Preclinical efficacy in therapeutic area guidelines from the U.S. Food and Drug Administration and the European Medicines Agency: a cross-sectional study.

BACKGROUND AND PURPOSE: Therapeutic area guidelines (TAGs) published by the EMA and the FDA offer guidance in planning the launch of a trial in a certain indication. We assessed and compared the guidance on preclinical efficacy of all available TAGs from EMA and FDA. EXPERIMENTAL APPROACH: EMA and FDA websites and databases were searched for all TAGs. A mixed deductive and inductive approach was applied to analyse and cluster content for preclinical efficacy. KEY RESULTS: A total of 114 EMA and 120 FDA TAGs were identified, covering 126 indications. Our core finding is that 75% of EMA TAGs and 58% from the FDA TAGs do not offer any guidance on preclinical efficacy. TAGs varied widely on the extent, nature and detail of guidance. CONCLUSIONS AND IMPLICATIONS: Guidance on preclinical efficacy in a consistent, comprehensive and explicit way that still allows for justified deviations is an important but neglected aspect of transparency for drug development. This transparency would help sponsors in designing preclinical studies and in negotiating more efficiently with regulators.

Preclinical efficacy studies in investigator brochures: Do they enable risk-benefit assessment?

Human protection policies require favorable risk-benefit judgments prior to launch of clinical trials. For phase I and II trials, evidence for such judgment often stems from preclinical efficacy studies (PCESs). We undertook a systematic investigation of application materials (investigator brochures [IBs]) presented for ethics review for phase I and II trials to assess the content and properties of PCESs contained in them. Using a sample of 109 IBs most recently approved at 3 institutional review boards based at German Medical Faculties between the years 2010-2016, we identified 708 unique PCESs. We then rated all identified PCESs for their reporting on study elements that help to address validity threats, whether they referenced published reports, and the direction of their results. Altogether, the 109 IBs reported on 708 PCESs. Less than 5% of all PCESs described elements essential for reducing validity threats such as randomization, sample size calculation, and blinded outcome assessment. For most PCESs (89%), no reference to a published report was provided. Only 6% of all PCESs reported an outcome demonstrating no effect. For the majority of IBs (82%), all PCESs were described as reporting positive findings. Our results show that most IBs for phase I/II studies did not allow evaluators to systematically appraise the strength of the supporting preclinical findings. The very rare reporting of PCESs that demonstrated no effect raises concerns about potential design or reporting biases. Poor PCES design and reporting thwart risk-benefit evaluation during ethical review of phase I/II studies.

Moving toward a paradigm shift in the regulatory requirements for pediatric medicines.

Over the past two decades, there has been growing concern over the lack of proper medication for children. This review attempts to evaluate the current progress of EU Pediatric Regulation made since 2007. The lack of properly evaluated pediatric medication has for long been a source of concern in the European Union. The drugs that were used in the past were often not properly evaluated, and dosage was arbitrarily calculated. Therefore, it was necessary to establish the Pediatric Regulation (EC no. 1901/2006) in the EU which would mandate research for pediatric drugs. Current legislations in place not only require mandatory research by pharma industry but also have guidelines to direct the quality of pediatric research performed. The main aim of this regulation was to advance high-quality research and development of pediatric drugs, thereby increasing the availability of safe and effective drugs for children. It also aimed to improve the information available on existing pediatric drugs. It has been 9 years since the pediatric regulation was framed. The pharma industry now sees pediatric research as an integral process of development. Drug companies which develop plans for a new drug, new form of drug, new indication, or new route of administration for adults are obliged to integrate in their development plan similar research for pediatric populations as well. CONCLUSION: It is hoped that the implementation of the current legislation will be reflected better in the future by the marketing of better and safer drugs for the pediatric population. The upcoming assessment to the European Commission in 2017 will further inform us on the impact after 10 years implementation of the legislation. What is Known: • The lack of properly evaluated pediatric medication has for long been a source of concern in the European Union. • Therefore, it was necessary to establish the EU Pediatric Regulation which would mandate research for pediatric drugs. What is New: • It has been 9 years since the pediatric regulation was framed, and the teething problems are slowly being overcome and the regulation is being used with increasing confidence. • As the Regulation is due for revision in 2017, this paper gives a current perspective on the impact of the regulation on availability and access to medicine for children.

Ethics Reporting in Biospecimen and Genetic Research: Current Practice and Suggestions for Changes.

