BIO 300, a nanosuspension of genistein, mitigates pneumonitis/fibrosis following high-dose radiation exposure in the C57L/J murine model

A Novel TGFβ Receptor Inhibitor, IPW-5371, Prevents Diet-induced Hepatic Steatosis and Insulin Resistance in Irradiated Mice

As the number of cancer survivors increases and the risk of accidental radiation exposure rises, there is a pressing need to characterize the delayed effects of radiation exposure and develop medical countermeasures. Radiation has been shown to damage adipose progenitor cells and increase liver fibrosis, such that it predisposes patients to developing metabolic-associated fatty liver disease (MAFLD) and insulin resistance. The risk of developing these conditions is compounded by the global rise of diets rich in carbohydrates and fats. Radiation persistently increases the signaling cascade of transforming growth factor β (TGFβ), leading to heightened fibrosis as characteristic of the delayed effects of radiation exposure. We investigate here a potential radiation medical countermeasure, IPW-5371, a small molecule inhibitor of TGFβRI kinase (ALK5). We found that mice exposed to sub-lethal whole-body irradiation and chronic Western diet consumption but treated with IPW-5371 had a similar body weight, food consumption, and fat mass compared to control mice exposed to radiation. The IPW-5371 treated mice maintained lower fibrosis and fat accumulation in the liver, were more responsive to insulin and had lower circulating triglycerides and better muscle endurance. Future studies are needed to verify the improvement by IPW-5371 on the structure and function of other metabolically active tissues such as adipose and skeletal muscle, but these data demonstrate that IPW-5371 protects liver and whole-body health in rodents exposed to radiation and a Western diet, and there may be promise in using IPW-5371 to prevent the development of MAFLD.

Biomaterials-mediated radiation-induced diseases treatment and radiation protection

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field.

Potential of Plant-Derived Compounds in Preventing and Reversing Organ Fibrosis and the Underlying Mechanisms

Increased production of extracellular matrix is a necessary response to tissue damage and stress. In a normal healing process, the increase in extracellular matrix is transient. In some instances; however, the increase in extracellular matrix can persist as fibrosis, leading to deleterious alterations in organ structure, biomechanical properties, and function. Indeed, fibrosis is now appreciated to be an important cause of mortality and morbidity. Extensive research has illustrated that fibrosis can be slowed, arrested or even reversed; however, few drugs have been approved specifically for anti-fibrotic treatment. This is in part due to the complex pathways responsible for fibrogenesis and the undesirable side effects of drugs targeting these pathways. Natural products have been utilized for thousands of years as a major component of traditional medicine and currently account for almost one-third of drugs used clinically worldwide. A variety of plant-derived compounds have been demonstrated to have preventative or even reversal effects on fibrosis. This review will discuss the effects and the underlying mechanisms of some of the major plant-derived compounds that have been identified to impact fibrosis.

Multicenter Phase 1b/2a Clinical Trial of Radioprotectant BIO 300 Oral Suspension for Patients With Non-Small Cell Lung Cancer Receiving Concurrent Chemoradiotherapy

PURPOSE

Radiation therapy is part of the standard treatment regimen for non-small cell lung cancer (NSCLC). Although radiation therapy is an effective tool to manage NSCLC, it can be associated with significant dose-limiting toxicities. These toxicities can lead to treatment interruption or early termination and worsening clinical outcomes in addition to reductions in patient quality of life. Based on preclinical efficacy for radioprotection of normal tissues, we evaluated the clinical utility of BIO 300 Oral Suspension (BIO 300; synthetic genistein nanosuspension) in patients with NSCLC.

METHODS AND MATERIALS

In this multicenter, open-label, single-arm, ascending dose phase 1b/2a study, patients were enrolled with newly diagnosed stage II-IV NSCLC planned for 60 to 70/1.8-2.0 Gy radiation therapy and concurrent weekly paclitaxel/carboplatin. Oral BIO 300 (cohort 1, 500 mg/d; cohort 2, 1000 mg/d; cohort 3, 1500 mg/d) was self-administered once daily starting 2 to 7 days before initiating concurrent chemoradiotherapy and continued until the end of radiation therapy. The primary endpoint was acute dose-limiting toxicities attributable to BIO 300. Secondary outcomes included pharmacokinetics, pharmacodynamics, overall toxicity profile, quality of life, local response rate, and survival.

