Phase I Trial Combining Chemokine-Targeting with Loco-Regional Chemoimmunotherapy for Recurrent, Platinum-Sensitive Ovarian Cancer Shows Induction of CXCR3 Ligands and Markers of Type 1 Immunity

Abstract

Purpose: Increased prevalence of cytotoxic T lymphocytes (CTL) in the tumor microenvironment (TME) predicts positive outcomes in patients with epithelial ovarian cancer (EOC), whereas the regulatory T cells (Treg) predict poor outcomes. Guided by the synergistic activity of TLR3 ligands, IFNα, and COX-2 blockers in selectively enhancing CTL-attractants but suppressing Treg-attractants, we tested a novel intraperitoneal chemoimmunotherapy combination (CITC), to assess its tolerability and TME-modulatory impact in patients with recurrent EOC.

Patients and methods: Twelve patients were enrolled in phase I portion of the trial NCT02432378, and treated with intraperitoneal cisplatin, intraperitoneal rintatolimod (dsRNA, TLR3 ligand), and oral celecoxib (COX-2 blocker). Patients in cohorts 2, 3, and 4 also received intraperitoneal IFNα at 2, 6, and 18 million units (MU), respectively. Primary objectives were to evaluate safety, identify phase 2 recommended dose (P2RD), and characterize changes in the immune TME. Peritoneal resident cells and intraperitoneal wash fluid were profiled via NanoString and Meso Scale Discovery (MSD) multiplex assay, respectively.

Results: The P2RD of IFNα was 6 MU. Median progression-free survival and overall survival were 8.4 and 30 months, respectively. Longitudinal sampling of the peritoneal cavity via intraperitoneal washes demonstrated local upregulation of IFN-stimulated genes (ISG), including CTL-attracting chemokines (CXCL-9, -10, -11), MHC I/II, perforin, and granzymes. These changes were present 2 days after chemokine modulation and subsided within 1 week.

Conclusions: The chemokine-modulating intraperitoneal-CITC is safe, tolerable, and associated with ISG changes that favor CTL chemoattraction and function. This combination (plus DC vaccine) will be tested in a phase II trial. See related commentary by Aranda et al., p. 1993.

©2022 American Association for Cancer Research.

Figures

Fig. 1.

Clinical trial diagram and summary of clinical responses. (A) Diagram of patient enrollment and cohort distribution. (B) Clinical trial schema. Additional details regarding the drug regimen and timing of biospecimen collection are included in the Methods section. * Celecoxib (200 mg) was administered daily throughout treatment; additional 200 mg was given on days of chemotherapy and CKM infusion. (C) Swimmer’s plot showing time of objective response (PR- partial response; SD- stable disease; PD- progressive disease) in relationship to duration of treatment and time of treatment cessation (x axis). The nine evaluable patients are individually shown (y axis) and color-coded according to the cohort. (D) Cell densities of IP wash samples collected longitudinally during treatment, from nine evaluable and two non-evaluable (NE) patients. Each patient is labeled with cohort number and patient number in each cohort (for example, patient 1.1 refers to cohort 1, patient 1).

Fig. 2.

Treatment-induced transcriptomic changes in IP washes. (A) Heatmaps and volcano plots of DE genes identified in IP washes by NanoString: C1D1 vs C2D1 (n=62, top), C2D1 vs C2D4 (n=397, middle), C3D1 vs C3D11 (n=41, bottom). Volcano plots show magnitude of response for the respective heatmaps on the left. Red dots represent individual DE genes with p-values ≤0.05 (y axis cut-off) and magnitudes of log2 FC > 0.58 (x axis cut-off). Green dots represent genes with above the cut-off for fold change but below the p-value cut-off. Gray dots are genes with non-significant (NS) p-values and log2 FC below cut-off. Individual DE genes are listed in Supplementary Table 1. (B) Venn diagram for DE genes shown in A. Cycle 1 (C2D1 vs C1D1); Cycle 2 (C2D4 vs C2D1); Cycle 3 (C3D11 vs C3D1). (C) GSEA histograms showing enrichment of DE genes at cycles 2 and 3 (chemo/CKM), in contrast to pattern observed at cycle 1 (chemo alone). The leading edge (most significant genes) are shown as vertical bars accumulated either left or right of the green line histogram, indicating the up- or down-regulated genes, respectively (D). Heatmaps of n=24 interferon stimulated genes (ISG, listed in textbox) after cycle 1 (top) and two days post-CKM in cycle 2 (bottom). (E) Heatmaps of n=26 interferon gamma induced genes (IFNg_IG, listed in textbox) after cycle 1 (top) and two days post-CKM in cycle 2 (bottom). Numbers on columns refer to patient cohort.

Fig. 3.

Protein changes in IP washes. (A) Concentration of 11 different analytes (listed in textbox) in IP washes measured with MSD. Heatmaps show upregulation (red) of protein expression at C2D4 compared to C2D1 and downregulation (green) at C2D9 compared to C2D4. (B) Heatmap showing upregulation for all markers, at C3D11 compared to C3D1. (C) MSD results for individual anlaytes at cycles 2 and 3. *** p

Fig 4.

Treatment-induced changes in tumor tissue. (A) Heatmaps of DE genes at baseline and interval surgery (5 patients, paired samples, n=43 DE genes, pPRF1) and granzyme B (GZMB) (p<0.05).