Siltuximab 400mg powder for solution for infusion vials

ABSTRACT: Chimeric antigen receptor T-cell (CAR-T) therapies are effective in many hematologic malignancies; however, adverse events including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) can affect a significant number of patients. Those who develop refractory CRS or ICANS have few treatment options. Siltuximab, a monoclonal antibody binding circulating interleukin-6, has been proposed to have clinical activity in both CRS and ICANS. We conducted a multicenter retrospective analysis of siltuximab treatment for CRS and ICANS after CAR-T therapy in a real-world cohort from 6 academic centers. Fifty-four patients were evaluated. Sixteen patients had CRS previously treated with tocilizumab and 17 patients had ICANS previously treated with steroids. Of the patients with CRS at the time of siltuximab, 75% had improvement in CRS grade. Of the patients with ICANS at the time of siltuximab, 60% had improvement in ICANS grade. To our knowledge, this is the largest cohort of patients treated with siltuximab for CRS and/or ICANS after CAR-T therapies. Siltuximab appeared to be effective for both CRS and ICANS, including previously treated toxicities. These data support the use of siltuximab in CRS and ICANS as well as provide rationale for future prospective studies.

Abstract licence: CC BY-NC-ND

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is an increasingly recognized disorder that occurs due to somatic mutations of a ubiquitin-activating enzyme encoded by ubiquitin-like modifier activating enzyme 1 gene, UBA1. Clinical findings associated with VEXAS syndrome include recurrent fevers, polychondritis, periorbital edema, pleural effusions, myocarditis and/or pericarditis, hepatosplenomegaly, myelodysplastic syndrome, cytopenias, inflammatory arthritis, neutrophilic dermatosis, and deep venous thrombosis. Novel renal manifestations like interstitial nephritis are infrequent, and to our knowledge, acute renal failure due to C3 glomerulonephritis (C3GN) has not yet been reported. Overwhelming systemic inflammation can result in morbid end-organ damage and death. While there is no formal guideline or established protocol for its management, treatment of VEXAS syndrome with tocilizumab, an interleukin-6 (IL-6)-directed therapy, has been described in the literature. Here, we report a case of a 71-year-old male patient presenting with C3GN as an initial manifestation of VEXAS syndrome and explore the rationale for our approach to treatment with IL-6 blockade. Our patient was initially treated with two inpatient doses of tocilizumab with successful transition to siltuximab in the outpatient setting. He continues to benefit from ongoing siltuximab treatment for more than one year to date without any safety issues or relapse of VEXAS syndrome.

Abstract licence: CC BY-NC-ND

BACKGROUND: Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are complications associated with CAR T-cell therapy. Siltuximab directly binds interleukin-6 (IL-6) and may be safe and effective as first-line therapy for CRS or ICANS. METHODS: A retrospective study was conducted on pediatric, adolescent and young adult (AYA) patients treated with siltuximab after CAR T-cell therapy for B-ALL. RESULTS: A total of 118 patients treated were included: 97 patients developed CRS (82%), and 26 patients (22%) developed ICANS. Sixty-five of those that developed CRS (55%), received treatment. In 46/65 (71%), tocilizumab was administered as anti-IL-6 drug, and 19/65 (29%) patients received siltuximab to treat tocilizumab-refractory CRS (n = 13, 68%), or as first-line CRS treatment (n = 6, 32%). Nine patients treated with siltuximab (47%) developed ICANS. With a median follow-up of 12.1 months, 7 patients remained alive. CONCLUSIONS: To the best of our knowledge, we present the largest reported cohort of patients treated with siltuximab for CRS following CAR T-cell therapy for B-ALL. Siltuximab's safety profile and its inhibition of IL-6 effects suggest that it should be investigated as first-line therapy in prospective clinical trials.

Abstract licence: CC BY

Background: Castleman disease (CD) is a very rare, non-malignant lymphoproliferative disorder that can be classified as unicentric or multicentric (MCD). MCD is associated with systemic symptoms, including organ dysfunction due to cytokine dysregulation, primarily interleukin-6 (IL-6). The anti-IL-6 monoclonal antibody siltuximab is recommended as a frontline treatment for idiopathic MCD (iMCD), but real-world data on its use in routine clinical practice are limited. This study aimed to assess disease response and survival outcomes in patients with iMCD treated with siltuximab therapy in real-world settings in Greece and Romania. Methods: This retrospective cohort study included adult patients with iMCD treated with siltuximab in clinical practice across Greece and Romania between January 2017 and December 2022. The primary endpoint was overall response rate and secondary endpoints included survival and safety outcomes. Response assessments were performed according to the Castleman Disease Collaborative Network guidelines. Patients were followed until death, loss to follow-up or study conclusion (October 2023). Results: Forty-eight patients with iMCD were included in the study. Mean age at baseline was 65 years, with significant age differences between patients from Greece (74 years) and Romania (54 years). The majority of patients were male (68.8%) and received one prior line of therapy (75%). Patients included in the study received a median of nine cycles of siltuximab. Response data were available for 38 patients. The overall response to siltuximab was 71.1%, with 55.3% of patients achieving a complete response, and 15.8% a partial response. The estimated overall survival rate at 3 years was 74% and the median survival was 123 months. The most common adverse events (> 5%) included elevated liver enzymes, anxiety, allergic reactions and nausea/diarrhea. Serious adverse events were experienced by 16.7% of the patients. Conclusions: Our results suggest that siltuximab-based therapy is effective in treating iMCD in real-world settings in Greece and Romania. To our knowledge, this study represents the largest real-world analysis of siltuximab in European patients with iMCD so far.

Abstract licence: CC BY-NC