Modern approaches for research with human biospecimens employ a variety of substantially different types of ethics approval and informed consent. In most cases, standard ethics reporting such as "consent and approval was obtained" is no longer meaningful. A structured analysis of 120 biospecimen studies recently published in top journals revealed that more than 85% reported on consent and approval, but in more than 90% of cases, this reporting was insufficient and thus potentially misleading. Editorial policies, reporting guidelines, and material transfer agreements should include recommendations for meaningful ethics reporting in biospecimen research. Meaningful ethics reporting is possible without higher word counts and could support public trust as well as networked research.

A brief literature and patent review of nanosuspensions to a final drug product.

Particle size reduction can be used for enhancing the dissolution of poorly water-soluble drugs in order to enhance bioavailability. In nanosuspensions, the particle size of the drug is reduced to nanometer size. Nanosuspensions after downstream processing into drug products have successfully shown its impact on formulation design, the augmentation of product life cycle, patent life, and therapeutic efficacy. Formulation considerations for the nanosuspension formulation, its processing into a solid form, and aspects of material characterization are discussed. Technology assessments and feasibility of upstream processes for nanoparticle creation, and subsequently transformation into a drug product via the downstream processes have been reviewed. This paper aims to bridge formulation and process considerations along with patent reviews and may provide further insight into understanding the science and the white space. An analysis of current patent outlook and future trends is described to fully understand the limitations and opportunities in intellectual property generation.

Effect of binders on the release rates of direct molded verapamil tablets using twin-screw extruder in melt granulation.

Conventional manufacturing of pharmaceutical tablets often involves single processes such as blending, granulation, milling and direct compression. A process that minimizes and incorporates all these in a single continuous step is desirable. The concept of omitting milling step followed by direct-molding of tablets utilizing a twin-screw extruder in a melt granulation process using thermoplastic binders was explored. The objective of this study was to investigate the effect of combining hydrophilic binder (HPMC K4M, PEO 1M), and hydrophobic binder (Compritol® ATO 888, Precirol® ATO 5) on the release profiles of direct-molded tablets and direct-compressed tablets from milled extrudates using a quality-by-design approach. It was identified that hydrophilic binder type and process significantly affects (p=0.005) the release profiles of verapamil. Moreover, two-way interaction analysis demonstrated that the combination of process with type of hydrophilic polymer (p=0.028) and the type of hydrophilic polymer with polymer ratio (p=0.033) significantly affected the release profiles. The formulation release kinetics correlated to Higuchi release model and the mechanism correlated to a non-Fickian release mechanism. The results of the present study indicated that direct-molded tablets with different release profiles can be manufactured without milling process and through a continuous melt granulation using twin-screw extruder with appropriate thermoplastic binder ratio.

Chlorin e6-polyvinylpyrrolidone mediated photodynamic therapy--A potential bladder sparing option for high risk non-muscle invasive bladder cancer.

BACKGROUND: Bladder sparing treatment options for high risk non-muscle invasive blader cancer (NMIBC) after intravesical Bacillus Calmette-Guerin (BCG) failure are limited. OBJECTIVE: To evaluate photodynamic therapy (PDT) using chlorin e6-polyvinylpyrrolidone (Ce6-PVP) as a bladder sparing therapy for NMIBC refractory to intravesical BCG therapy. MATERIALS AND METHODS: Between July 2004 and June 2009, patients with recurrent NMIBC after induction intravesical BCG therapy were treated with PDT performed with a 665nm laser and light dosimetry of 10-24J/cm(2). The patients underwent cystoscopic surveillance for tumour recurrence post PDT. Post treatment lower urinary tract symptoms and bladder capacity were also monitored. Serum and urine samples were collected for spectrometric quantification of photosensitizer levels. RESULTS: Five patients underwent PDT, with a total of seven treatments performed. One patient received intravenous Ce6-PVP, while the rest received intravesical Ce6-PVP.The median age was 80 years (mean 79 years, range 72-88 years). There were three patients with primary CIS of the bladder and two with T1 high grade TCC and CIS of the bladder. At a median follow-up of 29 months (mean 25 months, range 6-36 months), two patients were disease free, two patients developed recurrence and one patient progressed to muscle invasive disease. There were no immediate adverse effects. The patient receiving intravenous Ce6-PVP developed an enterovesical fistula 16 months post PDT. CONCLUSIONS: Despite being a small pilot study, intravesical Ce6-PVP mediated PDT is a feasible bladder sparing treatment option for recurrent high risk non-muscle invasive bladder carcinoma in selected individuals.

