FULL-THICKNESS MACULAR HOLE CLOSURE WITH TOPICAL MEDICAL THERAPY.

PURPOSE: To examine the efficacy and clinical characteristics of successful full-thickness macular hole closure with topical therapy. METHODS: Retrospective case series of full-thickness macular holes managed by a single retinal physician (DS) diagnosed and treated from 2017 to 22. RESULTS: Of 168 patients with full-thickness macular holes, 71 patients were started on steroid, carbonic anhydrase inhibitor, and nonsteroidal antiinflammatory (NSAID) drops. 49 patients (mean 67 years, 59% women) were included in the analysis, and 22 patients were excluded for poor follow-up. In total, 7/49 were secondary post-PPV holes and 42/49 were idiopathic. In addition, 18/49 eyes (36.7%) achieved closure on topical therapy, of which 13 were idiopathic. Hole size was directly correlated with odds of closure: for every 10 µm decrease in size and odds of closure increased by 1.2× ( P = 0.001, CI 1.1-1.4). Average time to closure was 107.2 days (range 20-512 days) and was not correlated with hole size ( P = 0.217, CI -0.478 to +1.938). The presence of VMT was found to be inversely related to successful closure (OR 6.1, P = 0.029, CI 1.2-31.3). There was no significant difference in final best-corrected visual acuity for eyes undergoing primary pars plana vitrectomy versus those trialing drops before undergoing pars plana vitrectomy ( P = 0.318, CI -0.094 to +0.112). CONCLUSION: In the first study to date to report the overall efficacy and clinical characteristics of successful macular hole closure with topical therapy, drops achieved an overall closure rate of 36.7%, with higher efficacy in smaller holes and those without VMT. Rates of MH narrowing and reduction in central foveal thickness acted as predictors of effectiveness of drop therapy.

Utility of real-world evidence in biosimilar development.

Biosimilar development refers to the process of creating a biologic drug that is similar to an existing approved biologic drug, also known as a reference drug. Due to the complex nature of biologics drugs and the inherent variability in their manufacturing process biosimilars are not identical but highly similar to the reference drug in terms of quality, safety, and efficacy. Efficacy and safety trials for biosimilars involve large numbers of patients to confirm comparable clinical performance of the biosimilar and the reference product in appropriately sensitive clinical indications and for appropriate sensitive endpoints. The objective of a biosimilar clinical data is to address slight differences observed at previous steps and to confirm comparable clinical performance of the biosimilar and the reference product. In recent years with advances in big data computing, there has been increasing interest to incorporate the totality of information from different data sources (e.g. Real World data and published literature) in design and conduct of clinical trial to support regulatory objectives. The biosimilar development is an ideal framework for utilization of Real-World Evidence in design of trials as potentially large amount of data are available for the reference dug. Hence there may be an opportunity to use RWD in establishing, improving or validating equivalence margins (EQM) for biosimilar designs, specifically in the case there is no historical published data in the intended sensitive population. In this article, we propose a variation of matching method that seems promising to identify the matched set from a real-world data for which the effect size of targeted endpoint would be comparable to historical data. We believe this is a reasonable approach because in design stage, we can view covariates and secondary endpoints as data feature that can be used in a matching method. This approach was illustrated through a case study which indicated the estimate of the primary endpoint is within 1% of published results and thus RWD may be used to justify or estimate the equivalence margin. To ensure consistent results we recommend using this approach in different indications and endpoint scenarios. Thus utilization of RWD/RWE can provide an important opportunity to increase access to biologic therapies, reducing cost by repurposing existing data.

I felt so much conflict instead of joy: an analysis of open-ended comments from people in British Columbia who declined care recommendations during pregnancy and childbirth.

BACKGROUND: No Canadian studies to date have examined the experiences of people who decline aspects of care during pregnancy and birth. The current analysis bridges this gap by describing comments from 1123 people in British Columbia (BC) who declined a test or procedure that their care provider recommended. METHODS: In the Changing Childbirth in BC study, childbearing people designed a mixed-methods study, including a cross-sectional survey on experiences of provider-patient interactions over the course of maternity care. We conducted a descriptive quantitative content analysis of 1540 open ended comments about declining care recommendations. RESULTS: More than half of all study participants (n = 2100) declined care at some point during pregnancy, birth, or the postpartum period (53.5%), making this a common phenomenon. Participants most commonly declined genetic or gestational diabetes testing, ultrasounds, induction of labour, pharmaceutical pain management during labour, and eye prophylaxis for the newborn. Some people reported that care providers accepted or supported their decision, and others described pressure and coercion from providers. These negative interactions resulted in childbearing people feeling invisible, disempowered and in some cases traumatized. Loss of trust in healthcare providers were also described by childbearing people whose preferences were not respected whereas those who felt informed about their options and supported to make decisions about their care reported positive birth experiences. CONCLUSIONS: Declining care is common during pregnancy and birth and care provider reactions and behaviours greatly influence how childbearing people experience these events. Our findings confirm that clinicians need further training in person-centred decision-making, including respectful communication even when choices fall outside of standard care.

