Impact of hydrolysis-mediated clearance on the pharmacokinetics of novel anaplastic lymphoma kinase inhibitors.

Compound 1 [(E)-4-fluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1S,4S)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], a new, potent, selective anaplastic lymphoma kinase (ALK) inhibitor with potential application for the treatment of cancer, was selected as candidate to advance into efficacy studies in mice. However, the compound underwent mouse-specific enzymatic hydrolysis in plasma to a primary amine product (M1). Subsequent i.v. pharmacokinetics studies in mice showed that compound 1 had high clearance (CL) and a short half-life. Oral dose escalation studies in mice indicated that elimination of compound 1 was saturable, with higher doses achieving sufficient exposures above in vitro IC(50). Chemistry efforts to minimize hydrolysis resulted in the discovery of several analogs that were stable in mouse plasma. Three were taken in vivo into mice and showed decreased CL corresponding to increased in vitro stability in plasma. However, the more stable compounds also showed reduced potency against ALK. Kinetic studies in NADPH-fortified and unfortified microsomes and plasma produced submicromolar K(m) values and could help explain the saturation of elimination observed in vivo. Predictions of CL based on kinetics from hydrolysis and NADPH-dependent pathways produced predicted hepatic CL values of 3.8, 3.0, 1.6, and 1.2 l/h⋅kg for compound 1, compound 2 [(E)-3,5-difluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], compound 3 [(E)-3-chloro-5-fluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], and compound 4 [(E)-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)-3-(trifluoromethyl)benzamide], respectively. The in vivo observed CLs for compounds 1, 2, 3, and 4 were 5.52, 3.51, 2.14, and 2.66 l/h⋅kg, respectively. These results indicate that in vitro metabolism kinetic data, incorporating contributions from both hydrolysis and NADPH-dependent metabolism, could be used to predict the systemic CL of compounds cleared via hydrolytic pathways provided that the in vitro assays thoroughly investigate the processes, including the contribution of other metabolic pathways and the possibility of saturation kinetics.

Novel cannabinoid receptor 1 inverse agonist CRB-913 enhances efficacy of tirzepatide, semaglutide, and liraglutidein the diet-induced obesity mouse model.

OBJECTIVE: Incretin receptor agonists are now standard of care in treating obesity. Their efficacy and tolerability might be further improved by combining them with compounds that offer orthogonal mechanisms of action. The cannabinoid type 1 receptor (CB1R) is a clinically validated therapeutic target in obesity, and several experimental CB1R inverse agonists have been shown to induce weight loss. METHODS: This study characterizes a novel CB1R inverse agonist (CRB-913) with similar preclinical potency to rimonabant but markedly reduced brain penetration. CRB-913 was tested as monotherapy and in combination with tirzepatide, semaglutide, or liraglutide in the diet-induced obesity (DIO) mouse model for body weight reduction. RESULTS: CRB-913 demonstrated enhanced plasma exposure (3.8-fold larger area under the curvelast ) and reduced brain levels (9.5-fold lower area under the curvelast ) than rimonabant. CRB-913 monotherapy yielded a dose-dependent decrease in body weight in DIO mice reaching -22% within 18 days. In further DIO studies in combination with tirzepatide, semaglutide, or liraglutide, CRB-913 (2.5 mg/kg) resulted in -32.6%, -28.8%, and -16.8% decreases in body weight on Day 18, respectively, with concomitant improvements in body fat content, liver triglycerides, and liver fat deposits. CONCLUSIONS: CRB-913 in combination with incretin analogues could deliver meaningful improvements over current standards of care for obesity and related conditions.

Identifying symptomatic adverse events using the patient-reported outcomes version of the common terminology criteria for adverse events in patients with non-small cell lung cancer with epidermal growth factor receptor exon 20 insertion mutations.

