Abstract BACKGROUND The CSF of patients with LMD have an innate, but not adaptive, immune cellular profile. Murine LMD models showed IT cDC1s were safe, induced a Th1 response (CD4+ CD8+ T cell and B cell dependent), cured most HER2+ LMD, and prevented LMD recurrence. We conducted a Phase I study of IT DCs and hypothesized the CSF would be remodeled to have a Th1 adaptive immunological profile. METHODS This is a Phase I single-arm, dose escalation study to establish 1) the safety and 2) associations between clinical outcomes Th2-related IL-4 was not elevated. Transcriptomics showed a marked increase in CD4+ T, CD8+ T and B cells with a reduction of tumor cells. Antibodies to HER2 or HER3 developed in four of five (80%) patients. CONCLUSION Our results suggest this approach activates CD4+ Th1 adaptive immune responses that drives adaptive antitumor activity which is otherwise lacking in LMD (NCT05809752).
Forsyth et al. (Fri,) studied this question.