First-in-Human, Healthy Volunteers Integrated Protocol of ETC-206, an Oral Mnk 1/2 Kinase Inhibitor Oncology Drug

In the last decade, drug development has tackled substantial challenges to improve efficiency and facilitate access to innovative medicines. Integrated clinical protocols and the investigation of targeted oncology drugs in healthy volunteers (HVs) have emerged as modalities with an increase in scope and complexity of early clinical studies and first‐in‐human (FIH) studies in particular. However, limited work has been done to explore the impact of these two modalities, alone or in combination, on the scientific value and on the implementation of such articulated studies. We conducted an FIH study in HVs with an oncology targeted drug, an Mnk 1/2 small molecule inhibitor. In this article, we describe results, advantages, and limitations of an integrated clinical protocol with an oncology drug. We further discuss and indicate points to consider when designing and conducting similar scientifically and operationally demanding FIH studies.

First-in-human phase 1 study of ETC-159 an oral PORCN inhbitor in patients with advanced solid tumours

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Background: The Wnt signalling pathway is involved in cellular proliferation, differentiation, migration and implicated in stem cell function in several cancers. ETC-159 is a selective small molecule inhibitor of porcupine, an enzyme required for palmitoylation and secretion of all Wnt ligands. In preclinical studies, ETC-159 induced tumour regression in patient-derived xenograft models. Methods: Open-label, multi-centre study to determine safety, maximum tolerated dose, pharmacokinetics, pharmacodynamics (PD) of ETC-159 given orally, once every other day in a 28d cycle. PD was evaluated by AXIN2 mRNA levels in whole blood and hair follicles and bone turnover by radiological and serum markers. Dose escalation was by ordinal continual reassessment method with a dose-limiting toxicity (DLT) period of 28d. Results: As of 18 Jan 2017, 16 patients (pts) were treated in 6 cohorts at 1 mg (2pts), 2 mg (2pts), 4 mg (3pts), 8 mg (4pts); 16 mg (3pts), and 30 mg (2pts). 80% were male, median age (range) was 55yr (19-68). One DLT was seen at 16 mg due to hyperbilirubinaemia. Adverse events (≥ 20%) were vomiting (32%); anorexia and fatigue (31%); dysgeusia and constipation (25%). ETC-159 Cmax increased with dose with a mean t1/2 of 14 hr. Plasma levels of ETC-159 that inhibited colony formation in vitro were attained from 4 mg onwards. Reduction of whole blood and hair follicle AXIN2 mRNA levels and doubling of serum β-CTX levels was first observed at 4 mg and at C1D15 in some patients. PD modulation increased with dose, consistent with on-target modulation of Wnt signalling. Two pts had β-CTX rise > 1000 pg/mL (reference limit) and a ≥ 5% reduction in bone density by C3D1. Both took vitamin D and calcium supplements and were given i.v. bisphosphonates. No responses were seen but 2 pts (2 mg: colorectal and 4 mg: peritoneal carcinoma) had stable disease for 6 and 8 cycles respectively. Dose-escalation is ongoing at 30 mg. Conclusions: ETC-159 inhibits Wnt signalling at doses that are well tolerated. β-CTX levels increased early on, and in two pts were associated with reduced bone mineral density. Early and regular monitoring of bone turnover is indicated. This study was sponsored by D3 which is funded by NMRC, NRF and BMRC Singapore. Clinical trial information: NCT02521844.

Safety and immunogenicity of a virus-like particle pandemic influenza A (H1N1) 2009 vaccine: results from a double-blinded, randomized Phase I clinical trial in healthy Asian volunteers

METHODS

A novel, fully bacterially produced recombinant virus-like particle (VLP) based influenza vaccine (gH1-Qbeta) against A/California/07/2009(H1N1) was tested in a double-blind, randomized phase I clinical trial at two clinical sites in Singapore. The trial evaluated the immunogenicity and safety of gH1-Qbeta in the presence or absence of alhydrogel adjuvant. Healthy adult volunteers with no or low pre-existing immunity against A/California/07/2009 (H1N1) were randomized to receive two intramuscular injections 21 days apart, with 100μg vaccine, containing 42μg hemagglutinin antigen. Antibody responses were measured before and 21 days after each immunization by hemagglutination inhibition (HAI) assays. The primary endpoint was seroconversion on Day 42, defined as percentage of subjects which reach a HAI titer ≥40 or achieve an at least 4-fold rise in HAI titer (with pre-existing immunity). The co-secondary endpoints were safety and seroconversion on Day 21.

RESULTS

A total of 84 Asian volunteers were enrolled in this study and randomized to receive the adjuvanted (n=43) or the non-adjuvanted (n=41) vaccine. Of those, 43 and 37 respectively (95%) completed the study. There were no deaths or serious adverse events reported during this trial. A total of 535 adverse events occurred during treatment with 49.5% local solicited symptoms, of mostly (76.4%) mild severity. The most common treatment-related systemic symptom was fatigue. The non-adjuvanted vaccine met all primary and secondary endpoints and showed seroconversion in 62.2% and 70.3% of participants respectively on Day 21 and Day 42. While the adjuvanted vaccine showed an increased seroconversion from 25.5% (Day 21) to 51.2% (Day 42), it did not meet the immunogenicity endpoint.