Effect of polyvinylpyrrolidone on the interaction of chlorin e6 with plasma proteins and its subcellular localization.

A photophysical study describing the effects of the polymer polyvinylpyrrolidone (PVP), on the binding interaction between chlorin e6 (Ce6) with bovine serum albumin (BSA) and human plasma proteins such as very low-density lipoprotein (VLDL), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) was performed using a steady-state fluorescence technique. Combined Ce6-PVP was found to have very stable photostability at three different temperatures (4°C, 21°C and 37°C) when dissolved in an aqueous solution containing 5% and 10% fetal calf serum. The partition coefficient of combined Ce6-PVP was relatively more hydrophilic than that of Ce6 alone. There was a marked increase in the emission profile of Ce6-PVP and the correlated bathochromic shift on the addition of proteins. These results also suggest that Ce6-PVP might have slightly greater association energy with VLDL in comparison to Ce6 alone. The co-localization of Ce6 and Ce6-PVP in cells was also assessed using confocal microscopy. The association of Ce6 with PVP resulted in an enhanced cellular uptake of Ce6 within the cytoplasmic compartment of cells. The present study supported the hypothesis that PVP improves the permeability of Ce6 through the biological membranes of cells.

Improved formulation of photosensitizer chlorin e6 polyvinylpyrrolidone for fluorescence diagnostic imaging and photodynamic therapy of human cancer.

An improved formulation of the photosensitizer chlorin e6 (Ce6) in combination with the hydrophilic polymer polyvinylpyrrolidone (PVP) was investigated for its potential clinical applications in fluorescence diagnosis and photodynamic therapy (PDT) of cancer. This study reports the comparative preclinical biodistribution and efficacy of Ce6 delivered with or without PVP versus dimethyl sulfoxide (DMSO). The safety and fluorescence pharmacokinetics of Ce6-PVP in humans was also accessed. Biodistribution results showed that Ce6-PVP had higher tumor to normal tissue ratio compared to the other formulations. The sensitivity and specificity derived from the area under the receiver operating characteristics curves showed that the formulations were able to discriminate tumor from peritumoral muscle in the following order: Ce6-PVP > Ce6 > Ce6-DMSO. In vitro PDT results showed that Ce6-PVP was found to induce selective phototoxicity in leukemic cells compared to peripheral mononuclear blood cells. In addition, in vivo light irradiation at 1h after Ce6-PVP was found to induce greater tumor necrosis without causing animal toxicity. In patients, preferential accumulation of Ce6-PVP was observed in angiosarcoma lesions compared to normal skin following intravenous administration. In conclusion, PVP significantly enhanced the Ce6 concentration in tumors compared with Ce6 alone and increased the therapeutic index of PDT without any side effects in animal model. No serious adverse events were observed in human as well.

Membrane transport enhancement of chlorin e6-polyvinylpyrrolidone and its photodynamic efficacy on the chick chorioallantoic model.

We have determined the influences of polyvinylpyrrolidone (PVP) on the topical delivery of chlorin e6 (Ce6) in malignant bladder cells. The chick chorioallantoic membrane (CAM) was used to model the tumor spheroids that resemble small residual bladder tumors prior to vascularization. Macroscopic fluorescence imaging showed that Ce6-PVP-induced fluorescence had a higher sensitivity and specificity for delineating tumor from the adjacent normal CAM compared to Ce6 alone. Nonlinear regression analyses have shown that Ce6-PVP has a longer half-life in the tumor compared to Ce6. The uptake ratio of Ce6-PVP was found to have a 2-fold increase across the CAM when compared to that of Ce6, indicating that PVP was able to facilitate diffusion of Ce6 across the membrane. Confocal laser scanning microscopy further confirmed that Ce6-PVP has better penetration in the CAM as well as in the tumor cells compared to Ce6. The present work contributes to our understanding of the Ce6-PVP drug-polymer system by demonstrating for the first time that the presence of PVP facilitates the transport of Ce6 across the chorioallantoic membrane.

Fluorescence detection of bladder cancer using urine cytology.

