Targeting pyruvate dehydrogenase kinase 1 overcomes EGFR C797S mutation-driven osimertinib resistance in non-small cell lung cancer

Osimertinib, a selective third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), effectively targets the EGFR T790M mutant in non-small cell lung cancer (NSCLC). However, the newly identified EGFR C797S mutation confers resistance to osimertinib. In this study, we explored the role of pyruvate dehydrogenase kinase 1 (PDK1) in osimertinib resistance. Patients exhibiting osimertinib resistance initially displayed elevated PDK1 expression. Osimertinib-resistant cell lines with the EGFR C797S mutation were established using A549, NCI-H292, PC-9, and NCI-H1975 NSCLC cells for both in vitro and in vivo investigations. These EGFR C797S mutant cells exhibited heightened phosphorylation of EGFR, leading to the activation of downstream oncogenic pathways. The EGFR C797S mutation appeared to increase PDK1-driven glycolysis through the EGFR/AKT/HIF-1α axis. Combining osimertinib with the PDK1 inhibitor leelamine helped successfully overcome osimertinib resistance in allograft models. CRISPR-mediated PDK1 knockout effectively inhibited tumor formation in xenograft models. Our study established a clear link between the EGFR C797S mutation and elevated PDK1 expression, opening new avenues for the discovery of targeted therapies and improving our understanding of the roles of EGFR mutations in cancer progression.

CDKN2 expression is a potential biomarker for T cell exhaustion in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC), the predominant primary hepatic malignancy, is the prime contributor to mortality. Despite the availability of multiple surgical interventions, patient outcomes remain suboptimal. Immunotherapies have emerged as effective strategies for HCC treatment with multiple clinical advantages. However, their curative efficacy is not always satisfactory, limited by the dysfunctional T cell status. Thus, there is a pressing need to discover novel potential biomarkers indicative of T cell exhaustion (Tex) for personalized immunotherapies. One promising target is Cyclin-dependent kinase inhibitor 2 (CDKN2) gene, a key cell cycle regulator with aberrant expression in HCC. However, its specific involvement remains unclear. Herein, we assessed the potential of CDKN2 expression as a promising biomarker for HCC progression, particularly for exhausted T cells. Our transcriptome analysis of CDKN2 in HCC revealed its significant role involving in HCC development. Remarkably, single-cell transcriptomic analysis revealed a notable correlation between CDKN2 expression, particularly CDKN2A, and Tex markers, which was further validated by a human cohort study using human HCC tissue microarray, highlighting CDKN2 expression as a potential biomarker for Tex within the intricate landscape of HCC progression. These findings provide novel perspectives that hold promise for addressing the unmet therapeutic need within HCC treatment.

Natural Product-Based Glycolysis Inhibitors as a Therapeutic Strategy for Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Resistant Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide. Targeted therapy against the epidermal growth factor receptor (EGFR) is a promising treatment approach for NSCLC. However, resistance to EGFR tyrosine kinase inhibitors (TKIs) remains a major challenge in its clinical management. EGFR mutation elevates the expression of hypoxia-inducible factor-1 alpha to upregulate the production of glycolytic enzymes, increasing glycolysis and tumor resistance. The inhibition of glycolysis can be a potential strategy for overcoming EGFR-TKI resistance and enhancing the effectiveness of EGFR-TKIs. In this review, we specifically explored the effectiveness of pyruvate dehydrogenase kinase inhibitors and lactate dehydrogenase A inhibitors in combating EGFR-TKI resistance. The aim was to summarize the effects of these natural products in preclinical NSCLC models to provide a comprehensive understanding of the potential therapeutic effects. The study findings suggest that natural products can be promising inhibitors of glycolytic enzymes for the treatment of EGFR-TKI-resistant NSCLC. Further investigations through preclinical and clinical studies are required to validate the efficacy of natural product-based glycolytic inhibitors as innovative therapeutic modalities for NSCLC.

Cosmosiin Induces Apoptosis in Colorectal Cancer by Inhibiting PD-L1 Expression and Inducing ROS

Immunotherapies, particularly those concerning immune checkpoint inhibitors, have transformed cancer treatment in recent years. Programmed death-ligand 1 (PD-L1) is a key target for immunotherapy that is overexpressed in the cells of colorectal cancer, a widespread malignant cancer that poses a significant healthcare challenge. This study investigated the effects of cosmosiin treatment on colorectal cancer cell lines. Cosmosiin is a naturally occurring flavone glycoside compound that has potential health benefits, including antioxidant and immunomodulatory effects. This study showed that cosmosiin effectively suppresses the expression of PD-L1 and triggers apoptosis, which is facilitated through pathways that are related to reactive oxygen species. These outcomes suggest that cosmosiin could be a promising candidate for an immune checkpoint inhibitor in the treatment of colorectal cancer.

Natural compounds as lactate dehydrogenase inhibitors: potential therapeutics for lactate dehydrogenase inhibitors-related diseases

Lactate dehydrogenase (LDH) is a crucial enzyme involved in energy metabolism and present in various cells throughout the body. Its diverse physiological functions encompass glycolysis, and its abnormal activity is associated with numerous diseases. Targeting LDH has emerged as a vital approach in drug discovery, leading to the identification of LDH inhibitors among natural compounds, such as polyphenols, alkaloids, and terpenoids. These compounds demonstrate therapeutic potential against LDH-related diseases, including anti-cancer effects. However, challenges concerning limited bioavailability, poor solubility, and potential toxicity must be addressed. Combining natural compounds with LDH inhibitors has led to promising outcomes in preclinical studies. This review highlights the promise of natural compounds as LDH inhibitors for treating cancer, cardiovascular, and neurodegenerative diseases.