RESULTS

Twenty-one participants were enrolled. No dose-limiting toxicities were reported. BIO 300 dosing did not alter chemotherapy pharmacokinetics. Adverse events were not dose-dependent, and those attributable to BIO 300 (n = 11) were all mild to moderate in severity (grade 1, n = 9; grade 2, n = 2) and predominantly gastrointestinal (n = 7). A dose-dependent decrease in serum transforming growth factor β1 levels was observed across cohorts. Based on safety analysis, the maximum tolerated dose of BIO 300 was not met. Patient-reported quality of life and weight were largely stable throughout the study period. No patient had progression as their best overall response, and a 65% tumor response rate was achieved (20% complete response rate).

CONCLUSIONS

The low toxicity rates, along with the pharmacodynamic results and tumor response rates, support further investigation of BIO 300 as an effective radioprotector.

Natural plant resource flavonoids as potential therapeutic drugs for pulmonary fibrosis

Pulmonary fibrosis is an enduring and advancing pulmonary interstitial disease caused by multiple factors that ultimately lead to structural changes in normal lung tissue. Currently, pulmonary fibrosis is a global disease with a high degree of heterogeneity and mortality rate. Nitidine and pirfenidone have been approved for treating pulmonary fibrosis, and the quest for effective therapeutic drugs remains unabated. In recent years, the anti-pulmonary fibrosis properties of natural flavonoids have garnered heightened attention, although further research is needed. In this paper, the resources, structural characteristics, anti-pulmonary fibrosis properties and mechanisms of natural flavonoids were reviewed. We hope to provide potential opportunities for the application of flavonoids in the fight against pulmonary fibrosis.

The radioprotectant nano-genistein enhances radiotherapy efficacy of lung tumors in mice

Background

Radiotherapy for non-small cell lung cancer (NSCLC) can be dose-limiting due to treatment-related toxicities. Genistein has been shown to be a robust radioprotective agent in preclinical models. A novel genistein oral nanosuspension formulation (nano-genistein) has demonstrated efficacy in mitigating radiation-induced lung damage in preclinical animal models. However, while those studies have confirmed that nano-genistein can protect normal lung tissue from radiation-induced toxicities, no studies have assessed the effect of nano-genistein on lung tumors. Here, we evaluated the impact of nano-genistein on the efficacy of radiation treatment of lung tumors in a mouse xenograft model.

Methods

Two separate studies were conducted utilizing human A549 cells implanted either dorsally within the upper torso or in the flank. Daily oral administration of nano-genistein (200 or 400 mg/kg/day) occurred prior to and after exposure to a single dose of thoracic or abdominal 12.5 Gy radiation. Tumor growth was monitored twice weekly, nano-genistein treatment continued for up to 20 weeks and histopathology of tissues was completed post euthanasia.

Results

Continuous nano-genistein dosing was safe across all study groups in both studies. Animals receiving nano-genistein better maintained body weight following irradiation compared to corresponding vehicle treated animals. Animals that received nano-genistein also had reduced tumor growth and improved normal lung histopathology compared to those receiving vehicle suggesting that nano-genistein does not protect tumors from radiotherapy but is radioprotective of the lungs. There were no treatment-related histopathological findings noted in the skin adjacent to the tumor, esophagus, or uterus.

Conclusions

These results, including the safety following extended dosing, support the continued evaluation of nano-genistein as an adjunctive treatment for patients with NSCLC undergoing radiotherapy and serve as the basis of a phase 1b/2a multicenter clinical trial.

Nanodrugs with intrinsic radioprotective exertion: Turning the double-edged sword into a single-edged knife

Ionizing radiation (IR) poses a growing threat to human health, and thus ideal radioprotectors with high efficacy and low toxicity still receive widespread attention in radiation medicine. Despite significant progress made in conventional radioprotectants, high toxicity, and low bioavailability still discourage their application. Fortunately, the rapidly evolving nanomaterial technology furnishes reliable tools to address these bottlenecks, opening up the cutting-edge nano-radioprotective medicine, among which the intrinsic nano-radioprotectants characterized by high efficacy, low toxicity, and prolonged blood retention duration, represent the most extensively studied class in this area. Herein, we made the systematic review on this topic, and discussed more specific types of radioprotective nanomaterials and more general clusters of the extensive nano-radioprotectants. In this review, we mainly focused on the development, design innovations, applications, challenges, and prospects of the intrinsic antiradiation nanomedicines, and presented a comprehensive overview, in-depth analysis as well as an updated understanding of the latest advances in this topic. We hope that this review will promote the interdisciplinarity across radiation medicine and nanotechnology and stimulate further valuable studies in this promising field.