OBJECTIVE: Tolerability and safety of treatments are important in oncology trials and should be informed by patient assessments. We identified the most relevant patient-reported symptomatic adverse events (AEs) to measure in patients with non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertion mutations. METHODS: This study selected relevant symptomatic AEs from 78 AEs available in the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) measurement system. Initially, symptomatic AEs were selected based on literature and product labeling reviews, and then core sets of symptomatic AEs were identified by patient and clinician interviews. Qualitative and descriptive analyses were performed using the data collected from three iterative rounds of patient interviews. RESULTS: During concept elicitation interviews involving 29 patients, 12 symptomatic AEs were identified and were then adapted into a 25-item PRO-CTCAE form for use in future clinical trials along with commonly used PRO measures. Cognitive interviews showed that the PRO-CTCAE items were easy to answer and appropriate for assessing the patients' experience with symptomatic AEs. This study also assessed disease symptoms, impacts, and overall patient experience. CONCLUSIONS: The 25-item PRO-CTCAE form captures the most relevant symptomatic AEs in this patient population, and it is available for future studies. Baseline characterization of AEs associated with this distinct patient group contributes to our broader knowledge about NSCLC and through platforms like Project Patient Voice will expand our understanding of treatment tolerability and safety for NSCLC. Ultimately, this data collection will help inform decision-making for patients, caregivers, healthcare providers, and regulators.

Single-Dose Pharmacokinetics and Tolerability of the Oral Epidermal Growth Factor Receptor Inhibitor Mobocertinib (TAK-788) in Healthy Volunteers: Low-Fat Meal Effect and Relative Bioavailability of 2 Capsule Products.

Mobocertinib (TAK-788) is a tyrosine kinase inhibitor under investigation for treatment of non-small cell lung cancer with activating EGFR exon 20 insertions. This study examined the safety; tolerability; pharmacokinetics (PK), including food effects; and bioavailability of mobocertinib in healthy volunteers. In part 1, fasted volunteers were randomized to placebo or mobocertinib in single-ascending-dose cohorts (20-160 mg). In part 2, mobocertinib (120/160 mg) was administered on day 1 of periods 1 and 2 under fasted or low-fat meal conditions (2-period, 2-sequence crossover design). In part 3, fasted volunteers received mobocertinib 160 mg in 1 of 2 capsule products on day 1 of periods 1 and 2 with 7-day washout. Safety and PK parameters were assessed. Sixty-nine volunteers were enrolled (mean age, 29 years; 75% male). The most common adverse events (AEs; ≥10% of volunteers) were gastrointestinal AEs (25%-50%) and headache (8%-31%). No serious AEs were reported. A low-fat meal did not affect the PK of mobocertinib or its active metabolites. The geometric mean terminal disposition phase half-life (20 hours) supported once-daily dosing. The 2 capsule products were bioequivalent. These data guided dosing and supported administration of mobocertinib without regard to low-fat meal intake in ongoing and planned clinical studies.

Targeting HER2 Exon 20 Insertion-Mutant Lung Adenocarcinoma with a Novel Tyrosine Kinase Inhibitor Mobocertinib.

No targeted treatments are currently approved for HER2 exon 20 insertion-mutant lung adenocarcinoma patients. Mobocertinib (TAK-788) is a potent irreversible tyrosine kinase inhibitor (TKI) designed to target human epidermal growth factor receptor 2 (HER2/ERBB2) exon 20 insertion mutations. However, the function of mobocertinib on HER2 exon 20 insertion-mutant lung cancer is still unclear. Here we conducted systematic characterization of preclinical models to understand the activity profile of mobocertinib against HER2 exon 20 insertions. In HER2 exon 20 insertion-mutant cell lines, the IC50 of mobocertinib was higher than poziotinib and comparable with or slightly lower than afatinib, neratinib, and pyrotinib. Mobocertinib had the lowest HER2 exon 20 insertion IC50/wild-type (WT) EGFR IC50 ratio, indicating that mobocertinib displayed the best selectivity profile in these models. Also, mobocertinib showed strong inhibitory activity in HER2 exon 20YVMA allograft and patient-derived xenograft models. In genetically engineered mouse models, HER2 exon 20G776>VC lung tumors exhibited a sustained complete response to mobocertinib, whereas HER2 exon 20YVMA tumors showed only partial and transient response. Combined treatment with a second antibody-drug conjugate (ADC) against HER2, ado-trastuzumab emtansine (T-DM1), synergized with mobocertinib in HER2 exon 20YVMA tumors. In addition to the tumor cell autonomous effect, sustained tumor growth control derived from M1 macrophage infiltration and CD4+ T-cell activation. These findings support the ongoing clinical development of mobocertinib (NCT02716116) and provide a rationale for future clinical evaluation of T-DM1 combinational therapy in HER2 exon 20YVMA insertion-mutant lung adenocarcinoma patients. SIGNIFICANCE: This study elucidates the potent inhibitory activity of mobocertinib against HER2 exon 20 insertion-mutant lung cancer and the synergic effect of combined mobocertinib and T-DM1, providing a strong rationale for clinical investigation.