Favorable Survival after Definitive Ablative RT in Surgically Resectable Pancreatic Cancer Patients

PURPOSE/OBJECTIVE(S)

Surgical resection has been considered the only curative option for patients with pancreatic adenocarcinoma (PDAC). Ablative RT ≥100Gy BED10 (A-RT) is associated with favorable survival in patients with locally advanced unresectable disease. We sought to evaluate A-RT outcomes in patients with technically resectable disease who did not undergo surgery.

MATERIALS/METHODS

Our prospectively maintained database of patients treated with A-RT was queried for consecutive patients with radiographic T1/T2 resectable PDAC. Patients were treated with a standardized technique within a large academic cancer center regional network. Ablative RT using several hypofractionated regimens was delivered on either standard Linacs with respiratory motion management, CBCT image guidance and selective adaptive replanning or MR-Linac with compression belt and daily on-line adaptive replanning. Freedom from local progression (FFLP), distant metastasis-free and overall survival (DMFS and OS, respectively) were analyzed using the Kaplan Meier estimates.

RESULTS

Between 2016 and 2022, 28 patients (54% male) with radiographically resectable PDAC received definitive A-RT. Median age was 80 (interquartile range, 77-84) years and 23 (82.1%) had KPS of 80 or below. Eighteen patients (64.3%) had T2 cancer, 5 (17.9%) were node positive, and 23 (82.1%) had head location. Median size was 2.6 (range, 1.6-4.0) cm with a median carbohydrate antigen 19-9 (CA19-9) of 160.5 (0-1823) U/mL. Twenty patients (71.4%) received induction chemotherapy for a median of 2.4 (0-6.2) months. RT regimens delivered on conventional Linacs unless otherwise indicated included 75Gy in 25 fractions (n = 15), 67.5Gy in 15 fractions (n = 10), 50Gy in 5 (N = 2, MR Linac), 60Gy in 10 (n = 1). 24-month FFLP and DMFS were 78.8% (52.3-91.7%) and 17.7% (95% CI, 5.8%-34.8%), respectively. 24-month and 48-month rate of OS from A-RT were 49.1% (95% CI, 27.53-67.5%) and 36.3 (95%16.0-57.1%). Grade 3 acute and late GI toxicity was noted in 3 and 1 patients, respectively, including 2 bleeding events treated with transfusions. There were no ≥ grade 4 events.

CONCLUSION

In patients with surgically resectable PDAC we found that definitive A-RT following multiagent induction therapy was associated with oncologic outcomes similar to resection with minimal toxicity.

Reappraisal of an Adequate Negative Margin Following Breast Conservation Therapy in Young Patients with Invasive Breast Cancer

PURPOSE/OBJECTIVE(S)

This study aimed to examine the relationship between resection margin (RM) width and ipsilateral breast tumor recurrence (IBTR). The current definition of an adequate negative margin was validated in young breast cancer patients (<40 years).

MATERIALS/METHODS

This study included 4,042 patients who underwent breast conservation therapy between 2006 and 2012. There were 595 women <40 years (14.7%). Re-excision to achieve a wider RM was not considered in patients with no ink on tumor. Systemic treatments were administered in 3,985 patients (98.6%). The impact of RM width on the incidence of IBTR was assessed using narrowly specified intervals (positive, >0 to <1 mm, 1 to <2 mm, 2 to <3 mm, and ≥3 mm).

RESULTS

A significant relationship was observed between RM width and incidence of IBTR. In young women, the 10-year cumulative incidence rates of IBTR were 21.6% for positive RM, 13.9% for >0 to <1 mm, 10.9% for 1 to <2 mm, 5.7% for 2 to <3 mm, and 5.8% for ≥3 mm (p <0.01). The corresponding incidence rates of IBTR in women ≥40 years were 8.6%, 8.0%, 4.4%, 2.7%, and 2.1%, respectively (p <0.01). The difference in the incidence of IBTR between each RM width interval increased over time, and the magnitude of the increment was greater in young women. RM width was the only risk factor for IBTR in young women.

CONCLUSION

The relationship between RM width and IBTR was definite in young women. Compared with women ≥40 years, young women might have long-term benefits from a wider RM than no ink on tumor.

Integrative Evaluation of the Clinical Significance Underlying Protein Arginine Methyltransferases in Hepatocellular Carcinoma

HCC is a major contributor to cancer-related mortality worldwide. Curative treatments are available for a minority of patients diagnosed at early stages; however, only a few multikinase inhibitors are available and are marginally effective in advanced cases, highlighting the need for novel therapeutic targets. One potential target is the protein arginine methyltransferase, which catalyzes various forms of arginine methylation and is often overexpressed in various cancers. However, the diverse expression patterns and clinical values of PRMTs in HCC remain unclear. In the present study, we evaluated the transcriptional expression of PRMTs in HCC cohorts using publicly available datasets. Our results revealed a significant association between PRMTs and prognosis in HCC patients with diverse clinical characteristics and backgrounds. This highlights the promising potential of PRMTs as prognostic biomarkers in patients with HCC. In particular, single-cell RNA (scRNA) sequencing analysis coupled with another human cohort study highlighted the pivotal role of PRMT1 in HCC progression, particularly in the context of Tex. Translating these findings into specific therapeutic decisions may address the unmet therapeutic needs of patients with HCC.

Mitochondria-associated programmed cell death as a therapeutic target for age-related disease

Mitochondria, ubiquitous double-membrane-bound organelles, regulate energy production, support cellular activities, harbor metabolic pathways, and, paradoxically, mediate cell fate. Evidence has shown mitochondria as points of convergence for diverse cell death-inducing pathways that trigger the various mechanisms underlying apoptotic and nonapoptotic programmed cell death. Thus, dysfunctional cellular pathways eventually lead or contribute to various age-related diseases, such as neurodegenerative, cardiovascular and metabolic diseases. Thus, mitochondrion-associated programmed cell death-based treatments show great therapeutic potential, providing novel insights in clinical trials. This review discusses mitochondrial quality control networks with activity triggered by stimuli and that maintain cellular homeostasis via mitohormesis, the mitochondrial unfolded protein response, and mitophagy. The review also presents details on various forms of mitochondria-associated programmed cell death, including apoptosis, necroptosis, ferroptosis, pyroptosis, parthanatos, and paraptosis, and highlights their involvement in age-related disease pathogenesis, collectively suggesting therapeutic directions for further research.

