Introduction

Advances in cancer immunotherapeutics have led to great interest in their potential to treat malignancies. Recently, preliminary and promising results have been reported in dogs with osteosarcoma (OSA). The critical role of T cells in anti-cancer immunity has been demonstrated in various immunotherapies. In this study, 50 dogs with OSA were randomized to receive ECI therapy which combines autologous tumor cell vaccines and adoptive ex vivo activated autologous T-cell transfer. The dogs also received interleukin (IL-2) post T-cells. Toxicities associated with immunotherapies have been reported, including cytokine release syndrome (CRS). Here we review the adverse events (AE) and CRS mitigation plan for dogs undergoing ECI adoptive T cell therapy.

Methods

All dogs underwent amputation surgery to initiate treatment and harvest tissue for autologous vaccine preparation. After administration of three vaccinations, T cells were harvested via apheresis and then ex vivo expanded and activated before being reinfused. Low dose IL-2 was given post infusion. Dogs were monitored for 4–6 hours after infusion.

Results

33% of dogs experienced a Grade 1/2 AE, with no Grade 3 or higher AEs reported.

Most common AEs reported were lethargy, pyrexia, and nausea.

Three dogs received dexamethasone, per protocol medical management/CRS mitigation plan, with two experiencing Grade 2 lethargy and one experiencing Grade 2 epistaxis.

We will review the impact of T-cell therapies in humans and dogs, and potential future approaches.

Conclusion

Preliminary safety data from ECI cohort (n=50) in the randomized ECI- OSA-04 study further confirms positive safety profile reported in the previously completed ECI-OSA-01 study (n=14).

Funding Information

ELIAS Animal Health provided funding for the study discussed in the abstract and honoraria to speaker/presenters.