Structure-activity relationships of middle-size cyclic peptides, KRAS inhibitors derived from an mRNA display.

Cyclic peptides are attracting attention as therapeutic agents due to their potential for oral absorption and easy access to tough intracellular targets. LUNA18, a clinical KRAS inhibitor, was transformed-without scaffold hopping-from the initial hit by using an mRNA display library that met our criteria for drug-likeness. In drug discovery using mRNA display libraries, hit compounds always possess a site linked to an mRNA tag. Here, we describe our examination of the Structure-Activity Relationship (SAR) using X-ray structures for chemical optimization near the site linked to the mRNA tag, equivalent to the C-terminus. Structural modifications near the C-terminus demonstrated a relatively wide range of tolerance for side chains. Furthermore, we show that a single atom modification is enough to change the pharmacokinetic (PK) profile. Since there are four positions where side chain modification is permissible in terms of activity, it is possible to flexibly adjust the pharmacokinetic profile by structurally optimizing the side chain. The side chain transformation findings demonstrated here may be generally applicable to hits obtained from mRNA display libraries.

Pituitary apoplexy in endocrinologically silent adenoma during somatostatin analog administration for pancreatic neuroendocrine tumor: A case report.

A dopamine agonist administered for prolactinoma treatment and pituitary stimulation tests are reported as risk factors for pituitary apoplexy. We report a case of an 82-year-old patient who suffered from pituitary apoplexy in an endocrinologically silent adenoma during lanreotide administration. The patient was diagnosed with a pancreatic neuroendocrine tumor with lymph node metastasis and treated with lanreotide for two years. An endoscopic endonasal transsphenoidal approach was used for tumor and hematoma removal. The specimen showed growth hormone and prolactin positivity and was diagnosed as pit1-lineage plurihormonal adenoma. The tumor also showed positivity for somatostatin receptor 2. Thus, lanreotide treatment is a risk factor for pituitary apoplexy even in silent adenoma.

Development of Orally Bioavailable Peptides Targeting an Intracellular Protein: From a Hit to a Clinical KRAS Inhibitor.

Cyclic peptides as a therapeutic modality are attracting a lot of attention due to their potential for oral absorption and accessibility to intracellular tough targets. Here, starting with a drug-like hit discovered using an mRNA display library, we describe a chemical optimization that led to the orally available clinical compound known as LUNA18, an 11-mer cyclic peptide inhibitor for the intracellular tough target RAS. The key findings are as follows: (i) two peptide side chains were identified that each increase RAS affinity over 10-fold; (ii) physico-chemical properties (PCP) including Clog P can be adjusted by side-chain modification to increase membrane permeability; (iii) restriction of cyclic peptide conformation works effectively to adjust PCP and improve bio-activity; (iv) cellular efficacy was observed in peptides with a permeability of around 0.4 × 10-6 cm/s or more in a Caco-2 permeability assay; and (v) while keeping the cyclic peptide's main-chain conformation, we found one example where the RAS protein structure was changed dramatically through induced-fit to our peptide side chain. This study demonstrates how the chemical optimization of bio-active peptides can be achieved without scaffold hopping, much like the processes for small molecule drug discovery that are guided by Lipinski's rule of five. Our approach provides a versatile new strategy for generating peptide drugs starting from drug-like hits.

Validation of a New Methodology to Create Oral Drugs beyond the Rule of 5 for Intracellular Tough Targets.

Establishing a technological platform for creating clinical compounds inhibiting intracellular protein-protein interactions (PPIs) can open the door to many valuable drugs. Although small molecules and antibodies are mainstream modalities, they are not suitable for a target protein that lacks a deep cavity for a small molecule to bind or a protein found in intracellular space out of an antibody's reach. One possible approach to access these targets is to utilize so-called middle-size cyclic peptides (defined here as those with a molecular weight of 1000-2000 g/mol). In this study, we validated a new methodology to create oral drugs beyond the rule of 5 for intracellular tough targets by elucidating structural features and physicochemical properties for drug-like cyclic peptides and developing library technologies to afford highly N-alkylated cyclic peptide hits. We discovered a KRAS inhibitory clinical compound (LUNA18) as the first example of our platform technology.

Multi-institutional survey of antiemetic therapy in lung cancer patients treated with carboplatin in Hokushin region.

