The Cytoprotective and Cytotoxic Functions of Autophagy in Response to mTOR Inhibitors.

The inhibitors of mammalian target of rapapmycin (mTOR), everolimus, temsirolimus and rapamycin, have a wide range of clinical utility; however, as is inevitably the case with other chemotherapeutic agents, resistance development constrains their effectiveness. One putative mechanism of resistance is the promotion of autophagy, which is a direct consequence of the inhibition of the mTOR signaling pathway. Autophagy is primarily considered to be a cytoprotective survival mechanism, whereby cytoplasmic components are recycled to generate energy and metabolic intermediates. The autophagy induced by everolimus and temsirolimus appears to play a largely protective function, whereas a cytotoxic function appears to predominate in the case of rapamycin. In this review we provide an overview of the autophagy induced in response to mTOR inhibitors in different tumor models in an effort to determine whether autophagy targeting could be of clinical utility as adjuvant therapy in association with mTOR inhibition.

Addition of temsirolimus to chemotherapy in children, adolescents, and young adults with intermediate-risk rhabdomyosarcoma (ARST1431): a randomised, open-label, phase 3 trial from the Children's Oncology Group.

BACKGROUND: The Children's Oncology Group defines intermediate-risk rhabdomyosarcoma as unresected FOXO1 fusion-negative disease arising at an unfavourable site or non-metastatic FOXO1 fusion-positive disease. Temsirolimus in combination with chemotherapy has shown promising activity in patients with relapsed or refractory rhabdomyosarcoma. We aimed to compare event-free survival in patients with intermediate-risk rhabdomyosarcoma treated with vincristine, actinomycin, and cyclophosphamide alternating with vincristine and irinotecan (VAC/VI) combined with temsirolimus followed by maintenance therapy versus VAC/VI alone with maintenance therapy. METHODS: ARST1431 was a randomised, open-label, phase 3 trial conducted across 210 institutions in Australia, Canada, New Zealand, and the USA. Eligible patients were those aged 40 years or younger with non-metastatic FOXO1-positive rhabdomyosarcoma or unresected FOXO1-negative rhabdomyosarcoma disease from unfavourable sites. Two other groups of patients were also eligible: those who had FOXO1-negative disease at a favourable site (excluding orbit) that was unresected; and those who were aged younger than 10 years with stage IV FOXO1-negative disease with distant metastases. Eligible patients had to have a Lansky performance status score of 50 or higher if 16 years or younger and a Karnofsky performance status score of 50 or higher if older than 16 years; all patients were previously untreated. Patients were randomised (1:1) in blocks of four and stratified by histology, stage, and group. Patients received intravenous VAC/VI chemotherapy with a cyclophosphamide dose of 1·2 g/m2 per dose per cycle with or without a reducing dose of intravenous weekly temsirolimus starting at 15 mg/m2 or 0·5 mg/kg per dose for those who weighed less than 10 kg. The total duration of therapy was 42 weeks followed by 6 months of maintenance therapy with oral cyclophosphamide plus intravenous vinorelbine for all patients. Temsirolimus was withheld during radiotherapy and for 2 weeks before any major surgical procedure. The primary endpoint was 3-year event-free survival. Data were analysed with a revised intention-to-treat approach. The study is registered with ClinicalTrials.gov (NCT02567435) and is complete. FINDINGS: Between May 23, 2016, and Jan 1, 2022, 325 patients were enrolled. In 297 evaluable patients (148 assigned to VAC/VI alone and 149 assigned to VAC/VI with temsirolimus), the median age was 6·3 years (IQR 3·0-11·3); 33 (11%) patients were aged 18 years or older; 179 (60%) of 297 were male. 113 (77%) of 148 patients were FOXO1 negative in the VAC/VI group, and 108 (73%) of 149 were FOXO1 negative in the VAC/VI with temsirolimus group. With a median follow-up of 3·6 years (IQR 2·8-4·5), 3-year event-free survival did not differ significantly between the two groups (64·8% [95% CI 55·5-74·1] in the VAC/VI group vs 66·8% [57·5-76·2] in the VAC/VI plus temsirolimus group (hazard ratio 0·86 [95% CI 0·58-1·26]; log-rank p=0·44). The most common grade 3-4 adverse events were anaemia (62 events in 60 [41%] of 148 patients in the VAC/VI group vs 89 events in 87 [58%] of 149 patients in the VAC/VI with temsirolimus group), lymphopenia (83 events in 65 [44%] vs 99 events in 71 [48%]), neutropenia (160 events in 99 [67%] vs 164 events in 105 [70%]), and leukopenia (121 events in 86 [58%] vs 132 events in 93 [62%]). There was one treatment-related death in the VAC/VI with temsirolimus group, categorised as not otherwise specified. INTERPRETATION: Addition of temsirolimus to VAC/VI did not improve event-free survival in patients with intermediate-risk rhabdomyosarcoma defined by their FOXO1 translocation status and clinical factors. Novel biology-based strategies are needed to improve outcomes in this population. FUNDING: The Children's Oncology Group (supported by the US National Cancer Institute, US National Institutes of Health).