Bladder cancer is the fourth most common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate in bladder cancer can be reduced by early treatment following pre-cancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimens, which is both invasive and time-consuming. In this study, ex vivo urine fluorescence cytology was investigated to offer an alternative timely and biopsy-free means for detecting bladder cancers. Sediments in patient urine samples were extracted and incubated with a novel photosensitizer, hypericin. Laser confocal microscopy was used to capture the fluorescence images at an excitation wavelength of 488 nm. Images were subsequently processed to single out the exfoliated bladder cancer cells from the other cells based on the cellular size. Intensity histograms of each targeted cell and feature vectors, derived from the histogram moments, were used to represent each sample. A difference in the distribution of the feature vectors of normal and low-grade cancerous bladder cancer cells were observed. A diagnostic algorithm for discriminating between normal and low-grade cancerous cells is elucidated in this report. This study suggests that the fluorescence intensity profiles of hypericin in bladder cells can potentially provide an automated quantitative means of early bladder cancer diagnosis.

Chlorin e6-polyvinylpyrrolidone as a fluorescent marker for fluorescence diagnosis of human bladder cancer implanted on the chick chorioallantoic membrane model.

The use of fluorescence diagnosis as a modern cancer diagnostic modality is rapidly gaining importance in the field of urology. It is based on the detection of distinctive light emission of tissues sensitized by fluorescent dyes, commonly referred to as photosensitizers, after irradiation with a specific light source. Therefore, the search for specific fluorescent dyes with high sensitivity and specificity for bladder cancer is constantly being sought after. The aim of this study is to investigate the use of a new formulation consisting a mixture of chlorin e6 and polyvinylpyrrolidone (Ce6-PVP) for the detection of human bladder cancer cells (MGH) implanted on the chick chorioallantoic membrane (CAM) model. Uptake kinetics studies were quantitatively determined for both systemic and topical administrations of Ce6-PVP to the normal CAM as well as the MGH human bladder tumor implanted on CAM using fluorescence imaging technique. Rapid elimination of Ce6-PVP was displayed following topical application compared to systemic administration in the normal CAM system. Ce6-PVP was found to localize selectively in the xenografted bladder tumor in contrast to the CAM tissue. Neither dark toxicity nor irritancy was observed on the CAM tissue at the dose of 2 mg/kg Ce6-PVP. In conclusion, the Ce6-PVP formulation appeared to have the potential as a fluorescent marker for fluorescence diagnosis of human bladder cancer.

Superiority of N-methyl pyrrolidone over albumin with hypericin for fluorescence diagnosis of human bladder cancer cells implanted in the chick chorioallantoic membrane model.

Formulations of hypericin (HY) with plasma protein have been conventionally used, but to date, no alternative pharmaceutical formulation has been developed for clinical use. Previously, it was reported that formulation of HY containing a biocompatible solvent and penetration enhancer, N-methyl pyrrolidone (NMP) was found to be effective for the delivery of HY across in vivo chick chorioallantoic membrane (CAM). This present study reports further investigations on the HY-NMP formulations in CAM implanted with human bladder cancer cells as a potential fluorescence diagnostic agent of cancer. The conventional formulation of HY (HY-HSA 0.5%) was included as control. The red-to-blue (I(R)/I(B)) intensity ratio of fluorescence images was used as a diagnostic algorithm, to differentiate the uptake of HY between tumor and adjacent regions on CAM. Results indicated that HY-NMP 0.05% was significantly better than HY-HSA 0.5%. The findings of the I(R)/I(B) ratios between tumor and adjacent tissues, indicated the potential of using NMP as an alternative to plasma protein in clinical fluorescence diagnosis with HY. The NMP formulations investigated were able to produce significantly higher contrast for tumor tissues and at earlier time points than was possible with HY-HSA 0.5%.

The potential application of chlorin e6-polyvinylpyrrolidone formulation in photodynamic therapy.

Much research has been focused on developing effective drug delivery systems for the preparation of chlorins as potential photosensitizers for PDT. This report describes the evaluation of a new water-soluble formulation of chlorin e6 consisting of a complex of trisodium salt chlorin e6 and polyvinylpyrrolidone (Ce6-PVP) for application in photodynamic therapy (PDT) with 2 specific aims: (i) to investigate its fluorescence kinetics in skin, normal and tumor tissue after intravenous administration, and (ii) to investigate its PDT efficacy. Our results demonstrate that this new formulation possesses photosensitizing properties with rapid accumulation in tumor tissue observed within 1 h after intravenous administration. Although high selectivity in tumor tissue was found between the period of 3 and 6 h, the efficacy of Ce6-PVP mediated PDT was best at 1 h drug-light interval. It is suggested that, the extent of tumor necrosis post PDT is dependent on the plasma concentration of Ce6-PVP, implying a vascular mediated cell death mechanism. A faster clearance rate of Ce6-PVP from the skin of nude mice was observed compared to Ce6. The new formulation of Ce6-PVP seems to show promise as an effective therapeutic agent.

