Neutrophilic dermatosis of the dorsal hands (NDDH) is a variant of Sweet syndrome that presents with erythematous bullae, papules/plaques, or pustules on the dorsal hands. It is most commonly associated with hematologic and solid organ malignancies, though cases of NDDH associated with inflammatory bowel disease, rheumatologic disorders, and medication exposure have also been described in the literature. Felty syndrome is a rare complication of long-standing rheumatoid arthritis characterized by neuropathy, splenomegaly, and neutropenia. Granulocyte colony stimulating factors (e.g., filgrastim) can be utilized to rescue the neutropenia observed in Felty syndrome, but this treatment may subsequently cause Sweet syndrome. Herein, we present a 64-year-old man with Felty syndrome and a complex medical history who presented with sudden onset, painful blisters located on the dorsal and palmar aspects of his bilateral hands. Given the patient\'s past medical history, a broad differential diagnosis, including disseminated fungal and viral infection was initially considered. A punch biopsy of the skin lesion disclosed neutrophilic dermatosis, which together with laboratory data satisfied the von den Driesch criteria for Sweet syndrome. As the lesions were localized exclusively on the patient\'s hands, the qualification of NDDH was also endorsed.

With the increased use of granulocyte colony-stimulating factor (G-CSF) preparations, there is concern about the increase in G-CSF-associated large-vessel vasculitis; however, there have been no previous reports of vasculitis caused by multiple types of G-CSF preparations. We experienced a case of drug-induced large-vessel vasculitis caused by two different G-CSF products, which was difficult to diagnose. When treating patients with a history of large-vessel vasculitis caused by pegfilgrastim, we need to pay attention to its recurrence when using other G-CSF preparations.

BACKGROUND: The intravenous form of fosfomycin, a bactericide antibiotic used to treat multiresistant bacterial infections is little prescribed. The most common reported adverse effects are hypokaliemia and hypernatremia. We describe a case of agranulocytosis, a rarely described side effect that may be fatal.
METHODS: A 45 year-old woman was admitted to the intensive care unit for post-surgical meningitis following meningioma resection. Meropenem and vancomycin were first introduced. A DRESS-syndrom with meropenem was suspected. Neutropenia was diagnosed three days after the introduction of parenteral fosfomycin and agranulocytosis four days later. Eosinophilia was also observed. A bone marrow aspiration was performed showing a disappearance of the neutrophil granulocyte line and a significant eosinophilia. Meropenem was discontinued. Fosfomycin was maintained and filgrastim was added. As filgrastim had no effect, the relationship with fosfomycin was suspected, so it was then withheld. An increase of the neutrophil count was observed. Because of the complexity of the case, the unfavorable course of the illness and the urgent need for revision surgery, a rechallenge with fosfomycin was done followed by a decrease of the neutrophil count.
CONCLUSIONS: This is the third paper reporting agranulocytosis induced by fosfomycin, and the first detailed description of a case. Based on chronological and semiological criteria and bibliographic data, the event was qualified as probable with the Naranjo adverse drug probability scale. Literature data is scarce. The summary of product characteristics mentions that only a few cases of transient neutropenia and agranulocytosis have been reported. An analysis of the FDA Adverse Event Reporting System Database highlighted a higher than expected frequency of agranulocytosis in patients treated with fosfomycin. Parenteral fosfomycin is often used in patients receiving other medications, so that it is rarely the only suspect. In our case, the results of the bone marrow aspiration, the sudden drop of the neutrophil count with concomitant eosinophilia and the absence of improvement despite the dose decrease, point towards an immuno-allergic mechanism. However, the overlap between the suspected DRESS induced by meropenem and the agranulocytosis do not allow to conclude with certainty on the causality. Awareness should be raised about this side effect.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease potentially induced by various causes. Very few reports have described HLH induced by granulocyte colony-stimulating factor (G-CSF) and those few previous reports have uniformly indicated that continuing G-CSF is unfeasible once HLH has been induced. A 52-year-old Japanese man who had been diagnosed with mantle cell lymphoma with systemic and central nervous system involvements received rituximab, hyper-fractionated cyclophosphamide, vincristine, Adriamycin and dexamethasone (R-HCVAD)/methotrexate and cytarabine. During the second cycle of R-HCVAD, the patient developed severe back pain, thrombocytopenia, elevated serum lactate dehydrogenase and ferritin levels, and hemophagocytosis in the bone marrow. Complete remission (CR) of mantle cell lymphoma was confirmed on whole-body computed tomography, brain magnetic resonance imaging, and bone marrow biopsy. The patient was diagnosed with HLH induced by filgrastim. HLH recovered with intravenous methylprednisolone at 1 g/day for 3 days, followed by oral prednisolone tapered off over 5 days. The patient continued chemotherapy with a change in the G-CSF formulation from filgrastim to lenograstim and prophylactic administration of corticosteroids. He safely completed scheduled chemotherapy without recurrence of HLH and successfully maintained CR of lymphoma. Although rare, G-CSF potentially induces HLH. Changing the G-CSF formulation and steroid prophylaxis may allow safe continuation of G-CSF.