Clinical outcomes with thin versus thick strut polymer-free biolimus-coated stents at 3 years.

BACKGROUND: For high bleeding-risk patients (HBR) undergoing percutaneous coronary intervention (PCI), the LEADERS FREE (LF) and LEADERS FREE II (LF II) trials established the safety and efficacy of a stainless steel polymer-free biolimus-coated stent (SS-BCS) with 30 days of dual antiplatelet treatment (DAPT). The LEADERS FREE III (LF III) trial investigated clinical outcomes after PCI with the next-generation cobalt-chromium thin-strut polymer-free biolimus-coated stent (CoCr-BCS) in HBR patients. AIMS: To report the final 3-year results of the LF III trial and compare them to LF II. METHODS: LF III was a prospective, multicentre, open-label single-arm study to evaluate the safety and efficacy of the CoCr-BCS stent. The primary safety endpoint was the composite of cardiac death (CD), myocardial infarction(MI) or definite/probable stent thrombosis (ST). The primary efficacy endpoint was clinically driven target lesion revascularisation (cd-TLR). We performed a propensity-matched comparison to the 3-year outcomes of LF II. RESULTS: After 3 years, CD/MI/ST had occurred in 57 patients (15%, 95% CI 11.8% to 19%) and cd-TLR in 23 (6.2%, 95% CI 4.1% to 9.2%) patients. In a propensity-matched comparison of patients treated with the CoCr-BCS versus the SS-BCS, there were similar rates of CD (6.6% vs 7.8%, p=0.50), MI (7.1% vs 8.3%, p=0.47) and definite/probable ST (1.1% vs 2%, HR 0.56, 95% CI 0.16 to 1.93, p=0.35). The rates of cd-TLR were 5.3% with CoCr-BCS versus 9.8% with SS-BCS (HR 0.54, 95% CI 0.31 to 0.96, p=0.03). CONCLUSION: LF III confirms the long-term safety and efficacy of the CoCr-BCS in HBR patients treated with 1 month of DAPT. TRIAL REGISTRATION NUMBER: NCT02843633, NCT03118895.

Temporal Trends in the Outcomes of Percutaneous Coronary Intervention With Zotarolimus Eluting Stents Versus Everolimus Eluting Stents: A Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: Long-term follow-up results of various trials comparing Zotarolimus eluting stents (ZES) with Everolimus eluting stents (EES) have been published recently. Additionally, over the last decade, there have been new trials comparing the ZES with various commercially available EES. We aim to conduct an updated meta-analysis in light of new evidence from randomized controlled trials (RCTs) to provide comprehensive evidence regarding the temporal trends in the clinical outcomes. METHODS: A comprehensive literature search was conducted across PubMed, Cochrane, and Embase. RCTs comparing ZES with EES for short (<2 years), intermediate (2-3 years), and long-term follow-ups (3-5 years) were included. Relative risk was used to pool the dichotomous outcomes using the random effects model employing the inverse variance method. All statistical analysis was conducted using Revman 5.4. RESULTS: A total of 18 studies reporting data at different follow-ups for nine trials (n = 14319) were included. At short-term follow-up (<2 years), there were no significant differences between the two types of stents (all-cause death, cardiac death, Major adverse cardiovascular events (MACE), target vessel myocardial infarction, definite or probable stent thrombosis or safety outcomes (target vessel revascularization, target lesion revascularization, target vessel failure, target lesion failure). At intermediate follow-up (2-3 years), EES was superior to ZES for reducing target lesion revascularization (RR = 1.28, 95% CI = 1.05-1.58, p < 0.05). At long-term follow-up (3-5 years), there were no significant differences between the two groups for any of the pooled outcomes (p > 0.05). CONCLUSION: ZES and EES have similar safety and efficacy at short, intermediate, and long-term follow-ups.

