Drug Benefit Research Articles

Progression-free survival as a primary end-point: Counting the cost

For some time in cancer clinical trials, overall survival (OS) has been the gold standard in determining the endpoint of the drug's efficacy. However, in recent times, there has been a gradual shift in the endpoint of drug efficacy towards progression-free survival (PFS). PFS has its merits, especially being cost-effective, but not without associated shortcomings. PFS is not an ideal surrogate for OS, and in some cases, the correlation is low to medium in strength with heterogeneity in the methodologies used. There have also been cases where PFS is used as an endpoint in place of OS, which was achieved, but with increased reports of significant adverse events/reduced quality of life (QoL) index. Current realities make using OS as an endpoint in some cancer drug trials a difficult task to demonstrate. However, even if PFS is used, data must be thoroughly assessed for quality of life indices and drug safety. It is therefore important that stakeholders in the business of cancer drug evaluation and trials note the risks and benefits of such drugs for the target population. In so doing, patient’s QoL would be paramount in therapeutic decision-making.

Clinical Benefit, Price, and Uptake for Cancer Biosimilars vs Reference Drugs in China

The high cost of biologics used to treat cancer has been an increasing burden in the world. In China, the recent approval of cancer biosimilar drugs to resolve this problem is promising, but evidence of clinical benefits, price, and uptake for these drugs is still lacking. To compare characteristics of pivotal clinical trials in China and other countries for biosimilars of bevacizumab, rituximab, and trastuzumab and investigate the efficacy or effectiveness, safety, and immunogenicity outcomes of cancer biosimilars compared with reference drugs by meta-analysis. For this systematic review and meta-analysis, PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched for published studies from database inception to February 1, 2023, using the search topics (cancers) AND (biosimilars). Randomized clinical trials and cohort studies that included patients with cancer were included. Two authors independently extracted the outcome estimates and characteristics for each study. A random-effects meta-analysis was performed to summarize the relative estimates with 95% CIs. This study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Clinical trial characteristics were collected for biosimilars of bevacizumab, rituximab, and trastuzumab. The relative estimates of efficacy or effectiveness (objective response rate, progression-free survival, and overall survival), safety, and immunogenicity outcomes were analyzed for biosimilars vs reference drugs. The weighted average price and uptake rate were evaluated for biosimilars relative to their reference drugs between 2015 and 2022. A total of 39 RCTs (involving 18 791 patients) and 10 cohort studies (involving 1998 patients) were included. The biosimilars of bevacizumab (16 RCTs; risk ratio [RR], 0.97; 95% CI, 0.93-1.01; P = .17), rituximab (12 RCTs; RR, 1.03; 95% CI, 0.98-1.08; P = .70), and trastuzumab (9 RCTs: RR, 1.04; 95% CI, 0.97-1.12; P = .29) met equivalence with reference biologics in regard to the objective response rate. The results summarized from cohort studies were consistent with those from RCTs. In 2022, cancer biosimilars were priced at 69% to 90% of the costs for the reference drugs, and their uptake reached 54% to 83% in China. This systematic review and meta-analysis indicated that cancer biosimilars provided comparable clinical benefits at lower prices compared with reference drugs. These findings suggest the potential feasibility of expediting the transition from reference drugs to biosimilars to benefit more patients with cancer.

Clinical benefit, development, innovation, trials, epidemiology, and price for cancer drugs and indications with multiple special FDA designations.