Pegfilgrastim is administered as an adjunct to chemotherapy to reduce the incidence of febrile neutropenia and associated infectious complications. Lupin\'s Pegfilgrastim is a proposed biosimilar to the U.S.-referenced Neulasta®. Demonstration of biosimilarity requires extensive physicochemical and functional characterization of the biosimilar, and demonstration of analytical similarity to the reference product, in addition to clinical studies. This work is a case study for demonstrating the analytical similarity of Armlupeg (Lupin\'s Pegfilgrastim) to Neulasta® with respect to structural and physicochemical attributes using several robust, orthogonal, and state-of-the-art techniques including high-end liquid chromatography, mass spectrometry, and spectroscopy techniques; circular dichroism; differential scanning calorimetry; nuclear magnetic resonance; analytical ultracentrifugation; and micro-flow imaging. Functional similarity was demonstrated using an in vitro cell proliferation assay to measure relative potency and surface plasmon resonance to measure receptor binding kinetics. Furthermore, comparative forced-degradation studies were performed to study the degradation of the products under stress conditions. The product attributes were ranked based on a critical quality attributes risk score according to their potential clinical impact. Based on criticality, all analyses were statistically evaluated to conclude analytical similarity. Lupin\'s Pegfilgrastim was comparable to Neulasta® as demonstrated via structural, functional, and purity analyses. Lupin\'s Pegfilgrastim complied with the quality and statistical ranges established using Neulasta®. Both products follow the same degradation pathways under stress conditions as observed in the forced-degradation studies. No new impurity or degradation product was observed in Lupin\'s Pegfilgrastim. These data conclusively demonstrate the analytical similarity of Lupin\'s Pegfilgrastim and Neulasta®.

We herein report an 83-year-old woman with filgrastim-associated aortitis during chemotherapy for relapsed diffuse large B-cell lymphoma. She had been treated with filgrastim as a prophylaxis for neutropenia during the fourth cycle of chemotherapy from day 9 to 18. On day 21, she developed a fever. Contrast-enhanced computed tomography revealed aortitis of the descending aorta. The fever abated with non-steroidal anti-inflammatory drug treatment. A literature review identified a small number of aortitis cases all caused by prophylactic use of granulocyte colony-stimulating factors (G-CSFs), among which short-acting filgrastim was rarely encountered. The present and previous findings imply a possible relationship between aortitis and prophylactic G-CSF usage.

In this article, we used administrative claims data from the OptumLabs Data Warehouse and American Hospital Association Annual Survey data to examine associations between hospital characteristics and uptake of biosimilar granulocyte colony-stimulating factor treatments. We found that 340B-participating hospitals and non-rural referral center (RRC) hospitals that reported owning rural health clinics were less likely to administer the lower-cost biosimilars, whereas the opposite was true for hospitals that are RRCs. To our knowledge, our study offers a first look at an underappreciated source of disparities in access to lower-cost medications such as biosimilars. Results from our study reveal opportunities for targeted policies to encourage adoption of lower-cost treatments, particularly among hospitals that serve rural communities where patients often have fewer choices in care site.

A vast number of therapeutic proteins are approved and available on the market. However, there are very limited analytical approaches available for the rapid determination of primary and higher-order structures which can be utilized for counterfeit identification. In the present study, filgrastim biosimilar products from different manufacturers were considered for developing discriminative orthogonal analytical techniques to determine structural variations. The developed intact mass analytical method and peptide mapping through LC-HRMS were able to differentiate three biosimilars based on deconvoluted mass and possible structural modification, respectively. Another structural attribute employed was charge heterogeneity through isoelectric focusing, which provides a snapshot of the presence of charge variants/impurities and was able to differentiate various marketed formulations of filgrastim. These three techniques can certainly differentiate the products that contain counterfeit drugs due to their capability concerning selectivity. Additionally, a unique HDX technique on LC-HRMS was developed, which can determine the labile hydrogen exposed to deuterium exchange in a specified time. HDX aids in identifying the workup process or changes in the host cell in the counterfeit product by differentiating the protein based on its higher-order structure.

OBJECTIVE: This study aimed to show the trend of neutrophil counts and frequency of febrile neutropenia after changing pegfilgrastim from 3.6 mg to 1.8 mg.
METHODS: This case-series study was performed between April 2016 and December 2021 at Hyogo Prefectural Amagasaki General Medical Center. All patients who reduced their normal dose of 3.6 mg pegfilgrastim to 1.8 mg due to adverse events or markedly elevated neutrophil counts were included. Any type of chemotherapy was acceptable. Patients who dropped out within 1 month of receiving 1.8 mg pegfilgrastim were excluded. The primary outcome was the neutrophil counts after receiving 1.8 mg pegfilgrastim. The secondary outcome was febrile neutropenia, which was evaluated by the Common Terminology Criteria for Adverse Events v5.0.
RESULTS: The study included seven patients who used a regimen of dose-dense epirubicin and cyclophosphamide, trastuzumab, pertuzumab, and docetaxel, docetaxel, or docetaxel and cyclophosphamide. After using 1.8 mg pegfilgrastim, neutrophil counts changed from a mean of 18,944 [standard deviation (SD)=-7,768] to only 4,447 (SD=1,224). The patients experienced grades 1 to 3 adverse events during the use of 1.8 mg and 3.6 mg pegfilgrastim doses, including febrile neutropenia, and pain. Four patients (57%) complained of grade 1 or 2 fatigue and anorexia. After switching from 3.6 mg pegfilgrastim to 1.8 mg, three patients (42%) experienced adverse events.
CONCLUSIONS: In patients who experienced adverse events due to markedly elevated neutrophil counts with pegfilgrastim, reducing the dose of pegfilgrastim by half may reduce adverse events.

A 71-year-old man with middle thoracic esophageal cancer was treated with neoadjuvant chemotherapy using docetaxel plus 5-FU plus cisplatin therapy and was also administered pegfilgrastim. Blood tests showed elevated white blood cell counts and C-reactive protein levels before the start of the third course. Contrast-enhanced computed tomography revealed wall thickening of the aortic arch. We diagnosed this as aortitis due to pegfilgrastim. Inflammation was improved with conservative treatment. We then performed video-assisted thoracoscopic esophagectomy. Drug-induced vasculitis should be included in the differential diagnosis of patients with elevated inflammation markers of unknown cause following the administration of granulocyte colony-stimulating factor preparations.