Diversity and complexity of cell death: a historical review

Death is the inevitable fate of all living organisms, whether at the individual or cellular level. For a long time, cell death was believed to be an undesirable but unavoidable final outcome of nonfunctioning cells, as inflammation was inevitably triggered in response to damage. However, experimental evidence accumulated over the past few decades has revealed different types of cell death that are genetically programmed to eliminate unnecessary or severely damaged cells that may damage surrounding tissues. Several types of cell death, including apoptosis, necrosis, autophagic cell death, and lysosomal cell death, which are classified as programmed cell death, and pyroptosis, necroptosis, and NETosis, which are classified as inflammatory cell death, have been described over the years. Recently, several novel forms of cell death, namely, mitoptosis, paraptosis, immunogenic cell death, entosis, methuosis, parthanatos, ferroptosis, autosis, alkaliptosis, oxeiptosis, cuproptosis, and erebosis, have been discovered and advanced our understanding of cell death and its complexity. In this review, we provide a historical overview of the discovery and characterization of different forms of cell death and highlight their diversity and complexity. We also briefly discuss the regulatory mechanisms underlying each type of cell death and the implications of cell death in various physiological and pathological contexts. This review provides a comprehensive understanding of different mechanisms of cell death that can be leveraged to develop novel therapeutic strategies for various diseases.

Southern ocean carbon and heat impact on climate

The Southern Ocean greatly contributes to the regulation of the global climate by controlling important heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal timescales are therefore impacted by oceanic processes taking place in the Southern Ocean, yet too little is known about these processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent processes at scales that are not well captured in current Earth system models. The Southern Ocean Carbon and Heat Impact on Climate programme was launched to address this knowledge gap, with the overall objective to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key physical processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. Here, we provide a brief overview of the programme, as well as a summary of some of the scientific progress achieved during its first half. Advances range from new evidence of the importance of specific processes in Southern Ocean ventilation rate (e.g. storm-induced turbulence, sea-ice meltwater fronts, wind-induced gyre circulation, dense shelf water formation and abyssal mixing) to refined descriptions of the physical changes currently ongoing in the Southern Ocean and of their link with global climate. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

Time-resolved Coulomb collision of single electrons

A series of recent experiments have shown that collision of ballistic electrons in semiconductors can be used to probe the indistinguishability of single-electron wavepackets. Perhaps surprisingly, their Coulomb interaction has not been seen due to screening. Here we show Coulomb-dominated collision of high-energy single electrons in counter-propagating ballistic edge states, probed by measuring partition statistics while adjusting the collision timing. Although some experimental data suggest antibunching behaviour, we show that this is not due to quantum statistics but to strong repulsive Coulomb interactions. This prevents the wavepacket overlap needed for fermionic exchange statistics but suggests new ways to utilize Coulomb interactions: microscopically isolated and time-resolved interactions between ballistic electrons can enable the use of the Coulomb interaction for high-speed sensing or gate operations on flying electron qubits.

Identification of Dental Implant Systems Using a Large-Scale Multicenter Data Set

This study aimed to evaluate the efficacy of deep learning (DL) for the identification and classification of various types of dental implant systems (DISs) using a large-scale multicenter data set. We also compared the classification accuracy of DL and dental professionals. The data set, which was collected from 5 college dental hospitals and 10 private dental clinics, contained 37,442 (24.8%) periapical and 113,291 (75.2%) panoramic radiographic images and consisted of a total of 10 manufacturers and 25 different types of DISs. The classification accuracy of DL was evaluated using a pretrained and modified ResNet-50 architecture, and comparison of accuracy performance and reading time between DL and dental professionals was conducted using a self-reported questionnaire. When comparing the accuracy performance for classification of DISs, DL (accuracy: 82.0%; 95% confidence interval [CI], 75.9%-87.0%) outperformed most of the participants (mean accuracy: 23.5% ± 18.5%; 95% CI, 18.5%-32.3%), including dentists specialized (mean accuracy: 43.3% ± 20.4%; 95% CI, 12.7%-56.2%) and not specialized (mean accuracy: 16.8% ± 9.0%; 95% CI, 12.8%-20.9%) in implantology. In addition, DL tends to require lesser reading and classification time (4.5 min) than dentists who specialized (75.6 ± 31.0 min; 95% CI, 13.1-78.4) and did not specialize (91.3 ± 38.3 min; 95% CI, 74.1-108.6) in implantology. DL achieved reliable outcomes in the identification and classification of various types of DISs, and the classification accuracy performance of DL was significantly superior to that of specialized or nonspecialized dental professionals. DL as a decision support aid can be successfully used for the identification and classification of DISs encountered in clinical practice.

AB0260 LONG-TERM EFFICACY AND SAFETY OF UPADACITINIB IN PATIENTS FROM CHINA, BRAZIL, AND SOUTH KOREA WITH RHEUMATOID ARTHRITIS AND AN INADEQUATE RESPONSE TO CONVENTIONAL SYNTHETIC DISEASE-MODIFYING ANTIRHEUMATIC DRUGS: RESULTS AT 64 WEEKS

Background:

Upadacitinib (UPA), an oral Janus kinase inhibitor, in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), showed significant improvements in clinical and functional measures compared with placebo (PBO) up to 12 weeks (wks), in patients (pts) from China, Brazil, and South Korea with rheumatoid arthritis (RA) and prior inadequate response to csDMARDs (csDMARD-IR).1

Objectives:

To assess the efficacy and safety of UPA up to 64 wks (long-term extension; LTE) in csDMARD-IR pts with RA from China, Brazil, and South Korea.