OBJECTIVE: Appropriate monitoring and management of chemotherapy-induced nausea and vomiting (CINV) with prophylactic antiemetics is important for cancer patients. This study was performed to validate the clinical practice of antiemetic use with carboplatin-based chemotherapy in lung cancer patients in the Hokushin region (Toyama, Ishikawa, Fukui, and Nagano prefectures), Japan. METHODS: We surveyed retrospective data of newly diagnosed and registered lung cancer patients initially treated with carboplatin-based chemotherapy in 21 principal hospitals in the Hokushin region linked with health insurance claims data between 2016 and 2017. RESULTS: A total of 1082 lung cancer patients (861 [79.6%] men, 221 [20.4%] women; median age 69.4 years [range, 33-89 years]). All patients received antiemetic therapy, with 613 (56.7%) and 469 patients (43.3%) receiving 5-hydroxytryptamine-3 receptor antagonist/dexamethasone double regimen and 5-hydroxytryptamine-3 receptor antagonist/dexamethasone/neurokinin-1 receptor antagonist triple regimen, respectively. However, the rates of double regimen and use of palonosetron were higher in Toyama and Fukui prefectures. Thirty-nine patients (3.6%) changed from double to triple regimen, while 41 patients (3.8%) changed from triple to double regimen after the second cycle, but six of these returned to triple antiemetics in subsequent cycles. CONCLUSION: Adherence to antiemetic guidelines in clinical practice was high in Hokushin region. However, rates of double and triple antiemetic regimens differed between the four prefectures. Simultaneous analysis of nationwide registry and insurance data was valuable for evaluating and comparing the differences in the status of antiemesis and management.

Epidemiological and therapeutic profiles of lung cancer patients in the Hokushin Region Japan: a retrospective hospital administrative database study.

OBJECTIVE: This study was performed to validate the epidemiology, initial treatment, and clinical practice of lung cancer patients in the Hokushin region, Japan. METHODS: We retrospectively surveyed data of 5503 newly diagnosed and registered lung cancer patients in 22 principal hospital-based cancer registries in Hokushin region linked with health insurance claims data for registered patients between 2016 and 2017. RESULTS: The patients consisted of 3677 (66.8%) men and 1826 (33.2%) women with a mean (range) age of 72.2 (27-103) years). Diagnoses were small cell lung cancer (n = 512, 9.4%), squamous cell carcinoma (n = 1083, 19.7%), and non-squamous non-small cell lung cancer (NSCLC; n = 3906, 70.9%). The population with stage I disease in Toyama prefecture (41.1%) was smaller than in the other three prefectures associated with reduced selection of initial surgical therapy and increased frequencies of stage IV disease (33.2%) and best supportive care (18.6%). Initial chemotherapy for stage IV non-squamous NSCLC consisted of tyrosine kinase inhibitors in 39.3% of cases for EGFR and 4% of cases for ALK-positive non-squamous NSCLC, followed by platinum compounds (25.9%) non-platinum compounds (12.9%), and immune checkpoint inhibitors (10.2%). Carboplatin was the commonly prescribed first-line cytotoxic chemotherapeutic agent (65.4% of patients under 75 years and in 96.7% of patients over 75 years). CONCLUSION: This study revealed real-world data on epidemiological and treatment status in lung cancer in four prefectures in Hokushin region, Japan. Simultaneous analysis of nationwide registry and insurance data could provide valuable insights for the development of lung cancer screening and medical treatment strategies. In addition, the comparative data analysis with other lesions or countries will be useful for evaluating the differences in clinical practice of cancer managements.

Discharge to home from a palliative care unit: impact on survival and factors associated with home death after the discharge: a cohort study.

BACKGROUND: Staying at home during the dying process is important for many patients; and palliative care units (PCUs) can help facilitate home death. This study compared patient survival between those who were discharged to home from a palliative care unit and those who were not, and aimed to identify the factors associated with home death after the discharge. METHODS: This retrospective cohort study used a database of patients admitted to a palliative care unit at Kouseiren Takaoka Hospital in Japan. All consecutive patients admitted to the hospital's PCU between October 2016 and March 2020 were enrolled. Patient survival and factors potentially associated with survival and place of death were obtained. A total of 443 patients with cancer were analyzed, and 167 patients were discharged to home and 276 were not. RESULTS: Propensity score matching analyses revealed that median survival time was significantly longer in patients who were discharged to home than those who were not (57 vs. 27 days, P < 0.001). Multiple logistic regression analysis identified that worse Palliative Prognostic Index (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.03-1.44, p = 0.025) and family members' desire for home death (OR = 6.30, 95% CI = 2.32-17.1, p < 0.001) were significantly associated with home death after their discharge. CONCLUSIONS: Discharge to home from palliative care units might have some positive impacts on patient survival.