Final 5-year report of BIONYX comparing the thin-composite wire-strut zotarolimus-eluting stent versus ultrathin-strut sirolimus-eluting stent.

BACKGROUND: The BIONYX randomized trial is the first study to evaluate the Resolute Onyx durable polymer-coated zotarolimus-eluting stent (ZES) in all-comers. Furthermore, it is the first trial to assess safety and efficacy of this stent versus the Orsiro biodegradable-polymer sirolimus-eluting stent (SES) in all-comers, paying particular attention to patients with diabetes. It has previously shown promising results until 3 years of follow-up. AIMS: We aimed to assess long-term clinical outcome after percutaneous coronary intervention (PCI) with Onyx ZES versus Orsiro SES at 5-year follow-up. METHODS: The main composite endpoint was target vessel failure (TVF): cardiac death, target vessel myocardial infarction, or target vessel revascularization. Time to primary and secondary endpoints was assessed using Kaplan-Meier methods, applying the log-rank test for between-group comparison. RESULTS: Follow-up was available in 2414/2488 (97.0%) patients. After 5 years, TVF showed no significant difference between Onyx ZES and Orsiro SES (12.7% vs. 13.7%, hazard ratio [HR] 0.94, 95% confidence interval [CI] [0.75-1.17], plog-rank = 0.55). Landmark analysis between 3- and 5-year follow-up found a lower target lesion revascularization rate for Onyx ZES (1.1% vs. 2.4%, HR 0.47, 95% CI [0.24-0.93], plog-rank = 0.026). A prespecified subgroup analysis showed no significant between-stent difference in clinical outcome among patients with diabetes. After treatment with Onyx ZES, patients aged ≥75 years had significantly lower rates of TVF (13.8% vs. 21.9%, HR 0.60, 95% CI [0.39-0.93], plog-rank = 0.023). CONCLUSIONS: The final 5-year analysis of the randomized BIONYX trial showed favorable and similar long-term outcomes of safety and efficacy for Onyx ZES and Orsiro SES in both all-comers and patients with diabetes.

Comparison of thrombogenicity in different types of drug-eluting stents during transition from DAPT to SAPT.

BACKGROUND: During the transition from dual antiplatelet therapy (DAPT) to single antiplatelet therapy (SAPT), previous studies have raised concerns about a rebound effect. We compared platelet and inflammatory cell adhesion on different types of stents in the setting of clopidogrel presence and withdrawal. METHODS: In Experiment 1, three pigs were administered with DAPT, that is, clopidogrel and acetylsalicylic acid (ASA), for 7 days. Each animal underwent an extracorporeal carotid arteriovenous shunt model implanted with fluoropolymer-coated everolimus-eluting stent (FP-EES), biodegradable-polymer sirolimus-eluting stent (BP-SES), and biodegradable-polymer everolimus-eluting stents (BP-EES). In Experiment 2, two pigs were administered DAPT, clopidogrel was then withdrawn at day 7, and SAPT with ASA was continued for next 21 days. Then flow-loop experiments with the drawn blood from each time point were performed for FP-EES, BioLinx-polymer zotarolimus-eluting stents (BL-ZES), and BP-EES. The rebound effect was defined as the statistical increase of inflammation and platelet adhesion assessed with immunohistochemistry on the stent-strut level basis from baseline to day-14 or 28. RESULTS: Both experiments showed platelet adhesion value was highest in BP-EES, while the least in FP-EES during DAPT therapy. There was no increase in platelet or inflammatory cell adhesion above baseline values (i.e., no therapy) due to the cessation of clopidogrel on the stent-strut level. Monocyte adhesion was the least for FP-EES with the same trend observed for neutrophil adhesion. CONCLUSIONS: No evidence of rebound effect was seen after the transition from DAPT to SAPT. FP-EES demonstrated the most favorable antithrombotic and anti-inflammatory profile regardless of the different experimental designs.

Biolimus-coated versus paclitaxel-coated balloons for coronary in-stent restenosis (BIO ASCEND ISR): a randomised, non-inferiority trial.

