A Novel Desensitization Protocol for Infliximab Hypersensitivity in a 13-Year Old Patient with Pustular Psoriasis

Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative

BACKGROUND

Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR.

METHODS

We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated.

RESULTS

From 2005 to 2020, 27 patients (Crohn's Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX.

CONCLUSION

IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics.What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation.What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity.How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

Novel approach to idursulfase and laronidase desensitization in type 2 and type 1 S mucopolysaccharidosis (MPS)

BACKGROUND

Idursulfase and laronidase are drugs used to treat Hunter syndrome (mucopolysaccharidosis type 2) and Scheie syndrome (mucopolysaccharidosis type 1 S), respectively. These are rare lysosomal storage disorders, leading to accumulation of glycosaminoglycans within lysosomes. Failure of early recognition of the disease and/or delay in starting the appropriate treatment result in severe clinical impairment and death. For almost 20 years, enzyme replacement therapy with recombinant proteins has represented the first line therapeutic option. However, administration of idursulfase and laronidase is associated with infusion-related hypersensitivity reactions, in approx. 20% of patients. In these patients, rapid desensitization by intravenous administration protocols has been used in order to avoid treatment discontinuation. This approach proved effective and safe. However, long-term tolerance could not be achieved. Thus, we decided to combine rapid desensitization with allergen immunotherapy-like desensitization.

RESULTS

Two patients with Hunter syndrome and one patient with Scheie syndrome developed severe allergy to idursulfase and laronidase, respectively, preventing them from continuing the otherwise indispensable therapy. In all three patients, the possible IgE-mediated nature of the reactions suffered was suggested by positive skin tests with the two enzymes, respectively. By devising 12-step, 3-dilution rapid desensitization protocols, we resumed the enzyme replacement therapy. However, the prolonged time required for administration (a not negligible pitfall, since therapy should be given weekly for life) and the persistent occurrence of reactions (mild but still requiring anti-allergic medication at full dosage) led us to combine rapid desensitization with a compact 11-step, 24-day allergen immunotherapy-like desensitization protocol. Thus, idursulfase and laronidase were injected subcutaneously, with a 500-fold increase from step 1 to step 11 for idursulfase and a 222-fold increase for laronidase. This strategy led to restoration of long-term tolerance, allowing weekly intravenous therapy administration under standard conditions, according to the manufacturer instructions, in the absence of side effects and with only precautionary low-dose premedication.

CONCLUSION

Rapid desensitization is a suitable and safe option in the case of idursulfase and laronidase allergy. Combination with subcutaneous allergen immunotherapy-like desensitization afforded restoration of enzyme replacement therapy given by the normal administration schedule, by inducing sustained tolerance.

Pharmacological Management of Pediatric Pustular Psoriasis

Therapeutic management of pustular psoriasis remains a challenge despite the rapid advance in psoriasis research and the development of drugs, especially biologics. Treatment guidelines have been established for pustular psoriasis, but no controlled studies are present for juvenile pustular psoriasis (JPP). Search of the literature reveals that current evidence of JPP treatment is limited to case reports and case series. Among the conventional drugs for JPP, oral retinoid is the most commonly used, yet concerns for growth disturbance exist. Cyclosporine and methotrexate have also been administered as first-line treatment. Etanercept is the first biological agent approved for juvenile plaque psoriasis, followed by adalimumab. However, infliximab is usually recommended for JPP because of the rapidity of onset, despite not being approved for use in pediatric psoriasis patients. More recently, secukinumab, ixekizumab, brodalumab, guselkumab, and risankizumab have been approved for adult pustular psoriasis in selected countries. Controlled studies are needed to prove the efficacy and long-term safety of the therapeutic treatments currently used for JPP.

Desensitization to biological agents used in rheumatology

Biological agents such as monoclonal antibodies and fusion proteins are widely used for the treatment of patients with various rheumatic disorders, influencing the quality of life, disability and even mortality in patients. However, biological agents can evoke adverse reactions of different grades of severity. Although drug avoidance remains a gold standard in the care of patients hypersensitive to medication, in certain clinical situations the culprit drug is the drug of choice and cannot be replaced by another equally effective compound. In such cases, desensitization can allow the patient to be treated within current guidelines and with the most effective treatment. The authors searched Medline and Scopus databases for English-language sources using the following key words: hypersensitivity, desensitization, biologicals, adalimumab, etanercept, adalimumab, certolizumab, golimumab, rituximab, infliximab, ixekizumab, tocilizumab, anakinra and canakinumab. The aim of our review is to present the current knowledge about desensitization to biological agents and some guidelines according to patient inclusion, contraindications, procedures, and safety requirements. Drug desensitization is a new issue in rheumatology, and the solution to the problem of allergic reactions to biological drugs, which gives patients with rheumatic diseases the opportunity to extend and prolong their therapy. The present article is one of the first widely discussing this topic in the biological treatment of rheumatic diseases.