This study analyzes the development, US Food and Drug Administration (FDA) approval, benefits, innovation, trials, epidemiology, and price of cancer drugs with multiple special designations: orphan, fast track, accelerated approval, priority review, and breakthrough therapy. In total, 355 FDA-approved cancer drug indications with 841 special designations were identified (2012-2022). Trial, epidemiology, and price data were collected from FDA labels, the Global Burden of Disease study, and Medicare and Medicaid. The association between efficacy outcomes and indications' number of special designations were compared in meta-analyses. Median development times were 7.3, 7.8, and 5.4 months (P = .027) for drugs with 0 to 1, 2 to 3, and 4 to 5 special designations, respectively. Multiple special designations were associated with higher biotechnological and clinical innovation. Median patient enrollment in trials were 615, 471, 398, 168, 104, and 120 (P < .001) for indications with 0 to 5 special designations. Drugs for rare diseases supported by open-label phase 1/2 trials of single-arm design were granted more special designations. Hazard ratios for overall survival (0.80 vs 0.73 vs 0.73 vs 0.69 vs 0.56 vs 0.52; P = .003) and progression-free survival (0.70 vs 0.61 vs 0.59 vs 0.44 vs 0.37 vs 0.67; P < .001) substantially declined while tumor response increased with more special designations. Mean monthly prices increased for drugs with 0 to 4 but not 5 special designations ($21 596 vs $14 753 vs $32 410 vs $41 240 vs $38 703 vs $19 184). Multiple special designations are associated with faster clinical development and greater benefits for patients with unmet needs but also with nonrobust trial evidence and a tendency toward higher drug prices.

Toward Educating the New Generations of Pharmacist-Scientist Based on the New Six-Year System

Based on its founding spirit of "Strong, Correct and Clear" Gifu Pharmaceutical University (hereinafter referred to as "the University") has adopted the human and environmentally friendly Pharmacy (Green Pharmacy) as its basic philosophy. As the University fulfills its social mission to enrich and strengthen education, research, and social activities, it faces many challenges. These include incorporation, fostering academia-industry-government collaboration, life-science center development and expanding the role of the affiliated pharmacy. The University will continually strive to recognize trends in the social environment and make the effort to respond to challenges when they arise. This effort will allow the University faculty and staff to maintain a sustainable institution that can respond to social challenges while continuing to share the benefits of education, research, and drug discovery/development with the community. The University is committed to train world class Pharmacist-Scientist. This review explains the rationale for the University's transition to a single six-year program. It also gives an update on the current status of education, research, and the mobile pharmacy (MP) since its introduction. Furthermore, it highlights advancements in academic-industry-government collaboration.

1704P Clinical benefit of cancer drugs approved by the US food and drug administration based on appropriateness of control arm and its change over time

1704P Clinical benefit of cancer drugs approved by the US food and drug administration based on appropriateness of control arm and its change over time

1938P Assessment of clinical benefit of cancer drugs recommended in National Comprehensive Cancer Network (NCCN) guidelines for advanced soft tissue sarcomas (STS) and bone sarcomas (BS)

1938P Assessment of clinical benefit of cancer drugs recommended in National Comprehensive Cancer Network (NCCN) guidelines for advanced soft tissue sarcomas (STS) and bone sarcomas (BS)

Challenges of Avoiding Congenital Disorders: Experiences of Pregnant Women in Northeastern Thailand

Maternal knowledge and behaviors attempting to prevent or avoid congenital disorders have not reached optimal levels. This qualitative descriptive study describes the challenges of avoiding congenital disorders from the experiences of pregnant women in northeastern Thailand. Data were collected between November 2017 and August 2019 from 18 pregnant women through in-depth interviews and analyzed using thematic analysis. Three themes reflecting challenges emerged. Firstly, ‘traditional beliefs’ were challenging regarding unclear and potential adverse outcomes. Secondly, the challenges of ‘contemporary beliefs’ included distinct views and inaccessible information, characterized as non-apprehension, non-comprehension, non-modernization, or non-precision to preventing congenital disorders. Finally, ‘daily life activities,’ in selectiveness in eating, attainment of mother-child healthiness, and harm avoidance were aimed at both congenital disorder prevention and fetal development promotion. Some significant challenging topics included: vulnerable periods; some taboos; nutrients for brain development; safety in food, working, and environment; concerns with dangers of physical activities, exercise, maternal stress, and medicines; and misperceived benefits of herbal drugs and fetal stimulation. Nursing and midwifery practice guidelines should integrate the concept of congenital disorders prevention into the promotion of fetal development using culturally-sensitive approaches. The found challenges should be overcome and further applied in refining the practice guidelines.

