Tumor-Infiltrating Lymphocytes Refine Outcomes in Triple-Negative Breast Cancer Treated with Anthracycline-Free Neoadjuvant Chemotherapy

PURPOSE

Stromal tumor-infiltrating lymphocytes (sTIL) are associated with pathologic complete response (pCR) and long-term outcomes for triple-negative breast cancer (TNBC) in the setting of anthracycline-based chemotherapy. The impact of sTILs on refining outcomes beyond prognostic information provided by pCR in anthracycline-free neoadjuvant chemotherapy (NAC) is not known.

EXPERIMENTAL DESIGN

This is a pooled analysis of two studies where patients with stage I (T>1 cm)-III TNBC received carboplatin (AUC 6) plus docetaxel (75 mg/m2; CbD) NAC. sTILs were evaluated centrally on pre-treatment hematoxylin and eosin slides using standard criteria. Cox regression analysis was used to examine the effect of variables on event-free survival (EFS) and overall survival (OS).

RESULTS

Among 474 patients, 44% had node-positive disease. Median sTILs were 5% (range, 1%-95%), and 32% of patients had ≥30% sTILs. pCR rate was 51%. On multivariable analysis, T stage (OR, 2.08; P = 0.007), nodal status (OR, 1.64; P = 0.035), and sTILs (OR, 1.10; P = 0.011) were associated with pCR. On multivariate analysis, nodal status (HR, 0.46; P = 0.008), pCR (HR, 0.20; P < 0.001), and sTILs (HR, 0.95; P = 0.049) were associated with OS. At 30% cut-point, sTILs stratified outcomes in stage III disease, with 5-year OS 86% versus 57% in ≥30% versus <30% sTILs (HR, 0.29; P = 0.014), and numeric trend in stage II, with 5-year OS 93% versus 89% in ≥30% versus <30% sTILs (HR, 0.55; P = 0.179). Among stage II-III patients with pCR, EFS was better in those with ≥30% sTILs (HR, 0.16; P, 0.047).

CONCLUSIONS

sTILs density was an independent predictor of OS beyond clinicopathologic features and pathologic response in patients with TNBC treated with anthracycline-free CbD chemotherapy. Notably, sTILs density stratified outcomes beyond tumor-node-metastasis (TNM) stage and pathologic response. These findings highlight the role of sTILs in patient selection and stratification for neo/adjuvant escalation and de-escalation strategies.

Assessment of a Genomic Assay in Patients With ERBB2-Positive Breast Cancer Following Neoadjuvant Trastuzumab-Based Chemotherapy With or Without Pertuzumab

Importance

Biomarkers to guide the use of pertuzumab in the treatment of early-stage ERBB2 (formerly HER2)-positive breast cancer beyond simple ERBB2 status are needed.

Objective

To determine if use of the HER2DX genomic assay (Reveal Genomics) in pretreatment baseline tissue samples of patients with ERBB2-positive breast cancer is associated with response to neoadjuvant trastuzumab-based chemotherapy with or without pertuzumab.

Design, Setting, and Participants

This is a retrospective diagnostic/prognostic analysis of a multicenter academic observational study in Spain performed during 2018 to 2022 (GOM-HGUGM-2018-05). In addition, a combined analysis with 2 previously reported trials of neoadjuvant cohorts with results from the assay (DAPHNe and I-SPY2) was performed. All patients had stage I to III ERBB2-positive breast cancer, signed informed consent, and had available formalin-fixed paraffin-embedded tumor specimens obtained prior to starting therapy.

Exposures

Patients received intravenous trastuzumab, 8 mg/kg, loading dose, followed by 6 mg/kg every 3 weeks in combination with intravenous docetaxel, 75 mg/m2, every 3 weeks and intravenous carboplatin area under the curve of 6 every 3 weeks for 6 cycles, or this regimen plus intravenous pertuzumab, 840 mg, loading dose, followed by an intravenous 420-mg dose every 3 weeks for 6 cycles.

Main Outcome and Measures

Association of baseline assay-reported pathologic complete response (pCR) score with pCR in the breast and axilla, as well as association of baseline assay-reported pCR score with response to pertuzumab.