Methods:

Pts were randomized to 12 wks of blinded treatment with UPA 15 mg once daily (QD) or PBO, in combination with csDMARDs. From Wk 12 onward, pts could continue to receive open-label UPA 15 mg QD. Efficacy endpoints were analyzed by original randomized treatment group sequences over 64 wks and included American College of Rheumatology (ACR) responses, and key remission and low disease activity measures. Non-responder imputation was used to handle missing data for binary endpoints. Treatment-emergent adverse events (TEAEs) per 100 patient-years (PY) were summarized for pts receiving ≥1 dose of UPA from baseline through to Wk 64.

Results:

Of 338 randomized pts who received ≥1 dose of study drug, 310 (91.7%) entered the LTE and 275 (81.4%) completed 64 wks of treatment. Among those initially randomized to UPA, the proportion of pts achieving 20%/50%/70% improvement in ACR criteria, and key remission and low disease activity measures increased over 64 wks of treatment (Figure 1). Improvements from baseline in the Health Assessment Questionnaire-Disability Index and pts’ assessment of pain were observed over 64 wks of UPA treatment (data not shown). By Wk 64, efficacy results for pts who switched from PBO to UPA at Wk 12 followed a similar trajectory to those originally randomized to UPA.

The observed rate of serious infections was 8.1 events/100 PY. Herpes zoster events were mostly non-serious, involving only 1 or 2 dermatomes. Most cases of hepatic disorders were Grade 1 or 2 hepatic transaminase elevations. There was 1 case of venous thromboembolic event (VTE; concurrent pulmonary embolism and deep vein thrombosis [DVT] in a patient with a history of DVT) and 3 cases of malignancy. Adjudicated major adverse cardiovascular events (Table 1) occurred in 2 pts (1 with non-fatal myocardial infarction and 1 with non-fatal stroke) who had underlying risk factors for cardiovascular disease. There were no deaths, active tuberculosis, or renal dysfunction.

Conclusion:

UPA 15 mg was effective in treating the signs and symptoms of RA and in improving physical function over 64 wks with no new safety signals1 in csDMARD-IR pts with RA from China, Brazil, and South Korea.

References:

[1]Zeng A, et al. Ann Rheum Dis 2020;79(Suppl 1):1016 [abstract SAT0160]

Table 1.

TEAEs at Wk 64

Event (E/100 PY)UPA 15 mg(n=322; PY=334.5)Any AE421.5 (399.8–444.1) Serious AE19.1 (14.7–24.4) AE leading to discontinuation of study drug9.0 (6.1–12.8) Deathsa0AEs of special interest Serious infection8.1 (5.3–11.7) Opportunistic infection0.9 (0.2–2.6) Herpes zoster9.0 (6.1–12.8) Hepatic disorder42.2 (35.5–49.7) Gastrointestinal perforation (adjudicated)0.3 (0.0–1.7) Any malignancy (excluding NMSC)0.6 (0.1–2.2) NMSC0.3 (0.0–1.7) MACE (adjudicated)b0.6 (0.1–2.2) VTE (adjudicated)c0.3 (0.0–1.7) Anemia11.1 (7.8–15.2) Neutropenia11.7 (8.3–15.9) Lymphopenia7.8 (5.1–11.4) CPK elevation11.1 (7.8–15.2)

aIncluding non-treatment-emergent deaths. bDefined as cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. cIncluding DVT and pulmonary embolism.

AE, adverse event; CPK, creatine phosphokinase; E, events; MACE, major adverse cardiovascular event; NMSC, non-melanoma skin cancer

Acknowledgements:

AbbVie funded this study; contributed to its design; participated in data collection, analysis, and interpretation of the data; and in the writing, review, and approval of the abstract. No honoraria or payments were made for authorship. Yanna Song, PhD, of AbbVie provided statistical support. Medical writing support was provided by Laura Chalmers, PhD, of 2 the Nth (Cheshire, UK), and was funded by AbbVie.

Disclosure of Interests:

Xiaofeng Zeng: None declared, Dongbao Zhao: None declared, Sebastiao Radominski: None declared, MAURO KEISERMAN: None declared, Chang-Keun Lee: None declared, Naomi Martin Employee of: AbbVie employee and may own stock or options, Sebastian Meerwein Employee of: AbbVie employee and may own stock or options, Yunxia Sui Employee of: AbbVie employee and may own stock or options, Won Park: None declared

POS0911 SIMILAR CLINICAL RESPONSES ACHIEVED WITH LOWER VERSUS STANDARD DOSES OF INFLIXIMAB BIOSIMILAR CT-P13 IN PATIENTS WITH ANKYLOSING SPONDYLITIS: REAL-WORLD RESULTS FROM THE RAAS STUDY

Background:

CT-P13, an infliximab biosimilar, is effective for treating ankylosing spondylitis (AS) at a dose of 5 mg/kg infused once every 6–8 weeks. Evidence suggests that patients with AS may benefit from a lower dose, and individualised dose/interval adjustments should be based on treatment response.

Objectives:

To analyse real-world treatment patterns (doses and infusion intervals) and outcomes for CT-P13-treated patients with AS over 5 years.

Methods:

The RAAS study collected medical record data for adults with AS treated with CT-P13 at five referral hospitals in the Republic of Korea (2012–2017). Patients were infliximab naïve at CT-P13 initiation (‘naïve’) or had switched to CT-P13 from reference infliximab (‘switched’). Patients were analysed by baseline dose (BD) (<4 mg/kg; ≥4–<5 mg/kg; ≥5 mg/kg), defined as the third (naïve) or first (switched) infusion dose. Baseline infusion intervals were the average of the three infusion intervals after BD. Over time, patients with both constant dose and infusion interval were compared with those with changes in dose and/or infusion interval. Data were analysed by Kruskal–Wallis test, chi-squared test and one-way analysis of variance, and drug survival by log-rank test.