CONCLUSION

In summary, non-adjuvanted gH1-Qbeta showed similar antibody mediated immunogenicity and a comparable safety profile in healthy humans to commercially available vaccines. These results warrant the consideration of this VLP vaccine platform for the vaccination against influenza infection (HSA CTC1300092).

Preclinical metabolism and pharmacokinetics of SB1317 (TG02), a potent CDK/JAK2/FLT3 inhibitor

SB1317 (TG02) is a novel small molecule potent CDK/JAK2/FLT3 inhibitor. To evaluate full potential of this development candidate, we conducted drug metabolism and pharmacokinetic studies of this novel anti-cancer agent. SB1317 was soluble, highly permeable in Caco-2 cells, and showed > 99% binding to plasma from mice, dog and humans. It was metabolically stable in human and dog liver microsomes relative to mouse and rat. SB1317 was mainly metabolized by CYP3A4 and CY1A2 in vitro. SB1317 did not inhibit any of the major human CYPs in vitro except CYP2D6 (IC50=1 μM). SB1317 did not significantly induce CYP1A and CYP3A4 in human hepatocytes in vitro. The metabolic profiles in liver microsomes from preclinical species were qualitatively similar to humans. In pharmacokinetic studies SB1317 showed moderate to high systemic clearance (relative to liver blood flow), high volume of distribution ( > 0.6 L/kg), oral bioavailability of 24%, ∼ 4 and 37% in mice, rats and dogs, respectively; and extensive tissue distribution in mice. The favorable ADME of SB1317 supported its preclinical development as an oral drug candidate.

Discovery of (2E)-3-{2-butyl-1-[2-(diethylamino)ethyl]-1H-benzimidazol-5-yl}-N-hydroxyacrylamide (SB939), an orally active histone deacetylase inhibitor with a superior preclinical profile

A series of 3-(1,2-disubstituted-1H-benzimidazol-5-yl)-N-hydroxyacrylamides (1) were designed and synthesized as HDAC inhibitors. Extensive SARs have been established for in vitro potency (HDAC1 enzyme and COLO 205 cellular IC(50)), liver microsomal stability (t(1/2)), cytochrome P450 inhibitory (3A4 IC(50)), and clogP, among others. These parameters were fine-tuned by carefully adjusting the substituents at positions 1 and 2 of the benzimidazole ring. After comprehensive in vitro and in vivo profiling of the selected compounds, SB939 (3) was identified as a preclinical development candidate. 3 is a potent pan-HDAC inhibitor with excellent druglike properties, is highly efficacious in in vivo tumor models (HCT-116, PC-3, A2780, MV4-11, Ramos), and has high and dose-proportional oral exposures and very good ADME, safety, and pharmaceutical properties. When orally dosed to tumor-bearing mice, 3 is enriched in tumor tissue which may contribute to its potent antitumor activity and prolonged duration of action. 3 is currently being tested in phase I and phase II clinical trials.

SB939, a novel potent and orally active histone deacetylase inhibitor with high tumor exposure and efficacy in mouse models of colorectal cancer

Although clinical responses in liquid tumors and certain lymphomas have been reported, the clinical efficacy of histone deacetylase inhibitors in solid tumors has been limited. This may be in part due to the poor pharmacokinetic of these drugs, resulting in inadequate tumor concentrations of the drug. SB939 is a new hydroxamic acid based histone deacetylase inhibitor with improved physicochemical, pharmaceutical, and pharmacokinetic properties. In vitro, SB939 inhibits class I, II, and IV HDACs, with no effects on other zinc binding enzymes, and shows significant antiproliferative activity against a wide variety of tumor cell lines. It has very favorable pharmacokinetic properties after oral dosing in mice, with >4-fold increased bioavailability and 3.3-fold increased half-life over suberoylanilide hydroxamic acid (SAHA). In contrast to SAHA, SB939 accumulates in tumor tissue and induces a sustained inhibition of histone acetylation in tumor tissue. These excellent pharmacokinetic properties translated into a dose-dependent antitumor efficacy in a xenograft model of human colorectal cancer (HCT-116), with a tumor growth inhibition of 94% versus 48% for SAHA (both at maximum tolerated dose), and was also effective when given in different intermittent schedules. Furthermore, in APC(min) mice, a genetic mouse model of early-stage colon cancer, SB939 inhibited adenoma formation, hemocult scores, and increased hematocrit values more effectively than 5-fluorouracil. Emerging clinical data from phase I trials in cancer patients indicate that the pharmacokinetic and pharmacologic advantages of SB939 are translated to the clinic. The efficacy of SB939 reported here in two very different models of colorectal cancer warrants further investigation in patients.