The delayed effects of acute radiation exposure (DEARE): characteristics, mechanisms, animal models, and promising medical countermeasures

PURPOSE

Terrorist use of nuclear weapons and radiation accidents put the human population at risk for exposure to life-threatening levels of radiation. Victims of lethal radiation exposure face potentially lethal acute injury, while survivors of the acute phase are plagued with chronic debilitating multi-organ injuries for years after exposure. Developing effective medical countermeasures (MCM) for the treatment of radiation exposure is an urgent need that relies heavily on studies conducted in reliable and well-characterized animal models according to the FDA Animal Rule. Although relevant animal models have been developed in several species and four MCM for treatment of the acute radiation syndrome are now FDA-approved, animal models for the delayed effects of acute radiation exposure (DEARE) have only recently been developed, and there are no licensed MCM for DEARE. Herein, we provide a review of the DEARE including key characteristics of the DEARE gleaned from human data as well as animal, mechanisms common to multi-organ DEARE, small and large animal models used to study the DEARE, and promising new or repurposed MCM under development for alleviation of the DEARE.

CONCLUSIONS

Intensification of research efforts and support focused on better understanding of mechanisms and natural history of DEARE are urgently needed. Such knowledge provides the necessary first steps toward the design and development of MCM that effectively alleviate the life-debilitating consequences of the DEARE for the benefit of humankind worldwide.

Biomarkers to Predict Lethal Radiation Injury to the Rat Lung

Currently, there are no biomarkers to predict lethal lung injury by radiation. Since it is not ethical to irradiate humans, animal models must be used to identify biomarkers. Injury to the female WAG/RijCmcr rat has been well-characterized after exposure to eight doses of whole thorax irradiation: 0-, 5-, 10-, 11-, 12-, 13-, 14- and 15-Gy. End points such as SPECT imaging of the lung using molecular probes, measurement of circulating blood cells and specific miRNA have been shown to change after radiation. Our goal was to use these changes to predict lethal lung injury in the rat model, 2 weeks post-irradiation, before any symptoms manifest and after which a countermeasure can be given to enhance survival. SPECT imaging with 99mTc-MAA identified a decrease in perfusion in the lung after irradiation. A decrease in circulating white blood cells and an increase in five specific miRNAs in whole blood were also tested. Univariate analyses were then conducted on the combined dataset. The results indicated that a combination of percent change in lymphocytes and monocytes, as well as pulmonary perfusion volume could predict survival from radiation to the lungs with 88.5% accuracy (95% confidence intervals of 77.8, 95.3) with a p-value of < 0.0001 versus no information rate. This study is one of the first to report a set of minimally invasive endpoints to predict lethal radiation injury in female rats. Lung-specific injury can be visualized by 99mTc-MAA as early as 2 weeks after radiation.

The Radioprotectant, BIO 300, Protects the Lungs from Total-Body Irradiation Injury in C57L/J Mice

Acute exposure to high dose radiation can cause acute radiation syndrome (ARS), a potentially life-threatening illness. Individuals that survive ARS are at risk of developing the delayed effects of acute radiation exposure, with the lungs being particularly susceptible (DEARE-lung). For individuals at risk of radiation exposure, there are no Food and Drug Administration-approved medical countermeasures (MCMs) for prophylactic or post-exposure use that can prevent or mitigate DEARE-lung. BIO 300 is a novel formulation of synthetic genistein that has been extensively studied as a prophylactic MCM for the hematopoietic subsyndrome of ARS (H-ARS). Here, we used a C57L/J mouse model of total-body irradiation (TBI) to investigate whether prophylactic administration of BIO 300 is able to prevent animals from developing DEARE-lung. Oral and parenteral formulations of BIO 300 administered prior to TBI were compared against standard of care, PEGfilgrastim, administered shortly after radiation exposure, and the combination of oral BIO 300 administered prior to TBI and with PEGfilgrastim administered post-exposure. All animals were exposed to 7.75 Gy cobalt-60 gamma-radiation and the primary endpoint was lung histopathology at 180 days post-TBI. Animals treated with BIO 300 had a significant reduction in the incidence of interstitial lung inflammation compared to vehicle groups for both the oral (0% vs. 47%) and parenteral (13% vs. 44%) routes of administration. Similar results were obtained for the incidence and severity of pulmonary fibrosis in animals treated with oral BIO 300 (incidence, 47% vs. 100% and mean severity score, 0.53 vs. 1.3) and parenteral BIO 300 (incidence, 63% vs. 100% and mean severity score, 0.69 vs. 1.7). PEGfilgrastim alone had no significant effect in reducing the incidence of inflammation or fibrosis compared to vehicle. The combination of oral BIO 300 and PEGfilgrastim significantly reduced the incidence of interstitial inflammation (13% vs. 46%) and the severity of pulmonary fibrosis (mean severity score, 0.93 vs. 1.6). Results in the C57L/J mice were compared to those in CD2F1 mice, which are less prone to lung injury following total-body irradiation. Taken together, these studies indicate that BIO 300 is a promising MCM that is able to prophylactically protect against DEARE-lung.