Results

The assay was evaluated in 155 patients with ERBB2-positive breast cancer (mean [range] age, 50.3 [26-78] years). Clinical T1 to T2 and node-positive disease was present in 113 (72.9%) and 99 (63.9%) patients, respectively, and 105 (67.7%) tumors were hormone receptor positive. The overall pCR rate was 57.4% (95% CI, 49.2%-65.2%). The proportion of patients in the assay-reported pCR-low, pCR-medium, and pCR-high groups was 53 (34.2%), 54 (34.8%), and 48 (31.0%), respectively. In the multivariable analysis, the assay-reported pCR score (as a continuous variable from 0-100) showed a statistically significant association with pCR (odds ratio [OR] per 10-unit increase, 1.43; 95% CI, 1.22-1.70; P < .001). The pCR rates in the assay-reported pCR-high and pCR-low groups were 75.0% and 28.3%, respectively (OR, 7.85; 95% CI, 2.67-24.91; P < .001). In the combined analysis (n = 282), an increase in pCR rate due to pertuzumab was found in the assay-reported pCR-high tumors (OR, 5.36; 95% CI, 1.89-15.20; P < .001) but not in the assay-reported pCR-low tumors (OR, 0.86; 95% CI, 0.30-2.46; P = .77). A statistically significant interaction between the assay-reported pCR score and the effect of pertuzumab in pCR was observed.

Conclusions and Relevance

This diagnostic/prognostic study demonstrated that the genomic assay predicted pCR following neoadjuvant trastuzumab-based chemotherapy with or without pertuzumab. This assay could guide therapeutic decisions regarding the use of neoadjuvant pertuzumab.

Abstract P3-01-04: A real-world evidence study of everolimus plus endocrine therapy beyond CDK4/6 inhibitors for HR+/HER2- advanced breast cancer

Introduction Since the approval a decade ago of everolimus in combination with endocrine therapy (ET), the treatment landscape of metastatic breast cancer (mBC) has changed dramatically. Endocrine monotherapy after progression to CDK4/6 inhibitors has shown a limited progression-free survival (PFS) below 3 months. Evidence of the efficacy of everolimus plus ET after CDK4/6 inhibitors is scarce. Methods We performed a retrospective observational study of patients with mBC treated with everolimus between September 2011 and April 2022 in 4 Spanish hospitals. Clinical and demographic data were collected from medical records. Our main objective was to estimate the median progression-free survival (mPFS) for everolimus + ET in patients previously treated with a CDK4/6 inhibitor. We also collected the adverse events (AE) related to everolimus. Quantitative variables were summarized with medians (range), and qualitative variables with proportions. We used the Kaplan-Meier method for survival estimates. Results We identified a total of 297 mBC patients treated with everolimus plus ET. The median follow-up time was 20 months (interquartile range: 1 – 97 months). In this cohort, the median age at diagnosis was 49 years (26 – 84 years). At the moment of starting everolimus, the median number of previous lines of treatment was 2 (0 – 12), 22% of patients were ‘de novo’ metastatic, 67% presented visceral involvement, 40% had received previous chemotherapy for advanced disease, and 51% (n=152) had received a previous CDK4/6 inhibitor. The ET combined with everolimus was exemestane (77%), fulvestrant (18%), and tamoxifen (5%). 45% of patients were alive at data cut-off. In patients previously treated with a CDK4/6 inhibitor, the estimated median PFS (mPFS) was 5.9 months (95%CI: 5.0 – 7.8 months). In patients without visceral involvement (n=52), mPFS was 7.2 months (95%CI: 5.5 – 11.0 months), and 5.6 months (95%CI: 3.9 – 7.8 months) in the presence of visceral metastasis (n=100). In patients without previous chemotherapy in the metastatic setting (n=109), mPFS was 7.2 months (95%CI: 5.9 – 8.4 months), and 4.6 months (95%CI: 3.1 – 5.7 months) for patients who had received previous chemotherapy (n=43). For patients without a previous CDK4/6 inhibitor (n=145), the median PFS was 8.3 months (95%CI: 6.4 – 10.3 months). Everolimus starting doses were 10 mg (83%), 5 mg (15%), and 7.5 mg (2%). Dexamethasone mouthwash was used by 44% of patients. The most frequent AE were mucositis (51%; 3% grade 3), anemia (41%; 3% grade 3), hyperglycemia (34%; 2% grade 3), rash (28%; 2% grade 3), neumonitis (21%; 2% grade 3), and diarrhea (17%; 1% grade 3). There were no grade 4-5 adverse events. Dose reduction was made in 35% of patients, and in 16% of patients the treatment was discontinued due to toxicity. Conclusions In our cohort, the use of everolimus plus ET in mBC patients previously treated with a CDK4/6 inhibitor showed a clinically significant benefit in terms of PFS, especially in patients without visceral metastasis, and no previous chemotherapy for advanced disease. In this real-world study, the toxicity profile of everolimus was manageable.

