Clinical Trial Diversity in Oncology: FDA Takes Action with Post-Marketing Requirements or Commitments.

In recent years, there has been a renewed focus on promoting the inclusion of patients from racial and ethnic minority groups in oncology clinical trials. FDA Oncology has long pointed to the underrepresentation of racial minorities in registration trials leading to approval. US FDA's Guidance on diversity discusses how diversity could be handled within clinical trials, giving recommendations on broadening eligibility criteria, inclusive trial practices, and alternative trial designs. While there is no specific guidance from the FDA on cancer clinical trials, the recommendation is to include a representative population applicable to the US population. With the recent renewed focus on diversity in oncology clinical trials, FDA Oncology has recently asked for the completion of a Diversity Plan during drug development and has issued post-marketing commitments and requirements at the time of approval. As FDA has started to issue post-marketing requirements or commitments regarding diversity in 2020, we sought to analyze the post-marketing studies asking for a study of racial and ethnic minorities issued by the FDA's Office of Oncologic Diseases (OOD). The analysis demonstrated the need to increase the enrollment of a diverse patient population in cancer clinical trials.

Real-time hyperspectral fluorescence imaging of pancreatic ß-cell dynamics with the image mapping spectrometer.

The development of multi-colored fluorescent proteins, nanocrystals and organic fluorophores, along with the resulting engineered biosensors, has revolutionized the study of protein localization and dynamics in living cells. Hyperspectral imaging has proven to be a useful approach for such studies, but this technique is often limited by low signal and insufficient temporal resolution. Here, we present an implementation of a snapshot hyperspectral imaging device, the image mapping spectrometer (IMS), which acquires full spectral information simultaneously from each pixel in the field without scanning. The IMS is capable of real-time signal capture from multiple fluorophores with high collection efficiency (∼65%) and image acquisition rate (up to 7.2 fps). To demonstrate the capabilities of the IMS in cellular applications, we have combined fluorescent protein (FP)-FRET and [Ca(2+)](i) biosensors to measure simultaneously intracellular cAMP and [Ca(2+)](i) signaling in pancreatic ß-cells. Additionally, we have compared quantitatively the IMS detection efficiency with a laser-scanning confocal microscope.

Snapshot advantage: a review of the light collection improvement for parallel high-dimensional measurement systems.

The snapshot advantage is a large increase in light collection efficiency available to high-dimensional measurement systems that avoid filtering and scanning. After discussing this advantage in the context of imaging spectrometry, where the greatest effort towards developing snapshot systems has been made, we describe the types of measurements where it is applicable. We then generalize it to the larger context of high-dimensional measurements, where the advantage increases geometrically with measurement dimensionality.

Depth-resolved image mapping spectrometer (IMS) with structured illumination.

We present a depth-resolved Image Mapping Spectrometer (IMS) which is capable of acquiring 4D (x, y, z, λ) datacubes. Optical sectioning is implemented by structured illumination. The device's spectral imaging performance is demonstrated in a multispectral microsphere and mouse kidney tissue fluorescence imaging experiment. We also compare quantitatively the depth-resolved IMS with a hyperspectral confocal microscope (HCM) in a standard fluorescent bead imaging experiment. The comparison results show that despite the use of a light source with four orders of magnitude lower intensity in the IMS than that in the HCM, the image signal-to-noise ratio acquired by the IMS is 2.6 times higher than that achieved by the equivalent confocal approach.

Oncology Products in the European Union: An Analysis of Regulatory Approvals with a CHMP Oral Explanation.

BACKGROUND: The oral explanation (OE) is a critical event during new marketing authorisation procedures in the European Union (EU). The primary objective of the present study was to investigate how many procedures, having an OE in front of the Committee for Medicinal Products for Human Use (CHMP), resulted in a regulatory approval for oncology products. METHODS: Procedures for new marketing authorisation applications (MAAs) and Type II variations (new indication) for oncology products with at least one OE (with or without a Scientific Advisory Group (SAG) meeting) and for which the outcome took place between 31 January 2016 to 31 January 2020 were included in the analysis. Publicly available agendas/meeting minutes and assessment reports were used to obtain information on the products. RESULTS: An OE occurred in about 20% of procedures (n = 28/150) for oncology products during the review period. The majority of procedures having an OE (61%), with or without any SAG meeting, led to MAA/Type II variation approval in the Centralised Procedure. It was also observed that in 41% of the cases a successful outcome was contingent upon willingness of the applicant to restrict the indication. CONCLUSION: A majority of oncology procedures that had an OE resulted in a positive outcome suggesting that such agency interaction is an important opportunity for the applicant to have a last chance to resolve any outstanding issues at the final stage of the procedure.

