Testosterone suppression with a unique form of leuprorelin acetate as a solid biodegradable implant in patients with advanced prostate cancer: results from four trials and comparison with the traditional leuprorelin acetate microspheres formulation.

BACKGROUND: There are two slow-release ready-to-use forms of leuprorelin acetate (1-month and 3-month) that are available as solid, biodegradable implants for the treatment of advanced, hormone-sensitive prostate cancer. These implants have been shown to be as effective as traditional leuprorelin acetate microspheres for achieving successful testosterone suppression (⩽0.5 ng/ml) and lowering prostate-specific antigen (PSA) levels. Here we further evaluate testosterone suppression levels from four clinical trials evaluating the 3-month leuprorelin implant, including analysis below the European Association of Urology (EAU) castration level (<0.2 ng/ml). METHODS: Studies were conducted in patients with locally advanced/metastatic prostate cancer: (1) a randomised, controlled single-dose study comparing the leuprorelin implant with leuprorelin microspheres; (2) a single-arm, single-dose study of the leuprorelin implant; (3 and 4) two long-term studies with the leuprorelin implant administered twice, 12 or 16 weeks apart. Patients received 3-month leuprorelin (5 mg) implant or 3-month leuprorelin (10.72 mg) microspheres. Testosterone levels were analysed using radioimmunoassay or ultrasensitive liquid chromatography tandem mass spectrometry. RESULTS: Both the leuprorelin implant and the leuprorelin microspheres achieved mean testosterone suppression (⩽0.5 ng/ml) within 4 weeks for >3 months. In both long-term, single-arm studies with the leuprorelin implant, median values of testosterone ⩽0.2 ng/ml were achieved at Week 4 and maintained until study completion (6 and 8 months); PSA decrease was also observed versus baseline. CONCLUSIONS: Long-lasting steady serum levels of testosterone, comparable with orchiectomy and consistent with the EAU-recommended castration level (<0.2 ng/ml), were achieved at Week 4 and maintained up to 8 months in men with advanced prostate cancer who received the leuprorelin implant.

Randomized equivalence trial: A novel multidose dry powder inhaler and originator device in adult and adolescent asthma.

BACKGROUND: Guideline-defined asthma control can be achieved and maintained in patients by treatment with fluticasone propionate-salmeterol (FP-Sal). OBJECTIVE: To compare the efficacy and safety of FP-Sal delivered via a novel multidose dry powder inhaler (mDPI) versus an originator device in adolescent and adult patients with moderate-to-severe persistent asthma. METHODS: Patients ages 12-65 years (N = 555) were randomized to treatment with FP-Sal novel mDPI 100 µg-50 µg or 500 µg-50 µg, or originator device 100 µg-50 µg or 500 µg-50 µg in a double-blind, double-dummy, parallel-group, multicenter study. Primary efficacy measures were absolute change in forced expiratory volume in 1 second (FEV1) from baseline and the area under the 12-hour serial FEV1 curve at the end of 12 weeks of treatment. Secondary end points included mean changes in FEV1; FEV1 % predicted; morning predose peak expiratory flow; daytime, nighttime, total asthma symptom scores; rescue medication use; percentage of patients with guideline-defined controlled asthma; global efficacy evaluation; patients' device preference; and safety. RESULTS: FP-Sal mDPI and originator device-mediated increases in FEV1 from baseline to the end of treatment were not significantly different, difference in least squares mean, -0.065 L (95% confidence interval, -0.154 to 0.024 L) at 100 µg-50 µg, and -0.032 L (95% confidence interval, -0.121 to 0.057 L) at 500 µg-50 µg). Both doses of FP-Sal mDPI improved FEV1 area under the 12-hour serial FEV1 curve from baseline and all secondary efficacy measures with no significant differences from the originator device at equivalent doses, with similar safety profiles. CONCLUSIONS: FP-Sal mDPI demonstrated equivalent efficacy and safety profile to the originator device and is an alternative in this patient group.

Bioequivalence of Sandoz methylphenidate osmotic-controlled release tablet with Concerta® (Janssen-Cilag).