Inverted Papilloma of the Orbit and Nasolacrimal System.

PURPOSE: Periocular inverted papilloma (IP) is a rare, locally aggressive tumor with a propensity for recurrence and malignant transformation. Historically treated via wide excision, this study examines the characteristics and management of periocular IP, comparing those confined to the nasolacrimal system with those invading the orbit. METHODS: An Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective, comparative case series was conducted in patients with IP of the orbit or nasolacrimal system across 15 clinical sites. RESULTS: Of 25 patients, 22 met inclusion criteria with 9 limited to the nasolacrimal system and 13 invading the orbit. Mean age was 60.4 years, 55% were women, all were unilateral. Mean follow-up was 48 months. Rates of smoking, dust and/or aerosol exposure, human papillomavirus (HPV) status, and inflammatory polyps were elevated compared to rates in the general population (45%, 18%, 18%, and 14%, respectively). Bony erosion on computed tomography scans was statistically significantly associated with orbit-invading IP (p = 0.002). Treatment involved all confined IP undergoing surgery alone while 39% of orbit-invading IP also received radiation therapy and/or chemotherapy (p = 0.054). Orbit-invading IP was more likely to be excised with wide margins than IP confined to the nasolacrimal system (85% vs. 22%, p = 0.007). Overall rates of malignancy, recurrence, and patient mortality from IP were found to be 27%, 23%, and 9%, respectively. CONCLUSIONS: IP invading the orbit typically requires aggressive therapy, while IP confined to the nasolacrimal system may be treated more conservatively. Using risk factors, characteristics, and outcomes, a treatment algorithm was created to guide management.

Shuddering attacks: A benign phenomenon in children.

QUESTION: A 2-year-old child was recently brought into my office for repeated episodes of neck stiffening and shivering movements of the shoulders and arms. The episodes last 4 to 5 seconds and occur more than 10 times per day, with no apparent pattern except increased frequency at mealtime. Although there has never been loss of consciousness, the parent was worried that these were seizures. The child was diagnosed by a neurologist as having shuddering attacks. Should I start antiepileptic medications for this child? ANSWER: Shuddering attacks are involuntary movements of the head and upper extremities that occur during normal activities and do not impair consciousness. Normal neurologic examination findings and normal electroencephalogram tracing will confirm that this child has shuddering attacks, a benign phenomenon that requires no further investigation or medical therapy. The condition is of unknown cause but is distinct from epilepsy and neither warrants nor responds to antiepileptic medications. Parents can be reassured that attacks will decrease in frequency and will spontaneously remit with age.

Les accès de frissonnement: Un phénomène bénin chez l'enfant.

QUESTION: Un enfant de 2 ans est récemment venu à ma clinique en raison d'épisodes répétés de raidissements du cou et de mouvements de frissons aux épaules et aux bras. Les épisodes durent de 4 à 5 secondes et se produisent plus de 10 fois par jour, sans modèle apparent, outre une fréquence accrue à l'heure des repas. Même s'il n'a pas eu de perte de conscience, les parents s'inquiétaient qu'il ait des convulsions. Un neurologue a diagnostiqué des accès de frissonnement. Devrais-je commencer des médicaments antiépileptiques pour cet enfant? RÉPONSE: Les accès de frissonnement sont des mouvements involontaires de la tête et des extrémités supérieures qui se produisent durant des activités normales et qui n'affectent pas la conscience. Des constatations normales à un examen neurologique et au tracé d'un électroencéphalogramme confirmeront que l'enfant a des accès de frissonnement, un phénomène bénin qui ne requiert pas d'examen plus approfondi ou de traitement médical. La cause de cet état est inconnue, mais il se distingue de l'épilepsie et ne nécessite pas de médicaments antiépileptiques, auxquels il ne répond pas. Les parents peuvent avoir l'assurance que les accès diminueront en fréquence et disparaîtront spontanément avec l'âge.

