Leveraging patient-centric sampling for clinical drug development and decentralized clinical trials: Promise to reality

Advances in the technologies to enable patient-centric sampling (PCS) have the potential to improve blood sample collection by enabling clinical trial participants to collect samples via self-collection or with the help of a caregiver in their home. Typically, blood samples to assess pharmacokinetics and pharmacodynamics of a drug during clinical development are collected at a clinical site via venous blood draw. In this position paper by the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ), the potential value PCS can bring to patients, to the clinical datasets generated, and to clinical trial sponsors is discussed, along with considerations for program decision making, bioanalytical feasibility, operations, and regulatory implications. With an understanding of the value of PCS and considerations when implementing during clinical drug development, we can bring the promise of PCS closer to reality and enable decentralized clinical trials.

An open-label, multiple ascending dose study of the anti-CTLA-4 antibody ipilimumab in viremic HIV patients

Expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4), a negative regulator of T-cell function, is increased in chronic HIV-1 infection. It was hypothesized that CTLA-4 blockade may enhance immune response to HIV-1 and result in better control of viremia. This open-label, multiple ascending dose study (NCT03407105)-the first to examine ipilimumab in participants with HIV-1 infection-assessed the safety, tolerability, and pharmacokinetics of ipilimumab, as well as whether ipilimumab enhanced immune response to HIV-1 and improved control of viremia. Twenty-four participants received 2 or 4 doses of ipilimumab (0.1, 1, 3, or 5 mg/kg) every 28 days. No serious adverse events (AEs) or dose-limiting toxicities were reported; one participant discontinued ipilimumab for an AE of grade 2 facial palsy. Twenty participants (83.3%) had ≥1 AE; all but 1 were grade 1 or 2. Eight participants (33.3%) had potentially immune-related AEs (7 had grade 1 diarrhea not requiring corticosteroids; 1 who had diarrhea also had transient antinuclear antibody positivity; 1 had grade 2 facial palsy requiring corticosteroids). Two participants (8.3%), one each in the 0.1- and 1-mg/kg dose groups, had a decrease from baseline HIV-1 RNA of 0.85 and 1.36 log10 copies/mL. Fourteen participants (58.3%) had an increase from baseline HIV-1 RNA (mean, 0.87 log10 copies/mL; range, 0.59-1.29). Of these 14 participants, all but 1 were in the higher ipilimumab dose groups (3 or 5 mg/kg). No pattern was noted regarding change from baseline in CD4 or CD8 T cells; ex vivo assessments of immune response were precluded because of inadequate cell viability. Serum concentration data for ipilimumab showed biphasic disposition, with steady state reached by dose 3. Ipilimumab treatment was well tolerated and was associated with variations in HIV-1 RNA in excess of expected repeat measures in most participants, but these were not related to combination antiretroviral therapy status or CD4 counts. The mechanism(s) underlying the increased variation in HIV-1 RNA is unclear and needs further study.

Lack of a Pharmacokinetic Interaction Between Saxagliptin and Dapagliflozin in Healthy Subjects: A Randomized Crossover Study

PURPOSE

This single-dose, open-label, randomized, 3-period, 3-treatment crossover drug-drug interaction study was conducted to evaluate differences in the pharmacokinetic properties of saxagliptin and dapagliflozin when coadministered.

METHODS

Healthy subjects (N = 42) were randomized to receive saxagliptin 5 mg alone, dapagliflozin 10 mg alone, or saxagliptin 5 mg plus dapagliflozin 10 mg coadministered; there was a washout period of ≥6 days between treatments. Serial blood samples for determining saxagliptin, 5-hydroxy saxagliptin (5-OH saxagliptin; major active metabolite) and dapagliflozin plasma concentrations and pharmacokinetic parameters were collected before and up to 60 hours after the dose. No interaction was to be concluded if the 90% CIs for the geometric mean ratios of the combination compared with each drug given alone for Cmax and AUCinf were within 0.80 to 1.25.

FINDINGS

The results indicated that dapagliflozin had no effect on the pharmacokinetic properties of saxagliptin, 5-OH saxagliptin, or saxagliptin total active moiety and vice versa. The 90% CIs for Cmax and AUCinf for all comparisons were contained entirely within the 0.80 to 1.25 equivalence intervals. Other pharmacokinetic parameters (apparent oral clearance or half-life) of saxagliptin or dapagliflozin were similar when each medicine was administered alone or when coadministered. No safety profile or tolerability findings of concern were observed during the study. All adverse events were mild, and no serious adverse events were reported.

IMPLICATIONS

These data indicate that coadministration of saxagliptin and dapagliflozin exhibits no pharmacokinetic interaction and is well tolerated. ClinicalTrials.gov identifier: NCT01662999.

Pre-absorption physicochemical compatibility assessment of 8-drug metabolic cocktail

A comprehensive 8-drug metabolic cocktail was designed to simultaneously target 6 Cytochrome P450 enzymes and 2 membrane transporters. This study aimed to assess the pre-absorption risk of this new metabolic cocktail which contained metoprolol, caffeine, midazolam, pravastatin, flurbiprofen, omeprazole, digoxin and montelukast. This paper describes a systematic approach to understand whether the co-administration of the 8 selected drug products, i.e., the physical mixing of these products in the human gastro-intestinal environment, will create any issue that may interfere with the individual drug dissolution which in turns modify the total amount or timing of their availability for absorption. The evaluation consisted of two steps. An initial evaluation was based on theoretical understanding of the physicochemical properties of the drugs and the gastro intestinal environment, followed by in vitro dissolution tests. The results indicated that the designer 8-drug cocktail has acceptable pre-absorption compatibility when dosed simultaneously, and recommended the progression of the cocktail into clinical validation study.

