Impact of siltuximab on patient-related outcomes in multicentric Castleman's disease

Idiopathic multicentric Castleman disease: An update in diagnosis and treatment advances

Idiopathic multicentric Castleman disease (iMCD) is a rare disease, and it is likely underdiagnosed because of the heterogeneity of clinical manifestations and laboratory findings. While the disease leads to significant morbidity and mortality, its causes are not yet fully elucidated. There have been significant advances in diagnosis and treatment of iMCD in the past decade, including the approval of the anti-IL-6 antibody siltuximab. In this review, we provide an update of the many new developments and publications surrounding iMCD.

Renal AA amyloidosis: presentation, diagnosis, and current therapeutic options: a review

Amyloid A amyloidosis is thought to be the second most common form of systemic amyloidosis behind amyloidosis secondary to monoclonal Ig. It is the result of deposition of insoluble fibrils in the extracellular space of tissues and organs derived from the precursor protein serum amyloid A, an acute phase reactant synthesized excessively in the setting of chronic inflammation. The kidney is the most frequent organ involved. Most patients present with proteinuria and kidney failure. The diagnosis is made through tissue biopsy with involvement of the glomeruli in most cases, but also often of the vessels and the tubulointerstitial compartment. The treatment usually targets the underlying etiology and consists increasingly of blocking the inflammatory cascade of cytokines with interleukin-1 inhibitors, interleukin-6 inhibitors, and tumor necrosis factor-α inhibitors to reduce serum amyloid A protein formation. This strategy has also shown efficacy in cases where an underlying etiology cannot be readily identified and has significantly improved the prognosis of this entity. In addition, there has been increased interest at developing effective therapies able to clear amyloid deposits from tissues, albeit with mitigated results so far.

Role of SARS-CoV-2-induced Cytokine Storm in Multi-Organ Failure: Molecular Pathways and Potential Therapeutic Options

Coronavirus disease 2019 (COVID-19) outbreak has become a global public health emergency and has led to devastating results. Mounting evidence proposes that the disease causes severe pulmonary involvement and influences different organs, leading to a critical situation named multi-organ failure. It is yet to be fully clarified how the disease becomes so deadly in some patients. However, it is proven that a condition called “cytokine storm” is involved in the deterioration of COVID-19. Although beneficial, sustained production of cytokines and overabundance of inflammatory mediators causing cytokine storm can lead to collateral vital organ damages. Furthermore, cytokine storm can cause post-COVID-19 syndrome (PCS), an important cause of morbidity after the acute phase of COVID-19. Herein, we aim to explain the possible pathophysiology mechanisms involved in COVID-19-related cytokine storm and its association with multi-organ failure and PCS. We also discuss the latest advances in finding the potential therapeutic targets to control cytokine storm wishing to answer unmet clinical demands for treatment of COVID-19.

Th17, Th22, and Myeloid-Derived Suppressor Cell Population Dynamics and Response to IL-6 in 4T1 Mammary Carcinoma

Immunotherapies relying on type 1 immunity have shown robust clinical responses in some cancers yet remain relatively ineffective in solid breast tumors. Polarization toward type 2 immunity and expansion of myeloid-derived suppressor cells (MDSC) confer resistance to therapy, though it remains unclear whether polarization toward type 3 immunity occurs or has a similar effect. Therefore, we investigated the involvement of type 3 T_h17 and T_h22 cells and their association with expanding MDSC populations in the 4T1 mouse mammary carcinoma model. T_h17 and T_h22 were detected in the earliest measurable mass at d 14 and remained present until the final sampling on d 28. In peripheral organs, T_h17 populations were significantly higher than the non-tumor bearing control and peaked early at d 7, before a palpable tumor had formed. Peripheral T_h22 proportions were also significantly increased, though at later times when tumors were established. To further address the mechanism underlying type 3 immune cell and MDSC recruitment, we used CRISPR-Cas9 to knock out 4T1 tumor production of interleukin-6 (4T1-IL-6-KO), which functions in myelopoiesis, MDSC recruitment, and T_h maturation. While 4T1-IL-6-KO tumor growth was similar to the control, the reduced IL-6 significantly expanded the total CD4⁺ T_h population and T_h17 in tumors, while T_h22 and MDSC were reduced in all tissues; this suggests that clinical IL-6 depletion combined with immunotherapy could improve outcomes. In sum, 4T1 mammary carcinomas secrete IL-6 and other factors, to polarize and reshape T_h populations and expand distinct T_h17 and T_h22 populations, which may facilitate tumor growth and confer immunotherapy resistance.

