Biosimilars in dermatology: identifying myths and knowledge gaps

Biosimilars are beginning to gain regulatory approval in the United States. Biosimilars are structurally near identical to the innovator and must demonstrate identical pharmacokinetics via the same binding affinity and biological function on assays. However, biologics are so complex that even the innovator company cannot produce exact duplicates; there is batch-to-batch variation. The International Psoriasis Council has outlined a biosimilarity index, which aims to standardize preclinical definitions of biosimilarity. Such an index, paired with post-approval monitoring, could provide a transparent, quantitative definition of biosimilarity. Such an index could increase trust in biosimilar medicines and the preclinical assessment process without increasing costs. As preclinical analyses are critical to biosimilar approval, manufacturers should devote proportionate resources to completing them. Dermatologists, who might reflexively look for indication-specific clinical data, might also shift their focus to preclinical variables. Finally, it should be noted that biosimilars provide more evidence of similarity than we have for different batches of the innovator product. Thus, any clinical testing standards, or lack thereof, for different batches of innovator products should also apply to biosimilars.

Non-Medical Switching in Dermatology: Cost-Conscious Policy or an Affront to Patient Safety?

Non-medical switching is when a patient's therapy is switched for reasons unrelated to health outcomes. Dermatologists are regularly affected by non-medical switching, as many of their complex patients are on expensive medications, which become first-line targets for cost-containment. This commentary examines the literature on non-medical switching and explores the push and pull factors used to drive medication regimen changes. The system-level cost savings of this practice are substantial and could be used to fund treatment for more vulnerable patients. While there is no substantiated evidence of worse outcomes post-switching, patients may suffer negative psychosocial consequences. Negative patient expectations, which are in part fueled by prescriber suspicion of non-medical switching, seem to contribute to this effect. While non-medical switching is not ideal for all patients, it has the potential to reduce cost while maintaining patient outcomes. The decision to switch should be made only after careful evaluation of the individual patient and their physical and psychological reserve.

Hereditary Tumor Syndromes with Skin Involvement

Cutaneous findings that appear in childhood may be the first sign of a hereditary tumor syndrome. Early detection of genodermatoses allows the patient and at-risk family members to be screened for associated malignancies. This article provides a brief description of the pathogenesis and clinical manifestations of various inherited disorders with skin involvement, along with treatment updates. Advances in molecular-based therapy have spurred development of novel treatment methods for various genodermatoses such as xeroderma pigmentosum (XP) and Gorlin-Goltz syndrome. Further studies are needed to better assess the efficacy of many of these new treatment options.

Adverse cutaneous effects of neratinib

Neratinib is a tyrosine kinase inhibitor that was FDA-approved for extended adjuvant treatment in adults with human epidermal growth factor receptors-2 (HER-2) positive breast cancer in 2017. Due to the novelty of the drug, there are no current reports in the literature of adverse cutaneous effects associated with neratinib therapy. We present a case of a woman on neratinib for HER-2 positive infiltrating ductal carcinoma of the right breast who presented to the dermatology clinic with changes to the fingernails, acne, and a rash on the face. Physical examination revealed erythema, induration, and some serum crust along the lateral nail folds of the right fourth and left third digits as well as monomorphic acneiform papules and pustules on the face. The timeline of the patient's paronychia and acneiform rash were consistent with a diagnosis of neratinib-associated skin changes. The patient was prescribed doxycycline to control the acneiform eruption. For the nails, she used mupirocin ointment as well as Listerine soaks. She experienced great improvement on this regimen at her 3-month follow-up visit. This case highlights similar cutaneous side effects to epidermal growth factor receptor (EGFR) inhibitors with a newer agent, neratinib, that have not been documented in the literature.