Snapshot Image Mapping Spectrometer (IMS) with high sampling density for hyperspectral microscopy.

A snapshot Image Mapping Spectrometer (IMS) with high sampling density is developed for hyperspectral microscopy, measuring a datacube of dimensions 285 x 285 x 60 (x, y, lambda). The spatial resolution is approximately 0.45 microm with a FOV of 100 x 100 microm(2). The measured spectrum is from 450 nm to 650 nm and is sampled by 60 spectral channels with average sampling interval approximately 3.3 nm. The channel's spectral resolution is approximately 8nm. The spectral imaging results demonstrate the potential of the IMS for real-time cellular fluorescence imaging.

Design and evaluation of an ultra-slim objective for in-vivo deep optical biopsy.

An estimated 1.6 million breast biopsies are performed in the US each year. In order to provide real-time, in-vivo imaging with sub-cellular resolution for optical biopsies, we have designed an ultra-slim objective to fit inside the 1-mm-diameter hypodermic needles currently used for breast biopsies to image tissue stained by the fluorescent probe proflavine. To ensure high-quality imaging performance, experimental tests were performed to characterize fiber bundle's light-coupling efficiency and simulations were performed to evaluate the impact of candidate lens materials' autofluorescence. A prototype of NA = 0.4, 250-microm field of view, ultra-slim objective optics was built and tested, yielding diffraction-limited performance and estimated resolution of 0.9 microm. When used in conjunction with a commercial coherent fiber bundle to relay the image formed by the objective, the measured resolution was 2.5 microm.

2,3-Disubstituted acrylamides as potent glucokinase activators.

The phenylacetamide 1 represents the archtypical glucokinase activator (GKA) in which only the R-isomer is active. In order to probe whether the chiral center could be replaced, we prepared a series of olefins 2 and show in the present work that these compounds represent a new class of GKAs. Surprisingly, the SAR of the new series paralleled that of the saturated derivatives with the exception that there was greater tolerance for larger alkyl and cycloalkyl groups at R(2) region in comparison to the phenylacetamides. In normal Wistar rats, the 2,3-disubstituted acrylamide analog 10 was well absorbed and demonstrated robust glucose lowering effects.

Development of image mappers for hyperspectral biomedical imaging applications.

A new design and fabrication method is presented for creating large-format (>100 mirror facets) image mappers for a snapshot hyperspectral biomedical imaging system called an image mapping spectrometer (IMS). To verify this approach a 250 facet image mapper with 25 multiple-tilt angles is designed for a compact IMS that groups the 25 subpupils in a 5 x 5 matrix residing within a single collecting objective's pupil. The image mapper is fabricated by precision diamond raster fly cutting using surface-shaped tools. The individual mirror facets have minimal edge eating, tilt errors of <1 mrad, and an average roughness of 5.4 nm.

Compact Image Slicing Spectrometer (ISS) for hyperspectral fluorescence microscopy.

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated component termed an image slicer. The demonstrated prototype can simultaneously acquire a 140 nm spectral range within its 2D field of view from a single image. The spectral resolution of the system is 5.6 nm. The FOV and spatial resolution of the ISS depend on the selected microscope objective and for the results presented is 45 x 45 microm(2) and 0.45 microm respectively. This proof-of-concept system can be easily improved in the future for higher (both spectral and spatial) resolution imaging. The system requires no scanning and minimal post data processing. In addition, the reflective nature of the image slicer and use of prisms for spectral dispersion make the system light efficient. Both of the above features are highly valuable for real time fluorescent-spectral imaging in biological and diagnostic applications.

Low cost, high performance, self-aligning miniature optical systems.