Immune-related adverse events of biological immunotherapies used in COVID-19

The use of biological immunotherapeutic drugs is one of the options currently being evaluated and employed to manage COVID-19, specifically monoclonal antibodies, which have shown benefit by regulating the excessive immune response seen in patients with severe infection, known as a cytokine storm. Tocilizumab has received particular importance for this clinical application, as has sarilumab. Both drugs share a substantial similarity in terms of pharmacodynamics, being inhibitors of the interleukin six receptor (IL-6Rα). Furthermore, sotrovimab, a neutralizing anti-SARS CoV-2 antibody, has gained the attention of the scientific community since it has recently been authorized under certain circumstances, positioning itself as a new therapeutic alternative in development. However, despite their clinical benefit, biological immunotherapies have the potential to generate life-threatening immune-related adverse events. Therefore it is essential to review their incidence, mechanism, and risk factors. This review aims to provide a comprehensive understanding of the safety of the biological immunotherapeutic drugs currently recommended for the treatment of COVID-19, provide a review of the known immune-mediated adverse events and explore the potential immune-related mechanisms of other adverse reactions.

Siltuximab is associated with improved progression-free survival in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare, heterogeneous disorder involving multicentric lymphadenopathy, systemic inflammation, and cytokine-driven organ dysfunction. Despite the approval of siltuximab-a monoclonal antibody against interleukin-6-for the treatment of iMCD, it is not known how long patients should receive siltuximab before determining whether the treatment is beneficial and should be continued. We performed post hoc analyses of the phase 2 randomized, double-blind, placebo-controlled trial of siltuximab for the treatment of patients with iMCD (NCT01024036) to determine the sequence of normalization of laboratory, clinical, and lymph node responses in patients who responded to siltuximab. Seventy-nine patients were enrolled in the trial (n=53 siltuximab; n=26 placebo plus best supportive care). Progression-free survival (PFS) was significantly improved in siltuximab-treated patients compared with placebo (P=0.0001). The median PFS was 14.5 months (95% CI, 13.6-upper bound not reached) for patients on placebo, but not reached for patients on siltuximab. In siltuximab-treated patients who achieved a durable tumor (radiologic) and symptomatic response (18/53 [34%]), the median time to normalization of abnormal laboratory tests and clinical endpoints occurred in the following sequence: thrombocytosis, symptomatic response, elevated C-reactive protein, hypoalbuminemia, anemia, lymph node response, hyperfibrinogenemia, and elevated immunoglobulin G. Siltuximab treatment prolongs PFS, rapidly improves symptomatology, and provides meaningful clinical benefit despite some laboratory tests and enlarged lymph nodes taking months to normalize in treatment responders. These data support the continued front-line use of siltuximab for iMCD, as recommended by international guidelines.

