anti-tumoral response in high-risk NB.