Pharma Medica Research (Canada)

Purpose: Previous pharmacokinetic studies conducted on atropine sulfate ophthalmical solution have utilized bioanalytical assays that lacked sufficient sensitivity to fully characterize the complete pharmacokinetic profile. To address these limitations, Pharma Medica Research Inc. has developed and validated an ultrasensitive bioanalytical method capable of accurately quantifying the active enantiomer, L-hyoscyamine, with a very low limit of quantitation of 0.500 pg/mL. The objective of this study was to evaluate the pharmacokinetics of L-hyoscyamine in healthy subjects using a highly sensitive bioanalytical assay. Methods: Ten subjects were administered 0.3 mg of Isopto Atropine solution into the conjunctival sac of the eye. Blood samples were taken as early as 2 min and up to 24 h following administration. The plasma samples were assayed for L-hyoscyamine using a chiral method with an analytical range of 0.500-500 pg/mL. The pharmacokinetic parameters were estimated using both a noncompartmental and compartmental approach. Results: The pharmacokinetics of L-hyoscyamine were fully characterized as there were no samples that were below the limit of quantitation following dosing. Using noncompartmental analysis, the mean Cmax was 467.9 ± 159.4 pg/mL with a median (range) Tmax of 0.5 (0.08-1) h. The mean area under the concentration-time curve was 1668.96 ± 436.02 h·pg/mL and the mean half-life was 3.91 ± 1.16 h. Overall, the study drug was well tolerated and no serious adverse events were reported. Conclusion: Through the utilization of a proprietary ultrasensitive bioanalytical method, a comprehensive investigation into the pharmacokinetics of L-hyoscyamine has been successfully conducted. This advanced method offers significant potential for optimizing study designs and facilitating in-depth examinations of the pharmacokinetics of ocularly administered atropine formulations.

BackgroundMDNA11 is an albumin-fused long-acting IL-2 agonist with enhanced affinity for IL-2Rb and no binding to IL-2Ra, resulting in potent CD8+ T and NK cell activation, limited Treg increase and reduced toxicities.1 ABILITY (A Beta-only IL-2 ImmunoTherapY) is a Phase 1/2 study evaluating the safety, pharmacokinetic (PK), pharmacodynamic (PD) and preliminary clinical activity of MDNA11 as monotherapy and in combination with Prembrolizumab in pre-treated patients with advanced solid tumors.MethodsThe dose-escalation phase of ABILITY uses a modified 3+3 design to determine the recommended dose for expansion (RDE). Patients received a fixed dose of 3, 10 or 30 μg/kg (dose levels 1–3; DL1–3) by intravenous infusion on a Q2W schedule. Step-up dosing was implemented starting at DL4 where patients received 2 or 3 priming doses prior to the target dose of 60 μg/kg (DL4), 90 μg/kg (DL5) or 120 μg/kg (DL6). Primary endpoints include incidence and severity of adverse events (AEs). Secondary endpoints include assessment of PK, PD and tumor response per RECISTv1.1 and iRECISTResultsAs of June 22, 2023, twenty dose limiting toxicity (DLT)-evaluable patients have been dosed with MDNA11 during monotherapy dose escalation (3–120 μg/kg). Tumor types enrolled included melanoma (n=11), renal cell carcinoma (n=2), pancreatic ductal adenocarcinoma (PDAC; n=2), sarcoma (n=2), tonsillar squamous cell carcinoma (n=1), gastro-esophageal adenocarcinoma (n=1) and lung adenocarcinoma (n=1). PK analysis showed dose-dependent increase in MDNA11 exposure. Immune profiling showed robust lymphocyte expansion, including increase in CD8+ T and NK cells and limited change in Tregs. There were no DLTs observed. The most common AEs were infusion related reaction (65%) comprising pyrexia (50%), nausea (45%), chills (35%), fatigue (30%) and diarrhea (25%), with the majority being grade 1–2 and resolved within 48–72 hours. Transient (~ 1week duration) transaminases increase was seen in 25% of patients. Tumor response was evaluated in 19 patients. Single-agent activity included stable disease (SD) observed in 6 patients, including a melanoma patient with SD beyond 1.5 year, and an ongoing partial response (PR) in a PDAC patient who had previously progressed on immune checkpoint inhibitor and is currently continuing on MDNA11 for > 1 year.ConclusionsMDNA11 is well tolerated with no DLTs up to target dose of 120 μg/kg on a Q2W schedule. Evidence of clinical activity includes SD in 6 of 19 patients in addition to a durable PR in a PDAC patient. Data analysis is ongoing to inform RDE selection.AcknowledgementsWe are grateful to all patients participating in this study.Trial RegistrationNCT: 05086692ReferenceMerchant R, Galligan C, Munegowda MA, et al. Fine-tuned long-acting interleukin-2 superkine potentiates durable immune responses in mice and non-human primate. 2022;10:e003155.Ethics ApprovalThe study was conducted with approval from institutional ethics committee and informed consent from participants.