The aim was to assess the bioequivalence of Sandoz methylphenidate osmotic-controlled release (OCR) tablets (Sandoz [Methylphenidate[ MPH OCR) with Concerta®, a methylphenidate formulation indicated for the treatment of attention deficit/hyperactivity disorder (ADHD). Four open-label, randomized, single-dose, two-way crossover bioequivalence studies were conducted in healthy subjects: three fasting studies with 54-, 36- and 18-mg doses of methylphenidate, and one fed study with the 54-mg dose. The d- and l-threo-methylphenidate plasma levels were quantified using liquid chromatographic methods with tandem mass spectrometry (LC MS/MS). Bioequivalence of the formulations was accepted if the 90% geometric confidence intervals of the ratio of least-squares means of Sandoz MPH OCR to Concerta® of ln-transformed area under the curve (AUC0-t ) and C max were within the acceptance range of 80-125%. All studies met the bioequivalence criteria, and 90% geometric confidence intervals for AUC0-t and C max were within the predefined range. All plasma concentration time curves for Sandoz MPH OCR under fasting conditions showed a biphasic profile comparable with Concerta®, confirmed by bioequivalence of the partial metrics AUC0-2h, AUC2-24 h, C max(0-2 h) and C max(2-24 h). Both products were well tolerated and no relevant differences in the safety profiles were observed. It was concluded that Sandoz MPH OCR is bioequivalent to Concerta® in terms of rate and extent of absorption when administered as a single dose of one extended-release tablet of 54, 36, or 18 mg under fasting conditions and at a dose of 54 mg under fed conditions.

Bioequivalence of two formulations of montelukast sodium 4 mg oral granules in healthy adults.

Montelukast is an effective and well-tolerated treatment for the prophylaxis and chronic treatment of asthma, acute prevention of exercise-induced bronchoconstriction and symptomatic relief of seasonal allergic rhinitis and perennial allergic rhinitis. The aim of the study was to compare bioavailability, and characterise the pharmacokinetic profile and safety of Sandoz generic montelukast 4 mg oral granules relative to Singulair(®) mini (Merck, Sharp & Dohme). An open-label, randomised, single-dose, two-treatment, two-period, two-sequence, two-way crossover bioequivalence study was conducted in healthy male volunteers aged 18-55 years, under fasting conditions. The duration of the clinical part of the trial was ≈ 11 days. Montelukast levels in plasma were quantified using a validated liquid chromatography tandem mass spectrometry method, and pharmacokinetic parameters calculated from the drug concentration-time profile using a non-compartmental model. A total of 40 subjects completed both study periods. The ratio test/reference of geometric least squares means was calculated for both formulations of montelukast for the In-transformed pharmacokinetic parameters; the 90% confidence intervals (CIs) were within the pre-defined limits of 80.00-125.00%: 92.2% (90% CI: 87.42-97.30%) for Cmax, 98.1% (90% CI: 94.49-101.81%) for AUC0-t and 97.6% (90% CI: 94.14-101.27%) for AUC0-∞. Two study subjects each reported one mild adverse event: dyspepsia (possibly related to study medication) and throat pain (not considered related to study medication). Sandoz montelukast 4 mg oral granules are bioequivalent to Singulair(®) 4 mg mini oral granules, with a similar safety profile. This suggests that these two preparations can be considered interchangeable in clinical practice.

Clinical development of two innovative pharmaceutical forms of leuprorelin acetate.