The most expensive aspects in producing high quality miniature optical systems are the component costs and long assembly process. A new approach for fabricating these systems that reduces both aspects through the implementation of self-aligning LIGA (German acronym for lithographie, galvanoformung, abformung, or x-ray lithography, electroplating, and molding) optomechanics with high volume plastic injection molded and off-the-shelf glass optics is presented. This zero alignment strategy has been incorporated into a miniature high numerical aperture (NA = 1.0 W) microscope objective for a fiber confocal reflectance microscope. Tight alignment tolerances of less than 10 microm are maintained for all components that reside inside of a small 9 gauge diameter hypodermic tubing. A prototype system has been tested using the slanted edge modulation transfer function technique and demonstrated to have a Strehl ratio of 0.71. This universal technology is now being developed for smaller, needle-sized imaging systems and other portable point-of-care diagnostic instruments.

Potent, selective MCH-1 receptor antagonists.

This paper describes the lead optimization of a new series of potent, selective, orally bioavailable, brain-penetrant MCH-1 receptor antagonists. A major focus of the work was to achieve a selectivity profile appropriate for in vivo efficacy studies and safety.

High numerical aperture microendoscope objective for a fiber confocal reflectance microscope.

A disposable high numerical aperture microendoscope objective has been designed, fabricated, and tested for use with a fiber confocal reflectance microscope. The objective uses high precision LIGA fabricated components to integrate imaging components and hydraulic suction lines into a housing that measures only 3.85 mm in outer diameter and 14.65 mm in length. The hydraulics are used to translate tissue through the focal plane for three dimensional imaging. This device is diffraction limited for lambda = 850 nm, has a numerical aperture of 1.0, a field of view of 250 microm, and a working distance of 450 microm. The objective is intended for in vivo imaging of precancerous cells.

Identification of RO4597014, a Glucokinase Activator Studied in the Clinic for the Treatment of Type 2 Diabetes.

To resolve the metabolite redox cycling associated with our earlier clinical compound 2, we carried out lead optimization of lead molecule 1. Compound 4 showed improved lipophilic ligand efficiency and demonstrated robust glucose lowering in diet-induced obese mice without a liability in predictive preclinical drug safety studies. Thus, it was selected as a clinical candidate and further studied in type 2 diabetic patients. Clinical data suggests no evidence of metabolite cycling, which is consistent with the preclinical profiling of metabolism.

Optimization of benzodiazepinones as selective inhibitors of the X-linked inhibitor of apoptosis protein (XIAP) second baculovirus IAP repeat (BIR2) domain.

The IAPs are key regulators of the apoptotic pathways and are commonly overexpressed in many cancer cells. IAPs contain one to three BIR domains that are crucial for their inhibitory function. The pro-survival properties of XIAP come from binding of the BIR domains to the pro-apoptotic caspases. The BIR3 domain of XIAP binds and inhibits caspase 9, while the BIR2 domain binds and inhibits the terminal caspases 3 and 7. While XIAP BIR3 inhibitors have previously been reported, they also inhibit cIAP1/2 and promote the release of TNFα, potentially limiting their therapeutic utility. This paper will focus on the optimization of selective XIAP BIR2 inhibitors leading to the discovery of highly potent benzodiazepinone 36 (IC50 = 45 nM), which has high levels of selectivity over XIAP BIR3 and cIAP1 BIR2/3 and shows efficacy in a xenograft pharmacodynamic model monitoring caspase activity while not promoting the release of TNFα in vitro.

Benzazepinones and benzoxazepinones as antagonists of inhibitor of apoptosis proteins (IAPs) selective for the second baculovirus IAP repeat (BIR2) domain.

XIAP is a key regulator of apoptosis, and its overexpression in cancer cells may contribute to their survival. The antiapoptotic function of XIAP derives from its BIR domains, which bind to and inhibit pro-apoptotic caspases. Most known IAP inhibitors are selective for the BIR3 domain and bind to cIAP1 and cIAP2 as well as XIAP. Pathways activated upon cIAP binding contribute to the function of these compounds. Inhibitors selective for XIAP should exert pro-apoptotic effects through competition with the terminal caspases. This paper details our synthetic explorations of a novel XIAP BIR2-selective benzazepinone screening hit with a focus on increasing BIR2 potency and overcoming high in vivo clearance. These efforts led to the discovery of benzoxazepinone 40, a potent BIR2-selective inhibitor with good in vivo pharmacokinetic properties which potentiates apoptotic signaling in a manner mechanistically distinct from that of known pan-IAP inhibitors.