BACKGROUNDDrug development in recurrent glioblastoma multiforme (rGBM) is challenging. For randomized controlled trials (RCTs) short survival horizons and limited life-prolonging treatment options may delay accrual and introduce bias through differential dropout of control patients. Comparing results of a single-arm Phase 2b trial of intratumoral delivery of MDNA55 (an interleukin-4 receptor targeted fusion protein) to an external control arm, we sought early efficacy insights and consideration by the FDA of incorporating an ECA in a Phase 3 registrational trial.METHODSUsing propensity score weighting, we compared rGBM patients from the Phase 2b trial (NCT02858895) (2017-2019) to patients from rGBM registries who had received standard of care therapies (2011-2019) and met eligibility requirements. Propensity scores were estimated using a logistic regression model with 11 covariates. We compared the propensity score weighted groups according to demographic and disease attributes before and after weighting and compared overall survival between the two groups.RESULTSThrough propensity score weighting, 43 (98%, 43/44) MDNA55 patients and 40.80 weighted ECA patients (from 62 unweighted registry patients) were identified for comparison. MDNA55 and ECA patients were balanced on all baseline characteristics (i.e., standardized mean difference ≤ 0.15). Compared to ECA patients, MDNA55 patients had a 37% lower hazard of death (hazard ratio 0.63, 95% confidence interval: 0.39,1.02).CONCLUSIONIn advance of a Phase 3 trial, comparison of Phase 2b trial results to an ECA suggests that MDNA55 may be efficacious in rGBM. In view of the known challenges associated with drug development for rGBM, these results provided a proof-of-concept for the design of a novel hybrid Phase 3 trial. This planned Phase 3 trial incorporates propensity score weighting to create a composite hybrid randomized and external control arm, an approach preferred by the FDA over full replacement of a randomized control with an external control.

Doravirine is a novel non-nucleoside reverse transcriptase inhibitor indicated for the treatment of human immunodeficiency virus type 1 infection. Because of potential concomitant administration with acid-reducing agents, a drug-interaction trial was conducted to evaluate the potential impact of these types of medications on doravirine pharmacokinetics. In an open-label, 3-period, fixed-sequence trial, healthy adult participants received the following: period 1, a single dose of doravirine 100mg; period 2, coadministration of a single dose of doravirine 100mg and an antacid (1600mg aluminum hydroxide, 1600mg magnesium hydroxide, and 160mg simethicone); period 3, 40mg pantoprazole once daily on days 1-5 coadministered with a single dose of doravirine 100mg on day 5. There was a minimum 10-day washout between periods. Plasma samples for pharmacokinetic evaluation were collected, and safety was assessed. Fourteen participants (8 male, 6 female) were enrolled, and 13 completed the trial. Geometric mean ratios (90% confidence intervals) for doravirine AUC0-inf , Cmax , and C24 for doravirine + antacid/doravirine were 1.01 (0.92-1.11), 0.86 (0.74-1.01), and 1.03 (0.94-1.12), respectively, and for doravirine + pantoprazole/doravirine were 0.83 (0.76-0.91), 0.88 (0.76-1.01), and 0.84 (0.77-0.92), respectively. Doravirine was generally well tolerated administered alone or with either of the acid-reducing agents. Coadministration of an aluminum/magnesium-containing antacid or pantoprazole did not have a clinically meaningful effect on doravirine pharmacokinetics, supporting the use of acid-reducing agents with doravirine.