BACKGROUND: The treatment of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation remains challenging in current clinical practice. AIMS: The study was conducted to investigate a novel biolimus-coated balloon (BCB) for the treatment of coronary DES-ISR compared with the best-investigated paclitaxel-coated balloon (PCB). METHODS: This was a prospective, multicentre, randomised, non-inferiority trial comparing a novel BCB with a clinically proven PCB for coronary DES-ISR. The primary endpoint was in-segment late lumen loss (LLL) at 9 months assessed by an independent core laboratory. Baseline and follow-up optical coherence tomography were performed in a prespecified subgroup of patients. RESULTS: A total of 280 patients at 17 centres were randomised to treatment with a BCB (n=140) versus a PCB (n=140). At 9 months, LLL in the BCB group was 0.23±0.37 mm compared to 0.25±0.35 mm in the PCB group; the mean difference between the groups was -0.02 (95% confidence interval [CI]: -0.12 to 0.07) mm; p-value for non-inferiority<0.0001. Similar clinical outcomes were also observed for both groups at 12 months. In the optical coherence tomography substudy, the neointimal area at 9 months was 2.32±1.04 mm2 in the BCB group compared to 2.37±0.93 mm2 in the PCB group; the mean difference between the groups was -0.09 (95% CI: -0.94 to 0.76) mm2; p=non-significant. CONCLUSIONS: This head-to-head comparison of a novel BCB shows similar angiographic outcomes in the treatment of coronary DES-ISR compared with a clinically proven PCB. (ClinicalTrials.gov: NCT04733443).

Deep response to a combination of mTOR inhibitor temsirolimus and dual immunotherapy of nivolumab/ipilimumab in poorly differentiated thyroid carcinoma with PTEN mutation: a case report and literature review.

Treating advanced thyroid cancer presents challenges due to its resistance to various treatment modalities, thereby limiting therapeutic options. To our knowledge, this study is the first to report the efficacy of temsirolimus in conjunction with dual immunotherapy of nivolumab/ipilimumab to treat heavily treated advanced PDTC. A 50-year-old female initially presented with a rapidly enlarging mass on her right neck. Subsequent diagnosis revealed poorly differentiated thyroid carcinoma, leading to a total thyroidectomy followed by post-operative radioablation therapy. After four years, an examination for persistent cough revealed a recurrence of the disease within multiple mediastinal nodes. Genetic analysis of blood samples uncovered somatic mutations in the tumor, specifically involving PTEN and TP53. The disease progressed despite palliative radiation, lenvatinib, and nivolumab/ipilimumab therapy. Consequently, temsirolimus, functioning as an mTOR inhibitor, was introduced as an adjunct to the nivolumab/ipilimumab regimen. This combination approach yielded remarkable clinical improvement and disease control for a duration of approximately six months. Temsirolimus likely suppressed the aberrantly activated PI3K/AKT/mTOR signaling pathway, facilitated by the PTEN genetic alteration, thus engendering an effective treatment response. This synergy between targeted agents and immunotherapy presents a promising therapeutic strategy for advanced PDTC patients with limited treatment alternatives. In previous clinical trials, mTOR inhibitors have demonstrated the ability to maintain stable disease (SD) in 65% to 74% for advanced thyroid cancer patients, including those with PDTC. When combined with other targeted therapies, the observed SD or partial response rates range from 80% to 97%. Many of these trials primarily involved differentiated thyroid carcinoma, with diverse genetic mutations. Thyroid cancer patients with alterations in the PI3K/mTOR/Akt appeared to benefit most from mTOR inhibitors. However, no clear association between the efficacy of mTOR inhibitors and specific histologies or genetic mutations has been established. Future studies are warranted to elucidate these associations.

Percutaneous Coronary Interventions Using a Ridaforolimus-Eluting Stent in Patients at High Bleeding Risk.

BACKGROUND: Patients treated with percutaneous coronary intervention are often considered to be at a high bleeding risk (HBR). Drug-eluting stents have been shown to be superior to bare-metal stents in patients with HBR, even when patients were given abbreviated periods of dual antiplatelet therapy (DAPT). Short DAPT has not been evaluated with the EluNIR ridaforolimus-eluting stent. The aim of this study was to evaluate the safety and efficacy of a shortened period of DAPT following implantation of the ridaforolimus-eluting stent in patients with HBR. METHODS AND RESULTS: This was a prospective, multicenter, binational, single-arm, open-label trial. Patients were defined as HBR according to the LEADERS-FREE (Prospective Randomized Comparison of the BioFreedom Biolimus A9 Drug-Coated Stent versus the Gazelle Bare-Metal Stent in Patients at High Bleeding Risk) trial criteria. After percutaneous coronary intervention, DAPT was given for 1 month to patients presenting with stable angina. In patients presenting with an acute coronary syndrome, DAPT was given for 1 to 3 months, at the investigator's discretion. The primary end point was a composite of cardiac death, myocardial infarction, or stent thrombosis up to 1 year (Academic Research Consortium definite and probable). Three hundred fifteen patients undergoing percutaneous coronary intervention were enrolled, and 56.4% presented with acute coronary syndrome; 33.7% were receiving oral anticoagulation. At 1 year, the primary end point occurred in 15 patients (4.9%), meeting the prespecified performance goal of 14.1% (P<0.0001). Stent thrombosis (Academic Research Consortium definite and probable) occurred in 2 patients (0.6%). Bleeding Academic Research Consortium type 3 and 5 bleeding occurred in 6 patients (1.9%). CONCLUSIONS: We observed favorable results in patients with HBR who underwent percutaneous coronary intervention with a ridaforolimus-eluting stent and received shortened DAPT, including a low rate of ischemic events and low rate of stent thrombosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03877848.