Continuous positive airway pressure for obstructive sleep apnea in children.

QUESTION: A 12-year-old child underwent adenotonsillectomy for treatment of obstructive sleep apnea (OSA) but continues to snore at night and struggles with attentiveness at school. The child's parent uses a continuous positive airway pressure (CPAP) machine at night and wonders whether the same therapy could be used in children. ANSWER: Unlike in adults, pediatric OSA is commonly related to adenotonsillar hypertrophy and is often amenable to treatment with adenotonsillectomy. As an alternative to surgery or in cases of postsurgical persistence of OSA, CPAP has shown effectiveness in improving both polysomnographic parameters and daytime neurobehavioural symptoms in children with OSA. Adherence to CPAP therapy is a challenge in children and requires parental education and special considerations such as a mask acclimatization period.

Clinical and biological predictors of response to standardised paediatric colitis therapy (PROTECT): a multicentre inception cohort study.

BACKGROUND: Lack of evidence-based outcomes data leads to uncertainty in developing treatment regimens in children who are newly diagnosed with ulcerative colitis. We hypothesised that pretreatment clinical, transcriptomic, and microbial factors predict disease course. METHODS: In this inception cohort study, we recruited paediatric patients aged 4-17 years with newly diagnosed ulcerative colitis from 29 centres in the USA and Canada. Patients initially received standardised mesalazine or corticosteroids, with pre-established criteria for escalation to immunomodulators (ie, thiopurines) or anti-tumor necrosis factor-α (TNFα) therapy. We used RNA sequencing to define rectal gene expression before treatment, and 16S sequencing to characterise rectal and faecal microbiota. The primary outcome was week 52 corticosteroid-free remission with no therapy beyond mesalazine. We assessed factors associated with the primary outcome using logistic regression models of the per-protocol population. This study is registered with ClinicalTrials.gov, number NCT01536535. FINDINGS: Between July 10, 2012, and April 21, 2015, of 467 patients recruited, 428 started medical therapy, of whom 400 (93%) were evaluable at 52 weeks and 386 (90%) completed the study period with no protocol violations. 150 (38%) of 400 participants achieved week 52 corticosteroid-free remission, of whom 147 (98%) were taking mesalazine and three (2%) were taking no medication. 74 (19%) of 400 were escalated to immunomodulators alone, 123 (31%) anti-TNFα therapy, and 25 (6%) colectomy. Low baseline clinical severity, high baseline haemoglobin, and week 4 clinical remission were associated with achieving week 52 corticosteroid-free remission (n=386, logistic model area under the curve [AUC] 0·70, 95% CI 0·65-0·75; specificity 77%, 95% CI 71-82). Baseline severity and remission by week 4 were validated in an independent cohort of 274 paediatric patients with newly diagnosed ulcerative colitis. After adjusting for clinical predictors, an antimicrobial peptide gene signature (odds ratio [OR] 0·57, 95% CI 0·39-0·81; p=0·002) and abundance of Ruminococcaceae (OR 1·43, 1·02-2·00; p=0·04), and Sutterella (OR 0·81, 0·65-1·00; p=0·05) were independently associated with week 52 corticosteroid-free remission. INTERPRETATION: Our findings support the utility of initial clinical activity and treatment response by 4 weeks to predict week 52 corticosteroid-free remission with mesalazine alone in children who are newly diagnosed with ulcerative colitis. The development of personalised clinical and biological signatures holds the promise of informing ulcerative colitis therapeutic decisions. FUNDING: US National Institutes of Health.

A large multicentre, randomized, double-blind, cross-over study in healthy volunteers to compare pharmacokinetics, pharmacodynamics and safety of a pegfilgrastim biosimilar with its US- and EU-reference biologics.

AIMS: Recombinant PEGylated human granulocyte colony-stimulating factor (pegfilgrastim) is indicated for the reduction of chemotherapy-induced neutropenia and prevention of febrile neutropenia. Biosimilar pegfilgrastim is expected to reduce the financial burden of this complication of chemotherapy. The aim of this study was to demonstrate biosimilarity between Sandoz biosimilar pegfilgrastim and its US- and EU-approved reference biologics. METHODS: Phase I, randomized, double-blind, single-dose, 3-period, 6-sequence cross-over, multicentre study to evaluate the pharmacokinetics, pharmacodynamics, safety and immunogenicity of Sandoz biosimilar pegfilgrastim with US- and EU-references in healthy adults. RESULTS: Pharmacokinetic and pharmacodynamic similarity was demonstrated between the 3 biologics, as the 90% confidence interval for all primary pharmacokinetic and pharmacodynamic endpoint comparisons were contained within the predefined similarity margins of 0.80-1.25. Safety, immunogenicity and tolerability were also similar. CONCLUSIONS: Sandoz biosimilar pegfilgrastim demonstrated pharmacokinetic and pharmacodynamic similarity to both US- and EU-reference biologics. No meaningful differences in safety, local tolerability and immunogenicity were identified.