Citation Format: Rodrigo Sánchez-Bayona, Manuel Alva, Alfonso López de sa, Yolanda Jerez Gilarranz, Ana Sánchez de torre, Pablo Tolosa, Alicia de luna, Sara López-Tarruella, Laura Lema, Fernando Moreno, Isabel Echavarria, Ainhoa Madariaga, Javier Benítez, Blanca Herrero, Macarena Rey, Justo Ortega, Salvador Gámez, Andrea Modrego, Rocío Martín Lozano, Luis Figuero-Pérez, Roberto Jiménez, Marta González Sevilla, Irene González, Marianela Bringas Beranek, María de toro, Tatiana Massarrah, María del Monte-Millán, Marina Pinardo, Luis Manso, Coralia Bueno-Muiño, José Ángel García-Sáenz, Miguel Martín, Eva Ciruelos. A real-world evidence study of everolimus plus endocrine therapy beyond CDK4/6 inhibitors for HR+/HER2- advanced breast cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-01-04.

Abstract P6-01-46: Independent validation of the HER2DX genomic test in HER2-positive breast cancer treated with neoadjuvant docetaxel, carboplatin, trastuzumab +/- pertuzumab (TCH/TCHP): a correlative analysis from a multicenter academic study

Background: HER2DX (Prat et al. EBiomedicine 2022) is a 27-gene prognostic (risk-score) and predictive (pathological complete response [pCR]-score) assay in early-stage HER2+ breast cancer based on clinical data and the expression of 4 gene signatures (immune, proliferation, luminal differentiation and HER2 amplicon). Here, we aim to evaluate, for the first time, the ability of HER2DX to predict pCR following neoadjuvant TCH or TCHP in HER2+ disease. Methods: Standardized HER2DX was performed in a central lab on baseline pre-treatment FFPE tumor biopsies from the GOM-HGUGM-2018-05 study in Spain, a consecutive retrospective series of patients (pts) with newly diagnosed stage I-III HER2+ breast cancer eligible for neoadjuvant therapy. Pts received standard 6 cycles of docetaxel, carboplatin and trastuzumab (TCH) or TCH with pertuzumab (TCHP) regimens. Primary aim was to test the ability of HER2DX pCR score to predict pCR (ypT0/is ypN0). Secondary objectives were to test the ability of HER2DX pCR score to predict pCR independently of clinical-pathological variables and the PAM50 subtype (HER2-enriched versus not), and to evaluate the association of HER2DX pCR score with the HER2DX risk-score. Logistic regression and receiver-operator curve (ROC) analysis were assessed. Statistical analyses were performed in R code 4.0.5. Results: HER2DX was evaluated in 155 pts (97%) enrolled in the study with available RNA (as of June 2022). Mean age of pts was 50 (range 22-74) and 55.2% of pts (n=85) were pre-menopausal. Clinical T2-4 disease represented 77.4% of cases (n=120), clinical node-positive disease (cN1-3) represented 63.9% of cases (n=99), and 68.0% of tumors (n=105) were hormone receptor-positive. The overall pCR rate was 57.4% (95% confidence interval [CI] 50-65): 52.2% (95% CI 40-64) with TCH (n=67) and 61.4% (95% CI 50-72) with TCHP (n=88). The proportion of HER2DX low-, medium- and high-pCR groups was 34.2%, 34.8% and 31.0%, respectively. HER2DX pCR score (as a continuous variable from 0 to 100) was significantly associated with pCR (odd ratio [OR]=1.03, p=5.91e-07). The pCR rates in HER2DX pCR-high and pCR-low groups were 75.0% and 28.0% (OR=7.6, 95% CI 3.2-19.1, p=7.14e-06), respectively. In pts treated with TCHP, the pCR rates in HER2DX pCR-high and pCR-low groups were 85.7% and 27.3% (OR=16.0, 95% CI 4.3-59.01, p=3.2e-05), respectively. The AUC ROC of HER2DX pCR score (as a continuous variable) and pCR status was 0.746 (in all pts) and 0.812 (in pts treated with TCHP). HER2DX pCR score was significantly associated with pCR independently of hormone receptor status, Ki67, age, menopausal status, pertuzumab use, clinical stage and PAM50 HER2-enriched subtype. The proportion of HER2DX low- and high-risk of relapse disease was 32.0% and 68.0%, respectively. The correlation of HER2DX pCR score and HER2DX risk-score was weak (coefficient=-0.17), as previously described. Proportion of cases according to both HER2DX scores and absolute difference of pCR rates between TCHP and TCH in each combined group is shown in Table. Conclusion: The HER2DX genomic test predicts pCR following neoadjuvant TCH or TCHP regimens independently of clinical-pathological variables and intrinsic subtype. The combination of both HER2DX scores might help better tailor systemic therapy in patients with newly diagnosed stage I-III HER2+ breast cancer.