A Review of Radiation-Induced Alterations of Multi-Omic Profiles, Radiation Injury Biomarkers, and Countermeasures

Increasing utilization of nuclear power enhances the risks associated with industrial accidents, occupational hazards, and the threat of nuclear terrorism. Exposure to ionizing radiation interferes with genomic stability and gene expression resulting in the disruption of normal metabolic processes in cells and organs by inducing complex biological responses. Exposure to high-dose radiation causes acute radiation syndrome, which leads to hematopoietic, gastrointestinal, cerebrovascular, and many other organ-specific injuries. Altered genomic variations, gene expression, metabolite concentrations, and microbiota profiles in blood plasma or tissue samples reflect the whole-body radiation injuries. Hence, multi-omic profiles obtained from high-resolution omics platforms offer a holistic approach for identifying reliable biomarkers to predict the radiation injury of organs and tissues resulting from radiation exposures. In this review, we performed a literature search to systematically catalog the radiation-induced alterations from multi-omic studies and radiation countermeasures. We covered radiation-induced changes in the genomic, transcriptomic, proteomic, metabolomic, lipidomic, and microbiome profiles. Furthermore, we have covered promising multi-omic biomarkers, FDA-approved countermeasure drugs, and other radiation countermeasures that include radioprotectors and radiomitigators. This review presents an overview of radiation-induced alterations of multi-omics profiles and biomarkers, and associated radiation countermeasures.

Armed Forces Radiobiology Research Institute/Uniformed Services University of the Health Sciences perspective on space radiation countermeasure discovery

There is a need to develop and deploy medical countermeasures (MCMs) in order to support astronauts during space missions against excessive exposures to ionizing radiation exposure. The radiation environment of extraterrestrial space is complex and is characterized by nearly constant fluences of elemental atomic particles (protons being a dominant particle type) with widely different energies and ionization potentials. Chronic exposure to such ionizing radiation carries both near- and long-term health risks, which are generally related to the relative intensity and duration of exposure. These radiation-associated health risks can be managed only to a limited extent by physical means, but perhaps they might be more effectively managed biomedically. The Armed Forces Radiobiology Research Institute/Uniformed Services University of the Health Sciences has a long history of researching and developing MCMs specifically designed to support terrestrial-based military missions involving a radiation-threat component. The development of MCMs for both low and high doses of radiation are major aims of current research, and as such can provide lessons learned for the development of countermeasures applicable to future space missions and its extraterrestrial radiation environment.

Pharmacokinetic and metabolomic studies with a BIO 300 Oral Powder formulation in nonhuman primates

BIO 300, a pharmaceutical formulation of genistein, is being developed as a radiation countermeasure to treat hematopoietic acute radiation syndrome (H-ARS) and the delayed effects of acute radiation exposure (DEARE). Several studies have affirmed its safety and efficacy in alleviating the damaging effects of ionizing radiation. However, dose optimization of any drug has always been an important area of research because unnecessarily high drug doses may result in serious complications. In this study, we assessed the pharmacokinetics (PK) and metabolic profiles of two different doses of a novel solid-dosage formulation of BIO 300 (BIO 300 Oral Powder; 100 mg/kg and 200 mg/kg), when administered orally to nonhuman primates (NHPs). While the T_max values of both doses remained the same, the area under the curve at 48 h (AUC_0-48) was tripled by doubling the dose. Additionally, we monitored serum samples for global metabolomic/lipidomic changes using high resolution mass spectrometry followed by functional pathway analysis prior to and at various time points up to 48 h post drug administration. Interestingly, the metabolomic profiles of sera from NHPs that received the lower dose demonstrated a transient perturbation in numerous metabolites between the 4 and 12 h time points. Eventually, the metabolite abundance reverted to near-normal by 48 h. These study results are consistent with our previous studies focused on the PK and metabolomic analysis for parenteral and oral aqueous nanosuspension formulations of BIO 300. This study affirms that administration of a single dose of up to 200 mg/kg of BIO 300 Oral Powder is safe in NHPs and conferred no metabolomic-mediated safety features.

Radiomitigation by Melatonin in C57BL/6 Mice: Possible Implications as Adjuvant in Radiotherapy and Chemotherapy

BACKGROUND/AIM

Melatonin (N-acetyl-5-methoxytryptamine), a chief secretory molecule of the pineal gland, has multiple properties, and numerous clinical investigations regarding its actions are in progress. This study investigated the radiomitigative role of melatonin in C57BL/6 mice.

