Pyoderma gangrenosum adverse event with Rituximab use: A postmarketing pharmacovigilance analysis

Pyoderma Gangrenosum: Treatment Options

Pyoderma gangrenosum is a rare neutrophilic dermatosis that leads to exceedingly painful ulcerations of the skin. Although the exact pathogenesis is not yet fully understood, various auto-inflammatory phenomena with increased neutrophil granulocyte activity have been demonstrated. Despite the limited understanding of the pathogenesis, it is no longer a diagnosis of exclusion, as it can now be made on the basis of validated scoring systems. However, therapy remains a major multidisciplinary challenge. Various immunosuppressive and immunomodulatory therapies are available for the treatment of affected patients. In addition, concomitant topical pharmacologic therapy, wound management and pain control should always be addressed. Corticosteroids and/or cyclosporine remain the systemic therapeutics of choice for most patients. However, in recent years, there has been an increasing number of studies on the positive effects of biologic therapies such as inhibitors of tumour necrosis factor-α; interleukin-1, interleukin-17, interleukin-23 or complement factor C5a. Biologics have now become the drug of choice in certain scenarios, particularly in patients with underlying inflammatory comorbidities, and are increasingly used at an early stage in the disease rather than in therapy refractory patients.

It's not always an infection: Pyoderma gangrenosum of the urogenital tract in two patients with multiple sclerosis treated with rituximab

B-cell depleting therapies such as rituximab and ocrelizumab are widely used for the treatment of Multiple Sclerosis but have increased risks of adverse reactions compared to earlier MS therapies. One rarely reported reaction is pyoderma gangrenosum (PG), an inflammatory, ulcerative, skin disease of unclear etiology. Here we describe a male and female patient, each with Relapsing-Remitting Multiple Sclerosis, and both of whom developed PG while on rituximab. Both PG diagnoses were supported by persistent fever, biopsy reports of sterile neutrophilia, and leukocytosis in the absence of an identifiable infectious agent. The diagnoses were further confirmed by dramatic clinical improvement following initiation of high dose steroids and intravenous immunoglobulins, and discontinuation of rituximab.

Rituximab and Pyoderma Gangrenosum: An Investigation of Disproportionality Using a Systems Biology-Informed Approach in the FAERS Database

BACKGROUND

Studies have found an increased risk of pyoderma gangrenosum associated with rituximab. The structural properties and pharmacological action of rituximab may affect the risk of pyoderma gangrenosum. Additionally, pyoderma gangrenosum is associated with autoimmune disorders for which rituximab is indicated.

OBJECTIVE

We aimed to determine whether rituximab is disproportionally associated with pyoderma gangrenosum using a systems biology-informed approach.

METHODS

Adverse event reports were extracted from the US Food and Drug Administration Adverse Event Reporting System (FAERS, 2013-20). The Bayesian Confidence Propagation Neural Network Information Component was used to test for disproportionality. Comparators used to determine potential causal pathways included all other medicines, all medicines with a similar structure (monoclonal antibodies), all medicines with the same pharmacological target (CD20 antagonists) and all medicines used for the same indication(s) as rituximab.

RESULTS

Thirty-two pyoderma gangrenosum cases were identified, 62.5% were female, with a median age of 48 years. There was an increased association of pyoderma gangrenosum with rituximab compared with all other medicines (exponentiated Information Component 6.75, 95% confidence interval (CI) 4.66-9.23). No association was observed when the comparator was either monoclonal antibodies or CD20 antagonists. Conditions for which an association of pyoderma gangrenosum with rituximab was observed were multiple sclerosis (6.68, 95% CI 1.63-15.15), rheumatoid arthritis (2.67, 95% CI 1.14-4.80) and non-Hodgkin's lymphoma (2.94, 95% CI 1.80-3.73).

CONCLUSIONS

Pyoderma gangrenosum was reported more frequently with rituximab compared with all other medicines. The varying results when restricting medicines for the same condition suggest the potential for confounding by indication. Post-market surveillance of biologic medicines in  FAERS should consider a multi-faceted approach, particularly when the outcome of interest is associated with the underlying immune condition being treated by the medicine of interest.

Real world adverse events of interspinous spacers using Manufacturer and User Facility Device Experience data

Background

Lumbar spinal stenosis is a condition of progressive neurogenic claudication that can be managed with lumbar decompression surgery or less invasive interspinous process devices after failed conservative therapy. Popular interspinous process spacers include X-Stop, Vertiflex and Coflex, with X-Stop being taken off market due to its adverse events profile.

Methods

A disproportionality analysis was conducted to determine whether a statistically significant signal exists in the three interspinous spacers and the reported adverse events using the Manufacturer and User Facility Device Experience (MAUDE) database maintained by the US Food and Drug Administration.

Results

Statistically significant signals were found with each of the three interspinous spacer devices (Coflex, Vertiflex, and X-Stop) and each of the following adverse events: fracture, migration, and pain/worsening symptoms.

Conclusions

Further studies such as randomized controlled trials are needed to validate the findings.