MMR assays identify patients with a low risk of recurrence. KRAS mutational analysis provides useful additional risk stratification to guide use of chemotherapy.
We present the use of drug-like molecules as a traveling wave (T-wave) ion mobility (IM) calibration sample set, covering the m/z range of 122.1-609.3, the nitrogen collision cross-section (Ω(N(2))) range of 124.5-254.3 Å(2) and the helium collision cross-section (Ω(He)) range of 63.0-178.8 Å(2). Absolute Ω(N(2)) and Ω(He) values for the drug-like calibrants and two diastereomers were measured using a drift-tube instrument with radio frequency (RF) ion confinement. T-wave drift-times for the protonated diastereomers betamethasone and dexamethasone are reproducibly different. Calibration of these drift-times yields T-wave Ω(N(2)) values of 189.4 and 190.4 Å(2), respectively. These results demonstrate the ability of T-wave IM spectrometry to differentiate diastereomers differing in Ω(N(2)) value by only 1 Å(2), even though the resolution of these IM experiments were ∼40 (Ω/ΔΩ). Demonstrated through density functional theory optimized geometries and ionic electrostatic surface potential analysis, the small but measurable mobility difference between the two diastereomers is mainly due to short-range van der Waals interactions with the neutral buffer gas and not long-range charge-induced dipole interactions. The experimental RF-confining drift-tube and T-wave Ω(N(2)) values were also evaluated using a nitrogen based trajectory method, optimized for T-wave operating temperature and pressures, incorporating additional scaling factors to the Lennard-Jones potentials. Experimental Ω(He) values were also compared to the original and optimized helium based trajectory methods.
The continuous 12-gene RS has been validated in a prospective study for assessment of recurrence risk in patients with stage II colon cancer after surgery and provides prognostic value that complements T stage and MMR. The TS was not predictive of chemotherapy benefit.
AIMSRT2104 is a novel, first-in-class, highly selective small molecule activator of the NAD + dependent deacetylase SIRT1. SRT2104 was dosed to healthy male and female volunteers in a series of phase 1 clinical studies that were designed to elucidate tolerability and pharmacokinetics associated with oral dosing to aid in dose selection for subsequent clinical trials.
METHODSIn the first-in-human study, there was both a single dose phase and 7 day repeat dose phase. Doses used ranged from 0.03 to 3.0 g. A radioactive microtracer study was subsequently conducted to determine systemic clearance, bioavailability and preliminary metabolism, and a crossover study was conducted to determine the effect of gender, formulation and feeding state on SRT2104 pharmacokinetics.
RESULTSSRT2104 was well tolerated in all of these studies, with no serious adverse reactions observed. SRT2104 displayed a dose-dependent, but sub-proportional increase in exposure following single dose and repeated dose administration. Accumulation of three-fold or less occurs after 7 days of repeat dosing. The mean bioavailability was circa 14% and the mean clearance was circa 400 ml min -1. Although there were no substantial effects on exposure resulting from gender or formulation differences, a notable food effect was observed, manifested as up to four-fold increase in exposure parameters.
CONCLUSIONSIn the absence of an optimized formulation of SRT2104, the food effect can be used to maximize exposure in future clinical studies. Combined with the good tolerability of all doses demonstrated in these studies, the favourable selectivity profile of SRT2104 allows for the use of this SIRT1 modulator for target validation in the clinic.
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