A phase I, first-in-human study of TAK-164, an antibody-drug conjugate, in patients with advanced gastrointestinal cancers expressing guanylyl cyclase C.

PURPOSE: Guanylyl cyclase C (GCC) is highly expressed in several gastrointestinal malignancies and preclinical studies suggest that it is a promising target for antibody-based therapeutics. This phase I trial assessed the safety and tolerability of TAK-164, an investigational, anti-GCC antibody-drug conjugate (NCT03449030). METHODS: Thirty-one patients with GCC-positive, advanced gastrointestinal cancers received intravenous TAK-164 on day 1 of 21-day cycles. Dose escalation proceeded based on cycle 1 safety data via a Bayesian model. RESULTS: Median age was 58 years (range 32-72), 25 patients (80.6%) had colorectal carcinoma, and median number of prior therapies was four. No dose-limiting toxicities (DLTs) were reported during cycle 1 DLT evaluation period. After cycle 2 dosing, 3 patients reported dose-limiting treatment-emergent adverse events (TEAEs): grade 3 pyrexia and grade 5 hepatic failure (0.19 mg/kg), grade 4 hepatic failure and platelet count decreased (0.25 mg/kg), grade 3 nausea, grade 4 platelet and neutrophil count decreased (0.25 mg/kg). The recommended phase II dose (RP2D) was 0.064 mg/kg. Common TAK-164-related TEAEs included platelet count decreased (58.1%), fatigue (38.7%), and anemia (32.3%). There was a dose-dependent increase in TAK-164 exposure over the range, 0.032-0.25 mg/kg. TAK-164 half-life ranged from 63.5 to 159 h. One patient (0.008 mg/kg) with high baseline GCC expression had an unconfirmed partial response. CONCLUSIONS: TAK-164 appeared to have a manageable safety profile at 0.064 mg/kg. Hepatic toxicity was identified as a potential risk. The RP2D of 0.064 mg/kg was considered insufficient to derive clinical benefit; there are no plans for further clinical development. CLINICAL TRIAL REGISTRATION: NCT03449030.

Sapanisertib Plus Exemestane or Fulvestrant in Women with Hormone Receptor-Positive/HER2-Negative Advanced or Metastatic Breast Cancer.

PURPOSE: This open-label, multicenter, phase IB/II study evaluated sapanisertib, a dual inhibitor of mTOR kinase complexes 1/2, plus exemestane or fulvestrant in postmenopausal women with hormone receptor-positive (HR+)/HER2-negative (HER2-) advanced/metastatic breast cancer. PATIENTS AND METHODS: Eligible patients had previously progressed on everolimus with exemestane/fulvestrant and received ≤3 (phase IB) or ≤1 (phase II) prior chemotherapy regimens. Patients received sapanisertib 3 to 5 mg every day (phase IB), or 4 mg every day (phase II) with exemestane 25 mg every day or fulvestrant 500 mg monthly in 28-day cycles. Phase II enrolled parallel cohorts based on prior response to everolimus. The primary objective of phase II was to evaluate antitumor activity by clinical benefit rate at 16 weeks (CBR-16). RESULTS: Overall, 118 patients enrolled in phase IB (n = 24) and II (n = 94). Five patients in phase IB experienced dose-limiting toxicities, at sapanisertib doses of 5 mg every day (n = 4) and 4 mg every day (n = 1); sapanisertib 4 mg every day was the MTD in combination with exemestane or fulvestrant. In phase II, in everolimus-sensitive versus everolimus-resistant cohorts, CBR-16 was 45% versus 23%, and overall response rate was 8% versus 2%, respectively. The most common adverse events were nausea (52%), fatigue (47%), diarrhea (37%), and hyperglycemia (33%); rash occurred in 17% of patients. Molecular analysis suggested positive association between AKT1 mutation status and best treatment response (complete + partial response; P = 0.0262). CONCLUSIONS: Sapanisertib plus exemestane or fulvestrant was well tolerated and exhibited clinical benefit in postmenopausal women with pretreated everolimus-sensitive or everolimus-resistant breast cancer.

Randomized Phase II Study of Paclitaxel plus Alisertib versus Paclitaxel plus Placebo as Second-Line Therapy for SCLC: Primary and Correlative Biomarker Analyses.

