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"Beumer, Jan H."
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Effect of removing race from glomerular filtration rate-estimating equations on anticancer drug dosing and eligibility: a retrospective analysis of National Cancer Institute phase 1 clinical trial participants
by
Nolin, Thomas D
,
Casal, Morgan A
,
Ivy, S Percy
in
Antineoplastic Agents - therapeutic use
,
Antineoplastic drugs
,
Antitumor agents
2021
Kidney function assessment by estimated glomerular filtration rate (eGFR) equations, such as the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation, is important to determine dosing and eligibility for anticancer drugs. Inclusion of race in eGFR equations calculates a higher eGFR at a given serum creatinine concentration for Black patients versus non-Black patients. We aimed to characterise the effect of removing race from the CKD-EPI equation on dosing and eligibility of anticancer drugs with kidney function cutoffs.
We did a retrospective analysis of patients enrolled in phase 1 studies sponsored by the Cancer Therapy Evaluation Program between January, 1995, and October, 2010. eGFR based on creatinine (eGFRCr) was calculated by the CKD-EPI equation and a version of the CKD-EPI equation without the race term (CKD-EPIwithout race). Estimated creatinine clearance (eClCr) was calculated by the Cockcroft-Gault equation. Dosing simulations based on each assessment of kidney function were done for ten anticancer drugs with kidney function cutoffs for dosing (oxaliplatin, capecitabine, etoposide, topotecan, fludarabine, and bleomycin) or eligibility (cisplatin, pemetrexed, bendamustine, and mitomycin) based on labelling approved by the US Food and Drug Administration or consensus guidelines. The absolute proportion of patients eligible or in each renal dosing range was calculated for each drug. Eligibility and dosing discordance rates were also calculated.
Demographics and laboratory values from 340 Black patients (172 men and 168 women) were used. Median age was 57 years (IQR 47–64), median bodyweight was 78·1 kg (67·0–89·8), median body surface area was 1·91 m2 (1·77–2·09), and median serum creatinine concentration was 0·9 mg/dL (0·8–1·1). Median eGFRCr or eClCr was 103 mL/min (85–122) calculated by CKD-EPI, 89 mL/min (73–105) by CKD-EPIwithout race, and 90 mL/min (72–120) by Cockcroft-Gault. Black patients were recommended to receive dose reductions or were rendered ineligible to receive drug more frequently when using CKD-EPIwithout race than when using CKD-EPI, but at a similar rate as when using Cockcroft-Gault. The number of patients ineligible for therapy or recommended to receive any renal dose adjustment when CKD-EPIwithout race versus CKD-EPI was used increased by 72% (from 25 of 340 to 43 of 340 patients) for cisplatin, by 120% (from five to 11) for pemetrexed, by 67% (from three to five) for bendamustine, by 150% (from ten to 25) for capecitabine, by 150% (from ten to 25) for etoposide, by 67% (from three to five) for topotecan, by 61% (from 74 to 119) for fludarabine, and by 163% (from eight to 21) for bleomycin. Up to 18% of patients had discordant recommendations using CKD-EPIwithout race versus CKD-EPI.
Removing race from the CKD-EPI equation will calculate a lower eGFR for Black patients and exclude more patients from receiving anticancer therapy, which could lead to undertreatment of Black patients with cancer and adversely affect their outcomes.
National Institutes of Health.
Journal Article
Exploring the Impact of the β-Catenin Mutations in Hepatocellular Carcinoma: An In-Depth Review
by
Rajabi, Mohammad Reza
,
Monga, Satdarshan P.
,
Saeed, Anwaar
in
Animal models
,
Animals
,
beta Catenin - genetics
2024
Liver cancer, primarily hepatocellular carcinoma, represents a major global health issue with significant clinical, economic, and psychological impacts. Its incidence continues to rise, driven by risk factors such as hepatitis B and C infections, nonalcoholic steatohepatitis, and various environmental influences. The Wnt/β-Catenin signaling pathway, frequently dysregulated in HCC, emerges as a promising therapeutic target. Critical genetic alterations, particularly in the CTNNB1 gene, involve mutations at key phosphorylation sites on β-catenin’s N-terminal domain (S33, S37, T41, and S45) and in armadillo repeat domains (K335I and N387 K). These mutations impede β-catenin degradation, enhancing its oncogenic potential. In addition to genetic alterations, molecular and epigenetic mechanisms, including DNA methylation, histone modifications, and noncoding RNAs, further influence β-catenin signaling and tumor progression. However, β-catenin activation alone is insufficient for hepatocarcinogenesis; additional genetic “hits” are required for tumor initiation. Mutations or alterations in genes such as Ras, c-Met, NRF2, and LKB1, when combined with β-catenin activation, significantly contribute to HCC development and progression. Understanding these cooperative mutations provides crucial insights into the disease and reveals potential therapeutic strategies. The complex interplay between genetic variations and the tumor microenvironment, coupled with novel therapeutic approaches targeting the Wnt/β-Catenin pathway, offers promise for improved treatment of HCC. Despite advances, translating preclinical findings into clinical practice remains a challenge. Future research should focus on elucidating how specific β-catenin mutations and additional genetic alterations contribute to HCC pathogenesis, leveraging genetically clengineered mouse models to explore distinct signaling impacts, and identifying downstream targets. Relevant clinical trials will be essential for advancing personalized therapies and enhancing patient outcomes. This review provides a comprehensive analysis of β-Catenin signaling in HCC, highlighting its role in pathogenesis, diagnosis, and therapeutic targeting, and identifies key research directions to improve understanding and clinical outcomes.