Real-World Persistency for Inflammatory Bowel Disease Biologics Using Patient Registry Data

Abstract Background Although it is a truism that drugs benefit patients only when taken, surprisingly little is known about real-world drug-use persistence and discontinuation, even for expensive biologic drugs. Methods We used longitudinal self-reported drug-use data from the inflammatory bowel disease (IBD) Partners registry of people with IBD to construct Kaplan–Meier drug-use persistency graphs for biologic drug-use spans that started between 2017 and 2022. Results We examined 2034 drug-use spans for 1594 survey participants. Most of the biologic drugs had a 75%+ persistency rate around the one-year mark and 60%+ persistency at the 3-year mark. The overall persistency and the differences in persistency between drugs were aligned with published literature. Conclusions This analysis demonstrates the feasibility of collecting IBD-specific patient-reported drug persistency data via a voluntary patient registry. Patient-reported persistency provides real-world drug persistency data and the patient’s perspectives as to why they discontinued use of the drug—a combination of data and perspective that is not available from any other real-world medical record, claim, and pharmacy data source that are valuable to physician, patients, payers, healthcare policymakers, and health technology assessment organizations.

Phage Display of Two Distinct Warheads to Inhibit Challenging Proteins.

Falling in between traditional small molecules and antibodies in size, peptides are emerging as a privileged therapeutic modality, one that can harness the benefits of both small molecule and antibody drugs. To discover potential peptide therapeutics, it is highly desirable to have high throughput screening platforms that can assess peptides with diverse and non-natural functional motifs. With this contribution, we present a novel phage library that incorporates two distinct designer groups. As an example, a pair of reversible covalent warheads was installed onto phage-displayed peptides to target a cysteine and a lysine. The double modification is realized by sequential modification of an N-terminal cysteine and then an internal cysteine using chemoselective chemistry. Screening of this double-warhead-presenting library against TEV protease readily revealed peptide inhibitors with single-digit micromolar potency. Importantly, our structure-activity studies demonstrate that both covalent warheads make important contributions to TEV protease inhibition. We envision that our strategy of double phage modification can be readily extended to build phage libraries with diverse structural motifs, allowing facile expansion of the chemical space coverable by phage display.

Planning Benefit-Risk Assessments Using Visualizations.

A Benefit Risk Assessment Plan (BRAP) describes the assessments planned to determine whether the benefits of an investigational drug outweigh the risks. The plan can have two sections, one with timelines for aligning resources with decision milestones and the other for pre-specifying assessments for decision milestones. Regulatory guidance recommends a proactive planning process over an ad-hoc process. However, very little has been published about proactive plans themselves. This article works through a hypothetical example visualizing a series of assessments across the drug development lifecycle. Based on a regulatory framework, the planning process starts with assessing the medical condition and current treatment options. These early assessments bring out major considerations in assessing the investigational drug.

Drug repurposing a compelling cancer strategy with bottomless opportunities: Recent advancements in computational methods and molecular mechanisms.

Drug discovery has customarily focused on a de novo design approach, which is extremely expensive and takes several years to evolve before reaching the market. Discovering novel therapeutic benefits for the current drugs could contribute to new treatment alternatives for individuals with complex medical demands that are safe, inexpensive, and timely. In this consequence, when pharmaceutically yield and oncology drug efficacy appear to have hit a stalemate, drug repurposing is a fascinating method for improving cancer treatment. This review gathered about how in silico drug repurposing offers the opportunity to quickly increase the anticancer drug arsenal and, more importantly, overcome some of the limits of existing cancer therapies against both old and new therapeutic targets in oncology. The ancient nononcology compounds' innovative potential targets and important signaling pathways in cancer therapy are also discussed. This review also includes many plant-derived chemical compounds that have shown potential anticancer properties in recent years. Here, we have also tried to bring the spotlight on the new mechanisms to support clinical research, which may become increasingly essential in the future; at the same time, the unsolved or failed clinical trial study should be reinvestigated further based on the techniques and information provided. These encouraging findings, combined together, will through new insight on repurposing more non-oncology drugs for the treatment of cancer.

