Radiation countermeasure agents: an update (2011 – 2014)

Introduction: Despite significant scientific advances over the past 60 years towards the development of a safe, nontoxic and effective radiation countermeasure for the acute radiation syndrome (ARS), no drug has been approved by the US FDA. A radiation countermeasure to protect the population at large from the effects of lethal radiation exposure remains a significant unmet medical need of the US citizenry and, thus, has been recognized as a high priority area by the government.

Area covered: This article reviews relevant publications and patents for recent developments and progress for potential ARS treatments in the area of radiation countermeasures. Emphasis is placed on the advanced development of existing agents since 2011 and new agents identified as radiation countermeasure for ARS during this period.

Expert opinion: A number of promising radiation countermeasures are currently under development, seven of which have received US FDA investigational new drug status for clinical investigation. Four of these agents, CBLB502, Ex-RAD, HemaMax and OrbeShield, are progressing with large animal studies and clinical trials. G-CSF has high potential and well-documented therapeutic effects in countering myelosuppression and may receive full licensing approval by the US FDA in the future.     

Nonhuman primates as models for the discovery and development of radiation countermeasures

Introduction: Despite significant scientific advances over the past six decades toward the development of safe and effective radiation countermeasures for humans using animal models, only two pharmaceutical agents have been approved by United States Food and Drug Administration (US FDA) for hematopoietic acute radiation syndrome (H-ARS). Additional research efforts are needed to further develop large animal models for improving the prediction of clinical safety and effectiveness of radiation countermeasures for ARS and delayed effects of acute radiation exposure (DEARE) in humans.

Area covered: The authors review the suitability of animal models for the development of radiation countermeasures for ARS following the FDA Animal Rule with a special focus on nonhuman primate (NHP) models of ARS. There are seven centers in the United States currently conducting studies with irradiated NHPs, with the majority of studies being conducted with rhesus monkeys.

Expert opinion: The NHP model is considered the gold standard animal model for drug development and approval by the FDA. The lack of suitable substitutes for NHP models for predicting response in humans serves as a bottleneck for the development of radiation countermeasures. Additional large animal models need to be characterized to support the development and FDA-approval of new radiation countermeasures.     

Medical countermeasures for unwanted CBRN exposures: part II radiological and nuclear threats with review of recent countermeasure patents

Introduction: The global threat of a chemical, biological, radiological, or nuclear (CBRN) disaster is an important priority for all government agencies involved in domestic security and public health preparedness. Radiological/nuclear (RN) attacks or accidents have become a larger focus of the United States Food and Drug administration (US FDA) over time because of their increased likeliness. Clinical signs and symptoms of a developing acute radiation syndrome (ARS) are grouped into three sub-syndromes named for the dominant organ system affected, namely the hematopoietic (H-ARS), gastrointestinal (GI-ARS), and neurovascular systems. The availability of safe and effective countermeasures against radiological/nuclear threats currently represents a significant unmet medical need.

Areas covered: This article reviews the development of RN threat medical countermeasures and highlights those specific countermeasures that have been recently patented and approved following the FDA Animal Rule. Patents for such agents from 2015 have been presented.

Expert opinion: Two granulocyte colony-stimulating factor (G-CSF)-based radiation countermeasures (Neupogen® (Amgen, Thousand Oaks, CA) and Neulasta® (Amgen, Thousand Oaks, CA)) have recently been approved by the FDA for treatment of H-ARS and both these agents are radiomitigators, used after radiation exposure. To date, there are no FDA-approved radioprotectors for ARS.     

Animal models for acute radiation syndrome drug discovery

Introduction: Although significant scientific advances have been made over the past six decades in developing safe, nontoxic and effective radiation/medical countermeasures (MCMs) for acute radiation syndrome (ARS), no drug has been approved by the US FDA. The availability of adequate animal models is a prime requisite under the criteria established by the FDA ‘animal rule’ for the development of novel MCMs for ARS and the discovery of biomarkers for radiation exposure.

Areas covered: This article reviews the developments of MCMs to combat ARS, with particular reference to the various animal models (rodents: mouse and rat; canine: beagle; minipigs and nonhuman primates [NHPs]) utilized for the in-depth evaluation. The objective, pathways and challenges of the FDA Animal Efficacy Rule are also discussed.