Effects of palifermin on antitumor activity of chemotherapeutic and biological agents in human head and neck and colorectal carcinoma xenograft models.

Damage to the gastrointestinal mucosa is a common dose-limiting toxicity of several anticancer therapies. Until recently, adequate control of oral mucositis was considered a significant unmet medical need, with most available treatments providing only palliative benefits without protecting the gastrointestinal epithelium from the damaging effects of cancer therapy. In 2005, palifermin [recombinant human keratinocyte growth factor (KGF)] was approved to decrease the incidence and duration of severe oral mucositis in patients with hematologic malignancies receiving myelotoxic therapy requiring hematopoietic stem cell support. Current trials are investigating the use of palifermin in solid tumor settings. The objective of this study was to determine whether combining palifermin with different chemotherapeutic or biological agents affected the antitumor activity of these agents in human head and neck (FaDu) and colorectal (HT29) carcinoma xenograft models. Nude CD1 mice were injected with 1 x 10(7) of either FaDu or HT29 cells, which express both KGF and epithelial growth factor receptors. Animals were treated with palifermin in various combinations with chemotherapeutic (5-fluorouracil and cisplatin) and/or biological (bevacizumab, cetuximab, and panitumumab) agents. Palifermin alone had no effect on either FaDu or HT29 tumor growth. Palifermin did not affect the therapeutic efficacy of 5-fluorouracil, cisplatin, cetuximab, bevacizumab, or panitumumab in any of the two- or three-way drug combinations tested in either model. The results of this study showed that palifermin did not promote the growth of two carcinoma cell lines that express functional KGF receptors and did not protect these tumor cells from the antitumor effects of several chemotherapeutic and biological agents.

Novel Oral mTORC1/2 Inhibitor TAK-228 Has Synergistic Antitumor Effects When Combined with Paclitaxel or PI3Kα Inhibitor TAK-117 in Preclinical Bladder Cancer Models.

Advanced bladder cancer is associated with a poor prognosis and limited treatment options. The PI3K/AKT/mTOR pathway is frequently activated in this disease and can be a potential therapeutic target for treatment intervention. We studied the antitumor efficacy of a new targeted therapy, TAK-228 (oral mTORC1/2 inhibitor), in preclinical models of bladder cancer. We evaluated the effects of TAK-228 in combination with a PI3Kα inhibitor (TAK-117) or with chemotherapy (paclitaxel). We used six bladder cancer cell lines and in vivo xenografts models. TAK-228 strongly inhibited cell proliferation in vitro, and reduced tumor growth and angiogenesis in vivo. Three possible biomarkers of response to TAK-228 (basal levels of 4E-BP1, p-4E-BP1/4E-BP1 ratio, or eIF4E/4E-BP1 ratio) were identified. The combination of TAK-228 and TAK-117 had synergistic effects in vitro and in vivo. Furthermore, TAK-228 demonstrated greater efficiency when combined with paclitaxel. TAK-228 also showed ex vivo activity in tumor tissue from patients with treatment-naïve bladder cancer. TAK-228 is a promising investigational agent that induces a strong effect on cell proliferation, tumor growth, and angiogenesis in bladder cancer models. High synergistic effects were observed with TAK-228 combined with a PI3K inhibitor or with chemotherapy. These results are currently being investigated in a clinic trial of TAK-228 plus paclitaxel in patients with metastatic bladder cancer (NCT03745911). IMPLICATIONS: Strong synergistic effects were observed when combining TAK-228 with TAK-117 (a PI3Kα inhibitor) or with paclitaxel chemotherapy. A phase II study at our institution is currently evaluating the efficacy of TAK-228 combined with paclitaxel in patients with metastatic bladder cancer.