Marinopyrrole derivative MP1 as a novel anti-cancer agent in group 3 MYC-amplified Medulloblastoma.

BACKGROUND: Medulloblastoma (MB) patients with MYC oncogene amplification or overexpression exhibit extremely poor prognoses and therapy resistance. However, MYC itself has been one of the most challenging targets for cancer treatment. Here, we identify a novel marinopyrrole natural derivative, MP1, that shows desirable anti-MYC and anti-cancer activities in MB. METHODS: In this study, using MYC-amplified (Group 3) and non-MYC amplified MB cell lines in vitro and in vivo, we evaluated anti-cancer efficacies and molecular mechanism(s) of MP1. RESULTS: MP1 significantly suppressed MB cell growth and sphere counts and induced G2 cell cycle arrest and apoptosis in a MYC-dependent manner. Mechanistically, MP1 strongly downregulated the expression of MYC protein. Our results with RNA-seq revealed that MP1 significantly modulated global gene expression and inhibited MYC-associated transcriptional targets including translation/mTOR targets. In addition, MP1 inhibited MYC-target metabolism, leading to declined energy levels. The combination of MP1 with an FDA-approved mTOR inhibitor temsirolimus synergistically inhibited MB cell growth/survival by downregulating the expression of MYC and mTOR signaling components. Our results further showed that as single agents, both MP1 and temsirolimus, were able to significantly inhibit tumor growth and MYC expression in subcutaneously or orthotopically MYC-amplified MB bearing mice. In combination, there were further anti-MB effects on the tumor growth and MYC expression in mice. CONCLUSION: These preclinical findings highlight the promise of marinopyrrole MP1 as a novel MYC inhibition approach for MYC-amplified MB.

Enhanced synergy of pacritinib with temsirolimus and sunitinib in preclinical renal cell carcinoma model by targeting JAK2/STAT pathway.

Pacritinib is an oral medication that inhibits several kinases including JAK2, FLT3, IRAK and STAT3. It has been recently approved to treat patients with thrombocytopenia and myelofibrosis. Studies are currently exploring the potential use of pacritinib in treating other types of cancer such as leukaemia, breast cancer and prostate cancer. Our study aimed to investigate the effects of pacritinib alone and its combination with standard of care in renal cell carcinoma (RCC). We showed that pacritinib dose-dependently decreased viability of RCC cells, with IC50 at nanomolar or low micromolar concentration rage. Pacritinib inhibited cell proliferation, decreased colony formation, and increased apoptosis. Interestingly, pacritinib exhibited synergistic effects when combined with temsirolimus and sunitinib, but antagonistic effects when combined with doxorubicin, in a panel of RCC cell lines. We also confirmed that the combination of pacritinib with temsirolimus and sunitinib resulted in synergistic effects in RCC mouse models, with complete inhibition of tumour growth throughout the treatment period. Mechanistic studies indicated that the inhibition of JAK2, but not IRAK, was the main contributor to the anti-RCC activity of pacritinib. Our study is the first to demonstrate that pacritinib shows promise as a treatment option for RCC and underscores the therapeutic potential of targeting the JAK2/STAT signalling pathway in RCC.

Brain-restricted mTOR inhibition with binary pharmacology.