Overall survival benefits of cancer drugs in the WHO Model List of Essential Medicines, 2015–2021

IntroductionWe examined overall survival (OS) benefits for targeted cancer drugs recommended for List of Essential Medicines (EMLs) since 2015. We assessed consistency of decisions in 2019 and 2021 with more...

Estimating the Impact of the Inflation Reduction Act on the Out-of-pocket Costs for Medicare Beneficiaries With Advanced Prostate Cancer.

Combination systemic therapy for advanced prostate cancer has reduced mortality, but high out-of-pocket costs impose financial barriers for patients. The Inflation Reduction Act's $2,000 out-of-pocket spending cap for Medicare's prescription drug benefit (Part D) can potentially lower out-of-pocket spending for beneficiaries starting in 2025. This study aims to compare out-of-pocket spending for commonly prescribed regimens for advanced prostate cancer before and after implementation of the Inflation Reduction Act. Medication regimens constructed to treat metastatic, hormone-sensitive prostate cancer consisted of baseline androgen deprivation therapy with traditional chemotherapy, androgen receptor inhibitors, and androgen biosynthesis inhibitors. Using 2023 Medicare Part B prices and the Medicare Part D plan finder, we estimated annual out-of-pocket costs under current law and under the Inflation Reduction Act's redesigned standard Part D benefit. Under current law, out-of-pocket costs for Part D drugs ranged from $464 to $11,336 per year. Under the Inflation Reduction Act, annual out-of-pocket costs for 2 regimens remained unchanged: androgen deprivation therapy with docetaxel and androgen deprivation therapy with abiraterone and prednisone. However, out-of-pocket costs for regimens using branded novel hormonal therapy were significantly lower under the 2025 law with potential savings estimated to be $9,336 (79.2%) for apalutamide, $9,036 (78.7%) for enzalutamide, and $8,480 (76.5%) for docetaxel and darolutamide. The $2,000 spending cap introduced by the Inflation Reduction Act may significantly decrease out-of-pocket costs and reduce financial toxicity associated with advanced prostate cancer treatment, impacting an estimated 25,000 Medicare beneficiaries.

Public Perspective on Hyperlipidemia Drugs and Sentiments About Hyperlipidemia on Twitter

Hyperlipidemia is a non-communicable disease (NCD) caused by several factors, such as a person's socioeconomic status, culture, customs, habits, and lifestyle. Through user interaction on social media, we can discover the model anti-hyperlipidemia by extracting information, complaints, suggestions, and calls for help about the treatment, which will play a role as an intervention to reduce hyperlipidemia in Indonesia. This study aimed to identify factors influencing perceptions of hyperlipidemia drugs and resulting sentiment on the social media platform Twitter. This study used user-uploaded tweet data to compare perceptions of hyperlipidemia drugs in 2020 and keywords for hyperlipidemia terms and medicine. Tweets related to anti-hyperlipidemia were extracted by issuing tweets containing advertisements, news, re-tweet, and content outside of health. The tweet data obtained was then carried out through content analysis, including point of view, theme, and sentiment analysis, to identify whether the resulting tweets are positive, neutral, or negative using the Support Vector Machine (SVM) method. We identified 1572 hyperlipidemia-related tweets and 153 specific tweets describing hyperlipidemia medications. Tweets about anti-hyperlipidemia showed 99 tweets from the first-person perspective, 23 from the second-person perspective, 22 from healthcare professionals, and nine unidentifiable (other). Sixty-three tweets talked about the benefits of lipid-lowering drugs, 17 complaint tweets, 49 suggestion tweets, 17 question tweets, and two side effect tweets. Assessing public perceptions and sentiment toward hyperlipidemia treatment can be used to develop strategies to increase treatment adherence, improve treatment outcomes, and target health promotion efforts.