Dose Optimization for Anticancer Drug Combinations: Maximizing Therapeutic Index via Clinical Exposure-Toxicity/Preclinical Exposure-Efficacy Modeling.

PURPOSE: Recommended phase II dose (RP2D) determination for combination therapy regimens is a constrained optimization problem of maximizing antitumor activity within the constraint of clinical tolerability to provide a wide therapeutic index. A methodology for addressing this problem was developed and tested using clinical and preclinical data from combinations of the investigational drugs TAK-117, a PI3Kα inhibitor, and TAK-228, a TORC1/2 dual inhibitor. EXPERIMENTAL DESIGN: Utilizing free fraction-corrected average concentrations, [Formula: see text] and [Formula: see text], which are the primary pharmacokinetic predictors of single-agent preclinical antitumor activity, a preclinical exposure-efficacy surface was characterized, allowing for nonlinear interactions between growth rate inhibition of the agents on a MDA-MB-361 cell line xenograft model. Logistic regression was used to generate an exposure-effect surface for [Formula: see text] and [Formula: see text] versus clinical toxicity outcomes [experiencing a dose-limiting toxicity (DLT)] in single-agent and combination dose-escalation studies. A maximum tolerated exposure curve was defined at which DLT probability was 25%; predicted antitumor activity along this curve was used to determine optimal RP2D. RESULTS: The toxicity constraint curve determined from early clinical data predicted that any clinically tolerable combination was unlikely to result in greater antitumor activity than either single-agent TAK-117 or TAK-228 administered at their respective MTDs. Similar results were obtained with 10 other cell lines, with one agent or the other predicted to outperform the combination. CONCLUSIONS: This methodology represents a general, principled way of evaluating and selecting optimal RP2D combinations in oncology. The methodology will be retested upon availability of clinical data from TAK-117/TAK-228 combination phase II studies.See related commentary by Mayawala et al., p. 6564.

Specific alternative HOX11 transcripts are expressed in paediatric neural tumours and T-cell acute lymphoblastic leukaemia.

HOX11 is a proto-oncogene, which is silent in normal mature T-cells, while being aberrantly activated in T-cell acute lymphoblastic leukaemia (T-ALL) by translocations t(10;14)(q24;q11) or t(7;10)(q35;q24). Although many oncogenes are expressed in alternative forms in cancer, thus far, only one form of the human HOX11 transcript has been reported. We describe here the identification of three alternative transcripts of the HOX11 proto-oncogene, expressed in primary T-ALL specimens. Using rapid amplification of cDNA ends (RACE) and targeted RT-PCR, we have sequenced 23 individual cDNA clones characterising these novel transcripts. Northern hybridisation identified particular novel exons expressed in T-ALL, which are not expressed in normal T-cells. To date, aberrant expression of HOX11 has only been associated with leukaemia. Our survey of a range of neuroblastoma and primitive neuroectodermal tumour (PNET) cell lines demonstrated the expression of these novel HOX11 transcripts in tumours of neural origin, while their expression was not detected in normal brain tissues. Strikingly, the dominant transcript in these neural tumour cell lines is more than 1 kb larger than the dominant transcript in T-ALL. These observations, combined with sequence data from several EST clones derived from medulloblastoma cDNA libraries, support a new hypothesis that HOX11 may also function as a neural oncogene or brain tumour marker.

Cross-contamination with tamoxifen induces transgene expression in non-exposed inducible transgenic mice.