Results:

Overall, 337 patients (219 naïve; 118 switched) were identified. Of those with BD data, 71, 117 and 82 patients had BDs of <4 mg/kg, ≥4–<5 mg/kg and ≥5 mg/kg, respectively. Most patients were male (74.8%). Patients with higher BDs tended to have higher Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores; switched patients had lower scores than naïve patients. Of 186 evaluable patients (118 naïve; 68 switched), 85 (46 naïve; 39 switched) did not have dose and/or interval changes (‘combined constant’ group). More naïve (n=72; 61.0%) versus switched (n=29; 42.6%) patients had dose and/or interval changes (‘combined changed’ group). Considering dose and interval separately, 18/235 evaluable patients (152 naïve; 83 switched) had dose changes (12 increased; 6 decreased) and 110/224 evaluable patients (140 naïve; 84 switched) had interval changes (79 increased; 31 decreased). Cumulative annual doses were similar between naïve and switched patients; switched patients had longer infusion intervals than naïve patients (Figure 1). There were no significant differences in drug survival between BD groups overall or for naïve and switched patients. BASDAI scores over time showed that disease activity was well controlled (Table 1). Patients in the combined changed versus combined constant group had greater improvements in BASDAI score.

Table 1.

BASDAI scores

GroupStatisticW0W54W102W156W210Combined constantTotal (N=85)n7273574231Mean (SD)5.50 (3.12)2.50 (1.71)2.35 (1.66)2.42 (1.66)2.36 (1.68)Median6.322.602.402.552.60Naïve (n=46)n3939261812Mean (SD)7.86 (1.45)2.49 (1.82)2.41 (1.75)2.34 (1.70)1.94 (1.58)Median7.802.201.751.901.44Switched (n=39)n3334312419Mean (SD)2.71 (2.07)2.50 (1.60)2.31 (1.60)2.48 (1.67)2.63 (1.73)Median2.582.752.502.802.70Combined changedTotal (N=101)n8785765335Mean (SD)5.68 (2.89)1.81 (1.45)1.58 (1.27)1.49 (1.34)1.40 (1.24)Median6.701.321.191.201.00Naïve (n=72)n6360543418Mean (SD)7.18 (1.37)2.01 (1.44)1.65 (1.22)1.54 (1.26)1.52 (0.97)Median7.301.831.351.311.35Switched (n=29)n2425221917Mean (SD)1.74 (1.94)1.33 (1.36)1.42 (1.41)1.39 (1.50)1.28 (1.50)Median0.920.800.850.700.58

SD, standard deviation; W, Week

Conclusion:

These real-world data demonstrate that adjusting dose and infusion interval can improve clinical outcomes for CT-P13-treated patients with AS. Drug survival and BASDAI results show that patients with lower baseline BASDAI receiving low CT-P13 doses can achieve the same outcomes as those dosed with ≥5 mg/kg. Findings support the lack of impact of switching from reference infliximab to CT-P13 on efficacy, underlining conclusions previously drawn for efficacy and safety.1

References:

[1]Kim T-H, et al. Clin Drug Investig 2020;40:541–53.

Acknowledgements:

Funding: This study was supported by Celltrion Healthcare Co., Ltd. (Incheon, Republic of Korea). Medical writing support was provided by Beatrice Tyrrell, DPhil (Aspire Scientific, Bollington, UK), and funded by Celltrion Healthcare Co., Ltd. (Incheon, Republic of Korea).

Disclosure of Interests:

Shin-Seok Lee: None declared, Tae-Hwan Kim: None declared, Won Park Consultant of: Celltrion, Inc., Yeong Wook Song: None declared, Chang-Hee Suh Speakers bureau: AbbVie Inc., Astellas Pharma Inc., Samsung Bioepis Co., Ltd, Consultant of: Celltrion Healthcare Co., Ltd., Eli Lilly and Company, GlaxoSmithKline plc, Janssen Pharmaceuticals, Yungjin Pharmaceutical, Co., Ltd, SooKyoung Kim Shareholder of: Celltrion Healthcare Co., Ltd., Employee of: Celltrion Healthcare Co., Ltd., DaeHyun Yoo Speakers bureau: Celltrion, Consultant of: Celltrion, Grant/research support from: Celltrion

Analysis of local invasion and regional spread in malignant sublingual gland tumour: Implications for surgical planning

Malignant tumours arising from the sublingual glands are very rare, and the extent and frequency of local invasion or regional spread in malignant sublingual gland tumour (MSLT) has not been fully studied due to the disease rarity. To provide comprehensive features of local and regional spread of MSLT, we reviewed 20 surgical cases for detailed pathological analyses among 26 cases diagnosed as having primary MSLT. Adenoid cystic carcinoma (ACC) was the most common pathological subtype, followed by mucoepidermoid carcinoma. Disease-free and overall survivals at 5 years were 76.1 % and 77.7 %, respectively. High-grade malignant tumours and grade 2-3 ACC accounted for 41.7 % and 85.7 %. Clinical and pathological extraparenchymal extensions were found in 34.6 % and 80.0 %, respectively. Tumour invasion to the lingual nerve and submandibular gland/ductal system were also detected in 40.0 % and 28.6 %. The incidences of lingual nerve invasion in ACC and ACC ≥4 cm were 30.8 % and 42.9 %. Regional nodal involvement occurred in seven of 26 cases, and all metastatic lymph nodes were found in neck levels Ib and IIa. In summary, a significant portion of MSLT cases consisted of high-grade tumours and grade 2-3 ACC; therefore local invasion into adjacent structures should be cautiously evaluated in cases of MSLT.