Citation Format: Coralia Bueno-Muiño, Isabel Echavarria, Sara López-Tarruella, Roche-Molina Marta, María del Monte-Millán, Tatiana Massarrah, Yolanda Jerez Gilarranz, Blanca Herrero, Salvador Gámez, Iván Márquez-Rodas, María Cebollero-Presmanes, Nevado Santos Manuel, Pilar de la Morena Barrio, Francisco Ayala de la Peña, José Ángel García-Sáenz, Fernando Moreno Antón, Álvaro Rodríguez Lescure, Teresa Quintanar, Diego Malón-Giménez, Laura Rodriguez-Lajusticia, Ana Isabel Ballesteros García, Dulce Bañón Torres, Lucía Villarejo, Nerea Lobato, Ainhoa Arias, Inmaculada Ocaña, Enrique Álvarez, Laia Paré, Mercedes Marín-Aguilera, Patricia Galván, Fara Brasó-Maristany, Ana Vivancos, Patricia Villagrasa, Joel S Parker, Charles M. Perou, Aleix Prat, Miguel Martín. Independent validation of the HER2DX genomic test in HER2-positive breast cancer treated with neoadjuvant docetaxel, carboplatin, trastuzumab +/- pertuzumab (TCH/TCHP): a correlative analysis from a multicenter academic study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-46.

A prospective observational study for a Federated Artificial Intelligence solution for moniToring mental Health status after cancer treatment (FAITH): study protocol

BACKGROUND

Depression is a common condition among cancer patients, across several points in the disease trajectory. Although presenting higher prevalence rates than the general population, it is often not reported or remains unnoticed. Moreover, somatic symptoms of depression are common in the oncological context and should not be dismissed as a general symptom of cancer. It becomes even more challenging to track psychological distress in the period after the treatment, where connection with the healthcare system typically becomes sporadic. The main goal of the FAITH project is to remotely identify and predict depressive symptoms in cancer survivors, based on a federated machine learning (ML) approach, towards optimization of privacy.

