Citations

Abstract Background: Hormone receptor-positive (HR+) breast cancer (BC) accounts for ~60-70% of all BC cases. CDK4/6i combined with endocrine therapy (ET) is the standard of care for first- and second-line therapy of patients with HR+ metastatic breast cancer (MBC) based on substantial improvements in progression free survival (PFS) and overall survival compared to ET alone. Unfortunately, most patients (pts) develop resistance to CDK4/6i. The mechanisms underlying CDK4/6i resistance have not been fully elucidated. Robust in vivo CDK4/6i resistant animal models from pts with de novo and acquired CDK 4/6i resistance are lacking. Patient-derived xenografts (PDXs) are important preclinical tools in oncology to advance our understanding of cancer biology and to evaluate drug response phenotypes. Unfortunately, the establishment of sustainable PDXs from pts with HR+ BC is much more difficult than from HR-negative BC. In order to obtain clinically relevant models that can be utilized to better understand mechanisms of primary and acquired resistance to ET and CDK4/6i, we report the development of PDXs from a prospective study in which percutaneous biopsies were obtained from women receiving palbociclib for the treatment of HR+ advanced or MBC (PROMISE; NCT03281902). Methods: PROMISE (Prospective Study to Evaluate the Role of Tumor Sequencing in Women Receiving Palbociclib for Advanced Hormone Receptor (HR)-Positive Breast Cancer) is a prospective trial which enrolled pts with HR+, HER2-negative MBC who planned to start treatment with palbociclib and letrozole (1st line [FL]) or palbociclib and fulvestrant (2nd line [SL]). For pts enrolled at Mayo Clinic Rochester (MCR), serial tumor biopsies were obtained prior to the start of treatment and at disease progression to establish PDXs. Because baseline take rate was low, we amended the protocol to attempt PDX generation after the 2nd cycle (C2) of therapy. Tissues were received within an hour of excision and were orthotopically implanted in the mammary fat pad of 6~8-week-old nonobese diabetic (NOD)/SCID/IL-2g-receptor null (NSG) mice. Tumor growth was defined as tumor volume ≥ 50 mm3. Tumor take rate was defined as percent of patients with development of at least one stably transplantable (passed at least for two generations) xenograft that was pathologically confirmed as BC. Results: Of the 50 pts enrolled at MCR, 37 were FL pts (2 ineligible) and 13 were SL pts (1 ineligible). Fresh tumor samples obtained pre-treatment from 43 eligible pts (32 FL), after C2 from 17 eligible pts (13 FL), and at disease progression from 10 eligible pts (5 FL) were implanted. Tumor growth was seen in at least one mouse from a pre-treatment specimen in 1 (3.1%) FL pt (confirmed BC) and 4 (36.4%) SL pts (2 confirmed BC); from end of C2 specimens in 2 (15.4%) FL pts and 2 (50%) SL pts (1 confirmed BC); and at progression in 1 (20%) FL pt and 2 (40%) SL pts (1 confirmed BC). The take rate from pre-treatment samples among FL pts was 1/32 (3.1%; 95% CI: 0.08-16.2%). Take rates in other groups are pending histological review. Discussion: In pts receiving palbociclib for HR+ MBC, the take rate using a pre-treatment percutaneous biopsy was low (3.1%) in the FL setting. However, higher growth rates were seen in the SL setting. The observation of higher growth rates at the end of C2 and at progression may relate to the activation of G1/S that occurs with withdrawal of palbociclib, and should be further studied. PDX remains a valuable tool for the evaluation of tumor biology and the development of new therapeutics, especially for those models established from pts with palbociclib and ET resistance. Proteogenomic and sequencing studies are ongoing to fully characterize these PDXs. Citation Format: Jia Yu, Vera J. Suman, Jun He, Jason P. Sinnwell, Ann M. Moyer, Bo Qin, Yayun Gu, Huan Zhang, Jodi M. Carter, Krishna R. Kalari, Brendan P. McMenomy, Minetta C. Liu, Tufia C. Haddad, Kathryn J. Ruddy, Fergus J. Couch, Alvaro Moreno-Aspitia, Donald W. Northfelt, Richard Weinshilboum, Ciara O'Sullivan, Matthew P. Goetz, Liewei Wang. Patient-derived xenografts (PDXs) generated from hormone receptor-positive breast cancer (BC) before and after cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) treatment: Initial findings from the PROMISE study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-01-07.