SAT0160 EFFICACY AND SAFETY OF UPADACITINIB IN PATIENTS FROM CHINA, BRAZIL, AND SOUTH KOREA WITH RHEUMATOID ARTHRITIS WHO HAVE HAD INADEQUATE RESPONSE TO CONVENTIONAL SYNTHETIC DISEASE-MODIFYING ANTIRHEUMATIC DRUGS

Background:

Upadacitinib (UPA), an oral, selective JAK-1 inhibitor was effective in global ph 3 trials in rheumatoid arthritis (RA) patients with inadequate response (IR)/intolerance to csDMARDs and bDMARDs.

Objectives:

This Phase 3, randomized, double-blind, placebo (PBO)-controlled study assessed the efficacy and safety of UPA in combination with csDMARDs in csDMARD-IR patients with RA from China, Brazil, and South Korea.

Methods:

Patients were randomized 1:1 to receive UPA 15 mg once daily (QD) or PBO in combination with csDMARDs. The primary endpoint was ACR20 response at Week 12, using non-responder imputation.

Results:

338 patients were randomized, and 310 (91.7%) completed Week 12. At Week 12, statistically significantly more patients receiving UPA vs PBO achieved the primary endpoint of ACR20 (71.6% vs 31.4%, p<0.001). UPA also demonstrated statistically significant improvements in all ranked secondary endpoints vs PBO at Week 12 (Table 1), including mean change in DAS28(CRP), HAQ-DI, and SF-36 PCS, and patients achieving DAS28(CRP) ≤3.2, DAS28(CRP) <2.6, and CDAI ≤10. Greater responses were also seen with UPA vs PBO for other key secondary endpoints including ACR50 and ACR70. Onset of UPA action was rapid with more patients on UPA achieving ACR20 by Week 1 (25.4% vs 5.9%, p<0.001). The frequency of AEs (61.5% vs 49.1%) and serious AEs (7.1% vs 3.0%) was higher with UPA vs PBO. The frequency of AEs of special interest was generally similar between UPA and PBO, with the exception of herpes zoster (1.8% vs 0.6%), hepatic disorders (9.5% vs 7.1%), neutropenia (3.0% vs 0%), and elevated creatine phosphokinase (1.8% vs 0.6%), which were higher with UPA. One case of breast cancer (on Day 1 of study) and one VTE (pulmonary embolism and deep vein thrombosis in a patient with history of deep vein thrombosis) were reported with UPA treatment.

Table 1.

Efficacy endpoints at Week 12

EndpointaUPA 15 mg QD (n=169)PBO(n=169)Primary endpointACR20, %71.6***31.4Secondary endpointsΔ DAS28(CRP)-2.56***-0.95Δ HAQ-DI-0.62***-0.18Δ SF-36 PCS8.93c***3.36dDAS28(CRP) ≤3.2, %46.2***13.6DAS28(CRP) <2.6, %29.6***5.3CDAI ≤10, %35.5***11.2ACR50, %b40.8***8.3ACR70, %b21.3***3.6ACR20 at Week 1, %b25.4***5.9

***p<0.001 vs PBO

aNRI for binary endpoints; ANCOVA with multiple imputation for DAS28(CRP) and HAQ-DI; mixed model repeated measures for other continuous endpoints

bUnranked secondary endpoint.cn=143.dn=149

Conclusion:

Efficacy of UPA was demonstrated in this csDMARD-IR population from China, Brazil, and South Korea. The safety of UPA was comparable with the global Phase 3 program.

Disclosure of Interests: :

Xiaofeng Zeng Consultant of: MSD Pharmaceuticals, Dongbao Zhao: None declared, Sebastiao Radominski: None declared, MAURO KEISERMAN Speakers bureau: Pfizer, Abbott, Actelion, AstraZeneca, Amgen, Roche, Bristol Myers Squibb, and Janssen and has received clinical trial honoraria from Pfizer, Amgen, AstraZeneca, Anthera Pharmaceuticals, Bristol-Myers Squibb, Biogen Idec Inc, Celltrion Inc., Eli Lilly, Human Genome Sciences, Novartis, Roche, Sanofi, UCB Inc., Chang-Keun Lee: None declared, Sebastian Meerwein Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Jeffrey Enejosa Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Yunxia Sui Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Mohamed-Eslam Mohamed Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Won Park: None declared

SAT0355 WNT SIGNALING CAN PLAY AN IMPORTANT ROLE IN VASCULAR CALCIFICATION IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Vascular calcification is highly correlated with atherosclerosis. Ankylosing spondylitis (AS) is associated with a process of accelerated atherosclerosis. Wnt signaling plays an important role in the pathogenesis of vascular calcification. However, there has been no study of the role of Wnt signaling in vascular calcification in patients with AS.

Objectives:

We investigated the relationship between vascular calcification and Wnt signaling in patients with AS.

Methods:

Sixteen male patients aged over 20 years with AS were enrolled. They fulfilled the modified New York criteria and each of their ankylosing spondylitis disease activity score was more than 2.1. Sex and age matched nineteen healthy controls were also recruited.

Mouse MOVAS vascular smooth muscle cell line (American Type Culture Collection, ATCC® CRL-2797™) were stabilized in maintain media for 24 hours. Then media were exchanged for the 10% serum of patients with AS or controls in maintain media. Cells were stimulated for another 72hours. We exchanged this medium with calcification medium. Cells were cultured until 2 weeks then stained with Alizarin Red S and the optical density (OD) was measured.

For Western blotting and RT-qPCR, cells were stabilized for 24 hours and stimulated for another 72 hours through the same procedure as that of Alizarin Red S staining. After cell stimulation, the level of mRNA and protein were measured by RT-qPCR and western blot, respectably. We measure the level of Low-density lipoprotein receptor-related protein (LRP)5, LRP6, Dickkopf-related protein 1, Wnt3a, matrix metalloproteinase-7(MMP-7), beta-catenin for canonical Wnt signaling; Receptor Tyrosine Kinase Like Orphan Receptor 2, Wnt5a, Runt-related transcription factor 2 (RUNX2) for non-canonical Wnt signaling. We also checked the level of Alkaline phosphatase (ALP), IL-17, IL-23 and TNF-a.