INTRODUCTION: We assessed the Aurora A kinase inhibitor, alisertib, plus paclitaxel (henceforth referred to as alisertib/paclitaxel) as second-line treatment for SCLC. METHODS: In this double-blind study, patients with relapsed or refractory SCLC were stratified by relapse type (sensitive versus resistant or refractory) and brain metastases and randomized 1:1 to alisertib/paclitaxel or placebo plus paclitaxel (henceforth referred to as placebo/paclitaxel) in 28-day cycles. The primary end point was progression-free survival (PFS). Associations of c-Myc expression in tumor tissue (prespecified) and genetic alterations in circulating tumor DNA (retrospective) with clinical outcome were evaluated. RESULTS: A total of 178 patients were enrolled (89 in each arm). The median PFS was 3.32 months with alisertib/paclitaxel versus 2.17 months with placebo/paclitaxel (hazard ratio [HR] = 0.77, 95% confidence limit [CI]: 0.557-1.067, p = 0.113 in the intent-to-treat population versus HR = 0.71, 95% CI: 0.509-0.985, p = 0.038 with corrected analysis applied). Among 140 patients with genetic alternations, patients with cell cycle regulator mutations (cyclin-dependent kinase 6 gene [CDK6], retinoblastoma-like 1 gene [RBL1], retinoblastoma-like 2 gene [RBL2], and retinoblastoma 1 gene [RB1]) had significantly improved PFS with alisertib/paclitaxel versus with placebo/paclitaxel (3.68 versus 1.80 months, respectively [HR = 0.395, 95% CI: 0.239-0.654, p = 0.0003]), and overall survival (7.20 versus 4.47 months, respectively [HR = 0.427, 95% CI: 0.259-0.704, p = 0.00085]). A subset of patients with c-Myc expression showed significantly improved PFS with alisertib/paclitaxel. The incidence of grade 3 or higher drug-related adverse events was 67% (58 patients) with alisertib/paclitaxel versus 22% (25 patients) with placebo/paclitaxel. Twelve patients (14%) versus 11 (12%) died on study, including four versus zero treatment-related deaths. CONCLUSIONS: Efficacy signals were seen with alisertib/paclitaxel in relapsed or refractory SCLC. c-Myc expression and mutations in cell cycle regulators may be potential predictive biomarkers of alisertib efficacy; further prospective validations are warranted.

Aurora A Functional Single Nucleotide Polymorphism (SNP) Correlates With Clinical Outcome in Patients With Advanced Solid Tumors Treated With Alisertib, an Investigational Aurora A Kinase Inhibitor.

BACKGROUND: Alisertib (MLN8237) is an investigational, oral, selective Aurora A kinase inhibitor. Aurora A contains two functional single nucleotide polymorphisms (SNPs; codon 31 [F/I] and codon 57 [V/I]) that lead to functional changes. This study investigated the prognostic and predictive significance of these SNPs. METHODS: This study evaluated associations between Aurora A SNPs and overall survival (OS) in The Cancer Genome Atlas (TCGA) database. The Aurora A SNPs were also evaluated as predictive biomarkers for clinical outcomes to alisertib in two phase 2 studies (NCT01045421 and NCT01091428). Aurora A SNP genotyping was obtained from 85 patients with advanced solid tumors receiving single-agent alisertib and 122 patients with advanced recurrent ovarian cancer treated with alisertib plus weekly paclitaxel (n=62) or paclitaxel alone (n=60). Whole blood was collected prior to treatment and genotypes were analyzed by PCR. FINDINGS: TCGA data suggested prognostic significance for codon 57 SNP; solid tumor patients with VV and VI alleles had significantly reduced OS versus those with II alleles (HR 1.9 [VI] and 1.8 [VV]; p<0.0001). In NCT01045421, patients carrying the VV alleles at codon 57 (n=53, 62%) had significantly longer progression-free survival (PFS) than patients carrying IV or II alleles (n=32, 38%; HR 0.5; p=0.0195). In NCT01091428, patients with the VV alleles at codon 57 who received alisertib plus paclitaxel (n=47, 39%) had a trend towards improved PFS (7.5months) vs paclitaxel alone (n=32, 26%; 3.8months; HR 0.618; p=0.0593). In the paclitaxel alone arm, patients with the VV alleles had reduced PFS vs modified intent-to-treat (mITT) patients (3.8 vs 5.1months), consistent with the TCGA study identifying the VV alleles as a poor prognostic biomarker. No significant associations were identified for codon 31 SNP from the same data set. INTERPRETATION: These findings suggest that Aurora A SNP at codon 57 may predict disease outcome and response to alisertib in patients with solid tumors. Further investigation is warranted.

Development and Validation of an ERCC1 Immunohistochemistry Assay for Solid Tumors.

CONTEXT: - Excision repair cross-complementation 1 (ERCC1) is a key enzyme in nuclear excision repair pathway and has a critical role in helping remove DNA adducts caused by cross-linking agents, such as platinum-containing cancer chemotherapies and other DNA-damaging therapeutic modalities. ERCC1 expression, evaluated by techniques such as immunohistochemistry, has been associated with clinical response; ERCC1+ tumors are more resistant to cisplatin treatment than are ERCC1- tumors. Although several immunohistochemistry, anti-ERCC1 antibodies are available, the 8F1 clone, in particular, has been used in many studies. Recent evidence has suggested that the 8F1 antibody cross-reacts with at least one other protein, raising concerns about the specificity of this clone. OBJECTIVE: - To design an immunohistochemistry assay to detect ERCC1 levels that show dynamic range and consistent analytic performance. DESIGN: - Two different primary antibodies to ERCC1, clones 4F9 and D6G6, were evaluated on formalin-fixed, paraffin-embedded tissue. We then performed a fit-for-purpose assay validation with the 4F9 clone, which included sensitivity assessment across several solid tumor types and evaluation of analytic parameters, such as precision and reproducibility. RESULTS: - The 4F9 clone was consistently superior to the D6G6 clone in the optimization phase. A range of expression was seen in ovarian, head and neck, non-small cell lung, and esophageal cancer samples when tested with the 4F9 clone. The antibody showed acceptable reproducibility (31.02%) and precision (16.06%). CONCLUSIONS: - This assay can be used to assess ERCC1 levels during clinical studies of patient tumors from a variety of tumor types.

