Immune checkpoint blockers (ICB) improve outcomes in metastatic melanoma (MM), but resistance limits benefit. This phase I/II (NCT02706353) study evaluated intratumoral sotigalimab (anti-CD40 agonist) with pembrolizumab in 32 patients with ICB-naïve MM. Primary endpoints were safety and objective response rate (ORR). Sotigalimab was well tolerated. At the recommended phase II dose, the ORR was 50%, and the disease control rate was 92%, with ORRs of 67% in injected and 50% in non-injected tumors. Multiomic analyses of tumor and blood showed that sotigalimab effectively engaged the CD40 pathway, boosting infiltration and activation of myeloid cells, including CD11c+DC-LAMP+ dendritic cells and macrophages. The combination therapy activated innate and adaptive immunity in injected tumors and cytotoxic responses in non-injected tumors. T-cell receptor sequencing showed increased T-cell clonality with expanded new clones shared across tumors. Clinical responses correlated with these immunologic changes but not with baseline features associated with response to anti-PD-1 monotherapy. SIGNIFICANCE:In this study, we provide compelling data that intratumoral sotigalimab combined with pembrolizumab is safe, activates antigen-presenting cells, and elicits broad innate and adaptive immune responses in both injected and non-injected tumors, supporting further randomized phase II trials to evaluate sotigalimab's potential to enhance anti-PD-1 therapy through "in situ" immunization.

Representativeness of Study Participants Table

Most common AEs (occurring in ≥10% of subjects) considered related to sotigalimab by the investigator (n = 33)

AbstractPurpose: Neoadjuvant chemoradiation (NCRT) followed by surgical resection represents a standard approach for patients with locally advanced esophageal/gastroesophageal junction (GEJ) cancers. Sotigalimab is a high-affinity CD40 agonist antibody capable of inducing and expanding antitumor immune responses by activating dendritic cells, T and B lymphocytes, NK cells, and M1 macrophages. This study examined the safety and efficacy of combining sotigalimab with NCRT in patients with esophageal or GEJ cancers. Patients and Methods: Patients with resectable (T1-3 Nx) adenocarcinoma or squamous cell carcinoma of the esophagus or GEJ were eligible. T1N0 and cervical tumors were excluded. Study treatment: weekly carboplatin/paclitaxel with concurrent radiation 5,040 cGy plus 3 to 4 doses of sotigalimab prior to Ivor Lewis esophagectomy. Primary efficacy endpoint was the pathologic complete response (path CR) rate. Results: Thirty-three patients were enrolled (adenocarcinoma 76%, squamous cell carcinoma 24%; and clinical stage III 67%). Ninety percent of patients received all planned doses of sotigalimab. The most common adverse events attributed to sotigalimab were nausea, fever/chills, fatigue, and cytokine release syndrome; most of these were grade 1 to 2. Grade ≥3 cytokine release syndrome was observed in 3 patients (9%). Twenty-five of the 29 efficacy-evaluable patients underwent an R0 resection (87.9%), with an overall path CR rate of 37.9% (11/29). Post-tumor samples demonstrated increased infiltration and activation of dendritic cells, monocytes, and cytotoxic T cells compared with baseline. Conclusions: Sotigalimab combined with NCRT for esophageal or GEJ cancers was generally well tolerated and achieved path CR rates that compare favorably with historical data and are promising for this treatment strategy. Clinical trial information: NCT03165994. Significance: The current study represents the first report to evaluate a CD40 agonist antibody in combination with concurrent chemoradiation in the neoadjuvant setting for patients with esophageal/GEJ cancers. This novel strategy was both safe and feasible, producing encouraging path CR rates that compare favorably with historical data. Our findings support the further evaluation of how immune-based therapies may be incorporated into perioperative treatment paradigms for upper gastrointestinal malignancies.

Treatment schema demonstrating changes in timing and dosing intervals of sotigalimab relative to the administration of neoadjuvant chemoradiation and surgery, based on sequential protocol amendments. Number of patients treated in each cohort: cohort A (n = 3); cohort B (n = 10); and cohort C (n = 20).

Total-Seq antibody targets and barcodes.