Pharmacological Treatments in Heart Failure With Mildly Reduced and Preserved Ejection Fraction: Systematic Review and Network Meta-Analysis

BackgroundMedical treatment for heart failure with preserved ejection (HFpEF) and heart failure with mildly reduced ejection fraction (HFmrEF) has weaker evidence compared with reduced ejection fraction, despite recent trials with an angiotensin receptor neprilysin inhibitor (ARNI) and sodium glucose co-transporter 2 inhibitors (SGLT2is). ObjectivesThe authors aimed to estimate the aggregate therapeutic benefit of drugs for HFmrEF and HFpEF. MethodsThe authors performed a systematic review of MEDLINE, CENTRAL, and Web of Science for randomized trials including patients with heart failure (HF) and left ventricular ejection fraction (LVEF) >40%, treated with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (analyzed together as renin-angiotensin system inhibitors [RASi]), beta-blockers (BBs), mineralocorticoid receptor antagonists (MRAs), digoxin, ARNI, and SGLT2i. An additive component network meta-analysis was performed. The primary outcome was a composite of cardiovascular (CV) death and first hospitalization for heart failure (HHF); secondary outcomes were CV death, total HHF, and all-cause mortality. ResultsThe authors identified 13 studies with a total of 29,875 patients and a mean LVEF of 56.3% ± 8.7%. ARNI, MRA, and SGLT2i separately, but not RASi, BB, or digoxin, reduced the primary composite outcome compared with placebo. The combination of ARNI, BB, MRA, and SGLT2i was the most effective (HR: 0.47 [95% CI: 0.31-0.70]); this was largely explained by the triple combination of ARNI, MRA, and SGLT2i (HR: 0.56 [95% CI 0.43-0.71]). Results were similar for CV death (HR: 0.63 [95% CI 0.43-0.91] for ARNI, MRA, and SGLT2i) or total HHF (HR: 0.49 [95% CI 0.33-0.71] for ARNI, MRA, and SGLT2i) alone. In a subgroup analysis, only SGLT2i had a consistent benefit among all LVEF subgroups, whereas the triple combination had the greatest benefit in HFmrEF, robust benefit in patients with LVEF 50% to 59%, and a statistically marginal benefit in patients with LVEF ≥60%. ConclusionsIn patients with HF and LVEF>40%, the quadruple combination of ARNI, BB, MRA, and SGLT2i provides the largest reduction in the risk of CV death and HHF; driven by the robust effect of the triple combination of ARNI, MRA, and SGLT2i. The benefit was more pronounced in HFmrEF patients.

Clinical research progress on BRAF V600E-mutant advanced colorectal cancer.

Colorectal cancer is one of the malignant tumors that pose a serious threat to human health. A particularly bad prognosis might be expected for colorectal tumors with the unique molecular subtype BRAF V600E mutation. With the development of precision therapy, the advent of molecularly targeted therapies and immune checkpoint inhibitors has improved the outcome of intermediate to advanced colorectal cancer. However, the duration of drug benefit is usually short, and overall survival and progression-free survival remain suboptimal. Therefore, investigators are exploring more rational, safe, and effective drug combination regimens through clinical trials to provide longer survival for patients with such genetic mutations with metastatic colorectal cancer (mCRC). This article reviews the progress of clinical research on molecularly targeted drugs, immune checkpoint inhibitors, first-line chemotherapeutic agents, and different combination therapy regimens (including different targeted drug combinations, immune combination targeting, and chemotherapy combination targeting) for colorectal cancer patients with BRAF V600E mutation, which provides a reference for further in-depth clinical exploration of the treatment of colorectal cancer patients with BRAF V600E mutation.

Ezrin Inhibition Overcomes Acquired Resistance to Vemurafenib in BRAFV600E-Mutated Colon Cancer and Melanoma Cells In Vitro.