Effect of Rifampin on the Pharmacokinetics of Apixaban, an Oral Direct Inhibitor of Factor Xa

OBJECTIVE

Apixaban is a substrate of cytochrome P450 3A4 (CYP3A4) and P-glycoprotein. The effects of rifampin, a strong inducer of CYP3A4 and P-glycoprotein, on the pharmacokinetics of oral and intravenous apixaban were evaluated in an open-label, randomized, sequential crossover study.

METHODS

Twenty healthy participants received single doses of apixaban 5 mg intravenously on day 1 and 10 mg orally on day 3, followed by rifampin 600 mg once daily on days 5-15. Finally, participants received single doses of apixaban 5 mg intravenously and 10 mg orally separately on days 12 and 14 in one of two randomized sequences.

RESULTS

Apixaban, given intravenously and orally, was safe and well tolerated when administered in the presence and absence of rifampin. Apixaban absolute oral bioavailability was 49 % when administered alone and 39 % following induction by rifampin. Rifampin reduced apixaban area under the plasma concentration-time curve from time zero to infinity (AUC∞) by 39 % after intravenous administration and by 54 % after oral administration. Rifampin induction increased mean clearance by 1.6-fold for intravenous apixaban and mean apparent clearance by 2.1-fold for oral apixaban, indicating rifampin affected both pre-systemic and systemic apixaban elimination pathways.

CONCLUSION

Co-administration of apixaban with rifampin reduced apixaban exposure via both decreased bioavailability and increased systemic clearance.

Bioequivalence of saxagliptin/dapagliflozin fixed-dose combination tablets compared with coadministration of the individual tablets to healthy subjects

Saxagliptin and dapagliflozin are individually indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. The bioequivalence of saxagliptin/dapagliflozin 2.5/5 mg and 5/10 mg fixed-dose combination (FDC) tablets compared with coadministration of the individual tablets and the food effect on both strengths of saxagliptin/dapagliflozin FDCs were evaluated in this open-label, randomized, single-dose crossover study. Healthy subjects were randomized to saxagliptin 2.5 mg + dapagliflozin 5 mg fasted, 2.5/5 mg FDC fasted, 2.5/5 mg FDC fed (Cohort 1) or saxagliptin 5 mg + dapagliflozin 10 mg fasted, 5/10 mg FDC fasted, 5/10 mg FDC fed (Cohort 2). Serial blood samples for pharmacokinetics of saxagliptin and dapagliflozin were obtained predose and up to 60 h postdose. Bioequivalence of FDC tablets versus individual components was concluded if the 90% CIs for FDC to individual component geometric mean ratios of C max, AUC 0-T, and AUC inf of both analytes were between 0.80 and 1.25. Seventy-two subjects were randomized; 71 (98.6%) completed the study. Saxagliptin/dapagliflozin 2.5/5 mg and 5/10 mg FDC tablets were bioequivalent to the individual tablets administered concomitantly. Food had no clinically meaningful effect on saxagliptin or dapagliflozin overall systemic exposure. Saxagliptin/dapagliflozin FDC tablets were bioequivalent to coadministration of the individual components in healthy subjects under fasted conditions and food had no clinically meaningful effect on bioavailability.

Inhibitory effect of ketoconazole on the pharmacokinetics of a multireceptor tyrosine kinase inhibitor BMS-690514 in healthy participants: assessing the mechanism of the interaction with physiologically-based pharmacokinetic simulations

BMS-690514, a selective inhibitor of the ErbB and vascular endothelial growth factor receptors, has shown antitumor activity in early clinical development. The compound is metabolized by multiple enzymes, with CYP3A4 responsible for the largest fraction (34%) of metabolism. It is also a substrate of P-glycoprotein (P-gp) in vitro. To assess the effect of ketoconazole on BMS-690514 pharmacokinetics, 17 healthy volunteers received 200 mg BMS-690514 alone followed by 100 mg BMS-690514 with ketoconazole (400 mg once daily for 4 days). The AUC(∞) of 100 mg BMS-690514 concomitantly administered with ketoconazole was similar to that of 200 mg BMS-690514 alone. The dose-normalized C(max) and AUC(∞) of BMS-690514 from the 100-mg BMS-690514/400-mg ketoconazole treatment increased by 55% and 127%, respectively, relative to those from 200 mg BMS-690514 alone. Prediction of the drug-drug interaction (DDI) using a population-based simulator (Simcyp) indicated that, in addition to CYP3A4 inhibition, the inhibition of P-gp by ketoconazole in the intestine, liver, and kidneys must be invoked to fully account for the DDI observed. This finding suggests that the inhibition of P-gp by ketoconazole, along with its effect on CYP3A4, needs to be considered when designing a DDI study of ketoconazole with a victim drug that is a dual substrate.