Abstract Mild cognitive impairment with the core clinical features of dementia with Lewy bodies is recognized as a prodromal stage of dementia with Lewy bodies. Although grey matter atrophy has been demonstrated in prodromal dementia with Lewy bodies, longitudinal rates of atrophy during progression to probable dementia with Lewy bodies are unknown. We investigated the regional patterns of cross-sectional and longitudinal rates of grey matter atrophy in prodromal dementia with Lewy bodies, including those who progressed to probable dementia with Lewy bodies. Patients with mild cognitive impairment with at least one core clinical feature of dementia with Lewy bodies (mean age = 70.5; 95% male), who were enrolled in the Mayo Clinic Alzheimer’s Disease Research Center and followed for at least two clinical evaluations and MRI examinations, were included (n = 56). A cognitively unimpaired control group (n = 112) was matched 2:1 to the patients with mild cognitive impairment by age and sex. Patients either remained stable (n = 28) or progressed to probable dementia with Lewy bodies (n = 28) during a similar follow-up period and pathologic confirmation was available in a subset of cases (n = 18). Cross-sectional and longitudinal rates of grey matter atrophy were assessed using voxel-based and atlas-based region of interest analyses. At baseline, prodromal dementia with Lewy bodies was characterized by atrophy in the nucleus basalis of Meynert both in those who remained stable and those who progressed to probable dementia with Lewy bodies (P < 0.05 false discovery rate corrected). Increase in longitudinal grey matter atrophy rates were widespread, with greatest rates of atrophy observed in the enthorhinal and parahippocampal cortices, temporoparietal association cortices, thalamus and the basal ganglia, in mild cognitive impairment patients who progressed to probable dementia with Lewy bodies at follow-up (P < 0.05 false discovery rate corrected). Rates of inferior temporal atrophy were associated with greater rates of worsening on the clinical dementia rating–sum of boxes. Seventeen of the 18 (94%) autopsied cases had Lewy body disease. Results show that atrophy in the nucleus basalis of Meynert is a feature of prodromal dementia with Lewy bodies regardless of proximity to progression to probable dementia with Lewy bodies. Longitudinally, grey matter atrophy progresses in regions with significant cholinergic innervation, in alignment with clinical disease progression, with widespread and accelerated rates of atrophy in patients who progress to probable dementia with Lewy bodies. Given the prominent neurodegeneration in the cholinergic system, patients with prodromal dementia with Lewy bodies may be candidates for cholinesterase inhibitor treatment.

INTRODUCTION: Eosinophilic gastritis (EG) is a chronic inflammatory disease of the stomach characterized by eosinophil-predominant gastric mucosal inflammation and gastrointestinal symptoms. The aim of this study was to prospectively evaluate endoscopic features in a large series of children and adults with EG to better understand the endoscopic manifestations and develop a standardized instrument for investigations. METHODS: Data were prospectively collected as part of the Consortium for Eosinophilic Gastrointestinal Disease Researchers, a national collaborative network. Endoscopic features were prospectively recorded using a system specifically developed for EG, the EG Endoscopic Reference System (EG-REFS). Correlations were made between EG-REFS and clinical and histologic features. RESULTS: Of 98 patients with EG, 65 underwent assessments using EG-REFS. The most common findings were erythema (72%), raised lesions (49%), erosions (46%), and granularity (35%); only 8% of patients with active histology (≥30 eosinophils/high-power field) exhibited no endoscopic findings. A strong correlation between EG-REFS scores and physician global assessment of endoscopy severity was demonstrated (Spearman r = 0.84, P < 0.0001). The overall score and specific components of EG-REFS were more common in the antrum than in the fundus or body. EG-REFS severity was significantly correlated with active histology, defined by a threshold of ≥30 eosinophils/high-power field ( P = 0.0002). DISCUSSION: Prospective application of EG-REFS identified gastric features with a strong correlation with physician global assessment of endoscopic activity in EG. Endoscopic features demonstrated greater severity in patients with active histology and a predilection for the gastric antrum. Further development of EG-REFS should improve its utility in clinical studies.