MATERIALS AND METHODS

Melatonin (100 mg/kg) was orally administered once daily starting at 1 h on day 1 and subsequently every 24 h until day 7 after whole-body irradiation (WBI) and survival was monitored for 30 days. The bone marrow, spleen, and intestine were studied to evaluate the mitigative potential of melatonin after radiation-induced damage.

RESULTS

Melatonin significantly improved the survival upto 60% and 90% after 9 Gy (lethal) and 7.5 Gy (sub-lethal) WBI, respectively. Melatonin alleviated WBI-induced myelosuppression and pancytopenia, and increased white blood cell, red blood cell, platelet, and lymphocyte (CD4⁺ and CD8⁺) counts in peripheral blood. Bone marrow and spleen cellularity were restored through enhanced haematopoiesis. Melatonin ameliorated the damage in the small intestine, and promoted recovery of villi length, crypts number, and goblet cell count.

CONCLUSION

Melatonin mitigates the radiation-induced injury in the gastrointestinal and haematopoietic systems. The observed radiomitigative properties of melatonin can also be useful in the context of adjuvant therapy for cancer and radiotherapy.

Interspecies Comparison and Radiation Effect on Pharmacokinetics of BIO 300, a Nanosuspension of Genistein, after Different Routes of Administration in Mice and Non-Human Primates

BIO 300, a suspension of synthetic genistein nanoparticles, is being developed for mitigating the delayed effects of acute radiation exposure (DEARE). The purpose of the current study was to characterize the pharmacokinetic (PK) profile of BIO 300 administered as an oral or parenteral formulation 24 h after sham-irradiation, total-body irradiation (TBI) with 2.5-5.0% bone marrow sparing (TBI/BMx), or in nonirradiated sex-matched C57BL/6J mice and non-human primates (NHP). C57BL/6J mice were randomized to the following arms in two consecutive studies: sham-TBI [400 mg/kg, oral gavage (OG)], TBI/BM2.5 (400 mg/kg, OG), sham-TBI [200 mg/kg, subcutaneous (SC) injection], TBI/BM2.5 (200 mg/kg, SC), sham-TBI (100 mg/kg, SC), or nonirradiated [200 mg/kg, intramuscular (IM) injection]. The PK profile was also established in NHP exposed to TBI/BM5.0 (100 mg/kg, BID, OG). Genistein-aglycone serum concentrations were measured in all groups using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The PK profile demonstrates 11% and 19% reductions in Cmax and AUC0-inf, respectively, among mice administered 400 mg/kg, OG, after TBI/BM2.5 compared to the sham-TBI control arm. Administration of 200 mg/kg SC in mice exposed to TBI/BM2.5 showed a 53% increase in AUC0-inf but a 28% reduction in Cmax compared to the sham-TBI mice. The relative bioavailability of the OG route compared to the SC and IM routes in mice was 9% and 7%, respectively. After the OG route, the dose-normalized AUC0-inf was 13.37 (ng.h/mL)/(mg/kg) in TBI/BM2.5 mice compared to 6.95 (ng.h/mL)/(mg/kg) in TBI/BM5.0 NHPs. Linear regression of apparent clearances and weights of mice and NHPs yielded an allometric coefficient of 1.06. Based on these data, the effect of TBI/BMx on BIO 300 PK is considered minimal. Future studies should use SC and IM routes to maximize drug exposure when administered postirradiation. The allometric coefficient is useful in predicting therapeutic drug dose regimens across species for drug approval under the FDA animal rule.

COVID-related fibrosis: insights into potential drug targets

INTRODUCTION

Lung injury in severe COVID-19 pneumonia can rapidly evolve to established pulmonary fibrosis, with prognostic implications in the acute phase of the disease and long-lasting impact on the quality of life of COVID-19 survivors. This is an emerging medical need, and it has been hypothesized that antifibrotic treatments could have a role in ameliorating the fibrotic process in the lungs of these patients.

AREAS COVERED

The safety and efficacy of available antifibrotic drugs (nintedanib and pirfenidone) and novel promising agents are being assessed in several ongoing clinical trials that were performed either in critically ill patients admitted to intensive care, or in discharged patients presenting fibrotic sequalae from COVID-19. Literature search was performed using Medline and Clinicaltrials.org databases (2001-2021).

EXPERT OPINION

Despite the strong rationale support the use of antifibrotic therapies in COVID-related fibrosis, there are several uncertainties regarding the timing for their introduction and the real risks/benefits ratio of antifibrotic treatment in the acute and the chronic phases of the disease. The findings of ongoing clinical trials and the long-term observation of longitudinal cohorts will eventually clarify the best management approach for these patients.