METHODS

FAITH will remotely analyse depression markers, predicting their negative trends. These markers will be treated in distinct categories, namely nutrition, sleep, activity and voice, assessed in part through wearable technologies. The study will include 300 patients who have had a previous diagnosis of breast or lung cancer and will be recruited 1 to 5 years after the end of primary cancer. The study will be organized as a 12-month longitudinal prospective observational cohort study, with monthly assessments to evaluate depression symptoms and quality of life among cancer survivors. The primary endpoint is the severity of depressive symptoms as measured by the Hamilton Depression Rating Scale (Ham-D) at months 3, 6, 9 and 12. Secondary outcomes include self-reported anxiety and depression symptoms (HADS scale), and perceived quality of life (EORTC questionnaires), at baseline and monthly. Based on the predictive models gathered during the study, FAITH will also aim at further developing a conceptual federated learning framework, enabling to build machine learning models for the prediction and monitoring of depression without direct access to user's personal data.

DISCUSSION

Improvements in the objectivity of psychiatric assessment are necessary. Wearable technologies can provide potential indicators of depression and anxiety and be used for biofeedback. If the FAITH application is effective, it will provide healthcare systems with a novel and innovative method to screen depressive symptoms in oncological settings.

TRIAL REGISTRATION

Trial ID: ISRCTN10423782 . Date registered: 21/03/2022.

Technical Challenges for CTC Implementation in Breast Cancer

Breast cancer is the most common neoplasm in women worldwide. Tissue biopsy, currently the gold standard to obtain tumor molecular information, is invasive and might be affected by tumor heterogeneity rendering it incapable to portray the complete dynamic picture by the absence of specific genetic changes during the evolution of the disease. In contrast, liquid biopsy can provide unique opportunities for real-time monitoring of disease progression, treatment response and for studying tumor heterogeneity combining the information of DNA that tumors spread in the blood (circulating tumor DNA) with CTCs analysis. In this review, we analyze the technical and biological challenges for isolation and characterization of circulating tumor cells from breast cancer patients. Circulating tumor cell (CTC) enumeration value is included in numerous clinical studies due to the prognostic's role of these cells. Despite this, there are so many questions pending to answer. How to manage lymphocytes background, how to distinguish the CTCs subtypes or how to work with frozen samples, are some of the issues that will discuss in this review. Based on our experience, we try to address these issues and other technical limitations that should be solved to optimize the standardization of protocols, sample extraction procedures, circulating-tumor material isolation (CTCs vs. ctDNA) and the very diverse methodologies employed, aiming to consolidate the use of CTCs in the clinic. Furthermore, we think that new approaches focusing on isolation CTCs in other body fluids such as cerebrospinal or ascitic fluid are necessary to increase the opportunities of circulating tumor cells in the practice clinic as well as to study the promising role of CTC clusters and their prognostic value in metastatic breast cancer.

Abstract PS4-12: Potential value of FOXA1 expression as genomic predictor of response to docetaxel and carboplatin neoadjuvant (NA) chemotherapy in patients with triple negative breast cancer (TNBC)