Cancer among children, adolescents and young adults in the Hokushin region, Japan, between 2010 and 2015.

Adolescents and young adults with cancer encounter age-related challenges. Cancer treatment and support are not always tailored to the needs of each patient due to difficulty in the collection of accurate data. The present study aimed to investigate cancer among children and adolescents and young adults in the four adjacent prefectures of Japan (Toyama, Ishikawa, Fukui and Nagano) by analyzing data from a unique regional cancer database. We retrieved and analyzed the data of pediatric and adolescent and young adult patients aged between 0 and 39 years at cancer diagnosis (including carcinoma in situ), which was registered in the Hokushin Ganpro database between 2010 and 2015. A total of 5718 cases (1571 males and 4147 females) were identified during this period. The overall male-to-female ratio was 1:2.6. There was no distinct difference in the number of cancer cases per 100 000 population between males and females until 19 years of age. The difference became more pronounced after 20 years of age. The number of cancer cases (per 100 000 population) in the 0-14-, 15-19-, 20-29- and 30-39-year age groups was estimated to be 13.4, 14.5, 44.0 and 101.5, respectively. Carcinomas were the most common type of cancer in the adolescents and young adults (15-39 years) population (74%), whereas they were not the predominant cancer type in the pediatric (0-14 years) population. Although further research is needed to understand the needs of adolescents and young adults with cancer, we believe that our findings will help guide efforts to improve the management strategy for adolescents and young adults with cancer.

Multi-institutional survey of cancer disparities in disabled patients in the region of northwestern Japan.

BACKGROUND: Potential disparities between cancer patients with and without disabilities remained to be validate in Japan. METHODS: We surveyed retrospective data on hospital cancer registration as well as information on disability certificates obtained through the Hokushin Ganpro database. In total, 93,545 cancer patients in 10 principal hospitals covering the region of northwestern Japan were registered with the Hokushin Ganpro database between 2010 and 2015. The database included the following data: diagnosis date, cancer type, staging, treatment, cancer detection process, and possession of a disability certificate. RESULTS: We found that 2983 patients, which accounted for 3.2% of the total patients, had disabilities. No significant differences in gender, age at diagnosis, cancer stage distribution, and cancer incidence rates were observed between the disabled and non-disabled patients. Even though the proportion of early-stage cancer among disabled patients differed only slightly from that in non-disabled patients, early-stage cancer was more frequently diagnosed in patients with disabilities during their regular hospital visits than in those without disabilities, who had more opportunity for early cancer detection during cancer screening. According to in-house data reflecting treatment period and process from a single hospital, all 16 disabled patients treated with chemotherapy completed the treatment until disease progression or end of predetermined cycles. CONCLUSION: These results indicate that deep disparities between cancer patients with and without disabilities are not apparent and that the disabled patients in the region of northwestern Japan receive appropriate hospital follow-up.

[Neutrophil-to-Lymphocyte Ratio(NLR)as a Predictive Indicator of the Response to Nivolumab in Patients with Oral Squamous Cell Carcinoma].