Safety analysis of proposed pegfilgrastim biosimilar in Phase I and Phase III studies.

Aim: This analysis compares safety data for Sandoz proposed biosimilar (LA-EP2006) and reference pegfilgrastim from a Phase I pharmacokinetic/pharmacodynamic study in healthy volunteers (HVs) and two Phase III confirmatory studies in patients with breast cancer (BC; total n = 808). Patients & methods: Baseline characteristics were summarized, and event rates of bone pain and headache calculated. Results: HVs in the Phase I pharmacokinetic/pharmacodynamic study were generally younger, with lower mean body mass index, versus BC patients in PROTECT-1/-2. Bone pain was the most frequent adverse event with similar incidences with reference versus proposed biosimilar in all studies. Conclusion: No differences in adverse events were found between Sandoz proposed biosimilar and reference pegfilgrastim, notwithstanding some differences between HVs and BC patients.

Controlling type 1 error rate for sequential, bioequivalence studies with crossover designs.

Sample size reestimation in a crossover, bioequivalence study can be a useful adaptive design tool, particularly when the intrasubject variability of the drug formulation under investigation is not well understood. When sample size reestimation is done based on an interim estimate of the intrasubject variability and bioequivalence is tested using the pooled estimate of intrasubject variability, type 1 error inflation will occur. Type 1 error inflation is caused by the pooled estimate being a biased estimator of the intrasubject variability. The type 1 error inflation and bias of the pooled estimator of variability are well characterized in the setting of a two-arm, parallel study. The purpose of this work is to extend this characterization to the setting of a crossover, bioequivalence study with sample size reestimation and to propose an estimator of the intrasubject variability that will prevent type 1 error inflation.

Proposed biosimilar pegfilgrastim shows similarity in pharmacokinetics and pharmacodynamics to reference pegfilgrastim in healthy subjects.

AIMS: This study aimed to demonstrate that the pharmacokinetic (PK) and pharmacodynamic (PD) profile of Sandoz proposed biosimilar pegfilgrastim (LA-EP2006) matches reference pegfilgrastim (Neulasta® ) in healthy subjects. Safety and immunogenicity were also assessed. METHODS: The phase I, randomized, double-blind, two-period crossover study consisted of two treatment periods separated by an 8-week washout period. Healthy subjects aged 18-45 were randomized to either proposed biosimilar/reference pegfilgrastim or reference pegfilgrastim/proposed biosimilar. Proposed biosimilar and reference pegfilgrastim were administered on Day 1 of each treatment period (single 6 mg subcutaneous injection). Blood samples for PK/PD analysis were taken predose and ≤336 h postdose. PK/PD similarity was claimed if 90% (PK) and 95% (PD) confidence intervals (CI) for geometric mean ratios of the area under the serum concentration-time curve (AUC) from time of dosing and extrapolated to infinity (AUC0-inf ), or to the last measurable concentration (AUC0-last ), maximum observed serum concentration (Cmax ), absolute neutrophil count (ANC) area under the effect curve from the time of dosing to the last measurable concentration (AUEC0-last ) and ANC maximum effect attributable to the therapy under investigation (Emax ) were completely contained within the predefined margin (0.8 to 1.25). RESULTS: Overall, 169 subjects completed the study. PK/PD similarity was demonstrated; 90% CIs of geometric mean ratio of proposed biosimilar/reference for PK: AUC0-inf (1.0559-1.2244), AUC0-last (1.0607-1.2328), Cmax (1.0312-1.1909) and 95% CIs for PD (ANC): AUEC0-last (0.9948-1.0366), Emax (0.9737-1.0169) were completely contained within predefined margin of 0.8 to 1.25. Both biologics had similar safety profiles, were well tolerated and had low incidence of anti-drug antibodies. No neutralizing or clinically relevant antibodies were detected. CONCLUSIONS: PK/PD similarity of Sandoz proposed biosimilar pegfilgrastim and reference pegfilgrastim was confirmed. No clinically meaningful differences in safety, tolerability and immunogenicity were observed in healthy subjects.