Microbiome study in irradiated mice treated with BIO 300, a promising radiation countermeasure

Background

The mammalian gut harbors very complex and diverse microbiota that play an important role in intestinal homeostasis and host health. Exposure to radiation results in dysbiosis of the gut microbiota leading to detrimental pathophysiological changes to the host. To alleviate the effects of irradiation, several candidate countermeasures are under investigation. BIO 300, containing synthetic genistein formulated as an amorphous solid dispersion or as an aqueous suspension of nanoparticles, is a promising candidate under advanced development. The aim of this study was to investigate the effects of BIO 300 on the gut microbiome and metabolome of mice exposed to ⁶⁰Co gamma-radiation. The gut microbiota and metabolome of control and drug-treated mice exposed to radiation was characterized by bacterial 16S rRNA amplicon sequencing and untargeted metabolomics.

Results

We found that irradiation altered the Firmicutes/Bacteroidetes ratio and significantly decreased the relative abundance of Lactobacillus, both in BIO 300-treated and control mice; however, the ratio returned to near normal levels in BIO 300-treated mice by day 14 post-irradiation. Concomitantly, we also observed corrective shifts in metabolic pathways that were perturbed after irradiation.

Conclusions

Overall, the data presented show that radiation exposure led to a relative depletion of commensals like Lactobacillus leading to an inflammatory metabolic phenotype while the majority of the drug-treated mice showed alleviation of this condition primarily by restoration of normal gut microbiota. These results indicate that the radioprotective effects of BIO 300, at least in part, may involve correction of the host-microbiome metabolic axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-021-00132-1.

A novel oral formulation of BIO 300 confers prophylactic radioprotection from acute radiation syndrome in mice

PURPOSE

Exposure to high doses of ionizing radiation can result in hematopoietic acute radiation syndrome (H-ARS) and delayed effects of acute radiation exposure (DEARE). There is no radiation medical countermeasure (MCM) approved by the U.S. Food and Drug Administration which can be used prior to radiation exposure to protect exposed individuals. Different formulations containing synthetic genistein (BIO 300) are being developed to counter the harmful effects of radiation exposure.

MATERIALS AND METHODS

We investigated the efficacy of a BIO 300 oral powder (OP) formulation as a prophylactic radiation MCM against a lethal dose of cobalt-60 gamma-radiation in CD2F1 male mice while comparing to other formulations of BIO 300 and Neulasta (PEGylated filgrastim), a standard of care drug for H-ARS.

RESULTS

BIO 300 OP provided significant radioprotection against ionizing radiation in mice when administered twice per day for six days prior to total-body radiation exposure. Its radioprotective efficacy in the murine model was comparable to the efficacy of a single subcutaneous (sc) injection of Neulasta administered after total-body radiation exposure.

CONCLUSIONS

Our results demonstrate that BIO 300 OP, which can be administered orally, is a promising prophylactic radiation countermeasure for H-ARS.

Lung Fibrosis after COVID-19: Treatment Prospects

At the end of 2019, a highly contagious infection began its ominous conquest of the world. It was soon discovered that the disease was caused by a novel coronavirus designated as SARS-CoV-2, and the disease was thus abbreviated to COVID-19 (COVID). The global medical community has directed its efforts not only to find effective therapies against the deadly pathogen but also to combat the concomitant complications. Two of the most common respiratory manifestations of COVID are a significant reduction in the diffusing capacity of the lungs (DLCO) and the associated pulmonary interstitial damage. One year after moderate COVID, the incidence rate of impaired DLCO and persistent lung damage still exceeds 30%, and one-third of the patients have severe DLCO impairment and fibrotic lung damage. The persistent respiratory complications may cause substantial population morbidity, long-term disability, and even death due to the lung fibrosis progression. The incidence of COVID-induced pulmonary fibrosis caused by COVID can be estimated based on a 15-year observational study of lung pathology after SARS. Most SARS patients with fibrotic lung damage recovered within the first year and then remained healthy; however, in 20% of the cases, significant fibrosis progression was found in 5-10 years. Based on these data, the incidence rate of post-COVID lung fibrosis can be estimated at 2-6% after moderate illness. What is worse, there are reasons to believe that fibrosis may become one of the major long-term complications of COVID, even in asymptomatic individuals. Currently, despite the best efforts of the global medical community, there are no treatments for COVID-induced pulmonary fibrosis. In this review, we analyze the latest data from ongoing clinical trials aimed at treating post-COVID lung fibrosis and analyze the rationale for the current drug candidates. We discuss the use of antifibrotic therapy for idiopathic pulmonary fibrosis, the IN01 vaccine, glucocorticosteroids as well as the stromal vascular fraction for the treatment and rehabilitation of patients with COVID-associated pulmonary damage.