Despite the advancements in targeted therapy for BRAFV600E-mutated metastatic colorectal cancer (mCRC), the development of resistance to BRAFV600E inhibition limits the response rate and durability of the treatment. Better understanding of the resistance mechanisms to BRAF inhibitors will facilitate the design of novel pharmacological strategies for BRAF-mutated mCRC. The aim of this study was to identify novel protein candidates involved in acquired resistance to BRAFV600E inhibitor vemurafenib in BRAFV600E-mutated colon cancer cells using an integrated proteomics approach. Bioinformatic analysis of obtained proteomics data indicated actin-cytoskeleton linker protein ezrin as a highly ranked protein significantly associated with vemurafenib resistance whose overexpression in the resistant cells was additionally confirmed at the gene and protein level. Ezrin inhibition by NSC305787 increased anti-proliferative and pro-apoptotic effects of vemurafenib in the resistant cells in an additive manner, which was accompanied by downregulation of CD44 expression and inhibition of AKT/c-Myc activities. We also detected an increased ezrin expression in vemurafenib-resistant melanoma cells harbouring the BRAFV600E mutation. Importantly, ezrin inhibition potentiated anti-proliferative and pro-apoptotic effects of vemurafenib in the resistant melanoma cells in a synergistic manner. Altogether, our study suggests a role of ezrin in acquired resistance to vemurafenib in colon cancer and melanoma cells carrying the BRAFV600E mutation and supports further pre-clinical and clinical studies to explore the benefits of combined BRAF inhibitors and actin-targeting drugs as a potential therapeutic approach for BRAFV600E-mutated cancers.

Post-Exposure Prophylaxis for COVID-19: A Systematic Review.

SARS-CoV-2 cause pneumonia can spread across the lung and lead to acute respiratory distress syndrome (ARDS) in severe cases. Post-exposure prophylaxis has shown great potential to prevent the transmission of some viral infections; however, such results for COVID-19 are still inconclusive. Therefore, the aim of this study was to systematically review the resources that utilized postexposure prophylaxis (PEP) for COVID-19 and the possible clinical benefits of such drugs. An organized search of relevant literature was done using the keywords and search queries on public databases of Cochrane, PubMed, Web of Science and Scopus from December 2019 to August 23, 2021. Original resources that had the inclusion criteria were included after two-phase title/abstract and full-text screenings. This review adhered to the Preferred Reporting Items for Systematic Reviews and MetaAnalysis (PRISMA) statement. Out of 841 retrieved records 17 resources were appropriate to include in the systematic review. Hydroxychloroquine with a daily dose of 400-800 mg and a duration of 5-14 days was the most frequently used agent for PEP. Chloroquine was recommended to use to control treatment in patients with mild to severe COVID-19 pneumonia. Other agents like Lopinavir-ritonavir (LPV/r), angiotensinconverting enzyme inhibitors (ACEIs), Angiotensin receptor blockers (ARBs), Vitamin D, arbidol, thymosin drugs, and Xin guan no.1 (XG.1, a Chinese formula medicine) have also been applied in some studies. Current evidence demonstrated no established clinical benefits of any drug as PEP in individuals with COVID-19. However, scarce indication occurs for the beneficial effects of some agents, but more studies are needed to explore such effects.

Critical Test of the Beneficial Consequences of Lifting the Ban on Direct-to-Consumer Advertising for Prescription Drugs in Italy: Experimental Exposure and Questionnaire Study