BACKGROUND: The immune checkpoint inhibitor (ICI) nivolumab has revolutionized the treatment for recurrent or metastatic advanced oral cancer. Because the response rate remains low, the identification of predictive indicators of the response to nivolumab is among the most critical issues. The neutrophil-to-lymphocyte ratio(NLR)is a potential predictive marker of the response to nivolumab in patients with various cancer types. However, the utility of the NLR as a biomarker for predicting the response of oral cancer patients to ICIs is poorly understood. PATIENTS AND METHODS: In this retrospective cohort study, we evaluated the association between NLR and nivolumab treatment outcome in 13 patients diagnosed with recurrent or metastatic oral squamous cell carcinoma(OSCC)treated with nivolumab at the Toyama University Hospital between December 2017 and December 2019. RESULTS: Complete response(CR)and partial response(PR)rates of 38.5%(5/13)and 0% (0/13), respectively, were observed in responders; stable disease(SD)and progressive disease(PD)rates of 7.7%(1/13) and 53.8%(7/13), respectively, were observed in non-responders. After nivolumab treatment, the median NLR among responders decreased to 3.3(3.0-3.9)from 4.1(3.7-4.3)during pre-treatment assessment and increased from 5.6(3.2- 9.2)at pre-treatment to 9.4(5.3-17.9)among non-responders. Moreover, patients with higher NLRs(≥5)in the post- treatment group had a significantly worse overall survival than those with lower NLRs(<5). Specifically, patients with a higher post-treatment NLR(≥10)had significantly worse outcomes for post-nivolumab salvage chemotherapy. CONCLUSION: The NLR could be a useful marker for predicting the treatment response to nivolumab or post-nivolumab salvage chemotherapy in OSCC patients.

[A Case of Lung Adenocarcinoma Presenting with Leptomeningeal Carcinomatosis Successfully Treated with Afatinib after Erlotinib-Induced Hepatotoxicity].

A 65-year-old man was diagnosed with leptomeningeal carcinomatosis based on the findings of cerebrospinal fluid cytology and magnetic resonance imaging(MRI).Treatment with erlotinib and bevacizumab was initiated, and partial improvement in consciousness and MRI findings were obtained.However, it was difficult to continue the treatment because of elevation in levels of liver enzymes and melena.We switched the treatment to afatinib monotherapy, and his consciousness improved immediately.Progression -free survival and overall survival from the initiation of the treatment with afatinib were 7 and 9.4 months, respectively. This clinical course suggests activity of afatinib for central nervous system lesions of EGFRmutated lung cancer.

[A Retrospective Study Analyzing the Clinical Course of Patients with Non-Small Cell Lung Cancer Receiving Local or Systemic Therapy after Post-Operative Recurrence].

BACKGROUND: While systemic therapy is one of the therapeutic options available for post-operative recurrence of non-small cell lung cancer, efficacy of local therapy for locoregional recurrence or limited metastatic lesions has also been reported. OBJECTIVE: We aimed to evaluate the clinical course of patients with post-operative recurrence(locoregional or limited metastatic lesion)after receiving local or systemic therapy. METHODS: Clinical data were retrospectively analyzed and survival duration was compared using the logrank test. RESULTS: A total of 22 patients were included. Median progression-free survival in patients receiving local therapy, systemic chemotherapy, or a combination of both therapies was 15.1 months, 6.3 months, and 13 months, respectively. Two patients receiving treatment with EGFR-TKI did not show disease progression at 41.3 months and 45.8 months(p=0.265). Median overall survivals in patients receiving local therapy, systemic chemotherapy, or a combination of both therapies were 26.5 months, 20 months, and 37.9 months, respectively(p=0.510). After the treatment, 6 patients showed regrowth of the recurrent lesion, 8 patients showed remote metastases, and 2 patients showed both regrowth of the recurrent lesion and remote metastases. CONCLUSION: Patients who received treatment including local therapy showed longer survival duration, but statistical significance was not detected. Our study suggested that regrowth of the recurrent lesion and remote metastases can be equally observed after treatment.

In vivo depletion of CD206+ M2 macrophages exaggerates lung injury in endotoxemic mice.

Although phenotypically polarized macrophages are now generally classified into two major subtypes termed proinflammatory M1 and anti-inflammatory M2 macrophages, a contributory role of lung M2 macrophages in the pathophysiological features of acute lung injury is not fully understood. Herein, we show in an endotoxemic murine model that M2 macrophages serve as key anti-inflammatory cells that play a regulatory role in the severity of lung injury. To study whether M2 macrophages can modify inflammation, we depleted M2 macrophages from lungs of CD206-diphtheria toxin (DT) receptor transgenic (Tg) mice during challenge with lipopolysaccharide. The i.p. administration of DT depleted CD206-positive cells in bronchoalveolar lavage fluid. The use of M2 macrophage markers Ym1 and arginase-1 identified pulmonary CD206-positive cells as M2 macrophages. A striking increase in neutrophils in bronchoalveolar lavage fluid cell contents was found in DT-treated CD206-DT receptor Tg mice. In CD206-DT receptor Tg mice given DT, endotoxin challenge exaggerated lung inflammation, including up-regulation of proinflammatory cytokines and increased histological lung damage, but the endotoxemia-induced increase in NF-κB activity was significantly reduced, suggesting that M2 phenotype-dependent counteraction of inflammatory insult cannot be attributed to the inhibition of the NF-κB pathway. Our results indicate a critical role of CD206-positive pulmonary macrophages in triggering inflammatory cascade during endotoxemic lung inflammation.