A Trans-Agency Workshop on the Pathophysiology of Radiation-Induced Lung Injury

Research and development of medical countermeasures (MCMs) for radiation-induced lung injury relies on the availability of animal models with well-characterized pathophysiology, allowing effective bridging to humans. To develop useful animal models, it is important to understand the clinical condition, advantages and limitations of individual models, and how to properly apply these models to demonstrate MCM efficacy. On March 20, 2019, a meeting sponsored by the Radiation and Nuclear Countermeasures Program (RNCP) within the National Institute of Allergy and Infectious Diseases (NIAID) brought together medical, scientific and regulatory communities, including academic and industry subject matter experts, and government stakeholders from the Food and Drug Administration (FDA) and the Biomedical Advanced Research and Development Authority (BARDA), to identify critical research gaps, discuss current clinical practices for various forms of pulmonary damage, and consider available animal models for radiation-induced lung injury.

All for one, though not one for all: team players in normal tissue radiobiology

PURPOSE

As part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.

CONCLUSIONS

The scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue.

Metabolomics-based predictive biomarkers of radiation injury and countermeasure efficacy: current status and future perspectives

INTRODUCTION

There is an urgent need for specific and sensitive bioassays to augment biodosimetric assessments of unwanted and excessive radiation exposures that originate from unexpected nuclear/radiological events, including nuclear accidents, acts of terrorism, or the use of a radiological dispersal device. If sufficiently intense, such ionizing radiation exposures are likely to impact normal metabolic processes within the cells and organs of the body, thus inducing multifaceted biological responses.

AREAS COVERED

This review covers the application of metabolomics, an emerging and promising technology based on quantitative and qualitative determinations of small molecules in biological samples for the rapid assessment of an individual's exposure to ionizing radiation. Recent advancements in the analytics of high-resolution chromatography, mass spectrometry, and bioinformatics have led to untargeted (global) and targeted (quantitative phase) approaches to identify biomarkers of radiation injury and countermeasure efficacy. Biomarkers are deemed essential for both assessing the radiation exposure levels and for extrapolative processes involved in determining scaling factors of a given radiation countering medicinal between experimental animals and humans.

EXPERT OPINION

The discipline of metabolomics appears to be highly informative in assessing radiation exposure levels and for identifying biomarkers of radiation injury and countermeasure efficacy.

Flavonoids and hERG channels: Friends or foes?

The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as K_V11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called "Torsades de Pointes". Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented.

Rational Design of Nanomaterials for Various Radiation-Induced Diseases Prevention and Treatment

Radiation treatments often unfavorably damage neighboring healthy organs and cause a series of radiation sequelae, such as radiation-induced hematopoietic system diseases, radiation-induced gastrointestinal diseases, radiation-induced lung diseases, and radiation-induced skin diseases. Recently, emerging nanomaterials have exhibited good superiority for these radiation-induced disease treatments. Given this background, the rational design principle of nanomaterials, which helps to optimize the therapeutic efficiency, has been an increasing need. Consequently, it is of great significance to perform a systematic summarization of the advances in this field, which can trigger the development of new high-performance nanoradioprotectors with drug efficiency maximization. Herein, this review highlights the advances and perspectives in the rational design of nanomaterials for preventing and treating various common radiation-induced diseases. Furthermore, the sources, clinical symptoms, and pathogenesis/injury mechanisms of these radiation-induced diseases will also be introduced. Furthermore, current challenges and directions for future efforts in this field are also discussed.

Mitigation of Radiation-induced Pneumonitis and Lung Fibrosis using Alpha-lipoic Acid and Resveratrol

BACKGROUND

Lung is a radiosensitive organ. Studies have shown that exposure of the lung to acute and high doses of radiation following inhalation of radioactive agents or an accidental radiological event may lead to pneumonitis and fibrosis, which are associated with a risk of death. So far, some agents have been studied for mitigation of pneumonitis and fibrosis following exposure of murine lung tissues to ionizing radiation. In this study, we aimed to detect the possible mitigatory effect of alpha-lipoic acid, resveratrol and their combination on mice pneumonitis and fibrosis markers following irradiation.

METHODS

25 mice were divided into 5 groups: control, radiation; radiation plus alpha-lipoic acid; radiation plus resveratrol; and radiation plus both resveratrol and alpha-lipoic acid. Mice chest regions were irradiated with 18 Gy using a cobalt-60 gamma rays source. Treatments started 24 h after irradiation and continued for two weeks. After 100 days, all mice were sacrificed and their lung tissues removed for histopathological evaluation.