Inducible transgenic mouse models that impose a constraint on both temporal and spatial expression of a given transgene are invaluable. These animals facilitate experiments that can address the role of a specific cell or group of cells within an animal or in a particular window of time. A common approach to achieve inducibility involves the site-specific recombinase 'Cre', which is linked to a modified version of one of various steroid hormone-binding domains. Thus, the expression of Cre is regulated such that a functional nuclear transgene product can only be generated with the addition of an exogenous ligand. However, critical requirements of this system are that the nuclear localization of the transgene product be tightly regulated, that the dosage of the inducing agent remains consistent among experimental animals and that the transgene cassette cannot express in the absence of the inducing agent. We used the Cre ER(T2) cassette, which is regulated by the addition of the estrogen antagonist tamoxifen to determine whether cross-contamination of tamoxifen between animals housed together can be a significant source of spurious results. We found that cross-contamination of exogenous tamoxifen does occur. It occurred in all animals tested. We suggest that the mechanism of contamination is through exposure to tamoxifen in the general environment and/or to coprophagous behavior. These results have important implications for the interpretation and design of experiments that use 'inducible' transgenic animals.

Rapid development of piperidine carboxamides as potent and selective anaplastic lymphoma kinase inhibitors.

Piperidine carboxamide 1 was identified as a novel inhibitor of anaplastic lymphoma kinase (ALK enzyme assay IC(50) = 0.174 µM) during high throughput screening, with selectivity over the related kinase insulin-like growth factor-1 (IGF1R). The X-ray cocrystal structure of 1 with the ALK kinase domain revealed an unusual DFG-shifted conformation, allowing access to an extended hydrophobic pocket. Structure-activity relationship (SAR) studies were focused on the rapid parallel optimization of both the right- and left-hand side of the molecule, culminating in molecules with improved potency and selectivity over IGF1R.

The discovery and optimization of a novel class of potent, selective, and orally bioavailable anaplastic lymphoma kinase (ALK) inhibitors with potential utility for the treatment of cancer.

A class of 2-acyliminobenzimidazoles has been developed as potent and selective inhibitors of anaplastic lymphoma kinase (ALK). Structure based design facilitated the rapid development of structure-activity relationships (SAR) and the optimization of kinase selectivity. Introduction of an optimally placed polar substituent was key to solving issues of metabolic stability and led to the development of potent, selective, orally bioavailable ALK inhibitors. Compound 49 achieved substantial tumor regression in an NPM-ALK driven murine tumor xenograft model when dosed qd. Compounds 36 and 49 show favorable potency and PK characteristics in preclinical species indicative of suitability for further development.

Comparison of 2 cell-based phosphoprotein assays to support screening and development of an ALK inhibitor.

Anaplastic lymphoma kinase (ALK) when expressed as a fusion protein with nucleophosmin (NPM) has been implicated as a driving oncogene in a subset of lymphomas. Recent reports of ALK expression in a number of other cancers have raised the possibility that an ALK inhibitor may benefit patients with these diseases as well. In a campaign to identify and develop a selective ALK inhibitor, 2 assays were devised to measure the phosphorylation of tyrosine residue 1604 of ALK (pY(1604) ALK). Amplified Luminescent Proximity Homogeneous Assay (AlphaScreen(®)) and phosflow platforms were used to detect modulation of pY(1604) ALK to determine the relative potency of a set of small-molecule inhibitors. Prior to making use of these assays in diverse settings, the authors attempted to ensure their equivalence with a direct comparison of their performance. The pY(1604) ALK assays correlated well both with each other and with assays of ALK enzyme activity or ALK-dependent cell proliferation. The AlphaScreen(®) assay was amenable to automation and enabled rapid, high-throughput compound assessment in an NPM-ALK-driven cell line, whereas the phosflow assay enabled the authors to characterize the activity of compounds with respect to their impact on targeted enzymes and pathways. Results show that both AlphaScreen(®) and phosflow ALK assays exhibited diverse characteristics that made them desirable for different applications but were determined to be equally sensitive and robust in the detection of inhibition of pY(1604) ALK.