Relationship of the urine cortisol level with the performance status of patients with lung cancer: a retrospective study.

PURPOSE: Cortisol plays an important role in the physical status of patients with end-stage lung cancer, but the association of urine cortisol levels with TNM stage/performance status (PS) is unclear in patients with advanced lung cancer receiving chemotherapy. The objective of this study was to examine this association. METHODS: In this single-center, retrospective, observational study, cortisol concentrations in 24-h pooled urine from 22 patients with advanced lung cancer were measured over 2 days. The mean concentration in each patient was compared with PS, TNM stage, and serum sodium and potassium ion levels. RESULTS: The 24-h urine cortisol levels were higher in PS2 or PS3 cases compared to PS1 (p < 0.05) and increased proportionally with PS. Urine cortisol also increased in N2 or N3 cases compared to N1 (p < 0.01) and also increased in M1 cases (p < 0.05). Urine cortisol levels were negatively correlated with serum sodium (R = -0.49, p < 0.05) and had a tendency for a positive correlation with serum potassium (R = 0.40, p = 0.06). CONCLUSION: The 24-h urine cortisol level increased in patients with advanced lung cancer undergoing chemotherapy. Low serum levels of potassium and high levels of sodium may indicate relative adrenal insufficiency.

Association of serum adiponectin with asthma and pulmonary function in the Japanese population.

Conflicting findings have been reported regarding the role of adiponectin in asthma. The aim of this study was to evaluate the association of adiponectin with pulmonary functions and asthma in the Japanese population. First, among a general population that participated in a previous study (group 1), we selected 329 subjects after excluding those with asthma, chronic obstructive pulmonary disease, and a smoking history and examined the associations of the serum total adiponectin levels with pulmonary functions. In a second cohort (group 2) consisting of 61 asthmatic patients and 175 control non-asthmatic subjects, we examined the associations between asthma and the levels of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms as well as the ratio of each isoform to total adiponectin level. Although the total adiponectin levels were not significantly different between the asthmatic and control subjects in group 2, the levels were significantly and positively associated with the forced expiratory volume in 1 s after adjustments for confounding factors (P < 0.05) in women in group 1. In group 2, the LMW adiponectin level was significantly higher and the MMW/total adiponectin ratio was significantly lower among the asthmatic subjects than among the control subjects after adjustments for confounding factors in both sexes (P < 0.05). The present study showed that a low total adiponectin level may lead to airway narrowing compatible with asthmatic airways in women, and higher LMW adiponectin levels and lower MMW/total adiponectin ratio are significantly associated with current asthma in both sexes.

Pseudo-Behçet's disease associated with tuberculosis: a case report and review of the literature.

Orogenital ulcer is one of the clinical manifestations of Behçet's disease (BD). However, orogenital ulcer may be observed in various conditions, such as complex aphthous dermatitis and herpes simplex virus infections. Therefore, orogenital ulcer along with skin lesions, including acne or erythema nodosum, may be misdiagnosed as BD, but is actually pseudo-BD instead. We report here a case of pseudo-BD due to Mycobacterium tuberculosis infection in which anti-tuberculous treatment resulted in complete resolution. Furthermore, we review the literature regarding the association of BD and M. tuberculosis infection.

[Efficacy and toxicity of pemetrexed monotherapy for previously untreated elderly patients with non-squamous cell lung cancer with wild-type(or unknown)EGFR status].

