Bortezomib-associated rash: a new recognizable and avoidable side-effect

Bortezomib-Induced Reticular Eruption in Patient with Multiple Myeloma

Bortezomib is the first proteasome inhibitor to treat a variety of malignancies and is currently part of the standard of care regimen for the initial treatment of patients with newly diagnosed multiple myeloma. While bortezomib is generally well tolerated, it has been associated with various side effects, which have limited its use in some patients. Here, we describe a unique case with histological confirmation of a reticular eruption that appeared at the site of a subcutaneous administration of bortezomib in a 62-year-old male who was newly diagnosed with IgG kappa multiple myeloma. A skin biopsy was performed, which revealed superficial perivascular dermatitis predominantly composed of lymphocytes with rare eosinophils. The patient was successfully treated with betamethasone dipropionate 0.05% cream. When consulted, dermatologists should advise the oncology team of multiple myeloma patients treated with bortezomib to maintain a high threshold before discontinuing the drug when a patient experiences an atypical, reticular rash following subcutaneous administration. Additionally, potent topical corticosteroids, such as betamethasone dipropionate 0.05% cream, should be considered in managing the cutaneous reticular eruptions related to bortezomib administration, in order to maintain an optimal treatment regimen for patients with multiple myeloma.

Design, synthesis and biological evaluation of triaryl compounds as novel 20S proteasome inhibitors

Thirty novel triaryl compounds were designed and synthesized based on the known proteasome inhibitor PI-1840. Most of them showed significant inhibition against the β5c subunit of human 20S proteasome, and five of them exhibited IC₅₀ values at the sub-micromolar level, which were comparable to or even more potent than PI-1840. The most active two (1c and 1d) showed IC₅₀ values of 0.12 and 0.18 μM against the β5c subunit, respectively, while they displayed no obvious inhibition against the β2c, β1c and β5i subunits. Molecular docking provided informative clues for the subunit selectivity. The potent and subunit selective proteasome inhibitors identified herein represent new chemical templates for further molecular optimization.

Bortezomib-induced acute interstitial nephritis

Acute interstitial nephritis (AIN) is one of the important causes of acute kidney injury (AKI) resulting from inflammatory tubulointerstitial injury induced by medications, infections and systemic diseases. Bortezomib has been increasingly used especially in renal related indications such as multiple myeloma and monoclonal gammopathy of renal significance. Severe allergic reactions from bortezomib treatment including AIN have not been described in the literature. We report a 47-year-old white man who developed biopsy-proven allergic AIN after treatment with bortezomib for his C3 glomerulonephritis. The patient's kidney function improved after treatment with glucocorticoid therapy and discontinuation of bortezomib, but worsened with recurrent AKI episode after re-initiation of bortezomib. His renal function improved after glucocorticoid therapy and discontinuation of bortezomib. To our knowledge, this is the first report of a biopsy-proven AIN from bortezomib.