NOTCH1 pathway activation is an early hallmark of SCL T leukemogenesis.

The acquired activation of stem cell leukemia (SCL) during T lymphopoiesis is a common event in T-cell acute lymphoblastic leukemia (T-ALL). Here, we generated tamoxifen (TAM)-inducible transgenic mice (lck-ER(T2)-SCL) to study the consequences of acquired SCL activation during T-cell development. Aberrant activation of SCL in thymocytes resulted in the accumulation of immature CD4(+)CD8(+) (double-positive, DP) cells by preventing normal surface expression of the T-cell receptor alphabeta (TCRalphabeta) complex. SCL-induced immature DP cells were further characterized by up-regulated NOTCH1 and generated noncycling polyclonal CD8(+)TCRbeta(low) cells. The prevalence of these cells was SCL dependent because TAM withdrawal resulted in their disappearance. Furthermore, we observed that SCL activation led to a dramatic up-regulation of NOTCH1 target genes (Hes-1, Deltex1, and CD25) in thymocytes. Strikingly, NOTCH1 target gene up-regulation was already observed after short-term SCL induction, implying that enhanced NOTCH signaling is mediated by SCL and is not dependent on secondary genetic events. These data represent the basis for a novel pathway of SCL-induced leukemogenesis and provide a functional link between SCL and NOTCH1 during this process.

The functional mapping of long-range transcription control elements of the HOX11 proto-oncogene.

Mapping of transcriptional control elements normally depends on the generation of a series of deletion mutants. The consequences of particular deletions are then functionally assessed by their ability to alter gene expression. The information derived from such investigations provides a general regulatory profile of the gene of interest, as well as generating a focus for future experiments. Due to the limitations of conventional DNA cloning methods, it has previously not been possible to use such an approach to rapidly assess the role of long-range regulatory elements that frequently lie further than 20 kb away from the coding region. In order to identify regulatory elements of the proto-oncogene HOX11 that may be mutated in a subset of childhood T-cell acute lymphoblastic leukaemia specimens, we generated nested deletions from a P1 artificial chromosome (PAC). This clone contained 95 kilobases (kb) of the HOX11 locus at 10q24; including 63 kb of 5' regulatory DNA. The deletion series was produced by the use of a recombination based cloning system and clones were subsequently transfected into mammalian cells. We have identified several long-range regulatory elements that mediate transcriptional control of HOX11. This approach is simple, rapid, and inexpensive. Furthermore, it generates multiple deletion clones in a single experiment. This novel approach opens up a new avenue for investigating long-range transcription control. Additionally, by allowing analysis of these elements in the natural context of large integrants the approach does not require the use of artificial extrachromosomal elements. This methodology can be applied to any gene cloned into a PAC or BAC vector and could also be useful in identifying appropriately sized deletion mutants for functional testing in transgenic models.

Cross-contamination with tamoxifen induces transgene expression in non-exposed inducible transgenic mice

Inducible transgenic mouse models that impose a constraint on both temporal and spatial expression of a given transgene are invaluable. These animals facilitate experiments that can address the role of a specific cell or group of cells within an animal or in a particular window of time. A common approach to achieve inducibility involves the site-specific recombinase ‘Cre’, which is linked to a modified version of one of various steroid hormone-binding domains. Thus, the expression of Cre is regulated such that a functional nuclear transgene product can only be generated with the addition of an exogenous ligand. However, critical requirements of this system are that the nuclear localization of the transgene product be tightly regulated, that the dosage of the inducing agent remains consistent among experimental animals and that the transgene cassette cannot express in the absence of the inducing agent. We used the Cre ER(T2) cassette, which is regulated by the addition of the estrogen antagonist tamoxifen to determine whether cross-contamination of tamoxifen between animals housed together can be a significant source of spurious results. We found that cross-contamination of exogenous tamoxifen does occur. It occurred in all animals tested. We suggest that the mechanism of contamination is through exposure to tamoxifen in the general environment and/or to coprophagous behavior. These results have important implications for the interpretation and design of experiments that use ‘inducible’ transgenic animals.