OBJECTIVES: Two innovative pharmaceutical forms of leuprorelin acetate have been developed as 1-month and 3-month implants for the treatment of advanced hormone-dependent prostate cancer. These products contain active substance dispersed homogeneously in a biodegradable polymer. Here we present the key results from the clinical development of these slow-release implant formulations of leuprorelin. METHODS: Two therapeutic studies of the 1-month implant were performed: a randomized, controlled study comparing the leuprorelin implant with leuprorelin prolonged-release microspheres (Enantone) as the active control; and a single-arm study of the leuprorelin implant. For the 3-month implant, four therapeutic studies were performed: a randomized, controlled study comparing the leuprorelin implant with leuprorelin prolonged-release microspheres (Trenantone) as the active control; a single-arm study of the leuprorelin implant; and two long-term studies with the 3-month implant administered twice, either 12 or 16 weeks apart. A pooled analysis of data from the comparator-controlled and single-arm studies of the 3-month implant was also conducted. The main inclusion criterion for all studies was histologically confirmed advanced prostate cancer, with primary endpoints based around successful testosterone suppression (≤0.5 ng/ml). RESULTS: In the comparator-controlled studies, both implants were as effective as the microspheres for achieving successful testosterone suppression and normalization of prostate-specific antigen (PSA) levels. Data from the single-arm and long-term studies were consistent with those from the comparator-controlled studies. In the pooled analysis, significantly more patients treated with the 3-month implant achieved successful testosterone suppression compared with the comparator (p ≤ 0.01). The safety profile of the implants in the comparator-controlled studies was similar to that of the prolonged-release microsphere formulation, and consistent with that of the luteinizing hormone-releasing hormone agonist class. CONCLUSIONS: The innovative 1-month and 3-month implants of leuprorelin acetate are at least as effective as leuprorelin acetate prolonged-release microspheres for achieving successful testosterone suppression and normalization of PSA in men with advanced hormone-dependent prostate cancer, with a comparable safety profile.

Pharmacodynamic equivalence study of two preparations of eye drops containing dorzolamide and timolol in healthy volunteers.

OBJECTIVE: The aim of the present study was to assess the pharmacodynamic equivalence (lowering of intraocular pressure) of two preparations of eye drops containing 20 mg dorzolamide (CAS 120279-96-1) and 5 mg timolol (CAS 26839-75-8). METHOD: The study was conducted as a monocentric, observer-blinded, randomized, single-dose, two-period crossover study in 38 healthy volunteers. Each volunteer received on day 1 in each period in a random way a single dose of 1 drop of the test or the reference formulation in the conjunctival sac of the right eye separated by a wash-out period of 7 days. Measurement of intraocular pressure (IOP) of the right eye (by a blinded observer) was performed on day 1 of each study period pre-dose and 2 h post dosing by means of Goldmann applanation tonometry. In order to investigate the pharmacodynamic equivalence of both products, the two-sided 95% confidence interval was calculated for the difference of the primary target parameter (absolute decrease in IOP 2 h post dose), by means of a parametric (ANOVA) statistical method. RESULTS: The results of the statistical evaluation of the primary target parameter "absolute decrease in IOP 2 h post dose" demonstrated a decrease in the IOP of 4.72 mmHg for the eye treated with the test formulation (dorzolamide 20 mg/ml + timolol 5 mg/ml eye drops) and 4.61 mmHg for the treated with the reference formulation. The mean difference was 0.11 mmHg. The 95% confidence interval was between -0.33 and 0.55 mmHg and thus entirely within the pre-defined equivalence range (+/- 1.5 mmHg). The results of the statistical evaluation of the secondary target parameter relative (as % of baseline) decrease in IOP 2 h post dose demonstrated essentially similar effectiveness in lowering the IOP by 27.63% (test formulation) and 27.12% (reference formulation), respectively. Both drug products were well tolerated. CONCLUSION: Both formulations showed comparable results obtained at a time probably equal to the maximum effect concerning the primary target parameter lowering of IOP 2 h post dose. The safety profile of both preparations showed no difference.

Bioequivalence of HX575 (recombinant human epoetin alfa) and a comparator epoetin alfa after multiple intravenous administrations: an open-label randomised controlled trial.

