CRISPR-Cas9 Editing of the HBG1 and HBG2 Promoters to Treat Sickle Cell Disease.

BACKGROUND: Sickle cell disease is caused by a defect in the ß-globin subunit of adult hemoglobin. Sickle hemoglobin polymerizes under hypoxic conditions, producing deformed red cells that hemolyze and cause vaso-occlusion that results in progressive organ damage and early death. Elevated fetal hemoglobin levels in red cells protect against complications of sickle cell disease. OTQ923, a clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-edited CD34+ hematopoietic stem- and progenitor-cell (HSPC) product, has a targeted disruption of the HBG1 and HBG2 (γ-globin) gene promoters that increases fetal hemoglobin expression in red-cell progeny. METHODS: We performed a tiling CRISPR-Cas9 screen of the HBG1 and HBG2 promoters by electroporating CD34+ cells obtained from healthy donors with Cas9 complexed with one of 72 guide RNAs, and we assessed the fraction of fetal hemoglobin-immunostaining erythroblasts (F cells) in erythroid-differentiated progeny. The gRNA resulting in the highest level of F cells (gRNA-68) was selected for clinical development. We enrolled participants with severe sickle cell disease in a multicenter, phase 1-2 clinical study to assess the safety and adverse-effect profile of OTQ923. RESULTS: In preclinical experiments, CD34+ HSPCs (obtained from healthy donors and persons with sickle cell disease) edited with CRISPR-Cas9 and gRNA-68 had sustained on-target editing with no off-target mutations and produced high levels of fetal hemoglobin after in vitro differentiation or xenotransplantation into immunodeficient mice. In the study, three participants received autologous OTQ923 after myeloablative conditioning and were followed for 6 to 18 months. At the end of the follow-up period, all the participants had engraftment and stable induction of fetal hemoglobin (fetal hemoglobin as a percentage of total hemoglobin, 19.0 to 26.8%), with fetal hemoglobin broadly distributed in red cells (F cells as a percentage of red cells, 69.7 to 87.8%). Manifestations of sickle cell disease decreased during the follow-up period. CONCLUSIONS: CRISPR-Cas9 disruption of the HBG1 and HBG2 gene promoters was an effective strategy for induction of fetal hemoglobin. Infusion of autologous OTQ923 into three participants with severe sickle cell disease resulted in sustained induction of red-cell fetal hemoglobin and clinical improvement in disease severity. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT04443907.).

Bioequivalence and food effect assessment for vildagliptin/metformin fixed-dose combination tablets relative to free combination of vildagliptin and metformin in Japanese healthy subjects.

OBJECTIVE: To assess the bioequivalence of vildagliptin/metformin fixeddose combination (FDC) tablets (50/250 mg and 50/500 mg) to free combinations of vildagliptin and metformin and the effect of food on the pharmacokinetics (PK) of vildagliptin and metformin following administration of 50/500 mg FDC tablets. METHODS: Two openlabel, randomized, single-center, singledose, 2-period crossover studies were conducted in Japanese healthy male volunteers. Participants were administered vildagliptin/ metformin FDC tablets (study I: 50/250 mg, study II: 50/500 mg) or their free combinations under fasted condition. Food effect (standard Japanese breakfast: fat, 20 - 30% with ~ 600 kcal in total) was assessed during an additional period in study II (50/500 mg). PK parameters (AUC, C(max), t(max), t(1/2)) were calculated for vildagliptin and metformin. RESULTS: In both studies, vildagliptin/metformin FDC tablets were bioequivalent to their respective free combinations. Administration of FDC tablets after meals had no effect on vildagliptin PK parameters. The rate of absorption of metformin decreased when administered under fed condition, as reflected by a prolonged t(max) (3 hours in fasted state vs. 4 hours in fed state) and decrease in C(max) by 26%, however, the extent of absorption (AUC(last)) was similar to that in the fasted state. CONCLUSIONS: Vildagliptin/metformin FDC tablets were bioequivalent to their free combinations. Food decreased the C(max) of metformin by 26%, while AUC(last) was unchanged, consistent with previous reports. No food effect was observed on the C(max) or AUC(last) of vildagliptin. Thus, food had no clinically relevant effects on the PK of metformin or vildagliptin.