Discovery of piragliatin--first glucokinase activator studied in type 2 diabetic patients.

Glucokinase (GK) activation as a potential strategy to treat type 2 diabetes (T2D) is well recognized. Compound 1, a glucokinase activator (GKA) lead that we have previously disclosed, caused reversible hepatic lipidosis in repeat-dose toxicology studies. We hypothesized that the hepatic lipidosis was due to the structure-based toxicity and later established that it was due to the formation of a thiourea metabolite, 2. Subsequent SAR studies of 1 led to the identification of a pyrazine-based lead analogue 3, lacking the thiazole moiety. In vivo metabolite identification studies, followed by the independent synthesis and profiling of the cyclopentyl keto- and hydroxyl- metabolites of 3, led to the selection of piragliatin, 4, as the clinical lead. Piragliatin was found to lower pre- and postprandial glucose levels, improve the insulin secretory profile, increase ß-cell sensitivity to glucose, and decrease hepatic glucose output in patients with T2D.

Novel glucokinase activators: a patent review (2008 - 2010).

IMPORTANCE OF THE FIELD: Small molecule glucokinase activators (GKAs) continue to represent a potential strategy to treat type 2 diabetes (T2D). Glucokinase (GK) primarily exerts its effect through modulatory actions in pancreatic ß-cells and hepatocytes. It couples insulin secretion in the pancreas with plasma glucose concentration and improves glucose utilization in the liver, thus, affecting two key aspects of glucose homeostasis. There has been an intense interest in GKAs within the pharmaceutical industry ever since the first report of a low molecular mass activator in 2003. The key drivers for this interest are the robust glucose lowering activity observed with GKAs in preclinical T2D animal models and early reports of efficacy in T2D patients. AREAS COVERED IN THIS REVIEW: The objective is to review GKA structures disclosed during the 2008 - 2010 period and classify them based on key structural features. For this purpose, only compound data from patent disclosures were used. WHAT THE READER WILL GAIN: The reader would gain a detailed view of structural diversity of the GKA field disclosed during the review period. TAKE HOME MESSAGE: There continues to be a high level of interest within the pharmaceutical industry in novel GKAs. Several new and highly potent structure types were reported for the first time in the past 3 years. Common features of all of them include a hydrogen bond donor-acceptor pair that makes contact with the backbone CO- and NH- bonds of Arg 63 residue on GK and two hydrophobic groups. During this review period, several GKAs progressed to Phase II clinical testing and the data on their safety and efficacy profiles are eagerly awaited.

Real-time snapshot hyperspectral imaging endoscope.

Hyperspectral imaging has tremendous potential to detect important molecular biomarkers of early cancer based on their unique spectral signatures. Several drawbacks have limited its use for in vivo screening applications: most notably the poor temporal and spatial resolution, high expense, and low optical throughput of existing hyperspectral imagers. We present the development of a new real-time hyperspectral endoscope (called the image mapping spectroscopy endoscope) based on an image mapping technique capable of addressing these challenges. The parallel high throughput nature of this technique enables the device to operate at frame rates of 5.2 frames per second while collecting a (x, y, λ) datacube of 350 × 350 × 48. We have successfully imaged tissue in vivo, resolving a vasculature pattern of the lower lip while simultaneously detecting oxy-hemoglobin.

Improving spatial resolution of a fiber bundle optical biopsy system.

To reduce the number of invasive tissue biopsies and needle aspirations performed during cancer screenings, endo-microscopes can be used to image tissue in vivo. However, when optical fiber bundles are used to transmit the image, the resolution of such systems is limited by undersampling due to the spacing of the bundle's individual fibers for a given field of view. We propose a method to increase the sampling of an optical biopsy system and thereby improve the system's resolution. The method involves taking several images, shifting the object and fiber bundle slightly relative to each other from one image to the next. Multiple shifting patterns were evaluated to determine which provided the greatest increase in resolution. The shifted images are later realigned and recombined by a custom algorithm. By combining four shifted images of a USAF resolution target, we were able to measure an improvement in the resolution of the system from approximately 3.9 µm to 2.2 µm. When tested on cultured cells, a visible increase in detail was detectable. This technique can provide the basis for improving the diagnostic abilities of optical biopsy systems.