Journal Article
Letrozole, abemaciclib and metformin in endometrial cancer: a non-randomized phase 2 trial
by
Campos, Susana
,
Cheng, Su-Chun
,
Horowitz, Neil
in
1-Phosphatidylinositol 3-kinase
,
692/4028/67/1059/602
,
692/4028/67/1517/1931
2025
Based on preclinical studies showing synergism with simultaneous inhibition of the estrogen receptor (ER), CDK4/6 and PI3K pathways and based on window of opportunity studies showing that metformin suppresses PI3K/mTOR signaling in endometrial cancer (EC), we conduct a non-randomized phase 2 study of letrozole/abemaciclib/metformin in ER positive endometrioid EC (NCT03675893). Primary objectives include objective response rate (ORR) and rate of progression-free survival (PFS) at 6 months (PFS6) while secondary objectives include PFS, overall survival, duration of response and toxicity. Twenty-five patients initiate protocol therapy [letrozole 2.5 mg orally (PO) once a day (qd), abemaciclib 150 mg PO twice a day (bid) and metformin 500 mg PO qd]. ORR is 32% (3 complete and 5 partial responses, 95% CI 14.9%-53.5%), Kaplan Meier estimate of PFS6 is 69.8% (95% CI 46.9%-84.3%) and median PFS is 19.4 months (95% CI 5.7 months–not estimable). No patients discontinue therapy because of toxicity. There are no objective responses among
TP53
mutated ECs and among NSMP (no specific molecular profile) tumors with
RB1
or
CCNE1
alterations;
CTNNB1
mutations correlate with clinical benefit. Pharmacokinetic analyses demonstrate that administration of letrozole and abemaciclib with metformin result in a more than 3-fold increase in metformin exposure.
Combined hormonal therapy and CDK4/6 inhibition face resistance challenges in endometrial cancer. Here, the authors present a phase 2, one-arm clinical trial, where metformin is combined with letrozole (hormonal therapy) and abemaciclib (a CDK4/6 inhibitor) reporting safety and efficacy in patients with endometrial cancer.
Journal Article
Pharmacology and pharmacokinetics of tazemetostat
2024
Tazemetostat, a novel oral selective inhibitor of enhancer of zeste homolog 2 (EZH2), was approved by the Food and Drug Administration (FDA) in 2020 for use in patients with advanced epithelioid sarcoma or relapsed/refractory (R/R) EZH2-mutated follicular lymphoma. These indications were approved by the FDA trough accelerated approval based on objective response rate and duration of response that resulted from phase 2 clinical trials. Tazemetostat competes with S-adenosylmethionine (SAM) cofactor to inhibit EZH2, reducing the levels of trimethylated lysine 27 of histone 3 (H3K27me3), considered as pharmacodynamic marker. Tazemetostat is orally bioavailable, characterized by rapid absorption and dose-proportional exposure, which is not influenced by coadministration with food or gastric acid reducing agents. It highly distributes in tissues, but with limited access to central nervous system. Tazemetostat is metabolized by CYP3A in the liver to 3 major inactive metabolites (M1, M3, and M5), has a short half-life and is mainly excreted in feces. Drug-drug interactions were shown with moderate CYP3A inhibitors as fluconazole, leading the FDA to recommend a 50% dose reduction, while studies investigating coadministration of tazemetostat with strong inhibitors/inducers are ongoing. No dosage modifications are recommended based on renal or hepatic dysfunctions. Overall, tazemetostat is the first-in-class EZH2 inhibitor approved by the FDA for cancer treatment. Current clinical studies are evaluating combination therapies in patients with several malignancies.
Journal Article
Combined PDGFR and HDAC Inhibition Overcomes PTEN Disruption in Chordoma
2015
The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR). Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway.
Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 of the 23 specimens, and chordoma cell lines, UCH-1 and UCH-2, were used for in vitro experiments.