Sabatolimab in combination with spartalizumab in patients with non-small cell lung cancer or melanoma who received prior treatment with anti-PD-1/PD-L1 therapy: a phase 2 multicentre study.

OBJECTIVE: This study evaluates the safety/efficacy of sabatolimab plus spartalizumab in patients with melanoma or non-small cell lung cancer (NSCLC). DESIGN, SETTING AND PARTICIPANTS: This is a phase 1-1b/2, open-label, multinational, multicentre study of patients with advanced/metastatic melanoma or NSCLC with ≥1 measurable lesion. INTERVENTIONS: Patients were given sabatolimab 800 mg every 4 weeks plus spartalizumab 400 mg every 4 weeks until unacceptable toxicity, disease progression and/or treatment discontinuation. OUTCOME MEASURES: The phase 2 primary outcome measure was overall response rate and secondary objectives included evaluation of the safety, tolerability, efficacy and pharmacokinetics of sabatolimab in combination with spartalizumab. RESULTS: 33 patients (melanoma n=16, NSCLC n=17) received sabatolimab plus spartalizumab. 31 (94%) experienced ≥1 adverse event (AE); 15 (46%) experienced grade 3/4 events. The most frequent grade ≥3 AEs for NSCLC were anaemia, dyspnoea and pneumonia (each n=2, 12%); for patients with melanoma, the most frequent grade ≥3 AEs were physical health deterioration, hypokalaemia, hypophosphataemia, pathological fracture and tumour invasion (each n=1; 6%). One (3%) patient discontinued treatment due to AE. Stable disease was seen in three patients with melanoma (19%) and six patients with NSCLC (35%). Median progression-free survival was 1.8 (90% CI 1.7 to 1.9) and 1.7 (90% CI 1.1 to 3.4) months for patients with melanoma and NSCLC, respectively. Patients with stable disease had higher expression levels of CD8, LAG3, programmed death-ligand 1 and anti-T-cell immunoglobulin and mucin-domain containing-3 at baseline. The pharmacokinetics profile of sabatolimab was consistent with the phase 1 study. CONCLUSIONS: Sabatolimab plus spartalizumab was well tolerated in patients with advanced/metastatic melanoma or NSCLC who had progressed following antiprogrammed death-1/antiprogrammed death-ligand 1 treatment. Limited antitumour activity was observed. The tolerability of sabatolimab administration supports the potential to explore treatment with sabatolimab in various combination regimens and across a spectrum of tumour types. TRIAL REGISTRATION NUMBER: NCT02608268.

A molecular glue degrader of the WIZ transcription factor for fetal hemoglobin induction.

Sickle cell disease (SCD) is a prevalent, life-threatening condition attributable to a heritable mutation in ß-hemoglobin. Therapeutic induction of fetal hemoglobin (HbF) can ameliorate disease complications and has been intently pursued. However, safe and effective small-molecule inducers of HbF remain elusive. We report the discovery of dWIZ-1 and dWIZ-2, molecular glue degraders of the WIZ transcription factor that robustly induce HbF in erythroblasts. Phenotypic screening of a cereblon (CRBN)-biased chemical library revealed WIZ as a previously unknown repressor of HbF. WIZ degradation is mediated by recruitment of WIZ(ZF7) to CRBN by dWIZ-1, as resolved by crystallography of the ternary complex. Pharmacological degradation of WIZ was well tolerated and induced HbF in humanized mice and cynomolgus monkeys. These findings establish WIZ degradation as a globally accessible therapeutic strategy for SCD.

Concentration of tacrolimus and major metabolites in kidney transplant recipients as a function of diabetes mellitus and cytochrome P450 3A gene polymorphism.