Upper Eyelid Blepharoplasty: A Novel Method to Predict and Improve Outcomes.

BACKGROUND: In some upper eyelid blepharoplasties, maximal skin removal may not result in desired outcomes; raising crease height can therefore be considered. Currently, there is no method to determine the amount of skin to be excised and/or crease elevation required to achieve a specific outcome. OBJECTIVE: This study extrapolated an equation to determine amount of skin excision and/or lid crease elevation needed to achieve a specific eyelid margin to fold distance (MFD). METHODS: This institutional review board-approved, HIPAA-compliant study was a prospective, nonrandomized clinical trial. Patients were included if aged 30 to 100 years old and underwent upper eyelid blepharoplasty with one surgeon between 2012 and 2014. Exclusion criteria were thyroid eye disease, myasthenia gravis, myotonic dystrophy, pregnancy, blepharoptosis, prior eyelid surgery or trauma, concurrent brow surgery, and topical alpha-agonists. The following data were collected preoperatively and at postoperative months 1 and 6: age, gender, BMI, brow position, MFD, margin to crease distance (distance between eyelid margin and crease, MCD), and vertical skin distance (distance between eyelid margin and brow, VSD). RESULTS: A total 322 eyelids of 164 patients underwent 208 skin excisions, 26 crease elevations, and 88 combined skin excision and crease elevation. Age, gender, and BMI category were all nonsignificant and excluded from the final model. This equation was extrapolated with regression analysis: Change in MFD = -0.40 + (-0.28 × Change VSD) + (0.53 × Change MCD) with |R| = 0.28. CONCLUSION: To better predict and obtain desired upper eyelid blepharoplasty outcomes, the authors created an equation.

Sequence Variation in the Response Element Determines Binding by the Transcription Factor p73.

How the sequence of a response element affects the binding of a transcription factor and, ultimately, the differential rate of transcription of genes under its control is not well-understood. In the case of the p73 transcription factor, it binds to >200 response elements to trigger developmental, cell arrest, and apoptotic pathways. The p73 response elements match the 20 bp consensus sequence of the p53 response elements that are formed by two 10 bp half-sites, where each half-site is an inverted repeat of two 5 bp quarter-sites. Using sedimentation velocity and fluorescence anisotropy experiments, we studied how systematic variations in the sequence of a half-site response element modify the DNA binding affinity of the p73 DNA-binding domain. We observed that each nucleotide position in the response element has a different influence in determining the binding of the p73 DNA-binding domain. The cytosine in the fourth position of each quarter-site is the largest determinant of DNA binding, followed by the nucleotide in the fifth position, and last, the first three positions show a slight regulatory preference for purines. Together with previous structural and functional results, our data suggest a hierarchical model of binding in which some nucleotide positions in the response element are more important than others in determining the binding of the transcription factor.

Effect of ketoconazole and diltiazem on the pharmacokinetics of apixaban, an oral direct factor Xa inhibitor.

AIM: Apixaban is an orally active inhibitor of coagulation factor Xa and is eliminated by multiple pathways, including renal and non-renal elimination. Non-renal elimination pathways consist of metabolism by cytochrome P450 (CYP) enzymes, primarily CYP3A4, as well as direct intestinal excretion. Two single sequence studies evaluated the effect of ketoconazole (a strong dual inhibitor of CYP3A4 and P-glycoprotein [P-gp]) and diltiazem (a moderate CYP3A4 inhibitor and a P-gp inhibitor) on apixaban pharmacokinetics in healthy subjects. METHOD: In the ketoconazole study, 18 subjects received apixaban 10 mg on days 1 and 7, and ketoconazole 400 mg once daily on days 4-9. In the diltiazem study, 18 subjects received apixaban 10 mg on days 1 and 11 and diltiazem 360 mg once daily on days 4-13. RESULTS: Apixaban maximum plasma concentration and area under the plasma concentration-time curve extrapolated to infinity increased by 62% (90% confidence interval [CI], 47, 78%) and 99% (90% CI, 81, 118%), respectively, with co-administration of ketoconazole, and by 31% (90% CI, 16, 49%) and 40% (90% CI, 23, 59%), respectively, with diltiazem. CONCLUSION: A 2-fold and 1.4-fold increase in apixaban exposure was observed with co-administration of ketoconazole and diltiazem, respectively.