On-target-off-tissue drug engagement is an important source of adverse effects that constrains the therapeutic window of drug candidates1,2. In diseases of the central nervous system, drugs with brain-restricted pharmacology are highly desirable. Here we report a strategy to achieve inhibition of mammalian target of rapamycin (mTOR) while sparing mTOR activity elsewhere through the use of the brain-permeable mTOR inhibitor RapaLink-1 and the brain-impermeable FKBP12 ligand RapaBlock. We show that this drug combination mitigates the systemic effects of mTOR inhibitors but retains the efficacy of RapaLink-1 in glioblastoma xenografts. We further present a general method to design cell-permeable, FKBP12-dependent kinase inhibitors from known drug scaffolds. These inhibitors are sensitive to deactivation by RapaBlock, enabling the brain-restricted inhibition of their respective kinase targets.

Tissue-restricted inhibition of mTOR using chemical genetics.

Mammalian target of rapamycin (mTOR) is a highly conserved eukaryotic protein kinase that coordinates cell growth and metabolism, and plays a critical role in cancer, immunity, and aging. It remains unclear how mTOR signaling in individual tissues contributes to whole-organism processes because mTOR inhibitors, like the natural product rapamycin, are administered systemically and target multiple tissues simultaneously. We developed a chemical-genetic system, termed selecTOR, that restricts the activity of a rapamycin analog to specific cell populations through targeted expression of a mutant FKBP12 protein. This analog has reduced affinity for its obligate binding partner FKBP12, which reduces its ability to inhibit mTOR in wild-type cells and tissues. Expression of the mutant FKBP12, which contains an expanded binding pocket, rescues the activity of this rapamycin analog. Using this system, we show that selective mTOR inhibition can be achieved in Saccharomyces cerevisiae and human cells, and we validate the utility of our system in an intact metazoan model organism by identifying the tissues responsible for a rapamycin-induced developmental delay in Drosophila.

Molecular determinants of outcomes in relapsed or refractory mantle cell lymphoma treated with ibrutinib or temsirolimus in the MCL3001 (RAY) trial.

Mantle cell lymphoma (MCL) is a rare, incurable lymphoma subtype characterized by heterogeneous outcomes. To better understand the clinical behavior and response to treatment, predictive biomarkers are needed. Using residual archived material from patients enrolled in the MCL3001 (RAY) study, we performed detailed analyses of gene expression and targeted genetic sequencing. This phase III clinical trial randomized patients with relapsed or refractory MCL to treatment with either ibrutinib or temsirolimus. We confirmed the prognostic capability of the gene expression proliferation assay MCL35 in this cohort treated with novel agents; it outperformed the simplified MCL International Prognostic Index in discriminating patients with different outcomes. Regardless of treatment arm, our data demonstrated that this assay captures the risk conferred by known biological factors, including increased MYC expression, blastoid morphology, aberrations of TP53, and truncated CCND1 3' untranslated region. We showed the negative impact of BIRC3 mutations/deletions on outcomes in this cohort and identified that deletion of chromosome 8p23.3 also negatively impacts survival. Restricted to patients with deletions/alterations in TP53, ibrutinib appeared to abrogate the deleterious impact on outcome. These data illustrate the potential to perform a molecular analysis of predictive biomarkers on routine patient samples that can meaningfully inform clinical practice.

Comparison of 1-Month and 12-Month Vessel Responses Between the Polymer-Free Biolimus A9-Coated Stent and the Durable Polymer Everolimus-Eluting Stent.

BACKGROUND: A polymer-free biolimus A9-coated stent (PF-BCS) may achieve better arterial healing than a durable polymer drug-eluting stent owing to its polymer-free feature.Methods and Results: This multicenter, prospective, observational study enrolled 105 patients (132 lesions) who underwent PF-BCS (51 patients, 71 lesions) or durable polymer everolimus-eluting stent (DP-EES, 54 patients, 61 lesions) implantation. Serial coronary angioscopy (CAS) and optical coherence tomography (OCT) examinations were performed at 1 and 12 months, and the serial vessel responses were compared between PF-BCS and DP-EES. The primary outcome measure was the incidence of subclinical intrastent thrombus on CAS. The secondary outcome measures were: adequate strut coverage (≥40 µm) on OCT and maximum yellow color grade on CAS. The incidence of thrombus was high at 1 month (100% vs. 93%, P=0.091), but decreased at 12 months (18% vs. 25%, P=0.56), without a significant difference between PF-BCS and DP-EES. The adequate strut coverage rate was significantly higher (84±14% vs. 69±22%, P<0.001) and yellow color was significantly less intense (P=0.012) at 12 months in PF-BCS than in DP-EES; however, they were not significantly different at 1 month (adequate strut coverage: 47±21% vs. 50±17%, P=0.40; yellow color: P=0.99). CONCLUSIONS: Although the thrombogenicity of PF-BCS was similar to that of DP-EES, the adequate coverage and plaque stabilization rates of PF-BCS were superior to those of DP-EES at 12 months.