1. Disposition of tacrolimus and its major metabolites, 13-O-desmethyl tacrolimus and 15-O-desmethyl tacrolimus, was evaluated in stable kidney transplant recipients in relation to diabetes mellitus and genetic polymorphism of cytochrome P450 (CYP) 3A. 2. Steady-state concentration-time profiles were obtained for 12-hour or 2-hour post-dose, in 20 (11 with diabetes) and 32 (24 with diabetes) patients, respectively. In addition, single nucleotide polymorphisms of the following genes: CYP3A4 (CYP3A4: CYP3A4*1B, -392A > G), 3A5 (CYP3A5: CYP3A5*3, 6986A > G) and P-glycoprotein (ABCB1: 3435C > T) were characterized. 3. Dose-normalized concentrations of tacrolimus or metabolites were higher in diabetic patients. CYP3A4*1B carriers and CYP3A5 expressers, independently or when assessed as a combined CYP3A4-3A5 genotype, had significantly lower dose-normalized pre-dose (C0/dose) and 2-hour post-dose (C2/dose) concentrations of tacrolimus and metabolites. Non-diabetic patients with at least one CYP3A4*1B and CYP3A5*1 allele had lower C0/dose as compared to the rest of the population. 4. Genetic polymorphism of CYP3A5 or CYP3A4 influence tacrolimus or metabolites dose-normalized concentrations but not metabolite to parent concentration ratios. The effect of diabetes on tacrolimus metabolism is subject to debate and requires a larger sample size of genetically stratified subjects.

Pharmacokinetic Interaction Between the MEK1/MEK2 Inhibitor Trametinib and Oral Contraceptives Containing Norethindrone and Ethinyl Estradiol in Female Patients With Solid Tumors.

This phase 1 postapproval study assessed the effect of the mitogen-activated protein kinase kinase enzyme 1/enzyme 2 inhibitor trametinib (2 mg once daily, repeat dosing) on the pharmacokinetics of combined oral contraceptives (COCs) containing norethindrone (NE; 1 mg daily) and ethinyl estradiol (EE; 0.035 mg daily) in 19 female patients with solid tumors. Compared with NE/EE administered without trametinib, NE/EE administered with steady-state trametinib was associated with a clinically nonrelevant 20% increase in NE exposure (area under the curve [AUC]) and no effect on EE exposure (geometric mean ratio [geo-mean] of NE/EE + trametinib to NE/EE [90%CI]: NE AUC calculated to the end of a dosing interval at steady-state [AUCtau ] 1.20 [1.02-1.41]; NE AUC from time zero to the last measurable concentration sampling time [AUClast ] 1.2 [0.999-1.45]; EE AUCtau 1.06 [0.923-1.22]; EE AUClast 1.05 [0.883-1.25]). Maximum serum concentration (Cmax ) of NE increased by 13% and Cmax of EE decreased by 8.5% when dosed with steady-state trametinib compared with COCs administered alone (geo-mean ratio [90%CI]: NE Cmax 1.13 [0.933-1.36]; EE Cmax 0.915 [0.803-1.04]). These results indicate that repeat-dose trametinib does not lower exposure to NE or EE and, hence, is unlikely to impact the contraceptive efficacy of COCs. The pharmacokinetic parameters of trametinib and its metabolite M5 were consistent with historic data of trametinib alone. Coadministration of trametinib and COCs was generally well tolerated in this study, with observed safety signals consistent with the known safety profile of trametinib and no new reported safety events. Overall, the findings indicate that hormonal COCs can be coadministered in female patients who receive trametinib monotherapy without compromising the contraceptive efficacy.

Development and validation of an HPLC-UV method for iodixanol quantification in human plasma.

Iodixanol is a widely used iso-osmolar contrast medium agent. Similar to iohexol, it can also be a good exogenous marker for the measurement of glomerular filtration rate (GFR). This article describes the development and validation of an HPLC-UV method for quantification of iodixanol in human plasma. Internal standard, iohexol (20 microl, 1 mg/ml), and perchloric acid (30 microl, 20%, v/v) were added to plasma samples (300 microl), followed by neutralization with 10 microl potassium carbonate (5M). Samples were centrifuged and 10 microl of the supernatant was injected onto a C(18) EPS analytical column (3 microm particle size, 150 mm x 4.6 mm). The extraction method yielded >95% recovery for both iodixanol and iohexol. The mobile phase consisted of 0.1% (w/v) sodium formate buffer and acetonitrile. Iohexol and iodixanol peaks were eluted at approximately 5 and 9 min, respectively using a fast gradient method. The assay lower limit of detection was 2.0 microg/ml and lower limit of quantification was 10 microg/ml. The calibration curves, assessed in six replicates, were linear over an iodixanol concentration range of 10-750 microg/ml. Intra- and inter-day accuracy was >95% and precision expressed as % coefficient of variation was <10%. This method is simple, accurate, precise and robust and can potentially be used for iodixanol quantification in large-scale clinical studies.