Following oral administration of abiraterone acetate, the parent compound abiraterone acetate is rapidly metabolized to abiraterone. To our knowledge, bioanalytical methods to date have not been able to detect the parent compound in human plasma, and bioassay was only performed on the metabolite. A highly sensitive bioanalytical method was developed and validated to measure plasma concentrations of the parent compound. In this study, both analytes were assayed and used to evaluate the full pharmacokinetic profile of abiraterone acetate tablets. This was an open-label, single-dose, one-period, one-treatment, pharmacokinetic study performed in 18 healthy subjects. Each subject was administered four tablets (corresponding to a total dose of 1000mg) of abiraterone acetate. Blood samples for pharmacokinetic analysis were collected up to 60h post-dose. Subjects' plasma concentrations for abiraterone acetate were assayed using highly sensitive validated bioanalytical methods with a lower limit of quantitation (LLOQ) of 0.5pg/ml for abiraterone acetate and 0.1ng/ml for abiraterone. Safety assessments were performed throughout the study. The pharmacokinetic results for abiraterone acetate showed a mean for the maximum plasma concentration (Cmax) of 54.67 ± 68.30pg/ml, and a median time to maximum concentrations (tmax) of 5.53h (range 2.67-35.00h). The means for area under the concentration-time curve (AUC) from time 0h to infinity (AUCinf) and AUC from time zero h to the time of the last measurable abiraterone acetate concentrations (AUCt) were 386.13 ± 266.80pg·h/ml and 460.07 ± 378.78pg·h/ml, respectively. The apparent elimination half-life (t1/2) showed a mean of 8.98 ± 3.92h. None of the adverse events that affected three subjects (16.7%) were related to the study drug. The ability to detect the low plasma abiraterone acetate concentrations, in addition to abiraterone, resulted in a complete characterization of the pharmacokinetics of abiraterone acetate that was not possible with other analytical methods that only measured the metabolite. The development of new bioanalytical methods such as these will allow for a more thorough understanding of the pharmacokinetics of abiraterone acetate, and this, in turn, can have an impact on both future examinations into abiraterone acetate pharmacokinetic behaviour and the evaluation of its generic formulations.

Patient cost sharing for contraceptive prescriptions was eliminated for certain insurance plans as part of the Affordable Care Act. We examined the impact of this change on women's patterns of choosing prescription contraceptive methods. Using claims data for a sample of midwestern women ages18-46 with employer-sponsored coverage, we examined the contraceptive choices made by women in employer groups whose coverage complied with the mandate, compared to the choices of women in groups whose coverage did not comply. We found that the reduction in cost sharing was associated with a 2.3-percentage-point increase in the choice of any prescription contraceptive, relative to the 30percent rate of choosing prescription contraceptives before the change in cost sharing. A disproportionate share of this increase came from increased selection of long-term contraception methods. Thus, the removal of cost as a barrier seems to be an important factor in contraceptive choice, and our findings about long-term methods may have implications for rates of unintended pregnancy that require further study.

Background Over the last year, the bioanalytical community strongly expressed their need for international harmonization of bioanalytical guidances through numerous international meetings and publications, and this need was acknowledged by several regulatory agencies [1–5]. Following the 4th Calibration and Validation Group (CVG) Workshop on Regulated Bioana lysis hosted in Montreal (April 2010), a unanimous consensus was reached for the global bioanalytical community to identify non-prescriptive, s ciencebased language that could form the basis of a proposed guidance document on bioana lysis [6]. Ideally, such guidance language would describe the rationale behind each bioanalytical requirement and would be presented for consideration by agencies and industry worldwide. A recent concrete action taken towards such global harmonization of bioanalytical guidances was the creation of the Global Bioana lysis Consortium (GBC). Drawing from representatives of scientific associations with involvement in regulated bioana lysis across the globe, the objective of the GBC is to merge existing or emerging bioanalytical guidances and create a unified document that can be presented to the regulatory authorities in various countries and regions. The development of the GBC is currently in process, with the intention to present plans and updates at upcoming bioanalytical meetings and to seek input from the scientists conducting bioana lysis [7]. At the 4th CVG Bioana lysis Workshop in Montreal, Canada, several Contract Research Organizations (CROs) highlighted the importance of having a strong and cohesive CRO contribution to the global harmonization process. Having CROs, academic laboratories and pharma ceutical industries appropriately represented was viewed as critical to identifying optimum language. Consequently, the proposal to build a Global CRO Council (GCC) arose, designed to be a distinct group consisting exclusively of bioanalytical CRO members conducting r egulated bioana lysis business. To initiate creation of the GCC, a special closed forum was held in Montreal on 14 September 2010, where 41 executive representatives from 32 bioanalytical CROs were present to discuss scientific harmonization issues and the institution of the GCC. This first CRO Formation of a Global Contract Research Organization Council for Bioana lysis