TP53 Sequencing and p53 Immunohistochemistry Predict Outcomes When Bevacizumab Is Added to Frontline Chemotherapy in Endometrial Cancer: An NRG Oncology/Gynecologic Oncology Group Study.

PURPOSE: The status of p53 in a tumor can be inferred by next-generation sequencing (NGS) or by immunohistochemistry (IHC). We examined the association between p53 IHC and sequence and whether p53 IHC alone, or integrated with TP53 NGS, predicts the outcome. METHODS: From GOG-86P, a randomized phase II study of chemotherapy combined with either bevacizumab or temsirolimus in advanced endometrial cancer, 213 cases had p53 protein expression data measured by IHC and TP53 NGS data. An analysis was designed to integrate p53 expression by IHC with the presence or absence of a TP53 mutation. These variables were further correlated with progression-free survival (PFS) and overall survival (OS) in the chemotherapy plus bevacizumab arms versus the chemotherapy plus temsirolimus arm. RESULTS: In the analysis of p53 IHC, the most striking treatment effect favoring bevacizumab was in cases where p53 was overexpressed (PFS hazard ratio [HR]: 0.46, 95% CI, 0.26 to 0.88; OS HR: 0.31, 95% CI, 0.16 to 0.62). On integrated analysis, patients with TP53 missense mutations and p53 protein overexpression had a similar treatment effect on PFS (HR: 0.41, 95% CI, 0.22 to 0.83) and OS (HR: 0.28, 95% CI, 0.14 to 0.59) favoring bevacizumab plus chemotherapy relative to temsirolimus plus chemotherapy. Concordance between TP53 NGS and p53 IHC was 88%. Concordance was 92% when cases with TP53 mutations and POLE mutations or mismatch repair deficiency were removed. CONCLUSION: IHC for p53 alone or when integrated with sequencing for TP53 identifies a specific, high-risk tumor genotype/phenotype for which bevacizumab is particularly beneficial in improving outcomes when combined with chemotherapy.

Inhibition of mTOR by temsirolimus overcomes radio-resistance in nasopharyngeal carcinoma.

Radio-resistance is a leading cause of nasopharyngeal carcinoma (NPC) treatment failure and identification of sensitising therapeutic targets is an unmet need to enhance clinical management. Given that the mammalian target of rapamycin (mTOR) signalling confers resistance to cancer therapy, we investigated whether mTOR contributes to radio-resistance in NPC and pharmacological inhibition of mTOR can overcome radio-resistance. We found that mTOR mRNA and protein levels, and phosphorylation of its downstream effector were increased in radio-resistant NPC compared with parental cells. mTOR inhibitor temsirolimus inhibits proliferation and induces apoptosis in a panel of NPC cell lines. Importantly, temsirolimus acts synergistically with radiation and is effective against radio-resistant cells. Using radio-resistant xenograft mouse model, we validated the efficacy of temsirolimus in preventing tumour formation and inhibiting tumour growth. Temsirolimus overcome radio-resistance in NPC via inhibiting mTOR signalling. Our work provides the pre-clinical evidence that the combination of radiation and mTOR inhibitor may be a therapeutic strategy in NPC. Our findings might accelerate the initiation of clinical trials on radio-resistant NPC patients using temsirolimus.

A phase I study of AZD2171 and Temsirolimus in patients with advanced gynecological malignancies.

PURPOSE: Temsirolimus, a mTOR inhibitor, and AZD2171, a VEGFR inhibitor, have independently shown activity in patients with gynecological malignancies. Understanding the pivotal role of the PI3K/PTEN/AKT/mTOR pathway in regulating angiogenesis, a phase I study utilizing Temsirolimus and AZD2171 was initiated to study the safety of targeting the mTOR and VEGF pathway in patients with recurrent or refractory gynecological malignancies. METHODS: Patients with advanced gynecological cancers were enrolled in this phase 1 study with Temsirolimus and AZD2171. A traditional 3 + 3 design was followed. The primary objective was to determine the MTD of the combination. Secondary objectives included efficacy, progression free survival (PFS) and toxicity profile. An expansion phase was planned after the MTD was determined. RESULTS: The study enrolled 11 patients over 16 months. All patients were enrolled in dose level 1. Due to toxicity, the trial was halted at dose level 1. No MTD was determined. The most common grade 3/4 toxicities included hypertension, thrombocytopenia, thromboembolic events, and hypertriglyceridemia. Five patients were evaluable for best overall clinical response. The best overall clinical response was stable disease. Two patients died without documented progression of disease. The median PFS was 7.2 months. CONCLUSIONS: Despite a conservative dose escalation, the toxicity data demonstrated that the combination of AZD2171 and Temsirolimus was not tolerable. Increased awareness of novel toxicities, pharmacological interactions, coupled with strict patient selection and early mitigation of side effects may enhance phase I clinical trial development.