Sotigalimab is an agonistic anti-CD40 mAb that can modulate antitumor immune responses. In a phase II clinical trial of sotigalimab combined with neoadjuvant chemoradiation (CRT) in locally advanced esophageal/gastroesophageal junction (E/GEJ) cancer with the primary outcome of efficacy as measured by pathologic complete response (pCR) rate, the combination induced pCR in 38% of treated patients. We investigated the mechanism of action of sotigalimab in samples obtained from this clinical trial. Tumor biopsies and peripheral blood samples were collected at baseline, following an initial dose of sotigalimab, and at the time of surgery after CRT completion from six patients. High dimensional single-cell techniques were used, including combined single-cell RNA-sequencing and proteomics (CITEseq) and multiplexed ion beam imaging, to analyze immune responses. Sotigalimab dramatically remodeled the immune compartment in the periphery and within the tumor microenvironment (TME), increasing expression of molecules related to antigen processing and presentation and altering metabolic pathways in myeloid cells. Concomitant with these changes in myeloid cells, sotigalimab treatment primed new T cell clonotypes and increased the density and activation of T cells with enhanced cytotoxic function. Sotigalimab treatment also induced a decrease in the frequency of Tregs in the TME. These findings indicate that a single dose of sotigalimab leads to enhanced antigen presentation that can activate T cells and induce new T cell clones. This restructuring of the TME provides elements which are critical to the development of effective antitumor immune responses and improved clinical outcomes.

Representativeness of Study Participants

Table S4 presents MCPyV-specific T-cell reactivity by patient

Table S1 shows maximum eligible tumor burden by tumor type.

ImportanceMetastatic soft tissue sarcomas (STSs) have limited systemic therapy options, and immunomodulation has not yet meaningfully improved outcomes. Intratumoral (IT) injection of the toll-like receptor 4 (TLR4) agonist glycopyranosyl lipid A in stable-emulsion formulation (GLA-SE) has been studied as immunotherapy in other contexts.ObjectiveTo evaluate the safety, efficacy, and immunomodulatory effects of IT GLA-SE with concurrent radiotherapy in patients with metastatic STS with injectable lesions.Design, Setting, and ParticipantsThis phase 1 nonrandomized controlled trial of patients with STS was performed at a single academic sarcoma specialty center from November 17, 2014, to March 16, 2016. Data analysis was performed from August 2016 to September 2022.InterventionsTwo doses of IT GLA-SE (5 μg and 10 μg for 8 weekly doses) were tested for safety in combination with concurrent radiotherapy of the injected lesion.Main Outcomes and MeasuresPrimary end points were safety and tolerability. Secondary and exploratory end points included local response rates as well as measurement of antitumor immunity with immunohistochemistry and T-cell receptor (TCR) sequencing of tumor-infiltrating and circulating lymphocytes.ResultsTwelve patients (median [range] age, 65 [34-78] years; 8 [67%] female) were treated across the 2 dose cohorts. Intratumoral GLA-SE was well tolerated, with only 1 patient (8%) experiencing a grade 2 adverse event. All patients achieved local control of the injected lesion after 8 doses, with 1 patient having complete regression (mean regression, −25%; range, −100% to 4%). In patients with durable local response, there were detectable increases in tumor-infiltrating lymphocytes. In 1 patient (target lesion −39% at 259 days of follow-up), TCR sequencing revealed expansion of preexisting and de novo clonotypes, with convergence of numerous rearrangements coding for the same binding sequence (suggestive of clonal convergence to antitumor targets). Single-cell sequencing identified these same expanded TCR clones in peripheral blood after treatment; these T cells had markedly enhanced Tbet expression, suggesting TH1 phenotype.Conclusions and RelevanceIn this nonrandomized controlled trial, IT GLA-SE with concurrent radiotherapy was well tolerated and provided more durable local control than radiotherapy alone. Patients with durable local response demonstrated enhanced IT T-cell clonal expansion, with matched expansion of these clonotypes in the circulation. Additional studies evaluating synergism of IT GLA-SE and radiotherapy with systemic immune modulation are warranted.Trial RegistrationClinicalTrials.gov Identifier: NCT02180698

Figure S1 shows Kaplan-Meier curves for progression-free and overall survival in patients with sarcoma.

Table 1 lists the most highly upregulated immune-related genes in the TME post-G100 treatment

Table S3 lists immune-related genes with the most statistically significant differences in induction between clinical responders versus non-responders

Figure S1 depicts the treatment schema for IT G100 in MCC

Figure S4 shows MCPyV-reactive T cells detected post-G100 treatment

Figure S2 shows the expression of TLR4 receptor complex genes at baseline

Table S2 lists immune-related genes with the greatest fold differences in induction between clinical responders versus non-responders

Figure S3 shows quantification of new and induced TCR clones in tumor and blood