Abstract Cytotoxic CD8+ T cells (CTL) are a crucial component of the immune system notable for their ability to eliminate rapidly proliferating malignant cells. However, the T-cell intrinsic factors required for human CTLs to accomplish highly efficient antitumor cytotoxicity are not well defined. By evaluating human CD8+ T cells from responders versus nonresponders to treatment with immune checkpoint inhibitors, we sought to identify key factors associated with effective CTL function. Single-cell RNA-sequencing analysis of peripheral CD8+ T cells from patients treated with anti–PD-1 therapy showed that cells from nonresponders exhibited decreased expression of the cytolytic granule-associated molecule natural killer cell granule protein-7 (NKG7). Functional assays revealed that reduced NKG7 expression altered cytolytic granule number, trafficking, and calcium release, resulting in decreased CD8+ T-cell–mediated killing of tumor cells. Transfection of T cells with NKG7 mRNA was sufficient to improve the tumor-cell killing ability of human T cells isolated from nonresponders and increase their response to anti–PD-1 or anti–PD-L1 therapy in vitro. NKG7 mRNA therapy also improved the antitumor activity of murine tumor antigen–specific CD8+ T cells in an in vivo model of adoptive cell therapy. Finally, we showed that the transcription factor ETS1 played a role in regulating NKG7 expression. Together, our results identify NKG7 as a necessary component for the cytotoxic function of CD8+ T cells and establish NKG7 as a T-cell–intrinsic therapeutic target for enhancing cancer immunotherapy. See related article by Li et al., p. 154.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The “Summary of the Guidelines Updates” section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Abstract Introduction: Light chain (AL) amyloidosis is a plasma cell disease characterized by the deposition of insoluble amyloid fibrils into organs leading to organ dysfunction and death. The analysis at 6 and 12 months of the ANDROMEDA study (NCT03201965) showed that the addition of subcutaneous (SC) daratumumab to the standard of care combination of bortezomib, cyclophosphamide, and dexamethasone (VCd) was superior to VCd alone, with higher rates of hematologic complete response (CR) and an acceptable safety profile. Based on these findings daratumumab with VCd (D-VCd) was approved for newly diagnosed AL amyloidosis in January 2021 in the US and June 2021 in the EU. Here, we present data from the analysis at 18 months of the ANDROMEDA study. Methods: ANDROMEDA is a randomized, open-label, active-controlled phase 3 study including patients with newly diagnosed AL amyloidosis with measurable hematologic disease, ≥1 involved organ, cardiac stage I-IIIA, estimated glomerular filtration rate ≥20 mL/min, and absence of symptomatic multiple myeloma. Patients were randomized (1:1) to D-VCd or VCd for 6 28-day cycles. Bortezomib (1.3 mg/m 2), cyclophosphamide (300 mg/m 2 up to 500 mg per week), and dexamethasone (20-40 mg) were administered weekly. SC daratumumab (1800 mg co-formulated with recombinant human hyaluronidase PH20 in 15 mL) was administered once weekly in cycles 1 and 2 and every 2 weeks in cycles 3 to 6. Patients in the D-VCd arm received only SC daratumumab after cycle 6, every 4 weeks (up to a total of 24 cycles from first dose). The primary endpoint was overall (ie, at any time) hematologic CR rate, defined here as normalization of free light chain (FLC) levels and ratio (FLCr) and negative serum and urine immunofixation, confirmed at a subsequent visit; normalization of uninvolved FLC level and FLCr were not required if involved FLC was lower than the upper limit of normal. Secondary endpoints included major organ deterioration progression-free survival (PFS), organ response rate, time to hematologic response, overall survival (OS), and safety. Results: A total of 388 patients were randomized to receive D-VCd (N=195) or VCd alone (N=193). At the May 2021 clinical cutoff, the median duration of treatment for D-VCd and VCd arms was 21.3 and 5.3 months, respectively. In the D-VCd arm, 149 patients (77.2%) received daratumumab monotherapy after completing 6 cycles of D-VCd; of those, 17 (11.4%) were still receiving treatment. The rates of deep hematological responses favored the D-VCd treatment arm (Table). At a median follow-up of 25.8 months, the rate of hematologic CR was significantly higher in the D-VCd arm vs the VCd arm (59.5% vs 19.2%; odds ratio [95% confidence interval (CI)], 6.03 [3.80-9.58]; P&lt;0.0001). Similarly, more patients achieved a very good partial response or better (≥VGPR) (D-VCd vs VCd, 79.0% vs 50.3%; odds ratio [95% CI], 3.74 [2.39-5.86]; P&lt;0.0001). Among patients who responded, the median time from randomization to ≥VGPR was shorter in the D-VCd arm (0.56 months) vs the VCd arm (0.82 months). Comparable to the cardiac response analysis at 6 months (D-VCd vs VCd, 42% vs 22%), greater cardiac response rates were achieved with D-VCd compared with VCd at 18 months (53% vs 24%). Similarly, renal response rates remained superior with D-VCd vs VCd alone at 18 months (58% vs 26% compared with 6 months [54% vs 