BACKGROUND: HX575 is a human recombinant epoetin alfa that was approved for use in Europe in 2007 under the European Medicines Agency biosimilar approval pathway. Therefore, in order to demonstrate the bioequivalence of HX575 to an existing epoetin alfa, the pharmacokinetic and pharmacodynamic response to steady state circulating concentrations of HX575 and a comparator epoetin alfa were compared following multiple intravenous administrations. METHODS: An open, randomised, parallel group study was conducted in 80 healthy adult males. Subjects were randomised to multiple intravenous doses of 100 IU/kg body weight of HX575 or of the comparator epoetin alfa three-times-weekly for four weeks. Serum epoetin concentrations were measured using an enzyme-linked immunosorbent assay and pharmacokinetic parameters for the two treatments were compared. The time course and area under the effect curve ratio of haematological characteristics were used as surrogate parameters for efficacy evaluation. RESULTS: The haematological profiles of both treatments were similar, as determined from their population mean curves and the AUECHb ratio and 90% confidence interval (99.9% [98.5-101.2%]), the primary pharmacodynamic endpoint of this study. The pharmacokinetic parameters after the treatments showed minor differences after single dosing, but not at steady state doses. After multiple doses, HX575 was bioequivalent to the comparator with respect to the rate and extent of exposure of exogenous epoetin (AUCtau ratio and 90% confidence interval: 89.2% [82.5-96.2%]). Study medication was well tolerated with no clinically relevant differences between safety profiles of the treatments. Anti-epoetin antibodies were not detected. CONCLUSION: HX575 and the comparator epoetin alfa were bioequivalent at steady state circulating drug concentrations with respect to their pharmacokinetic profile and pharmacodynamic action. This supports the conclusion that HX575 and the comparator epoetin alfa, when administered intraveneously, will be equally efficacious and may be interchangeable as therapy.

HX575, recombinant human epoetin alfa, for the treatment of chemotherapy-associated symptomatic anaemia in patients with solid tumours.

BACKGROUND: Recombinant human epoetin alfa, HX575, is the first biosimilar erythropoiesis-stimulating agent (ESA) with European marketing authorisation. The primary objective of this double-blind, randomised, multicentre study was to assess the efficacy and safety of HX575 in treating chemotherapy-associated symptomatic anaemia in patients with solid tumours. PATIENTS AND METHODS: The patients (n = 114) were treated with HX575 or active control (epoetin alfa) at 150 IU/kg body weight 3 times weekly for 12 weeks, increased to 300 IU/kg body weight 3 times weekly if the haemoglobin/reticulocyte increase was insufficient after 4 or 8 weeks. RESULTS: With HX575, haemoglobin increased by > or =20 g/l in 62% (37/60 patients). The confidence interval (48.2%, 73.9%) was entirely above the pre-defined 30% threshold. Both groups showed similar results for safety profiles and secondary efficacy parameters. Transfusion requirements were 32% (19/60) (HX575) and 38% (13/34) (epoetin alfa). CONCLUSIONS: In treating chemotherapy-associated symptomatic anaemia in patients with solid tumours, the biosimilar ESA, HX575, is efficacious with a safety profile as expected for the therapeutic area.

Bioequivalence of HX575 (recombinant human epoetin alfa) and a comparator epoetin alfa after multiple subcutaneous administrations.

AIM: To compare the steady-state pharmacokinetics and pharmacodynamics (PK/PD) of two erythropoesis-stimulating agents (ESA), HX575 (Binocrit, Sandoz GmbH, Holzkirchen, Germany), human recombinant epoetin alfa approved as the first biosimilar ESA, and a comparator epoetin alfa, following multiple subcutaneous administrations. METHODS: An open, randomized, parallel group study was conducted in 80 healthy adult males. Subjects were randomized to multiple subcutaneous doses of 100 IU/kg body weight of HX575 or of the comparator epoetin alfa 3 times weekly for 4 weeks. RESULTS: The hematological profiles of both treatments were similar, as determined from the population mean curves and area under the effect curve (AUEC) ratios. HX575 met the predefined biosimilarity criteria with respect to the ratio and 90% confidence interval of the AUEC(Hb) (98.9% [97.7-100.2%]), the primary PD endpoint. The PK of the two treatments were also similar as shown by the AUC(0-48) ratios and 90% confidence intervals, 94.3% [84.7-105.0%] and 96.9% [88.2-106.5%], respectively. Study medication was well tolerated and neutralizing anti-epoetin antibodies were not detected. CONCLUSIONS: HX575 and the comparator epoetin alfa were bioequivalent with respect to their PK/PD, supporting the conclusion that both, when administered subcutaneously, will be equally efficacious and may be interchangeable as therapy.

Analysis of pooled plasma samples as a predictor for proving bioequivalence of drugs with a long elimination half-life. The example of phenprocoumon.