Castleman disease

Castleman disease (CD), a heterogeneous group of disorders that share morphological features, is divided into unicentric CD and multicentric CD (MCD) according to the clinical presentation and disease course. Unicentric CD involves a solitary enlarged lymph node and mild symptoms and excision surgery is often curative. MCD includes a form associated with Kaposi sarcoma herpesvirus (KSHV) (also known as human herpesvirus 8) and a KSHV-negative idiopathic form (iMCD). iMCD can present in association with severe syndromes such as TAFRO (thrombocytopenia, ascites, fever, reticulin fibrosis and organomegaly) or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes). KSHV-MCD often occurs in the setting of HIV infection or another cause of immune deficiency. The interplay between KSHV and HIV elevates the risk for the development of KSHV-induced disorders, including KSHV-MCD, KSHV-lymphoproliferation, KSHV inflammatory cytokine syndrome, primary effusion lymphoma and Kaposi sarcoma. A CD diagnosis requires a multidimensional approach, including clinical presentation and imaging, pathological features, and molecular virology. B cell-directed monoclonal antibody therapy is the standard of care in KSHV-MCD, and anti-IL-6 therapy is the recommended first-line therapy and only treatment of iMCD approved by the US FDA and EMA.

Autoinflammatory Diseases and Cytokine Storms-Imbalances of Innate and Adaptative Immunity

Innate and adaptive immune responses have a well-known link and represent the distinctive origins of several diseases, many of which may be the consequence of the loss of balance between these two responses. Indeed, autoinflammation and autoimmunity represent the two extremes of a continuous spectrum of pathologic conditions with numerous overlaps in different pathologies. A common characteristic of these dysregulations is represented by hyperinflammation, which is an exaggerated response of the immune system, especially involving white blood cells, macrophages, and inflammasome activation with the hyperproduction of cytokines in response to various triggering stimuli. Moreover, hyperinflammation is of great interest, as it is one of the main manifestations of COVID-19 infection, and the cytokine storm and its most important components are the targets of the pharmacological treatments used to combat COVID-19 damage. In this context, the purpose of our review is to provide a focus on the pathogenesis of autoinflammation and, in particular, of hyperinflammation in order to generate insights for the identification of new therapeutic targets and strategies.

Unravelling the broader complexity of IL-6 involvement in health and disease

The classification of interleukin-6 (IL-6) as a pro-inflammatory cytokine undervalues the biological impact of this cytokine in health and disease. With broad activities affecting the immune system, tissue homeostasis and metabolic processes, IL-6 displays complex biology. The significance of these involvements has become increasingly important in clinical settings where IL-6 is identified as a prominent target for therapy. Here, clinical experience with IL-6 antagonists emphasises the need to understand the context-dependent properties of IL-6 within an inflammatory environment and the anticipated or unexpected consequences of IL-6 blockade. In this review, we will describe the immunobiology of IL-6 and explore the gamut of IL-6 bioactivity affecting the clinical response to biological drugs targeting this cytokine pathway.

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.

Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997

Idiopathic multicentric Castleman disease with Sjögren's syndrome and secondary membranous nephropathy: a case report and review of the literature

Background

Idiopathic multicentric Castleman disease (iMCD) is an uncommon lymphoproliferative disorder and lacks treatment consensus. Herein, we report a case of iMCD complicated with Sjögren’s syndrome (SS) and secondary membranous nephropathy (SMN).

Case presentation

A 45-year-old female with dry mouth for 3 months and anasarca and proteinuria for 2 months was admitted. She also experienced chest tightness, wheezing, fever, weight loss, moderate proteinuria and hypoalbuminemia. A computed tomography (CT) scan revealed a tissue mass in the thymus area and enlarged multiple lymph nodes. Her symptoms did not improve after resection of the thymus mass. The pathological findings were “reactive hyperplasia of the mediastinal lymph nodes and thymic hyperplasia”. Lymph node biopsy findings confirmed iMCD with human herpes virus-8 (HHV-8) negativity. Based on anti-nuclear antibody (ANA) 1:320, anti-SSA and anti-SSB antibody positivity, salivary flow less than 0.1 ml/min and lip biopsy with focal lymphocytic sialadenitis, SS was diagnosed. Kidney biopsy showed secondary membranous nephropathy with endocapillary cell proliferation and infiltration of plasma cells and lymphocytes in the tubulointerstitium. Serum interleukin-6 (IL-6) levels were significantly increased, and therapy with tocilizumab (anti-IL-6 receptor antibody) worked well. The combination of cyclophosphamide (CyS) with methylprednisolone (MP) maintained satisfactory remission.