Loss of heterozygosity (LOH) at the phosphatase and tensin homolog (PTEN) locus was observed in 6 specimens (26%). PTEN disruption statistically correlated with increased Ki-67 proliferation index, an established marker of poor outcome for chordoma. Compared to wild type, PTEN deficient chordomas displayed increased proliferative rate, and responded less favorably to PDGFR inhibition. PTEN gene restoration abrogated this growth advantage. Chordomas are characterized by intratumoral hypoxia and local invasion, and histone deacetylase (HDAC) inhibitors are capable of attenuating both hypoxic signaling and cell migration. The combination of PDGFR and HDAC inhibition effectively disrupted growth and invasion of PTEN deficient chordoma cells.
Loss of heterozygosity of the PTEN gene seen in a subset of chordomas is associated with aggressive in vitro behavior and strongly correlates with increased Ki-67 proliferative index. Combined inhibition of PDGFR and HDAC attenuates proliferation and invasion in chordoma cells deficient for PTEN.
Journal Article
Association of SULT2A1 Locus With Abiraterone Clearance in the Alliance A031201: Randomized Phase III Study of Enzalutamide Compared With Enzalutamide Plus Abiraterone for Metastatic Castration‐Resistant Prostate Cancer
2025
Enzalutamide and abiraterone are hormonal treatments that improve survival in metastatic castration‐resistant prostate cancer. Identifying genetic variants associated with the clearance of these drugs may aid in improved dosing and outcomes. We performed genetic association studies of enzalutamide and abiraterone oral clearance in the Alliance A031201 clinical trial. Genome‐wide genotyping was performed with the primary analysis limited to European‐descent participants. Pharmacogene metabolic phenotypes were estimated using PyPGx and Stargazer. Associations of metabolic activity groups for CYP3A4, CYP3A5, CYP2C19 and SLCO1B1 with enzalutamide clearance (N = 706) and CYP3A4, SLCO2B1 and UGT1A4 with abiraterone clearance (N = 323) were tested by linear regression. Targeted SNP associations were assessed for abiraterone clearance at loci proximal to major metabolizing genes. Full genome‐wide association studies were performed for both sets of clearance values. No significant associations were identified between metabolic phenotypes and enzalutamide or abiraterone oral clearance SNPs in the SULT2A1 5′ flanking region were significantly associated with lower abiraterone clearance, (rs296373, minor allele frequency = 0.15, β = −0.457, p = 3.2E‐06). Liver protein and liver and adrenal gland gene expression QTL databases indicated significantly lower SULT2A1 expression patterns for individuals carrying associated alleles, likely explaining the lower abiraterone oral clearance. CYP2C8*3 was associated with higher enzalutamide clearance (p = 0.012), but this was not significant after correction for multiple testing. This study is the first to identify the genetic association of SULT2A1, known to be involved in the metabolism of steroids in the liver and adrenal glands, with abiraterone clearance. Genetic variation in SULT2A1 may be useful to inform personalized dosing of abiraterone. ClinicalTrials.gov Identifier: NCT01949337
Journal Article
The schedule of ATR inhibitor AZD6738 can potentiate or abolish antitumor immune responses to radiotherapy
by
Clump, David A.
,
Schamus-Haynes, Sandra
,
Tavakoli, Meysam
in
Animal models
,
Animals
,
Antigens
2023
Inhibitors of the DNA damage signaling kinase ATR increase tumor cell killing by chemotherapies that target DNA replication forks but also kill rapidly proliferating immune cells including activated T cells. Nevertheless, ATR inhibitor (ATRi) and radiotherapy (RT) can be combined to generate CD8+ T cell-dependent antitumor responses in mouse models. To determine the optimal schedule of ATRi and RT, we determined the impact of short-course versus prolonged daily treatment with AZD6738 (ATRi) on responses to RT (days 1-2). Short-course ATRi (days 1-3) plus RT caused expansion of tumor antigen-specific, effector CD8+ T cells in the tumor-draining lymph node (DLN) at 1 week after RT. This was preceded by acute decreases in proliferating tumor-infiltrating and peripheral T cells and a rapid proliferative rebound after ATRi cessation, increased inflammatory signaling (IFN-β, chemokines, particularly CXCL10) in tumors, and an accumulation of inflammatory cells in the DLN. In contrast, prolonged ATRi (days 1-9) prevented the expansion of tumor antigen-specific, effector CD8+ T cells in the DLN, and entirely abolished the therapeutic benefit of short-course ATRi with RT and anti-PD-L1. Our data argue that ATRi cessation is essential to allow CD8+ T cell responses to both RT and immune checkpoint inhibitors.