The role of aberrant VHL/HIF pathway elements in predicting clinical outcome to pazopanib therapy in patients with metastatic clear-cell renal cell carcinoma.

PURPOSE: Inactivation of von Hippel-Lindau (VHL) gene in clear-cell renal cell carcinoma (RCC) leads to increased levels of hypoxia-inducible factors (HIF) and overexpression of HIF target genes, such as VEGF and others. VEGF-targeted agents are standard in advanced clear-cell RCC but biomarkers of activity are lacking. EXPERIMENTAL DESIGN: We analyzed tumor tissue samples from metastatic clear-cell RCC patients who received pazopanib as part of clinical trial VEG102616. We evaluated several components of the VHL/HIF pathway: VHL gene inactivation (mutation and/or methylation), HIF-1α and HIF-2α immunohistochemistry staining, and HIF-1α transcriptional signature. We evaluated the association of these biomarkers with best overall response rate (ORR) and progression-free survival (PFS) to pazopanib, a standard first-line VEGF-targeted agent. RESULTS: The VEG102616 trial enrolled 225 patients, from whom 78 samples were available for tumor DNA extraction. Of these, 70 patients had VHL mutation or methylation. VHL gene status did not correlate with ORR or PFS. Similarly, HIF-1α (65 samples) and HIF-2α (66 samples) protein levels (high vs. low) did not correlate with ORR or PFS to pazopanib. The HIF-1α transcriptional signature (46 samples) was enriched in tumors expressing high HIF-1α levels. However, the HIF-1α gene expression signature was not associated with clinical outcome to pazopanib. CONCLUSIONS: In patients with advanced clear-cell RCC, several potential biomarkers along the VHL/HIF-1α/HIF-2α axis were not found to be predictive for pazopanib activity. Additional efforts must continue to identify biomarkers associated with clinical outcome to VEGF-targeted agents in metastatic RCC.

NMDA receptor antagonism: escalation of aggressive behavior in alcohol-drinking mice.

RATIONALE: Memantine is a potential treatment for alcoholic patients, yet few studies investigate the effect of concurrent treatment with memantine and ethanol on aggression. We evaluated aggressive behavior following ethanol consumption and treatment with glutamatergic drugs to characterize interactions between these compounds. OBJECTIVE: This study aimed to use rodent models of aggression to examine interactions between glutamatergic compounds and ethanol. MATERIALS AND METHODS: Once male CFW mice reliably self-administered 1 g/kg ethanol or water, they were assessed for aggression in resident-intruder confrontations. Alternatively, aggression was evaluated following a social-instigation procedure. Animals were then injected with memantine, ketamine, neramexane, MTEP, or LY379268 before aggressive confrontations. Effects of the pharmacological manipulations on salient aggressive and non-aggressive behaviors were analyzed. RESULTS: Moderate doses of memantine, neramexane, and MTEP interacted with ethanol to increase the frequency of attack bites while ketamine did not. The highest dose of LY379268, an mGluR(2/3) agonist, reduced both aggressive and non-aggressive behaviors after water and ethanol self-administration. Attack bites increased with social instigation and decreased with administration of high doses of MTEP and LY379268. Memantine and MTEP both reduced attack bite frequency in the instigation condition without reducing locomotor behavior. CONCLUSIONS: Memantine and neramexane interacted with ethanol to heighten aggression. The binding characteristics of these compounds allow for 'partial trapping' by which some NMDARs are unblocked between depolarizations. We propose that this feature may contribute to the differential aggression-heightening interactions between these compounds and ethanol. MTEP also interacted with ethanol to escalate aggression, possibly through inhibition of mGluR(5) modulation of NMDARs.

The glomuvenous malformation protein Glomulin binds Rbx1 and regulates cullin RING ligase-mediated turnover of Fbw7.

Fbw7, a substrate receptor for Cul1-RING-ligase (CRL1), facilitates the ubiquitination and degradation of several proteins, including Cyclin E and c-Myc. In spite of much effort, the mechanisms underlying Fbw7 regulation are mostly unknown. Here, we show that Glomulin (Glmn), a protein found mutated in the vascular disorder glomuvenous malformation (GVM), binds directly to the RING domain of Rbx1 and inhibits its E3 ubiquitin ligase activity. Loss of Glmn in a variety of cells, tissues, and GVM lesions results in decreased levels of Fbw7 and increased levels of Cyclin E and c-Myc. The increased turnover of Fbw7 is dependent on CRL and proteasome activity, indicating that Glmn modulates the E3 activity of CRL1(Fbw7). These data reveal an unexpected functional connection between Glmn and Rbx1 and demonstrate that defective regulation of Fbw7 levels contributes to GVM.