Nivolumab, an immune checkpoint modulator, acts by binding to the programmed cell death 1 (PD-1) receptor on T cells, which blocks the inhibition of T cells. Nivolumab ultimately leads to stimulation of the T-cell response1 and overcomes evasive adaptations of certain cancers. Cutaneous adverse events (AEs) have been reported in approximately 20% to 40% of patients treated with the anti–PD-1 class of drugs, including nivolumab.2-4 The most common cutaneous AEs include pruritus; vitiligo; and various forms of rash, such as lichenoid dermatitis, psoriasiform eruptions, and bullous pemphigoid.1-3,5-7 We report a patient with non–small cell lung cancer being treated with nivolumab who developed a bullous lichenoid eruption consistent with the diagnosis of lichen planus pemphigoides (LPP).
An 87-year-old woman presented with a pruritic rash on the trunk and extremities of 3 weeks’ duration. Her medical history included stage IV non–small cell lung cancer, congestive heart failure, coronary artery disease, chronic kidney disease, and hypertension. Her long-term medications were ipratropium-albuterol, alendronate, amlodipine, aspirin, carvedilol, colesevelam, probiotic granules, and bumetanide. She was previously treated with carboplatin and docetaxel, which were discontinued secondary to fatigue, diarrhea, poor appetite, loss of taste, and a nonspecific rash. Six months later (approximately 3 months prior to the onset of cutaneous symptoms), she was started on nivolumab monotherapy every 14 days for a total of 9 infusions.
At the current presentation, physical examination revealed erythematous crusted erosions on the trunk and extremities and 1 flaccid bulla on the back. A punch biopsy revealed lichenoid dermatitis. The patient returned 2 weeks later with worsening of cutaneous manifestations, including more blisters and erosions. Figure 1 shows the clinical appearance of the eruption on the patient’s leg. At this time, additional biopsies revealed a subepidermal bullous lichenoid eruption with eosinophils (Figure 2). Direct immunofluorescence (DIF) was negative; however, indirect immunofluorescence (IIF) revealed weak linear staining for IgG antibodies along the basement membrane zone on monkey esophagus substrate. Examination of salt-split skin was noncontributory. The patient improved with a 2-week oral prednisone taper (starting at 40 mg daily). The dose was decreased incrementally over the course of 2 weeks from 40 mg to 20 mg to 0 mg. Because of the presumed grade 3 (severe) cutaneous drug eruption linked to nivolumab and further discussion with the medical oncology team, the patient decided to cease therapy. Since cessation of therapy, she has been seen twice for follow-up. At 2-month follow-up, she presented with drastic improvement of the eruption, and at 1 year she has continued to forego any further treatment for the stable and nonprogressing malignancy.
The interaction between the PD-1 receptor and its ligands, programmed death ligand 1 (PD-L1) and programmed death ligand 2, is an immune checkpoint.8,9 Under normal physiologic conditions, this checkpoint serves to prevent autoimmunity.10 When the PD-1 receptor is left unbound, T cells are more inclined to mount an immune response. If the receptor is ligand bound, the response of T cells is suppressed via mechanisms such as anergy or apoptosis.8 Tumor cells are known to produce PD-L1 as an adaptive resistance mechanism to evade immunity.8 Nivolumab is a human monoclonal antibody that targets the PD-1 receptor, thereby preventing the interaction with its ligand and allowing for unsuppressed activity of T cells.10 This therapy ultimately blocks the tumor’s local immune suppression mechanisms, which allows T cells to recognize cancer antigens.10