Expert opinion: There are a number of well-defined animal models, the mouse, canine and NHP, that are being used for the development of MCMs. Additional animal models, such as the minipig, are under development to further assist in the identification, efficacy testing and approval of MCMs under the FDA Animal Efficacy Rule.     

Medical countermeasures for unwanted CBRN exposures: Part I chemical and biological threats with review of recent countermeasure patents

Introduction: The threat of chemical, biological, radiological, and nuclear (CBRN) warfare has been addressed as the uppermost risk to national security since the terrorist attacks on 11 September 2001. Despite significant scientific advances over the past several decades toward the development of safe, non-toxic and effective countermeasures to combat CBRN threats, relatively few countermeasures have been approved by the US Food and Drug Administration (US FDA). Therefore, countermeasures capable of protecting the population from the effects of CBRN attack remain a significant unmet medical need. Chemical and biological (CB) threat agents can be particularly hazardous due to their effectiveness in small quantities and ease of distribution.

Area covered: This article reviews the development of countermeasures for CB threats and highlights specific threats for which at least one countermeasure has been approved following the FDA Animal Rule. Patents of CB countermeasures since 2010 have been included.

Expert opinion: Nine CB countermeasures have received FDA approval for use in humans following the Animal Rule, and a number of promising CB countermeasures are currently under development. In the next few years, we should expect to have multiple countermeasures approved by the FDA for each indication allowing for more flexible and effective treatment options.     

Drug discovery strategies for acute radiation syndrome

Introduction: There are at the minimum two major, quite different approaches to advance drug discovery. The first being the target-based drug discovery (TBDD) approach that is commonly referred to as the molecular approach. The second approach is the phenotype-based drug discovery (PBDD), also known as physiology-based drug discovery or empirical approach.

Area covered: The authors discuss, herein, the need for developing radiation countermeasure agents for various sub-syndromes of acute radiation syndromes (ARS) following TBDD and PBDD approaches. With time and continuous advances in radiation countermeasure drug development research, the expectation is to have multiple radiation countermeasure agents for each sub-syndrome made available to radiation exposed victims.

Expert opinion: The majority of the countermeasures currently being developed for ARS employ the PBDD approach, while the TBDD approach is clearly under-utilized. In the future, an improved drug development strategy might be a ‘hybrid’ strategy that is more reliant on TBDD for the initial drug discovery via large-scale screening of potential candidate agents, while utilizing PBDD for secondary screening of those candidates, followed by tertiary analytics phase in order to pinpoint efficacious candidates that target the specific sub-syndromes of ARS.     

Pharmacological management of ionizing radiation injuries: current and prospective agents and targeted organ systems

ABSTRACT

Introduction: There is a limited array of currently available medicinals that are useful for either the prevention, mitigation or treatment of bodily injuries arising from ionizing radiation exposure.

Area covered: In this brief article, the authors review those pharmacologic agents that either are currently being used to counter the injurious effects of radiation exposure, or those that show promise and are currently under development.

Expert opinion: Although significant, but limited progress has been made in the development and fielding of safe and effective pharmacotherapeutics for select types of acute radiation-associated injuries, additional effort is needed to broaden the scope of drug development so that overall health risks associated with both short- and long-term injuries in various organ systems can be reduced and effectively managed. There are several promising radiation countermeasures that may gain regulatory approval from the government in the near future for use in clinical settings and in the aftermath of nuclear/radiological exposure contingencies.     

Almotriptan for the acute treatment of adolescent migraine

Importance of the field: Migraine is a common problem affecting 10 – 20% of adolescents. Its treatment has three fundamental components: bio-behavioral interventions, preventive measures, and acute drug therapy. In June 2009, the US FDA approved almotriptan, a 5-HT1B/1D receptor agonist, for the acute treatment of migraine in adolescents aged 12 – 17 years – the first ‘triptan’ to be approved for adolescents.

Areas covered in this review: This review will provide an overview of migraine in adolescents focusing on epidemiology, pathophysiology, classification and a review of treatment options with attention on the evidence from the past 5 years surrounding almotriptan.