27%]). A total of 79 deaths occurred (D-VCd, N=34; VCd, N=45). In the D-VCd arm, only 1 additional grade 3/4 treatment-emergent adverse event occurred over 18 months vs 12 months (119 [61.7%] vs 118 [61.1%] patients) and no additional infusion-related reactions were reported. OS will be analyzed and major organ deterioration PFS will be updated after approximately 200 events have occurred. Conclusions: These results demonstrate the sustained clinical benefits of D-VCd vs VCd in terms of hematologic and organ responses with longer follow-up, although it should be noted that many patients in the D-VCd arm received daratumumab monotherapy following 6 cycles of D-VCd, while patients in the VCd group stopped study treatment. Nevertheless, the study continues to support the use of D-VCd over VCd alone in patients with newly diagnosed AL amyloidosis. Following its recent approval, D-VCd represents a new SOC for patients with AL amyloidosis. Figure 1 Figure 1. Disclosures Comenzo: Prothena Biosciences: Consultancy, Research Funding; Takeda: Research Funding; Unum: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding; Caelum: Consultancy, Research Funding; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Janssen: Patents & Royalties: WO2016187546A1, Research Funding. Palladini: Pfizer: Honoraria; Siemens: Honoraria; Janssen Global Services: Honoraria, Other: advisory board fees. Kastritis: Pfizer: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Genesis Pharma: Honoraria. Minnema: Janssen: Consultancy; BMS: Consultancy; Kite/Gilead: Consultancy; Celgene: Other: Travel expenses; Alnylam: Consultancy; Cilag: Consultancy. Wechalekar: Amgen: Research Funding; Janssen: Consultancy; Takeda: Honoraria; Celgene: Honoraria; Caelum Biosciences: Other: Clinical Trial Funding; Alexion, AstraZeneca Rare Disease: Consultancy. Jaccard: Pfizer: Honoraria; Abbvie: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees. Dispenzieri: Janssen: Consultancy, Research Funding; Sorrento Therapeutics: Consultancy; Oncopeptides: Consultancy; Alnylam: Research Funding; Pfizer: Research Funding; Takeda: Research Funding. Lee: Karyopharm: Consultancy; Celgene: Consultancy; Takeda Pharmaceuticals: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Research Funding; Sanofi: Consultancy; Genentech: Consultancy; Legend Biotech: Consultancy; Janssen: Consultancy, Research Funding; Oncopetides: Consultancy; Bristol Myers Squibb: Consultancy; Regeneron: Research Funding. Sanchorawala: Oncopeptide: Research Funding; Karyopharm: Research Funding; Sorrento: Research Funding; Pfizer: Honoraria; Proclara: Membership on an entity's Board of Directors or advisory committees; Regeneron: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Research Funding; Celgene: Research Funding. Gibbs: AbbVie: Consultancy; Janssen, Celgene, Amgen, Takeda, BMS and Pfizer: Consultancy, Honoraria. Mollee: Janssen, Pfizer: Research Funding; Amgen, BMS, Janssen, Caelum, EUSA, Pfizer, SkylineDx, Takeda: Membership on an entity's Board of Directors or advisory committees, Other: No personal fees received. Venner: BMS: Honoraria; Amgen: Research Funding; Celgene: Research Funding; Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Pfizer: Honoraria. Schönland: Janssen: Honoraria, Other: Travel grants, Research Funding; Pfizer: Honoraria; Takeda: Honoraria, Other: Travel grants; Prothena: Honoraria, Other: Travel grants; Sanofi: Research Funding. Suzuki: Abie: Honoraria; Sanofi: Honoraria; Novartis: Honoraria; ONO: Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Janssen: Consultancy, Honoraria. Kim: BMS: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Cibeira: Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Akcea: Honoraria, Membership on an entity's Board of Directors or advisory committees. Beksac: Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Libby: Genentech: Research Funding; BMS: Research Funding; GSK: Research Funding; Janssen: Consultancy, Research Funding. Valent: Caelum Biosciences: Other: Clinical Trial Funding; Celgene Corporation: Speakers Bureau; Takeda Pharmaceuticals: Speakers Bureau; Amgen: Speakers Bureau. Hungria: Amgen, BMS, Celgene, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings/travel ; Abbvie: Honoraria; Sanofi: Honoraria, Other: Support for attending meetings/travel ; Takeda: Honoraria. Wong: Amgen: Consultancy; Genentech: Research Funding; Fortis: Research Funding; Janssen: Research Funding; GloxoSmithKlein: Research Funding; Dren Biosciences: Consultancy; Caelum: Research Funding; BMS: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees. Rosenzweig: Janssen: Consultancy, Speakers Bureau; Bristol Myers Squibb: Speakers Bureau; Akcea: Speakers Bureau; Takeda: Speakers Bureau; Onocopeptides: Speakers Bureau. Bumma: Amgen, Sanofi: Speakers Bureau; Janssen, Oncopeptides, Sanofi: Consultancy. Tran: Janssen: Current Employment, Current equity holder in publicly-traded company. Qin: Janssen: Current Employment. Khaled: Jazz: Honoraria; Astellas: Honoraria; Alexion: Honoraria, Speakers Bureau; Omeros: Honoraria; Janssen: Current Employment. Vermeulen: Janssen: Current Employment, Current equity holder in publicly-traded company.