Journal Article
Pharmacology and pharmacokinetics of elacestrant
2023
Elacestrant, a novel oral selective estrogen receptor (ER) degrader (SERD), was approved by the Food and Drug Administration (FDA) on January 27, 2023, for use in patients with ER and/or progesterone receptor (PR)-positive and HER2-negative metastatic breast cancer whose tumors harbor an ESR1 missense mutation (ESR1-mut), after at least one line of endocrine therapy (ET). The FDA made its decision based on the randomized phase 3 EMERALD trial, which met its primary endpoint of improved median progression-free survival (mPFS) with elacestrant monotherapy versus standard-of-care endocrine monotherapy in the overall intention to treat population; however, this benefit was largely driven by the ESR1-mut cohort. Elacestrant is a dose-dependent mixed ER agonist/antagonist, which at high doses acts as a direct ER antagonist as well as selective downregulator of ER. It is 11% bioavailable, primarily metabolized by CYP3A4 in the liver and excreted in feces. This leads to drug–drug interactions with strong CYP3A4 inhibitors and inducers, such as itraconazole and rifampin, respectively. In accordance with its clearance route, dose reduction is recommended in patients with moderate hepatic dysfunction but not in renal dysfunction. Studies evaluating elacestrant in severe hepatic dysfunction as well as in patients from racial and ethnic minority groups are ongoing. Overall, elacestrant is the first orally bioavailable SERD approved by the FDA for use in patients with metastatic breast cancer. Current clinical trials are ongoing evaluating it in the adjuvant setting in patients with early stage ER-positive breast cancers.
Journal Article
ATR kinase inhibitor AZD6738 potentiates CD8+ T cell–dependent antitumor activity following radiation
2018
DNA-damaging chemotherapy and radiation therapy are integrated into the treatment paradigm of the majority of cancer patients. Recently, immunotherapy that targets the immunosuppressive interaction between programmed death 1 (PD-1) and its ligand PD-L1 has been approved for malignancies including non-small cell lung cancer, melanoma, and head and neck squamous cell carcinoma. ATR is a DNA damage-signaling kinase activated at damaged replication forks, and ATR kinase inhibitors potentiate the cytotoxicity of DNA-damaging chemotherapies. We show here that the ATR kinase inhibitor AZD6738 combines with conformal radiation therapy to attenuate radiation-induced CD8+ T cell exhaustion and potentiate CD8+ T cell activity in mouse models of Kras-mutant cancer. Mechanistically, AZD6738 blocks radiation-induced PD-L1 upregulation on tumor cells and dramatically decreases the number of tumor-infiltrating Tregs. Remarkably, AZD6738 combines with conformal radiation therapy to generate immunologic memory in complete responder mice. Our work raises the possibility that a single pharmacologic agent may enhance the cytotoxic effects of radiation while concurrently potentiating radiation-induced antitumor immune responses.
Journal Article
Effect of age on the pharmacokinetics of busulfan in patients undergoing hematopoietic cell transplantation; an alliance study (CALGB 10503, 19808, and 100103)
2014
Purpose
Older patients with acute myeloid leukemia (AML) and myelodysplastic syndrome have often been excluded from myeloablative-conditioning regimens containing busulfan because of non-disease-related morbidity and mortality. We hypothesized that busulfan clearance (BuCL) in older patients (>60 years) would be reduced compared to that in younger patients, potentially explaining observed differences in busulfan tolerability.
Methods
AML patients in three CALGB hematopoietic cell transplantation studies were treated with a conditioning regimen using IV busulfan, dosed at 0.8 mg/kg. Plasma busulfan concentrations were determined by LC–MS and analyzed by non-compartmental methods. BuCL was normalized to actual (ABW), ideal (IBW), or corrected (CBW) body weight (kg). Differences in BuCL between age groups were examined using the Wilcoxon rank sum test.
Results
One hundred and eighty-five patients were accrued; 174 provided useable pharmacokinetic data. Twenty-nine patients ≥60 years old (median 66; range 60–74) had a significantly higher BuCL versus those <60 years old (median 50; range 18–60): BuCL 236 versus 168 mL/min,
p
= 0.0002; BuCL/ABW 3.0 versus 2.1 mL/min/kg,
p
= 0.0001; BuCL/IBW 3.8 versus 2.6 mL/min/kg,
p
= 0.0035; BuCL/CBW 3.4 versus 2.6 mL/min/kg,
p
= 0.0005. Inter-patient variability in clearance (CV %) was up to 48 % in both age groups. Phenytoin administration, a potential confounder, did not affect BuCL, regardless of weight normalization (
p
> 0.34).
Conclusions
Contrary to our hypothesis, BuCL was significantly higher in older patients compared to younger patients in these studies and does not explain the previously reported increase in busulfan toxicity observed in older patients.
Journal Article