What the reader will gain: Given its recent FDA approval, it is important to for clinicians and pharmacists to become familiar with the clinical spectrum of migraine in teenagers and with recent evidence on this newly approved agent, almotriptan.

Take home message: Almotriptan is a safe, effective, and approved agent for the acute treatment of migraine headache in adolescents.     

Update on the pharmacotherapy for myelodysplastic syndromes

Introduction: For many decades, myelodysplastic syndromes (MDS) were a poorly understood disease group with no approved therapies, and patient management largely relied upon supportive care and intensive chemotherapy. The last decade has seen many scientific and therapeutic advances culminating in the US FDA approval of three drugs for the treatment of these complex malignancies: lenalidomide, azacitidine and decitabine.

Areas covered: This review summarizes the major prognostic risk models that guide treatment decisions and examines the available literature on the mechanism of action and efficacy of each of the approved agents. The authors also discuss evidence supporting the use of other therapies that have entered the standard of care including growth factors, immunosuppressive therapy and stem-cell transplantation.

Expert opinion: While significant progress has been made in understanding the molecular basis of MDS, much of this has yet to translate into therapeutic benefit. Each of the available treatment modalities has shortcomings, and both combination strategies and novel agents are under investigation in clinical trials to improve outcomes.     

Taxane anticancer agents: a patent perspective

Introduction:Paclitaxel and docetaxel were two epoch-making anticancer drugs and have been successfully used in chemotherapy for a variety of cancer types. In the year 2010, a new taxane, cabazitaxel, was approved by FDA for use in combination with prednisone for the treatment of metastatic hormone-refractory prostate cancer. Albumin-bound paclitaxel (nab?-paclitaxel; abraxane) nanodroplet formulation was another notable invention (FDA approval 2005 for refractory, metastatic, or relapsed breast cancer). Abraxane in combination with gemcitabine for the treatment of pancreatic cancer was approved by FDA in 2013. Accordingly, there have been a huge number of patent applications dealing with taxane anticancer agents in the last 5 years. Thus, it is a good time to review the progress in this area and find the next wave for new developments.

Area covered: This review covers the patent literature from the year 2010 to early 2015 on various aspects of taxane-based chemotherapies and drug developments.

Expert opinion: Three FDA-approved taxane anticancer drugs will continue to expand their therapeutic applications, especially through drug combinations and new formulations. Inspired by the success of abraxane, new nano-formulations are emerging. Highly potent new-generation taxanes will play a key role in the development of efficacious tumor-targeted drug delivery systems.     

A safety review of the medications used to treat atopic dermatitis

Introduction: Atopic dermatitis (AD) is a common disease in children and adults which causes severe physical discomfort and psychosocial distress. Recently novel therapies for AD have been FDA approved for use which creates the need to review the safety surrounding current FDA approved AD medications.

Areas covered: Published clinical studies involving topical and oral FDA approved medications for AD are included in this review. Authors used PubMed research database to search for clinical trials involving AD patients.

Expert opinion: AD is a common disease which currently has limited FDA approved medications. Given the chronicity of this disease, medications are needed which control disease while minimizing side effects to allow for long term use. Newer approved medications show promise but safety data is limited given their relatively new utilization for AD.     

Are biosimilars patentable?

Introduction: This paper explores whether, and under what circumstances, a biosimilar approved in the United States under the Biologics Price Competition and Innovation Act (hereafter ‘BPCIA’) can be patented. The possibility that a biosimilar product could have meaningful patent protection arises from specific requirements for biosimilarity under the BPCIA, which account for the fact that manufacturing processes of biologics are inherently imprecise. The requirements for biosimilar approval may provide sufficient leeway to a biosimilar applicant to patent structural or formulation differences that provide non-clinical but business-relevant advantages over the reference molecule, such as improved shelf-life or ease of manufacture, without compromising clinical biosimilarity.

Areas covered: Examination of the BPCIA and related Acts, Food and Drug Administration (FDA) guidance papers, case law, patent database searching, and relevant scholarly articles.