Background: TNBC is a particularly aggressive subtype with high recurrence rates and poor long-term survival. Anthracycline-free regimens based on docetaxel plus carboplatin (TCb) achieve around 50-55% pathologic complete responses (pCR) which correlates with better survival outcomes. Identification of genomic predictors of response is key to individualize therapies for this heterogeneous breast cancer (BC) subgroup. FOXA1 is a pioneer factor for androgen (AR) and estrogen receptors (ER). Its under-expression has been linked to cancer stemness in TNBC and better prognosis in ER-positive BC. The differential expression of AR, FOXA1 and BRCA1 is associated with sensitivity to chemotherapy in TNBC patients. Data support the plasticity role of FOXA1 driving basal to luminal BC cells by inducing luminal genes but also by repressing the basal phenotype and thus, tumor aggressiveness, although its role as a biomarker in TNBC is still controversial. We have analyzed RNAseq data of FOXA1 and AR in a series of TNBC tumors homogenously treated with neoadjuvant TCb to study their correlation with survival and response. Methodology: 300 TNBC patients have been included in a multicenter, prospective, non-randomized trial aimed to identify predictors of response to TCb in the neoadjuvant setting (NCT01560663). 278/300 patients were evaluable. PAM50 subtypes (NanoString nCounter) and RNAseq (HiSeq2500) were analyzed for those patients with both available samples and evaluable pathological response (n=208). Correlations were studied by the Kendall method. Linear or logistic regressions were adjusted for univariant analysis depending on numerical or categorical response variables, respectively. Results: FOXA1 and AR were differentially expressed between basal and non-basal tumor subtypes (PAM50), being overexpressed in non-basal (p&lt;0.001 for both FOXA1 and AR). FOXA1 and AR were significantly overexpressed in non-basal subtypes from the Vanderbilt TNBC-type classification (36/208) as well. Both genes expression showed a significant correlation with several luminal marker genes. AR was significantly associated with ANXA9 (p=0,008), GATA3 (p=0,00002) and XBP1 (p&lt;0.001), while FOXA1 expression was positively associated with ANXA9 (p=0,03), ESR1 (p&lt;0.001),GATA3 (p&lt;0.001) and XBP1 (p&lt;0.001). In terms of response, significant differences in FOXA1 expression levels were found between responders and non-responders by Residual Disease Burden (RCB) classification taking response as binary variable of PCR vs RCB-I/II/III (p=0.003) as well as pCR/RCB-I vs RCB-II/III (p=0.008) with responders showing a lower FOXA1 expression level. The same analysis for AR expression did not show statistically significant differences. Within the PAM50 basal subgroup, neither AR nor FOXA1 individual gene expression (172/208) showed association with response. For survival, with a median follow-up of 36 months, neither FOXA1 nor AR showed significant impact on EFS or OS per univariate Cox regression analysis (EFS: HRFOXA1 1.076; p=0.307; HRAR 1.156, p=0.084 and OS: HRFOXA11.120, p=0.140; HRAR 1.152, p=0.121). Conclusions: Within our cohort, FOXA1 expression is a better predictor of response to NA chemotherapy than AR. FOXA1 is overexpressed in TNBC tumors who do not achieve pCR with neoadjuvant TCb chemotherapy, correlating with non-basal tumor subtypes. This suggests that measuring FOXA1 expression levels in patients with TNBC could be useful to predict response to TCb regimen enabling physicians to select more effective alternative NA schemes in this population.

Citation Format: Sara López-Tarruella, María del Monte-Millán, Enrique Alvarez, Yolanda Jerez, José Ángel García Saenz, Isabel Echavarria, Fernando Moreno, Ivan Márquez-Rodas, Coralia Bueno-Muiño, Blanca Herrero, Maria Cebollero, Rocío Ramos-Medina, Nerea Lobato, Ricardo González del Val, Maria Isabel Palomero, Santiago Lizarraga, Uriel Bohn, Ana Isabel Ballesteros, Patricia Rincón, Tatiana Massarrah, Inmaculada Ocaña, Lucía Villarejo, Charles M Perou, Miguel Martin. Potential value of FOXA1 expression as genomic predictor of response to docetaxel and carboplatin neoadjuvant (NA) chemotherapy in patients with triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS4-12.

Concordance of Genomic Variants in Matched Primary Breast Cancer, Metastatic Tumor, and Circulating Tumor DNA: The MIRROR Study

PURPOSE

Genetic heterogeneity between primary tumors and their metastatic lesions has been documented in several breast cancer studies. However, the selection of therapy for patients with metastatic breast cancer and the search for biomarkers for targeted therapy are often based on findings from the primary tumor, mainly because of the difficulty of distant metastasis core biopsies. New methods for monitoring genomic changes in metastatic breast cancer are needed (ie, circulating tumor DNA [ctDNA] genomic analysis). The objectives of this study were to assess the concordance of genomic variants between primary and metastatic tumor tissues and the sensitivity of plasma ctDNA analysis to identify variants detected in tumor biopsies.

PATIENTS AND METHODS

Next-generation sequencing technology was used to assess the genomic mutation profile of a panel of 54 cancer genes in matched samples of primary tumor, metastatic tumor, and plasma from 40 patients with metastatic breast cancer.

RESULTS

Using Ion Torrent technology (ThermoFisher Scientific, Waltham, MA), we identified 110 variants that were common to the primary and metastatic tumors. ctDNA analysis had a sensitivity of 0.972 in detecting variants present in both primary and metastatic tissues. In addition, we identified 13 variants in metastatic tissue and ctDNA not present in primary tumor.