Results:

The level of OD of MOVAS cells treated with serum from AS patients (19.503 ± 6.422, mean ± SD) was significantly higher than that from controls (10.994 ± 4.291) (P=0.000, Mann-Whitney test). The protein level of MMP-7 and beta-catenin of MOVAS cells treated with serum from AS patients (1.881 ± 0.687; 1.301 ± 0.342) was significantly higher than that from controls (0.779 ± 0.48; 0.854 ± 0.285) respectively (P=0.005,: P=0.002, Mann-Whitney test). The mRNA level of RUNX2, ALP, IL-17 and IL-23 of serum from AS patients (2.697 ± 1.46; 2.687 ± 1.753; 2.253 ± 1.128; 2.574 ± 1.142) was significantly higher than that from controls (1.396 ± 0.587; 1.696 ± 0.637; 1.358 ± 0.473; 1.386 ± 0.714) respectively (P=0.000; P=0.037; P=0.044; P=0.007, Mann-Whitney test). There was positive correlation between the mRNA level of WNT5a and RUNX2 (rho=-0.705, p=0.002, Spearman rank correlation coefficient) and the protein level of WNT5a and ALP, MMP-7 and TNF-a, MMP-7 and IL-17, MMP-7 and IL-23 (rho=-0.601, p=0.039; rho=-0.769, p=0.026; rho=-0.828, p=0.011; rho=-0.777, p=0.003), respectively.

Conclusion:

1. Vascular smooth muscle cell calcification was increased in patients with ankylosing spondylitis than those of the control group.

2. The level of several molecules(i.e. Beta-catenin, RUNX2, MMP-7) related to Wnt signaling of vascular smooth muscle cells treated with serum of patients with AS was elevated significantly compared to those of controls and positively related.

3. Wnt signaling can play an important role in vascular calcification in patients with ankylosing spondylitis.

Acknowledgments:

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03030825)

Disclosure of Interests:

None declared

Incidence, survival, and risk of cardiovascular events in adult inflammatory myopathies in South Korea: a nationwide population-based study

OBJECTIVE

Epidemiological studies on inflammatory myopathies (IMs) show widely variable results, and studies on Asians are lacking. Despite emerging interest in the cardiovascular disease (CVD) risk associated with IMs, the prevalence of CVD in IM patients and its impact on mortality remain unclear. We conducted a nationwide, population-based study on the incidence, mortality, and associated major CVD events of IMs in the Republic of Korea over 11 years.

METHOD

Using the nationwide, population-based National Health Insurance claims database and the Rare Intractable Disease registration programme, we estimated incidence, mortality, and CVD occurrence. Survival was examined using the Kaplan-Meier method. Mortality rate in IMs with CVD was analysed by Cox proportional hazards regression.

RESULTS

There were 3014 incident cases, 640 of whom died during the study period. The mean annual incidence was 7.16/10⁶. Dermatomyositis (DM) and polymyositis (PM) had 5 year survival rates of 76.8% and 79.3%, respectively. Cardiovascular events occurred in 155 patients and 40.6% of IM patients with CVD died. Acute myocardial infarction in men had the highest risk of any CVD event in both DM [standardized incidence ratio (SIR) 4.2, 95% confidence interval (95% CI) 2.4-7.2] and PM (SIR 3.5, 95% CI 1.8-7.0). Haemorrhagic stroke had the highest hazard ratio (HR) in both DM (HR 2.31, 95% CI 1.13-4.70) and PM patients (HR 2.10, 95% CI 1.03-4.27) compared with the general population with CVD.

CONCLUSION

We found persistently low incidence, poor survival, and high major CVD incidence in IMs, and increased mortality in IMs with CVD.

Impact of genomic alterations on lapatinib treatment outcome and cell-free genomic landscape during HER2 therapy in HER2+ gastric cancer patients

Background

To identify predictive markers for responders in lapatinib-treated patients and to demonstrate molecular changes during lapatinib treatment via cell-free genomics.

Patients and methods

We prospectively evaluated the efficacy of combining lapatinib with capecitabine and oxaliplatin as first line neoadjuvant therapy in patients with previously untreated, HER2-overexpressing advanced gastric cancer. A parallel biomarker study was conducted by simultaneously performing immunohistochemistry and next-generation sequencing (NGS) with tumor and blood samples.

Results

Complete response was confirmed in 7/32 patients (21.8%), 2 of whom received radical surgery with pathologic-confirmed complete response. Fifteen partial responses (46.8%) were observed, resulting in a 68.6% overall response rate. NGS of the 16 tumor specimens demonstrated that the most common co-occurring copy number alteration was CCNE1 amplification, which was present in 40% of HER2+ tumors. The relationship between CCNE1 amplification and lack of response to HER2-targeted therapy trended toward statistical significance (66.7% of non-responders versus 22.2% of responders harbored CCNE1 amplification; P = 0.08). Patients with high level ERBB2 amplification by NGS were more likely to respond to therapy, compared with patients with low level ERBB2 amplification (P = 0.02). Analysis of cfDNA showed that detectable ERBB2 copy number amplification in plasma was predictive to the response (100%, response rate) and changes in plasma-detected genomic alterations were associated with lapatinib sensitivity and/or resistance. The follow-up cfDNA genomics at disease progression demonstrated that there are emergences of other genomic aberrations such as MYC, EGFR, FGFR2 and MET amplifications.

Conclusions

The present study showed that HER2+ GC patients respond differently according to concomitant genomic aberrations beyond ERBB2, high ERBB2 amplification by NGS or cfDNA can be a positive predictor for patient selection, and tumor genomic alterations change significantly during targeted agent therapy.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Background

In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy.

Methods

This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled.

Acknowledgement

This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018).

Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-04-02.