Expert opinion: Legislative and regulatory requirements for the approval of a biosimilar under the BPCIA are focused on clinical results and allow a degree of leeway for differences to exist between a biosimilar’s structure and non-clinical components and those of the biosimilar’s reference molecule. This leeway can be exploited to provide the biosimilar with potentially patentable business-relevant advantages over its reference product while maintaining clinical biosimilarity to the reference product.     

Drug design strategies for the treatment of prostate cancer

Introduction: While metastatic prostate cancer remains an incurable tumor, remarkable progress has been made with novel drug design strategies for this incurable disease. Several new agents, including hormonal analogues, cytotoxic chemotherapy drugs, radionuclides and innovative targeted therapies, have recently been approved by the FDA for use in advanced and/or metastatic castrate-resistant prostate cancer. Furthermore, a growing number of new diagnostic or predictive genetic tests have also been incorporated into the management of this disease. Immunotherapy-based approaches have shown promise and have led to drug approvals. Other experimental approaches such as vascular targeting are in early translational clinical trials.

Areas covered: Herein, the authors outline select state-of-the-art approaches in the field. They also discuss the current challenges and future opportunities in the medical care of prostate cancer patients.

Expert opinion: An inherent challenge in the treatment of prostate cancer is to determine which patients need immediate aggressive treatment versus active surveillance. For patients needing aggressive treatment, integrating the sequence of therapeutic interventions, to provide the most benefit, remains a challenge that clinicians face. Recently, several genetic tests have been approved, facilitating early treatment decisions. Innovative targeted therapies are moving towards clinical applications, providing treatment options for tumors previously considered refractory to androgen ablation treatment.     

The adverse-effect profile of lacosamide

ABSTRACT

Introduction: Lacosamide has been used in epilepsy patients in the United States, Europe and Asia since it was approved by the FDA in 2008. Many patients have benefited from this drug as a new generation of sodium channel blocker. With the worldwide use of this drug, its adverse effects have gradually emerged, especially some rare adverse events.

Areas covered: The present review aims to summarize the adverse effects of lacosamide reported in the literature in recent years to promote the safe clinical application of the drug.

Expert opinion: In more than 10 years of experience in drug usage, adverse reactions of lacosamide have also been gradually discovered. The review showed that lacosamide is safe and effective in antiepileptic treatment, and its common side effects are dizziness, headache, drowsiness, diplopia, and cardiovascular abnormalities. Skin rashes, hematotoxicity and heart damage, psychological symptoms and suicide risk have also been reported and emphasized.     

The therapeutic potential of RNA regulation in neurological disorders

ABSTRACT

Introduction: Gene regulation is the term used to describe the mechanisms by which a cell increases or decreases the amount of a gene product (RNA or protein). In complex organs such as the brain, gene regulation is of the utmost importance; aberrations in the regulation of specific genes can lead to neurological disorders. Understanding these mechanisms can create new strategies for targeting these disorders and progress is being made. Two drugs that function at the RNA level (nusinersen and eteplirsen) have now been approved by the FDA for the treatment of Spinomuscular atrophy and Duchenne muscular dystrophy, respectively; several other compounds for neurological disease are currently being investigated in preclinical studies and clinical trials.

Areas covered: We highlight how gene regulation at the level of RNA molecules can be used as a therapeutic strategy to treat neurological disorders. We provide examples of how such an approach is being studied or used and discuss the current hurdles.

Expert opinion: Targeting gene expression at the RNA level is a promising strategy to treat genetic neurological disorders. Safe administration, long-term efficacy, and potential side effects, however, still need careful evaluation before RNA therapeutics can be applied on a larger scale.     

Drug delivery in soft tissue engineering

Introduction: Tissue defects, sustained through disease or trauma, present enormous challenges in regenerative medicine. Modern tissue engineering (TE) aims at replacing or repairing these defects through a combined approach of biodegradable scaffolds, suitable cell sources and appropriate environmental cues, such as biomolecules presented on scaffold surfaces or sustainably released from within.

Areas covered: This review provides a brief overview of the various drugs and bioactive molecules of interest to TE, as well as a selection of materials that have been proposed for TE scaffolds and matrices in the past. It then proceeds to discuss encapsulation, immobilization and controlled release strategies for bioactive proteins, before discussing recent advances in this area with a special focus on soft TE.