Abstract Background: There is suggestive evidence that inflammation is related to ovarian cancer survival. However, more research is needed to identify inflammation-related factors that are associated with ovarian cancer survival and to determine their combined effects. Methods: This analysis used pooled data on 8,147 women with invasive epithelial ovarian cancer from the Ovarian Cancer Association Consortium. The prediagnosis inflammation-related exposures of interest included alcohol use; aspirin use; other nonsteroidal anti-inflammatory drug use; body mass index; environmental tobacco smoke exposure; history of pelvic inflammatory disease, polycystic ovarian syndrome, and endometriosis; menopausal hormone therapy use; physical inactivity; smoking status; and talc use. Using Cox proportional hazards models, the relationship between each exposure and survival was assessed in 50% of the data. A weighted inflammation-related risk score (IRRS) was developed, and its association with survival was assessed using Cox proportional hazards models in the remaining 50% of the data. Results: There was a statistically significant trend of increasing risk of death per quartile of the IRRS [HR = 1.09; 95% confidence interval (CI), 1.03–1.14]. Women in the upper quartile of the IRRS had a 31% higher death rate compared with the lowest quartile (95% CI, 1.11–1.54). Conclusions: A higher prediagnosis IRRS was associated with an increased mortality risk after an ovarian cancer diagnosis. Further investigation is warranted to evaluate whether postdiagnosis exposures are also associated with survival. Impact: Given that pre- and postdiagnosis exposures are often correlated and many are modifiable, our study results can ultimately motivate the development of behavioral recommendations to enhance survival among patients with ovarian cancer.

AbstractIntroductionWe examined the temporal sequence of the core features in probable dementia with Lewy bodies (DLB).MethodsIn 488 patients with probable DLB, the onset of each core feature and time to diagnosis was determined for men and women, and a pathologic subgroup (n = 209).ResultsREM sleep behavior disorder (RBD) developed before the other core features in men and women. Men were more likely to have RBD and were diagnosed with probable DLB earlier than women. Visual hallucinations developed after the other core features in men, but in women, they appeared earlier and concurrently with fluctuations and parkinsonism. Women were older and more cognitively impaired at first visit, were less likely to have RBD, more likely to be diagnosed with probable DLB later than men, and more likely to have neocortical tangles.DiscussionAn earlier latency to probable DLB was associated with men, RBD, and Lewy body disease without neocortical tangles.

Background Remote limb ischemic postconditioning (RLIPoC) has been demonstrated to protect against ischemic stroke. However, the underlying mechanisms of RLIPoC mediating cross‐organ protection remain to be fully elucidated. Methods and Results Ischemic stroke was induced by middle cerebral artery occlusion for 60 minutes. RLIPoC was performed with 3 cycles of 10‐minute ischemia followed by 10‐minute reperfusion of the bilateral femoral arteries immediately after middle cerebral artery reperfusion. The percentage of regulatory T cells (Tregs) in the spleen, blood, and brain was detected using flow cytometry, and the number of Tregs in the ischemic hemisphere was counted using transgenic mice with an enhanced green fluorescent protein‐tagged Foxp3. Furthermore, the metabolic status was monitored dynamically using a multispectral optical imaging system. The Tregs were conditionally depleted in the depletion of Treg transgenic mice after the injection of the diphtheria toxin. The inflammatory response and neuronal apoptosis were investigated using immunofluorescent staining. Infarct volume and neurological deficits were evaluated using magnetic resonance imaging and the modified neurological severity score, respectively. The results showed that RLIPoC substantially reduced infarct volume, improved neurological function, and significantly increased Tregs in the spleen, blood, and ischemic hemisphere after middle cerebral artery occlusion. RLIPoC was followed by subsequent alteration in metabolites, such as flavin adenine dinucleotide and nicotinamide adenine dinucleotide hydrate, both in RLIPoC‐conducted local tissues and circulating blood. Furthermore, nicotinamide adenine dinucleotide hydrate can mimic RLIPoC in increasing Tregs. Conversely, the depletion of Tregs using depletion of Treg mice compromised the neuroprotective effects conferred by RLIPoC. Conclusions RLIPoC protects against ischemic brain injury, at least in part by activating and maintaining the Tregs through the nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide hydrate pathway.