The results of pooled plasma analysis in a bioequivalence trial provide information comparable with that of the mean concentration vs. time curves for each formulation. Although it seems feasible that pool plasma analysis will have similar or even greater advantages in cases of bioequivalence trials with a parallel-group design, no such data has been published in the literature probably due to the limited number of such trials. The present study was designed with the aim to investigate the prediction value of pool plasma analysis in a bioequivalence trial with phenprocoumon (CAS 435-972). The study was performed as a monocentric, randomized, open clinical trial in two parallel groups of healthy male volunteers (31 per group), all of which received a single oral dose of 3 mg phenprocoumon. Serial blood samples were drawn for the pharmacokinetic analysis pre-dose, and 0.33, 0.67, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 12, 24, 48, 96, 144, 192, and 240 h after drug administration. Pool plasma was prepared for each sampling point and each formulation. Drug concentrations were measured by means of an HPLC method. A comparison between the pool plasma results and the results of individual analysis revealed a very good correspondence regarding the parameters AUC, Cmax and t(max). The present trial demonstrates that the method of time-wise pooling provides reliable information not only in cross-over trials but also in trials with parallel groups of volunteers.

PK-PD modelling of the effect of cefaclor on four different bacterial strains.

The effect of cefaclor against relevant bacterial strains was studied by employing a combined in vivo pharmacokinetic (PK)-in vitro pharmacodynamic (PD) approach. For this purpose selected isolates of Escherichia coli, Moraxella catarrhalis, Haemophilus influenzae and Streptococcus pneumoniae were exposed in vitro to the interstitial cefaclor profile obtained in vivo in the interstitial space fluid of human tissue after administration of commonly used doses of cefaclor and the change in the number of colony forming units per millilitre (CFU/ml) versus time was monitored. Fitting of the data using a modified E(max)-model resulted in a set of mean pharmacodynamic parameters (k0, k(max), EC50) for each bacterial strain. The parameters derived from these experiments were used in a computer-simulation of the antibacterial effects for different dosing regimens and formulations of cefaclor, notably an immediate (IR) and a modified (MR) release formulation. Dosage regimens were compared using the ratio between the number of bacteria remaining after 24 h of a given treatment (N24h). The results indicate that the number of bacteria of all investigated strains killed per day is equivalent when the same daily dose is administered twice a day with the MR dosage form than when given three times a day with the IR dosage form, in spite of the fact that the MR dosage form has approximately 20% lower bioavailability. Best results were obtained with the three-times a day regimen of the MR formulation. In conclusion, the present in vivo-PK/in vitro-PD simulations of the antimicrobial effects of cefaclor indicate that a twice-daily treatment with a MR formulation may offer a convenient and safe alternative to the conventional tid treatment.

Comparative target site pharmacokinetics of immediate- and modified-release formulations of cefaclor in humans.

Optimal dosing of beta-lactam antibiotics aims at maximizing the time at which drug levels in the interstitial space fluid (ISF)--the fluid that surrounds the causative microorganisms at the target site--exceed the minimal inhibitory concentration (MIC). One potentially attractive strategy to achieve this goal is to administer antibiotics as oral sustained-release formulations. The present study was designed to test the hypothesis that sustained-release formulations could lead to a more suitable pharmacokinetic profile in the ISF at the relevant target site. For this purpose, time versus cefaclor concentration profiles attained in the ISF were measured following administration of two formulations, an immediate- (500 mg IR) and a modified-release formulation in two different doses (500 mg MR and 750 mgMR) in a three-way crossover study of healthy male volunteers (n = 12). For the measurement of unbound cefaclor concentrations in the ISF of human skeletal muscle, the in vivo microdialysis technique was employed. For all three formulations, unbound cefaclor concentration in the ISF closely followed individual plasma concentration profiles in a dose-dependent pattern, with ISF to unbound plasma ratios ranging from 0.67 to 0.73. The mean residence time was found to be significantly longer for the MR formulations versus the IR formulation. The data of the present study indicate that time above MIC values at the target site can be substantially prolonged if an antibiotic is administered as a sustained-release product.