Evaluation of the effect of naproxen on the pharmacokinetics and pharmacodynamics of apixaban.

AIM: To assess pharmacokinetic and pharmacodynamic interactions between naproxen (a non-steroidal anti-inflammatory drug) and apixaban (an oral, selective, direct factor-Xa inhibitor). METHOD: In this randomized, three period, two sequence study, 21 healthy subjects received a single oral dose of apixaban 10 mg, naproxen 500 mg or co-administration of both. Blood samples were collected for determination of apixaban and naproxen pharmacokinetics and pharmacodynamics (anti-Xa activity, international normalized ratio [INR] and arachidonic acid-induced platelet aggregation [AAI-PA]). Adverse events, bleeding time and routine safety assessments were also evaluated. RESULTS: Apixaban had no effect on naproxen pharmacokinetics. However, following co-administration, apixaban AUC(0,∞), AUC(0,t) and Cmax were 54% (geometric mean ratio 1.537; 90% confidence interval (CI) 1.394, 1.694), 55% (1.549; 90% CI 1.400, 1.713) and 61% (1.611; 90% CI 1.417, 1.831) higher, respectively. Mean (standard deviation [SD]) anti-Xa activity at 3 h post-dose was approximately 60% higher following co-administration compared with apixaban alone, 4.4 [1.0] vs. 2.7 [0.7] IU ml(-1) , consistent with the apixaban concentration increase following co-administration. INR was within the normal reference range after all treatments. AAI-PA was reduced by approximately 80% with naproxen. Co-administration had no impact beyond that of naproxen. Mean [SD] bleeding time was higher following co-administration (9.1 [4.1] min) compared with either agent alone (5.8 [2.3] and 6.9 [2.6] min for apixaban and naproxen, respectively). CONCLUSION: Co-administration of naproxen with apixaban results in higher apixaban exposure and appears to occur through increased apixaban bioavailability. The effects on anti-Xa activity, INR and inhibition of AAI-PA observed in this study were consistent with the individual pharmacologic effects of apixaban and naproxen.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple doses of apixaban in healthy Japanese male subjects.

OBJECTIVE: This was a randomized, placebo-controlled, double-blind, sequential, ascending-dose study to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple oral doses of apixaban in healthy Japanese male subjects. METHODS: The study was conducted using three sequential dose panels: apixaban 2.5 mg, 5 mg, and 10 mg given twice daily. For each dose panel, subjects were randomly assigned to receive oral apixaban (n = 6) or matching placebo (n = 2) for 7 days. The pharmacokinetics of apixaban and effect on pharmacodynamic variables (clotting assays and anti-Xa activity) were assessed on day 1 and day 7 of treatment. Safety was assessed throughout the study. Only after the preceding dose was confirmed to be safe and well-tolerated subjects were enrolled into the next-higher-dose panel. RESULTS: Apixaban was safe and well-tolerated in these healthy Japanese male subjects across the doses evaluated. On day 7, peak plasma concentrations were reached ~ 3 hours postdose, and increases in peak plasma concentration (C(max)), trough plasma concentration, and area under the plasma concentration-time curve across one dosing interval (12 hours) were tested dose-proportional across the dose range. A modest degree of accumulation was observed that was similar for all doses (accumulation index of 1.7 to 2.0), and renal clearance was consistent across doses (0.91 L/h - 1.07 L/h). Exposure-dependent prolongation of prothrombin time, activated partial thromboplastin time, modified prothrombin time, and increases in anti-Xa activity were observed after single and multiple doses of apixaban. CONCLUSIONS: Apixaban was safe and well-tolerated in healthy Japanese subjects. The pharmacokinetic profile of apixaban following multiple twice-daily doses was linear, and exposure parameters such as C(max), observed at ~ 3 hours post-dose, and area under the plasma concentration-time curve increased in a dose-proportional manner. Pharmacodynamic profiles closely followed the apixaban plasma concentration-time profiles.

Dose finding with the sequential parallel comparison design.

The sequential parallel comparison design (SPCD) is a two-stage design recommended for trials with possibly high placebo response. A drug-placebo comparison in the first stage is followed in the second stage by placebo nonresponders being re-randomized between drug and placebo. We describe how SPCD can be used in trials where multiple doses of a drug or multiple treatments are compared with placebo and present two adaptive approaches. We detail how to analyze data in such trials and give recommendations about the allocation proportion to placebo in the two stages of SPCD.