CONCLUSION

We identified genomic variants present in metastatic biopsies and plasma ctDNA that were not present in the primary tumor. Deep sequencing of plasma ctDNA detected most DNA variants previously identified in matched primary and metastatic tissues. ctDNA might aid in therapy selection and in the search for biomarkers for drug development in metastatic breast cancer.

Evidence for irreversible inhibition of glycogen synthase kinase-3β by tideglusib

Tideglusib is a GSK-3 inhibitor currently in phase II clinical trials for the treatment of Alzheimer disease and progressive supranuclear palsy. Sustained oral administration of the compound to a variety of animal models decreases Tau hyperphosphorylation, lowers brain amyloid plaque load, improves learning and memory, and prevents neuronal loss. We report here that tideglusib inhibits GSK-3β irreversibly, as demonstrated by the lack of recovery in enzyme function after the unbound drug has been removed from the reaction medium and the fact that its dissociation rate constant is non-significantly different from zero. Such irreversibility may explain the non-competitive inhibition pattern with respect to ATP shown by tideglusib and perhaps other structurally related compounds. The replacement of Cys-199 by an Ala residue in the enzyme seems to increase the dissociation rate, although the drug retains its inhibitory activity with decreased potency and long residence time. In addition, tideglusib failed to inhibit a series of kinases that contain a Cys homologous to Cys-199 in their active site, suggesting that its inhibition of GSK-3β obeys to a specific mechanism and is not a consequence of nonspecific reactivity. Results obtained with [(35)S]tideglusib do not support unequivocally the existence of a covalent bond between the drug and GSK-3β. The irreversibility of the inhibition and the very low protein turnover rate observed for the enzyme are particularly relevant from a pharmacological perspective and could have significant implications on its therapeutic potential.

Dual binding site acetylcholinesterase inhibitors: potential new disease-modifying agents for AD

The therapeutic potential of acetylcholinesterase (AChE) inhibitors has been strengthened recently by evidence showing that besides their role in cognitive function, they might contribute to slow down the neurodegeneration in Alzheimer's disease (AD) patients. It is known that AChE exerts secondary noncholinergic functions, related to its peripheral anionic site, in cell adhesion and differentiation, and recent findings also support its role in mediating the processing and deposition of beta-amyloid (Abeta) peptide. AChE is one of the proteins that colocalizes with Abeta peptide deposits in the brain of AD patients and promotes Abeta fibrillogenesis by forming stable AChEA beta complexes. Additionally, it has also been postulated that AChE binds through its peripheral site to the Abeta nonamyloidogenic form and acts as a pathological chaperone inducing a conformational transition to the amyloidogenic form (Inestrosa et al., 1996; Bartolini et al., 2003). Anew series of dual binding site AChE inhibitors has been designed and synthesized as new potent AChE inhibitors, which might simultaneously alleviate cognitive deficits and behave as disease-modifying agents by inhibiting Abeta peptide aggregation through binding to both catalytic and peripheral sites of the enzyme.

Design, Synthesis, and Biological Evaluation of Dual Binding Site Acetylcholinesterase Inhibitors: New Disease-Modifying Agents for Alzheimer's Disease

New dual binding site acetylcholinesterase (AChE) inhibitors have been designed and synthesized as new potent drugs that may simultaneously alleviate cognitive deficits and behave as disease-modifying agents by inhibiting the beta-amyloid (A beta) peptide aggregation through binding to both catalytic and peripheral sites of the enzyme. Particularly, compounds 5 and 6 emerged as the most potent heterodimers reported so far, displaying IC50 values for AChE inhibition of 20 and 60 pM, respectively. More importantly, these dual AChE inhibitors inhibit the AChE-induced A beta peptide aggregation with IC50 values 1 order of magnitude lower than that of propidium, thus being the most potent derivatives with this activity reported up to date. We therefore conclude that these compounds are very promising disease-modifying agents for the treatment of Alzheimer's disease (AD).