Temsirolimus combined with cyclophosphamide and etoposide for pediatric patients with relapsed/refractory acute lymphoblastic leukemia: a Therapeutic Advances in Childhood Leukemia Consortium trial (TACL 2014-001).

Phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in acute lymphoblastic leukemia (ALL). The TACL2014-001 phase I trial of the mTOR inhibitor temsirolimus in combination with cyclophosphamide and etoposide was performed in children and adolescents with relapsed/refractory ALL. Temsirolimus was administered intravenously (IV) on days 1 and 8 with cyclophosphamide 440 mg/m2 and etoposide 100 mg/m2 IV daily on days 1-5. The starting dose of temsirolimus was 7.5 mg/m2 (DL1) with escalation to 10 mg/m2 (DL2), 15 mg/m2 (DL3), and 25 mg/m2 (DL4). PI3K/mTOR pathway inhibition was measured by phosphoflow cytometry analysis of peripheral blood specimens from treated patients. Sixteen heavily-pretreated patients were enrolled with 15 evaluable for toxicity. One dose-limiting toxicity of grade 4 pleural and pericardial effusions occurred in a patient treated at DL3. Additional dose-limiting toxicities were not seen in the DL3 expansion or DL4 cohort. Grade 3/4 non-hematologic toxicities occurring in three or more patients included febrile neutropenia, elevated alanine aminotransferase, hypokalemia, mucositis, and tumor lysis syndrome and occurred across all doses. Response and complete were observed at all dose levels with a 47% overall response rate and 27% complete response rate. Pharmacodynamic correlative studies demonstrated dose-dependent inhibition of PI3K/mTOR pathway phosphoproteins in all studied patients. Temsirolimus at doses up to 25 mg/m2 with cyclophosphamide and etoposide had an acceptable safety profile in children with relapsed/refractory ALL. Pharmacodynamic mTOR target inhibition was achieved and appeared to correlate with temsirolimus dose. Future testing of next-generation PI3K/mTOR pathway inhibitors with chemotherapy may be warranted to increase response rates in children with relapsed/refractory ALL.

Polymer-free biolimus-A9-eluting stent performance according to renal impairment: insights from the RUDI-FREE registry.

AIMS: Patients with chronic kidney disease (CKD) are at increased risk of cardiovascular disease and have a worse prognosis after percutaneous coronary interventions (PCI). The BioFreedom polymer-free biolimus-A9-eluting stent (PF-BES) has shown promising results in patients at high bleeding risk; however, its performance in CKD patients has yet to be analyzed. METHODS: The all-comers RUDI-FREE registry documented patients undergoing PCI with PF-BES in routine clinical practice. Patients were stratified into three groups according to their estimated glomerular filtration rate (eGFR): preserved renal function, mild renal insufficiency (RI), and with moderate to severe RI (eGFR ≥ 90, between 90 and 45, and <45 ml/min/1.73 m2, respectively). The primary safety end point was a patient-oriented composite end point of cardiovascular death, myocardial infarction (MI), and definite or probable stent thrombosis (ST). The primary efficacy end point was target lesion revascularization (TLR). RESULTS: The registry documented 1,104 consecutive patients treated with PF-BES: 258 (23.4%) with preserved renal function, whereas 712 (64.7%) and 131 (11.9%) had mild and moderate to severe RI, respectively. At 1 year, the primary safety end point was significantly higher in patients with moderate to severe RI (3.5% vs. 2.8% vs. 11.5%; P < 0.001). Conversely, TLR proved similar among groups (0.4% vs. 1.8% vs. 0.8%; P = 0.235). CONCLUSIONS: Patients with worse renal function had increased risk of the composite of cardiovascular deaths, MI, and definite or probable ST. However, the PF-BES showed similar efficacy despite differences in renal function. These findings need to be confirmed in large-scale randomized trials.