Conclusions

Our case of iMCD with SS and SMN is rare. There is a need for increased awareness of the disease to avoid unnecessary procedures and misdiagnoses. IL-6 was extremely high, and there was a rapid response to anti-IL-6 receptor agents. The combination of CyS with MP maintained complete remission.

[Monoclonal antibodies for anti-infective therapy]

Sera of animal origin and hyperimmunoglobulins have dominated serum therapy for a century. Although numerous monoclonal antibodies (MABs) have been developed since the end of the 1980s, particularly for the treatment of immunological and oncological diseases, it will take 20 years before the first anti-infective MAB is approved in the European Union. Interestingly, to combat the COVID-19 pandemic, numerous MABs, which are approved in particular for immunological indications, are currently being used to treat the consequences of SARS-CoV‑2 infection, such as pneumonia or hyperimmune reactions.The approved monoclonal antibodies for the treatment of infectious diseases are presented here. In addition, an overview of the current developments, in particular in the treatment of SARS-CoV‑2 infection, is provided.

Targeting Janus Kinases and Signal Transducer and Activator of Transcription 3 to Treat Inflammation, Fibrosis, and Cancer: Rationale, Progress, and Caution

Before it was molecularly cloned in 1994, acute-phase response factor or signal transducer and activator of transcription (STAT)3 was the focus of intense research into understanding the mammalian response to injury, particularly the acute-phase response. Although known to be essential for liver production of acute-phase reactant proteins, many of which augment innate immune responses, molecular cloning of acute-phase response factor or STAT3 and the research this enabled helped establish the central function of Janus kinase (JAK) family members in cytokine signaling and identified a multitude of cytokines and peptide hormones, beyond interleukin-6 and its family members, that activate JAKs and STAT3, as well as numerous new programs that their activation drives. Many, like the acute-phase response, are adaptive, whereas several are maladaptive and lead to chronic inflammation and adverse consequences, such as cachexia, fibrosis, organ dysfunction, and cancer. Molecular cloning of STAT3 also enabled the identification of other noncanonical roles for STAT3 in normal physiology, including its contribution to the function of the electron transport chain and oxidative phosphorylation, its basal and stress-related adaptive functions in mitochondria, its function as a scaffold in inflammation-enhanced platelet activation, and its contributions to endothelial permeability and calcium efflux from endoplasmic reticulum. In this review, we will summarize the molecular and cellular biology of JAK/STAT3 signaling and its functions under basal and stress conditions, which are adaptive, and then review maladaptive JAK/STAT3 signaling in animals and humans that lead to disease, as well as recent attempts to modulate them to treat these diseases. In addition, we will discuss how consideration of the noncanonical and stress-related functions of STAT3 cannot be ignored in efforts to target the canonical functions of STAT3, if the goal is to develop drugs that are not only effective but safe. SIGNIFICANCE STATEMENT: Key biological functions of Janus kinase (JAK)/signal transducer and activator of transcription (STAT)3 signaling can be delineated into two broad categories: those essential for normal cell and organ development and those activated in response to stress that are adaptive. Persistent or dysregulated JAK/STAT3 signaling, however, is maladaptive and contributes to many diseases, including diseases characterized by chronic inflammation and fibrosis, and cancer. A comprehensive understanding of JAK/STAT3 signaling in normal development, and in adaptive and maladaptive responses to stress, is essential for the continued development of safe and effective therapies that target this signaling pathway.