Abstract P3-12-12: Impact of regional nodal irradiation for breast cancer patients with supraclavicular and/or internal mammary lymph node involvement: A multicenter, retrospective study (KROG 16-14)

Purpose: To evaluate the treatment outcomes of radiotherapy (RT) for breast cancer with ipsilateral supraclavicular (SCL) and/or internal mammary (IMN) lymph node involvement.

Methods: A total of 353 patients from 11 institutions were included. One hundred and thirty-six patients had SCL involvement, 148 had IMN involvement, and 69 had both. All patients received neoadjvant systemic therapy followed by breast conserving surgery or mastectomy, and postoperative RT to whole breast/chest wall. As for regional lymph node irradiation, SCL RT was given to 344 patients, and IMN RT to 236 patients. The median RT dose was 50.4 Gy.

Results: The median follow-up duration was 61 months (range, 7-173). In-field progression was present in SCL (n=20) and/or IMN (n=7). The 5-year disease-free survival (DFS) and overall survival rates were 57.8% and 75.1%, respectively. On multivariate analysis, both SCL/IMN involvement, number of axillary lymph node ≥4, triple negative subtype, and mastectomy were significant adverse prognosticators for DFS (p = 0.022, 0.001, 0.001, and 0.004, respectively). Regarding the impact of regional nodal irradiation, SCL RT dose ≥54 Gy was not associated with DFS (5-yr rate, 52.9% vs. 50.9%, p = 0.696) in SCL-involved patients, and the receipt of IMN RT was not associated with DFS (5-yr rate, 56.1% vs. 78.1%, p = 0.099) in IMN-involved patients.

Conclusion: Neoadjuvant chemotherapy followed by surgery and postoperative RT achieved an acceptable in-field regional control rate in patients with SCL and/or IMN involvement. However, a higher RT dose to SCL or IMN RT was not associated with the improved DFS in these patients.

Citation Format: Kim K, Jeong Y, Shin KH, Kim JH, Ahn SD, Kim SS, Suh C-O, Kim YB, Choi DH, Park W, Cha J, Chun M, Lee DS, Lee SY, Kim JH, Park HJ. Impact of regional nodal irradiation for breast cancer patients with supraclavicular and/or internal mammary lymph node involvement: A multicenter, retrospective study (KROG 16-14) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-12.

Human skin-depigmenting effects of resveratryl triglycolate, a hybrid compound of resveratrol and glycolic acid

OBJECTIVES

Resveratryl triglycolate (RTG) is a hybrid compound derived by the esterification of resveratrol with glycolic acid. This compound has been previously shown to inhibit cellular melanin synthesis in vitro. This study aimed to examine the in vivo skin-depigmenting efficacy of RTG in human participants.

METHODS

In total, 22 women aged between 25 and 49 years with Fitzpatrick skin type III or IV were enrolled. Their forearms were exposed to UV to induce artificial pigmentation. The test product containing 0.4% RTG or the control product was applied twice daily for up to 8 weeks after the artificial pigmentation. The participants visited the research centre every 2 weeks and were subjected to skin assessments.

RESULTS

Visual assessment of pigmentation degree and instrumental analysis of melanin index, skin lightness (L* value) and skin colour (individual typology angle, ITAo ) indicated enhanced depigmentation of the skin in the test group, compared with the control group, in Weeks 6 and 8 (P < 0.05). No adverse skin reactions were observed in any of the participants during the entire test.

CONCLUSION

This study demonstrated the skin-depigmenting effects of RTG in human participants.

Incidence and risk factors for healthcare utilisation among patients discharged on outpatient parenteral antimicrobial therapy

Outpatient parenteral antimicrobial therapy (OPAT) programmes facilitate hospital discharge, but patients remain at risk of complications and consequent healthcare utilisation (HCU). Here we elucidated the incidence of and risk factors associated with HCU in OPAT patients. This was a retrospective, single-centre, case-control study of adult patients discharged on OPAT. Cases (n = 63) and controls (n = 126) were patients that did or did not utilise the healthcare system within 60 days. Characteristics associated with HCU in bivariate analysis (P ≤ 0.2) were included in a multivariable logistic regression model. Variables were retained in the final model if they were independently (P < 0.05) associated with 60-day HCU. Among all study patients, the mean age was 55 ± 16, 65% were men, and wound infection (22%) and cellulitis (14%) were common diagnoses. The cumulative incidence of 60-day unplanned HCU was 27% with a disproportionately higher incidence in the first 30 days (21%). A statin at discharge (adjusted odds ratios (aOR) 0.23, 95% confidence intervals (CIs) 0.09-0.57), number of prior admissions in past 12 months (aOR 1.48, 95% CIs 1.05-2.10), and a sepsis diagnosis (aOR 4.62, 95% CIs 1.23-17.3) were independently associated with HCU. HCU was most commonly due to non-infection related complications (44%) and worsening primary infection (31%). There are multiple risk factors for HCU in OPAT patients, and formal OPAT clinics may help to risk stratify and target the highest risk groups.

Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model

The simulation of Sahel rainfall and its onset during the West African Monsoon (WAM) remains a challenge for current state-of-the-art climate models due to their persistent biases, especially in the tropical Atlantic region. Here we show that improved representation of Atlantic Cold Tongue (ACT) development is essential for a more realistic seasonal evolution of the WAM, which is due to a further inland migration of the precipitation maximum. The observed marked relationship between ACT development and Sahel rainfall onset only can be reproduced by a climate model, the Kiel Climate Model (KCM), when sufficiently high resolution in its atmospheric component is employed, enabling enhanced equatorial Atlantic interannual sea surface temperature variability in the ACT region relative to versions with coarser atmospheric resolution. The ACT/Sahel rainfall relationship in the model critically depends on the correct seasonal phase-locking of the interannual variability rather than on its magnitude. We compare the KCM results with those obtained from climate models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5).