Population pharmacokinetic modeling and noncompartmental analysis demonstrated bioequivalence between metformin component of metformin/vildagliptin fixed-dose combination products and metformin immediate-release tablet sourced from various countries.

Metformin is the first-line pharmacotherapy choice for treating type-2 diabetes mellitus, alone or in combination with other antidiabetic drugs. During the development of immediate-release (IR) metformin containing novel fixed-dose combination (FDC) products, several health-authorities require sponsors to demonstrate bioequivalence between FDC products and the country-sourced metformin for market approval. Eight bioequivalence studies that compared metformin/vildagliptin FDC product (test) to metformin IR tablet sourced from various countries (reference) were conducted. A population pharmacokinetic (PPK) analysis of pooled metformin concentration-time data was performed to evaluate whether country-sourced metformin is a significant covariate. The PPK analysis demonstrated that there was no clinically relevant effect of metformin source or race/ethnicity on metformin pharmacokinetics. Also, noncompartmental analysis conducted showed that 90%CI of geometric mean ratios of test to reference metformin formulations, calculated for maximum-concentration and exposure parameters, were within the 80%-125% criteria, indicating comparable metformin exposure regardless of the country-sourced metformin IR formulation. These results are consistent with the biopharmaceutics properties of metformin and provide scientific evidence that after assessing in vitro dissolution of novel FDC formulation, additional bioequivalence studies with multiple countries' reference products may not be required once bioequivalence is established with 1 country-sourced IR metformin formulation.

Modelling the sitagliptin effect on dipeptidyl peptidase-4 activity in adults with haematological malignancies after umbilical cord blood haematopoietic cell transplantation.

BACKGROUND AND OBJECTIVES: Dipeptidyl peptidase-4 (DPP4) inhibition is a potential strategy to increase the engraftment rate of haematopoietic stem/progenitor cells. A recent clinical trial using sitagliptin, a DPP4 inhibitor approved for type 2 diabetes mellitus, has been shown to be a promising approach in adults with haematological malignancies after umbilical cord blood (UCB) haematopoietic cell transplantation (HCT). On the basis of data from this clinical trial, a semi-mechanistic model was developed to simultaneously describe DPP4 activity after multiple doses of sitagliptin in subjects with haematological malignancies after a single-unit UCB HCT. METHODS: The clinical study included 24 patients who received myeloablative conditioning followed by oral sitagliptin with single-unit UCB HCT. Using a nonlinear mixed-effects approach, a semi-mechanistic pharmacokinetic-pharmacodynamic model was developed to describe DPP4 activity from these trial data, using NONMEM version 7.2 software. The model was used to drive Monte Carlo simulations to probe the various dosage schedules and the attendant DPP4 response. RESULTS: The disposition of sitagliptin in plasma was best described by a two-compartment model. The relationship between sitagliptin concentrations and DPP4 activity was best described by an indirect response model with a negative feedback loop. Simulations showed that twice daily or three times daily dosage schedules were superior to a once daily schedule for maximal DPP4 inhibition at the lowest sitagliptin exposure. CONCLUSION: This study provides the first pharmacokinetic-pharmacodynamic model of sitagliptin in the context of HCT, and provides a valuable tool for exploration of optimal dosing regimens, which are critical for improving the time to engraftment in patients after UCB HCT.

Multidrug resistance-associated protein 2 (MRP2/ABCC2) haplotypes significantly affect the pharmacokinetics of tacrolimus in kidney transplant recipients.