In Vitro Phase I Cytochrome P450 Metabolism, Permeability and Pharmacokinetics of SB639, a Novel Histone Deacetylase Inhibitor in Preclinical Species

In vitro liver microsomal stability, permeability, pharmacokinetics (PK) and oral bioavailability of SB639, a novel HDACi (Histone Deacetylase inhibitor), were determined. The in vitro metabolism was examined in mouse, rat, dog and human liver microsomes. The permeability and efflux potential of SB639 were determined using Caco-2 cell monolayers. To determine pharmacokinetics and oral bioavailability, blood samples were drawn at pre-determined intervals up to 24 h post-dose after single intravenous (i.v.) or oral (p.o.) administration of SB639 to mouse or rat. The concentrations of SB639 in plasma samples were determined by a validated LC-MS/MS method. In vitro liver microsomal stability data revealed that SB639 was stable in human and dog liver microsomes, unstable in mouse and rat liver microsomes. The Caco-2 data has shown that SB639 is highly permeable with an apparent permeability of 3.01.10(-6) cm/s at 10 microM. After oral administration, maximum concentrations of SB639 were achieved within 0.5 h of post dose. Following i.v. administration, the concentration of SB639 declined in a bi-exponential fashion with terminal elimination half-life of 1.67 h for mice and 1.12 h for rats. The systemic clearance and volume of distribution of SB639 in mice were 15.8 l/h/kg and 38 l/kg, respectively, while the respective values in rats were 3.84 l/h/kg and 3.67 l/kg. Elimination half-life in rats ranged between 1.12-2.26 h. Absolute oral bioavailability of SB639 in mouse and rat was 13% and 10%, respectively. In conclusion, the superior potency, physicochemical and PK properties of SB639 compared to the recently FDA approved drug Zolinza (Suberoylanilide hydroxamic acid or Vorinostat) in the preclinical setting makes it a potential clinical candidate.

Development and validation of high-performance liquid chromatography–tandem mass spectrometry assay for 6-(3-benzoyl-ureido)-hexanoic acid hydroxyamide, a novel HDAC inhibitor, in mouse plasma for pharmacokinetic studies

A liquid chromatography/tandem mass spectrometric method for the quantification of 6-(3-benzoyl-ureido)-hexanoic acid hydroxyamide (EX-2), a novel histone deacetylase (HDAC) inhibitor, in mouse plasma was developed to support in-house pharmacokinetic (PK) studies in the lead optimization stage. In order to determine the PK parameters for EX-2 in comparison to other HDAC inhibitors such as suberoylanilide hydroxamic acid (SAHA), PXD-101 and LBH-589, which are currently in different stages of clinical trials, research-grade bio-analytical method validations were carried out for EX-2 and these reference HDAC inhibitors, which were synthesized by in-house medicinal chemists. The components of validation consisted of specificity, extraction efficiency, signal-response of calibration standards, lower limit of quantification, autosampler stability and accuracy and precision of quality control samples. The validated LC/MS/MS methods were accurate and precise. The calibration curve ranged from 1 to 1600 ng/mL for all the analytes. The methods developed were used to quantify EX-2 and other HDAC inhibitors in mouse plasma obtained from pharmacokinetic studies. The results suggest that EX-2 has better PK parameters compared with the reference drugs and is a promising drug development candidate.

First-in-class pan caspase inhibitor developed for the treatment of liver disease

A series of oxamyl dipeptides were optimized for pan caspase inhibition, anti-apoptotic cellular activity and in vivo efficacy. This structure-activity relationship study focused on the P4 oxamides and warhead moieties. Primarily on the basis of in vitro data, inhibitors were selected for study in a murine model of alpha-Fas-induced liver injury. IDN-6556 (1) was further profiled in additional in vivo models and pharmacokinetic studies. This first-in-class caspase inhibitor is now the subject of two Phase II clinical trials, evaluating its safety and efficacy for use in liver disease.

Diluted venous blood appears arterial: implications for central venous cannulation

IMPLICATIONS

There is always a danger of arterial puncture during central venous access. One can usually identify an inadvertent arterial puncture when the aspirated blood is bright red. This sign is removed if one were to put saline in the aspirating syringe, as dusky venous blood turns bright red on dilution.

Survey of availability of iodine-enriched salt in Sarawak

Three hundred and forty five salt samples were randomly taken from 106 sources where iodised salts were supplied or put for sale in all areas gazetted as endemic goitre areas in Sarawak. The samples were analysed for the presence of iodine. In areas in Sibu, Sarikei and Kapit Divisions, 53-70% of salt put for sale were iodised while in the other 6 Divisions, it was less than 27%. As iodisation of salt is an interventive measure in addressing the goitre problem in the State, regular monitoring of iodisation facilities and iodine content of iodised salt in the affected areas is important to ensure the effectiveness of the programme.