Background There are only two countries in the world (the United States and New Zealand) that allow the pharmaceutical branch to advertise prescription medication directly to consumers. There is pressure on governments to allow direct-to-consumer advertising (DTCA) for prescription drugs elsewhere too. One argument the industry uses frequently is the claim that exposure to DCTA, through various methods and occasions, is supposed to improve customers’ knowledge of a disease and treatment. This argument has been part of the health care community’s wider discussion of whether DTCA of prescription drugs benefits the population’s general interest or is only an attempt to increase the sales of the pharmaceutical branch. Belief in true learning by DTCA is rooted in concepts of empowered consumers and their autonomous and empowered decision-making. Objective In this study, we tested the hypotheses that contact with DTCA increases recipients’ literacy/knowledge, especially regarding the side effects of treatment (hypothesis 1), and empowerment (hypothesis 2). We further hypothesized that DTCA exposure would not increase depression knowledge (ie, about treatments, symptoms, and prevalence) (hypothesis 3). Methods A snowball sample of 180 participants was randomly split into three experimental groups receiving (1) a traditional information sheet, (2) a DTCA video clip for an antidepressant prescription drug, or (3) both. The video was original material from the United States translated into Italian for the experiment. Dependent variables were measures of depression knowledge (regarding treatments, symptoms and prevalence, and antidepressant side effects), depression literacy, and empowerment. Results None of the experimental groups differed significantly from the others in the empowerment measure (hypothesis 2 not confirmed). Partial confirmation of hypothesis 1 was obtained. Lower values on the depression literacy scale were obtained when participants had been given the video compared to the sheet condition. However, the general depression knowledge and its subscale on side effects reached higher scores when participants were exposed to the DTCA, alone or in combination with the information sheet. Finally, participants showed lower scores on knowledge about treatment and symptoms or prevalence after watching the video compared to the sheet condition (hypothesis 3 confirmed). Symptoms and prevalence knowledge increased only when the video was presented in combination with the sheet. Conclusions There is no evidence for an increase in empowerment following DTCA exposure. An increase in knowledge of the side effects of the medication was observed in the group exposed to the DTCA video. This was the only result that confirmed the hypothesis of the beneficial effect of DTCA videos on knowledge. Written information proved to be the most suitable way to convey knowledge on treatments and symptoms prevalence. Our findings support the necessity of studying health literacy and patient empowerment together and the consequences of such an increase in knowledge in terms of help-seeking behavior.

Glutamine metabolic microenvironment drives M2 macrophage polarization to mediate trastuzumab resistance in HER2-positive gastric cancer.

Trastuzumab is a first-line targeted therapy for human epidermal growth factor receptor-2 (HER2)-positive gastric cancer. However, the inevitable occurrence of acquired trastuzumab resistance limits the drug benefit, and there is currently no effective reversal measure. Existing researches on the mechanism of trastuzumab resistance mainly focused on tumor cells themselves, while the understanding of the mechanisms of environment-mediated drug resistance is relatively lacking. This study aimed to further explore the mechanisms of trastuzumab resistance to identify strategies to promote survival in these patients. Trastuzumab-sensitive and trastuzumab-resistant HER2-positive tumor tissues and cells were collected for transcriptome sequencing. Bioinformatics were used to analyze cell subtypes, metabolic pathways, and molecular signaling pathways. Changes in microenvironmental indicators (such as macrophage, angiogenesis, and metabolism) were verified by immunofluorescence (IF) and immunohistochemical (IHC) analyses. Finally, a multi-scale agent-based model (ABM) was constructed. The effects of combination treatment were further validated in nude mice to verify these effects predicted by the ABM. Based on transcriptome sequencing, molecular biology, and in vivo experiments, we found that the level of glutamine metabolism in trastuzumab-resistant HER2-positive cells was increased, and glutaminase 1 (GLS1) was significantly overexpressed. Meanwhile, tumor-derived GLS1 microvesicles drove M2 macrophage polarization. Furthermore, angiogenesis promoted trastuzumab resistance. IHC showed high glutamine metabolism, M2 macrophage polarization, and angiogenesis in trastuzumab-resistant HER2-positive tumor tissues from patients and nude mice. Mechanistically, the cell division cycle 42 (CDC42) promoted GLS1 expression in tumor cells by activating nuclear factor kappa-B (NF-κB) p65 and drove GLS1 microvesicle secretion through IQ motif-containing GTPase-activating protein 1 (IQGAP1). Based on the ABM and in vivo experiments, we confirmed that the combination of anti-glutamine metabolism, anti-angiogenesis, and pro-M1 polarization therapy had the best effect in reversing trastuzumab resistance in HER2-positive gastric cancer. This study revealed that tumor cells secrete GLS1 microvesicles via CDC42 to promote glutamine metabolism, M2 macrophage polarization, and pro-angiogenic function of macrophages, leading to acquired trastuzumab resistance in HER2-positive gastric cancer. A combination of anti-glutamine metabolism, anti-angiogenesis, and pro-M1 polarization therapy may provide a new insight into reversing trastuzumab resistance.