BACKGROUND: The efficacy of docetaxel, vinorelbine, or gemcitabine monotherapy in previously untreated elderly patients with non-small cell lung cancer has been reported.Pemetrexed monotherapy has shown clinically equivalent efficacy to docetaxel, a standard therapeutic option, in patients with previously treated non-small cell lung cancer and in those with a lower incidence of toxicity such as febrile neutropenia. OBJECTIVE: In the present study, we aimed to investigate the efficacy and toxicity of pemetrexed in previously untreated elderly patients with non-squamous cell lung cancer and compare the results with those of docetaxel, considered a standard chemotherapeutic agent. METHODS: We retrospectively reviewed the medical records of patients with non-squamous cell lung cancer with wild-type(or unknown)epidermal growth factor receptor status who received pemetrexed or docetaxel monotherapy as first-line chemotherapy. RESULTS: We analyzed 6 patients with lung adenocarcinoma in the pemetrexed group and 6 patients with lung adenocarcinoma in the docetaxel group. The median progression-free survival was 3.6 months for patients receiving pemetrexed and 3.1 months for those receiving docetaxel(p=0.45). The median overall survival was 14.8 months in the pemetrexed group and 10.9 months in the docetaxel group(p=0.36).Patients who received docetaxel were more likely to have grade 3 or 4 neutropenia and febrile neutropenia than those receiving pemetrexed.However, 2 patients who received pemetrexed showed grade 3 pneumonitis. CONCLUSION: Pemetrexed monotherapy is a promising treatment for previously untreated elderly patients with non-squamous cell lung cancer.

Multifocal fatty liver nodules mimicking a metastatic disease: A case report.

Multifocal fatty liver nodules can present a diagnostic challenge due to their resemblance to metastatic liver disease. This case report illustrates the complexity of such scenarios through the presentation of a middle-aged male patient. Despite the common nature of fatty liver disease, characterized by hepatocyte fat accumulation leading to diffuse and uniform liver lesions, rare instances exhibit heterogeneous appearances. The case underlines the potential confusion arising from imaging modalities when multiple small nodules disperse throughout the liver, mimicking multifocal tumors or metastases. The report emphasizes the critical role of comprehensive diagnostic procedures in preventing misdiagnosis and unwarranted interventions. Effective management hinges on multidisciplinary collaboration among specialists, ensuring accurate differentiation and appropriate treatment. This study serves as a reminder of the intricacies involved in interpreting multifocal fatty liver nodules that may masquerade as metastatic disease, highlighting the need for precision in clinical practice.

Prescription Pattern of Anamorelin; a Therapeutic Agent for Cancer Cachexia.

Background: The commercial availability of anamorelin, Japan's first therapeutic agent for cancer cachexia in 2021, led to an investigation into its prescription patterns at Toyama University Hospital. Objective: We aimed to analyze anamorelin prescription trends and outcomes among cancer cachexia patients. Methods: A retrospective study from July 2021 to December 2022 examined 88 cases, assessing demographics, cancer types, prescription locations, and meal intake changes. Results: Anamorelin usage was predominant during chemotherapy, especially for pancreatic cancer in outpatient settings. Approximately 30% experienced increased meal intake. Chemotherapy-initiated cases had a longer median duration (55 days) compared with best supportive care only cases (12 days). Conclusion: Anamorelin demonstrated significant prescription patterns, particularly during chemotherapy for pancreatic cancer in outpatient settings, suggesting potential efficacy enhancements when administered with chemotherapy in cancer cachexia management. The study underscores the importance of tailored approaches to optimize anamorelin's therapeutic benefits.

Pure Red Cell Aplasia and Chromosomal Abnormality in a Patient With Lung Adenocarcinoma Receiving Immune Checkpoint Inhibitors: A Case Report.

BACKGROUND/AIM: Immune checkpoint inhibitors can induce immune-related adverse events in various organs, thus careful observation is required. CASE REPORT: A 69-year-old man was diagnosed with advanced lung adenocarcinoma and treated with combined therapy of carboplatin plus pemetrexed plus pembrolizumab. After two cycles of treatment, anemia was noted. Myelosuppression due to cytotoxic anticancer agents was suspected and the cytotoxic agents were discontinued, followed by three courses of pembrolizumab monotherapy. However, the anemia persisted, requiring red blood cell transfusions. A bone marrow biopsy revealed erythroblast hypoplasia and chromosomal abnormalities, resulting in a diagnosis of pure red cell aplasia. These adverse events were considered immune-related because of the treatment history with an immune checkpoint inhibitor, and 60 mg/day (1 mg/kg/day) of prednisolone was initiated. Anemia improved, and it did not recur during the tapering of prednisolone. CONCLUSION: Immune-related pure red cell aplasia should be considered for patients presenting anemia during treatment with immune checkpoint inhibitors.