Role of IL-6 signalling in Polycystic Ovarian Syndrome associated inflammation

Polycystic ovarian syndrome is a major factor contributing to the increasing incidence of infertility around the world. The metabolic effects of prolonged exposure to PCOS have been well determined from previous studies and seem to be detrimental in the long run. Studies have shown a multitude of conditions like insulin resistance, obesity and cardiovascular disorders to be associated with PCOS. This makes PCOS a syndrome requiring utmost attention in terms of women's health and reproduction. Interleukin-6 is one of the many cytokines released by adipocytes from fat deposits in the body. This review focuses on the Interleukin 6 signaling pathway and the data available on inflammatory modulators due to its significance PCOS mediated inflammation. There is noteworthy evidence of elevated IL-6 concentration in PCOS subjects that has been discussed in detail. The regulation of IL-6 levels in the body is in turn, maintained by a close relation with other cytokines, especially by a key regulator, NF-κB. Being involved in a multitude of other pathological conditions like rheumatoid arthritis, cardiovascular disorders, asthma, colon cancer and many more, the role of IL-6 is also investigated in PCOS in search of a probable reason for underlying inflammatory condition. On summarizing the IL-6 signaling pathway and therapeutic exploitation of the same, we see that IL-6 targeted drugs may be an efficient way of treating PCOS associated inflammation.

Long-term safety of siltuximab in patients with idiopathic multicentric Castleman disease: a prespecified, open-label, extension analysis of two trials

BACKGROUND

Siltuximab is recommended by international consensus as a first-line treatment for idiopathic multicentric Castleman disease on the basis of durable efficacy and safety data. This study was done to assess the long-term safety and activity of siltuximab over up to 6 years of treatment.

METHODS

This study is a prespecified open-label extension analysis of a phase 1 trial (NCT00412321) and a phase 2 trial (NCT01024036), done at 26 hospitals worldwide. Patients in both studies were at least 18 years old with histologically confirmed, symptomatic Castleman disease. This extension study enrolled 60 patients who completed the previous trials without disease progression on siltuximab. Patients received siltuximab infusions of 11 mg/kg every 3 weeks (which could be extended to 6 weeks) for up to 6 years. Descriptive statistics were used to summarise the data. No formal hypothesis testing was performed. The primary endpoint was the safety of siltuximab, assessed at each dosing cycle. The study was registered with ClinicalTrials.gov, number NCT01400503 and with EudraCT, number 2010-022837-27.

FINDINGS

Patient enrolment into the phase 1 trial was from June 20, 2005, to Sept 15, 2009, and enrolment into the phase 2 trial was from Feb 9, 2010, to Feb 3, 2012. Patients were enrolled in this long-term extension from April 1, 2011, to Jan 15, 2014. Median follow-up was 6 years (IQR 5·11-7·76). Median treatment duration, from the beginning of the previous trials to the end of the present study, was 5·5 years (IQR 4·26-7·14). Siltuximab was well tolerated; however, adverse events of grade 3 or worse were reported in 36 (60%) of 60 patients with the most common being hypertension (eight [13%]), fatigue (five [8%]), nausea (four [7%]), neutropenia (four [7%]), and vomiting (three [5%]). 25 (42%) patients reported at least one serious adverse event, which most commonly was an infection (eight [13%]). Only two serious adverse events, polycythaemia and urinary retention, were considered related to siltuximab treatment. 18 patients discontinued before study completion, either to receive siltuximab locally (eight) or because of progressive disease (two), adverse events (two), or other reasons (six). No deaths were reported.

INTERPRETATION

These results show that siltuximab is well tolerated long term and provides important evidence for the feasibility of the life-long use required by patients with idiopathic multicentric Castleman disease.

FUNDING

Janssen R&D and EUSA Pharma.

Multicentric Castleman disease with TAFRO syndrome and Sjögren's

We describe a patient with Castleman's disease with TAFRO syndrome and concurrent Sjögren's syndrome and investigate whether the autoimmune process may have accelerated the onset of her Castleman's disease. Patient was treated with R-CVP therapy with remission of symptoms although there is no current standard treatment.