Fluorescence imaging and phototoxicity effects of new formulation of chlorin e6-polyvinylpyrrolidone.

Evaluations of the efficiency of a new formulation of chlorin consisting of a complex of trisodium salt chlorin e6 (Ce6) and polyvinylpyrrolidone (PVP) in photodynamic therapy (PDT) and fluorescence diagnosis was performed on poorly differentiated human bladder carcinoma murine model with the following specific aims: (i) to qualitatively evaluate the fluorescence accumulation in human bladder tumor, (ii) to determine fluorescence distribution of Ce6-PVP using the tissue extraction technique and fluorescence imaging technique, (iii) to compare the fluorescence distribution of Ce6, Ce6-PVP and Photofrin in skin of nude mice, and (iv) to investigate phototoxicity caused by different parameters (drug-light interval, drug dose, irradiation fluence rate and total light fluence) in PDT. The fluorescence of the Ce6-PVP formulation was determined either by fluorescence imaging measurements or by chemical extraction from the tissues displaying similar trends of distribution. Our results demonstrated that the Ce6-PVP formulation possesses less in vivo phototoxic effect compared to Ce6 alone. The phototoxicity revealed a strong dependence on the drug and light dosimetry as well as on the drug-light interval. In PDT, the Ce6-PVP compound was most toxic at the 1h drug-light interval at 200J/cm(2), while Ce6 alone was most toxic at a light dose of more that 50J/cm(2) at the 1 and 3h drug-light interval. We also confirmed that Ce6-PVP has a faster clearance compared to Ce6 alone or Photofrin. This eliminates the need for long-term photosensitivity precautions. In conclusion, the Ce6-PVP formulation seems to be a promising photosensitizer for fluorescence imaging as well as for photodynamic treatment.

Enhanced photodynamic activity of hypericin by penetration enhancer N-methyl pyrrolidone formulations in the chick chorioallantoic membrane model.

Hypericin (HY) was examined for photodynamic therapy (PDT)-induced vascular damage using the chick chorioallantoic membrane (CAM) model. Clinically, plasma protein was used to solubilize HY. Upon binding to albumin, free HY available to be transported through the membrane may be limited. Hence, formulations containing a biocompatible solvent, N-Methyl pyrrolidone (NMP), have the potential to enhance HY delivery into solid tumors. At suitable concentrations, NMP and/or light irradiation did not produce antivascular damage. Hypericin-PDT effects showed to be HY and NMP concentrations-dependent. These findings indicate that NMP is a promising solvent and penetration enhancer for HY-PDT clinical applications.

Transport of hypericin across chick chorioallantoic membrane and photodynamic therapy vasculature assessment.

This study examined the transport of a photosensitizer (hypericin, HY) using the chick chorioallantoic membrane (CAM) as a model of transport after topical administration. The model correlates both the photosensitizer uptake and anti-vasculature effects after photodynamic therapy (PDT). HY formulations were prepared using N-methyl pyrrolidone (NMP) as a solvent and penetration enhancer. Fertilized chicken eggs were disinfected and incubated at 37.4 degrees C and 60% humidity. Formulations were applied on CAM and incubated for 30 min in the dark. Subsequently, the solutions were removed from the CAM surface and the HY concentration was determined. The CAM was exposed to a fixed light dose of 10 J/cm2 at 50 mW/cm2. The vascular damage induced by the light was quantitatively measured using image-processing techniques. The uptake ratio of HY in 4.8% NMP (HD group) to that of 0.6% NMP (LD group) was found to be 1.96. This ratio is correlated with the vascular damage caused by the PDT effect of HY. The HD treated CAM showed a vessel regression that was 2.37 times higher than that of LD treated CAM. This paper reports the first attempt to develop a quantitative transport study for HY using CAM and to explore the relationship between the vascular regression and amount of drug of uptake. The model has potential for other similar transport studies.