Expert opinion: Overall, minimal clinical success has been achieved so far in using growth factor, morphogen, or adhesion factor modified scaffolds and matrices; only one growth factor delivery system (Regranex Gel), has been approved by the FDA for clinical use, with only a handful of other growth factors being approved for human use so far. However, many more growth factors are currently in clinical Phase I – II or preclinical trials and many delivery systems utilize materials already approved by the FDA for other purposes. With respect to drug delivery in soft TE, a combination of increased research efforts in hydrogel and support material development as well as growth factor development is needed before clinical success is realized.     

Efficacy and safety of bromfenac 0.075% formulated in DuraSite for pain and inflammation in cataract surgery

ABSTRACT

Introduction: Bromfenac is a topical ophthalmic non-steroidal anti-inflammatory drug (NSAID) used to reduce pain and treat post-operative inflammation after cataract surgery. Bromfenac 0.075% in the DuraSite? vehicle is a newly-approved formulation which has been shown to be efficacious and safe for use in cataract surgery to reduce pain and treat inflammation. It has been shown to have a slightly better posterior segment ocular bioavailability compared to similar topical ophthalmic NSAIDs. However, there is a paucity of studies investigating its role in the prevention and treatment of post-operative pseudophakic cystoid macular edema.

Areas covered: In this review, the authors provide an overview of similar products available, describe the novelty of bromfenac 0.075% in the DuraSite vehicle, and discuss the relevant clinical studies to determine if the formulation is safe and efficacious.

Expert opinion: Bromfenac 0.075% in the DuraSite vehicle is a new topical ophthalmic medication which has been approved by the FDA for the prevention of pain and treatment of post-operative inflammation. It provides cataract surgeons with an additional medication for cataract surgery. However, no robust studies have been performed showing the effect that it has on the reduction or prevention of post-operative pseudophakic cystoid macular edema.     

Investigational drugs for treating agitation in persons with dementia

Introduction: Agitation is common and distressing in persons with dementia, but safe, effective treatments remain elusive. In this review, the authors describe investigational compounds in ongoing or recently completed clinical trials for this indication and provide an opinion on how they may meet current therapeutic needs.

Areas covered: Phase II and phase III clinical trials for agitation in persons with dementia were searched in US and EU clinical trial registries and in the medical literature for the period January 2013-February 2016

Expert opinion: The authors searches identified 24 recent clinical trials investigating new treatments for agitation in persons with dementia. Candidate drugs in phase III development included the antipsychotic brexpiprazole, the antidepressant citalopram, the novel compound AVP-786 (deuterated-dextromethorphan/quinidine combination) and the cannabinoid nabilone. Of the compounds in phase II clinical trials, ELND005 (scyllo-inositol) is intended to progress into phase III development, based on evidence from a subgroup analysis and biomarker data. After many years without an FDA/EMA (Food and Drug Administration/European Medicines Agency) approved medication to treat agitation in persons with dementia, we may see the arrival of the first approved drug in the near future.     

Bepotastine besilate for the treatment of perennial allergic rhinitis

ABSTRACT

Introduction: Bepotastine besilate (BB) is a second-generation H1-antihistamine that, as an ophthalmic solution, is approved in the United States by the Food and Drug Administration (FDA) for the treatment of allergic conjunctivitis. In other countries, the oral presentation of BB is widely used for the improvement of symptoms of allergic rhinitis (AR) as well as urticaria and chronic pruritus with results similar to those by other drugs of the same class.

Areas covered: This article was created from a comprehensive literature search with information taken from clinical trials. The articles that have been selected evaluate the clinical and non-clinical pharmacology of BB as well as its use in AR and its efficiency in the improvement of symptoms, its safety, common adverse effects, and overall experiences of its use.

Expert opinion: BB is effective and well-tolerated in the treatment of allergic rhinitis. Side effects are infrequent in patients with AR who do not have kidney or liver disease. Clinical trial experience with oral bepotastine outside the United States has confirmed its safety. BB can be useful as a therapeutic option in patients with AR who would like to explore an alternative to the currently available once-daily oral H1-antihistamines.