Treatment of multicentric Castleman disease through combination of tocilizumab, lenalidomide and glucocorticoids: Case report

RATIONALE

Castleman's disease (CD) is a rare lymphoproliferative disease. Compared to unicentric CD, multicentric Castleman disease (MCD) displays poorer prognosis and great variance to different therapies. Though chemotherapy, immunization therapy, and glucocorticoids have been used in the treatment of MCD, its optimal treatment is still controversial.

PATIENT CONCERNS

A 47-year-old woman was admitted due to poor appetite, general fatigue, puffiness of face, systemic rash, and abdominal distension. On physical examination, the patient displayed as general lymphadenopathy, splenomegaly, hepatomegaly, and shifting dullness.

DIAGNOSES

After biopsy of her swollen lymph node and laboratory tests, her initial diagnosis was hyaline vascular-CD.

INTERVENTIONS

She was treated with combination of tocilizumab, lenalidomide, and glucocorticoids.

OUTCOMES

This patient achieved complete remission (CR) with all her indexes returned to be normal. Her blood routines and biochemical examinations were still normal during the following period.

LESSONS

We reported a case with multicentric Castleman's disease (MCD) which acquired quite good remission after combination treatment with tocilizumab, lenalidomide, and glucocorticoids. Our report provided powerful evidence for displaying the efficiency and safety of target therapy against unicentric Castleman disease.

Targeting IL-6 or IL-6 Receptor in Rheumatoid Arthritis: What's the Difference?

Interleukin-6 (IL-6) signaling is a critical target in inflammatory pathways. Today, tocilizumab (TCZ) and sarilumab (SAR), two IL-6 receptor-inhibiting monoclonal antibodies, are widely used in the treatment of rheumatoid arthritis (RA), with a favorable efficacy/safety profile. Successful introduction of such agents in the treatment of RA has encouraged the development of other agents targeting different points of the pathway. Sirukumab (SRK), a human anti-IL-6 monoclonal antibody, has been evaluated in clinical trials and showed largely similar clinical efficacy compared with TCZ and other IL-6 pathway-targeting agents. Furthermore, the drug safety profile seemed to reflect the profile of adverse effects and laboratory abnormalities seen in other inhibitors of the IL-6 pathway. However, increased death rates under SRK treatment compared with placebo raised safety concerns, which led to the decision by the FDA to decline the approval of SRK in August 2017. However, during the 18-week true placebo-controlled period, mortality rates were identical in the placebo- and SRK-treated patients. Comparisons after week 18 may be confounded by some factors, and also the 'crossover' design resulted in various treatment groups with varying drug exposure periods. The limited placebo exposure relative to SRK exposure makes interpretation of mortality rates difficult. We do not know whether the imbalance in mortality rates seen for SRK is a true safety signal or a result of bias due to the study design. Therefore, further long-term clinical data as well as basic research is needed to allow deeper insight into IL-6 signaling.

CTL019 (tisagenlecleucel): CAR-T therapy for relapsed and refractory B-cell acute lymphoblastic leukemia

Over the past decades, survival of patients with acute lymphoblastic leukemia (ALL) has dramatically improved, but the subgroup of patients with relapsed/refractory ALL still continues to have dismal prognosis. As an emerging therapeutic approach, chimeric antigen receptor-modified T-cells (CAR-T) represent one of the few practice-changing therapies for this subgroup of patients. Originally conceived and built in Philadelphia (University of Pennsylvania), CTL019 or tisagenlecleucel, the first CAR-T approved by the US Food and Drug Administration, showed impressive results in refractory/relapsed ALL since the publication on two pediatric patients in 2013. It is in this context that we provide a review of this product in terms of manufacturing, pharmacology, toxicity, and efficacy studies. Evaluation and management of toxicities, particularly cytokine release syndrome and neurotoxicity, is recognized as an essential part of the patient treatment with broader use of IL-6 receptor inhibitor. An under-assessed aspect, the quality of life of patients entering CAR-T cells treatment, will also be reviewed. By their unique nature, CAR-T cells such as tisagenlecleucel operate in a different way than typical drugs, but also provide unique hope for B-cell malignancies.