BACKGROUND AND OBJECTIVE: Tacrolimus is an immunosuppressive drug used for the prevention of the allograft rejection in kidney transplant recipients. It exhibits a narrow therapeutic index and large pharmacokinetic variability. Tacrolimus is mainly metabolized by cytochrome P450 (CYP) 3A4 and 3A5 and effluxed via ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp), encoded by ABCB1 gene. The influence of CYP3A5*3 on the pharmacokinetics of tacrolimus has been well characterized. On the other hand, the contribution of polymorphisms in other genes is controversial. In addition, the involvement of other efflux transporters than P-gp in tacrolimus disposition is uncertain. The present study was designed to investigate the effects of genetic polymorphisms of CYP3As and efflux transporters on the pharmacokinetics of tacrolimus. SUBJECTS AND METHODS: A total of 500 blood concentrations of tacrolimus from 102 adult stable kidney transplant recipients were included in the analyses. Genetic polymorphisms in CYP3A4 and CYP3A5 genes were determined. In addition, the genes of efflux transporters including P-gp (ABCB1), multidrug resistance-associated protein (MRP2/ABCC2) and breast cancer resistance protein (BCRP/ABCG2) were genotyped. For ABCC2 gene, haplotypes were determined as follows: H1 (wild type), H2 (1249G>A), H9 (3972C>T) and H12 (-24C>T and 3972C>T). Population pharmacokinetic analysis was performed using nonlinear mixed effects modeling. RESULTS: Analyses revealed that the CYP3A5 expressers (CYP3A5*1 carriers) and MRP2 high-activity group (ABCC2 H2/H2 and H1/H2) showed a decreased dose-normalized trough concentration of tacrolimus by 2.3-fold (p < 0.001) and 1.5-fold (p = 0.007), respectively. The pharmacokinetics of tacrolimus were best described using a two-compartment model with first order absorption and an absorption lag time. In the population pharmacokinetic analysis, CYP3A5 expressers and MRP2 high-activity groups were identified as the significant covariates for tacrolimus apparent clearance expressed as 20.7 × (age/50)(-0.78) × 2.03 (CYP3A5 expressers) × 1.40 (MRP2 high-activity group). No other CYP3A4, ABCB1 or ABCG2 polymorphisms were associated with the apparent clearance of tacrolimus. CONCLUSIONS: This is the first report showing that MRP2/ABCC2 has a crucial impact on the pharmacokinetics of tacrolimus in a haplotype-specific manner. Determination of the ABCC2 as well as CYP3A5 genotype may be useful for more accurate tacrolimus dosage adjustment.

Development and validation of a rapid and sensitive assay for simultaneous quantification of midazolam, 1'-hydroxymidazolam, and 4-hydroxymidazolam by liquid chromatography coupled to tandem mass-spectrometry.

Midazolam is an ultra short acting benzodiazepine derivative and a specific probe for phenotyping cytochrome P450 (P450) 3A4/5 activity. A rapid, sensitive, and selective LC-MS/MS method was developed for simultaneous quantitation of midazolam and its metabolites (1'-hydroxymidazolam and 4-hydroxymidazolam). Deuterated (D5) analog of midazolam was utilized as an internal standard. Sample preparation either from human plasma (100 microL) or liver microsomal incubations involved a simple protein precipitation using acetonitrile (900 microL) with an average recovery of >90% for all compounds. The chromatographic separation was achieved using Zorbax-SB Phenyl, Rapid Resolution HT (2.1 mm x 100 mm, 3.5 microm) and a gradient elution with 10 mM ammonium acetate in 10% methanol (A) and acetonitrile (B). The flow rate was 0.25 mL/min and total run time was 5.5 min. Calibration curves were linear over the concentration range of 0.100-250 ng/mL. The lower limit of quantitation (LLOQ) was 0.1 ng/mL for all three analytes. The accuracy and precision, estimated at LLOQ and three concentration levels of quality control samples in six replicates, were within 85-115%. In conclusion, a robust, simple and highly sensitive analytical method was developed and validated for the analysis of midazolam and its metabolites. This method is suitable for characterizing the P450 3A4/5 activity in vitro or in human pharmacokinetic studies allowing administration of smaller doses of midazolam.