RESULTS

Pathological study showed that exposure to radiation led to severe pneumonitis and moderate fibrosis after 100 days. Both resveratrol and alpha-lipoic acid, as well as their combination could mitigate pneumonitis and fibrosis markers. Although, resveratrol could not mitigate infiltration of most inflammatory cells as well as inflammation and vascular damage, alpha-lipoic acid and its combination were able to mitigate most damaged markers.

CONCLUSION

Alpha-lipoic acid and its combination with resveratrol were able to mitigate fibrosis and pneumonitis markers in mice lung tissues following lung irradiation. Although resveratrol has a protective effect on some markers, it has a weaker effect on lung injury. In conclusion, our results suggest that the combination of resveratrol and alpha-lipoic acid has a potent mitigatory effect compared to the single forms of these agents.

BIO 300: a promising radiation countermeasure under advanced development for acute radiation syndrome and the delayed effects of acute radiation exposure

INTRODUCTION

There are no radioprotectors currently approved by the United States Food and Drug Administration (US FDA) for either the hematopoietic acute radiation syndrome (H-ARS) or for the acute radiation gastrointestinal syndrome (GI-ARS). There are currently, however, three US FDA-approved medicinals that serve to mitigate acute irradiation-associated hematopoietic injury.

AREA COVERED

We present the current status of a promising radiation countermeasure, BIO 300 (a genistein-based agent), that has been extensively investigated in murine models of H-ARS and models of the delayed effects of acute radiation exposure (DEARE) and is currently being evaluated in large animal models. It is also being developed for the prevention of radiation-induced toxicities associated with solid tumor radiotherapy and is the subject of two active Investigational New Drug (IND) applications. We have included a listing and brief review of significant investigations of this promising medical countermeasure.

EXPERT OPINION

BIO 300 is a leading radioprotector under advanced development for H-ARS and DEARE, as well as for select oncologic indication(s). Efficacy following oral administration (po), lack of clinical side effects, storage at ambient temperature, and intended dual use makes BIO 300 an ideal candidate for military and civilian use as well as for storage in the Strategic National Stockpile.

Commonalities Between COVID-19 and Radiation Injury

As the multi-systemic components of COVID-19 emerge, parallel etiologies can be drawn between SARS-CoV-2 infection and radiation injuries. While some SARS-CoV-2-infected individuals present as asymptomatic, others exhibit mild symptoms that may include fever, cough, chills, and unusual symptoms like loss of taste and smell and reddening in the extremities (e.g., "COVID toes," suggestive of microvessel damage). Still others alarm healthcare providers with extreme and rapid onset of high-risk indicators of mortality that include acute respiratory distress syndrome (ARDS), multi-organ hypercoagulation, hypoxia and cardiovascular damage. Researchers are quickly refocusing their science to address this enigmatic virus that seems to unveil itself in new ways without discrimination. As investigators begin to identify early markers of disease, identification of common threads with other pathologies may provide some clues. Interestingly, years of research in the field of radiation biology documents the complex multiorgan nature of another disease state that occurs after exposure to high doses of radiation: the acute radiation syndrome (ARS). Inflammation is a key common player in COVID-19 and ARS, and drives the multi-system damage that dramatically alters biological homeostasis. Both conditions initiate a cytokine storm, with similar pro-inflammatory molecules increased and other anti-inflammatory molecules decreased. These changes manifest in a variety of ways, with a demonstrably higher health impact in patients having underlying medical conditions. The potentially dramatic human impact of ARS has guided the science that has identified many biomarkers of radiation exposure, established medical management strategies for ARS, and led to the development of medical countermeasures for use in the event of a radiation public health emergency. These efforts can now be leveraged to help elucidate mechanisms of action of COVID-19 injuries. Furthermore, this intersection between COVID-19 and ARS may point to approaches that could accelerate the discovery of treatments for both.

Pre-clinical evaluation of an innovative oral nano-formulation of baicalein for modulation of radiation responses

There is an unmet medical need for non-toxic and effective radiation countermeasures for prevention of radiation toxicity during planned exposures. We have earlier shown that intraperitoneal administration of baicalein (BCL) offers significant survival benefit in animal model. Safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of baicalein has been reported in pre-clinical model systems and also in healthy human volunteers. However, clinical translation of baicalein is hindered owing to poor bioavailability due to lipophilicity. In view of this, we fabricated and characterized in-situ solid lipid nanoparticles of baicalein (SLNB) with effective drug entrapment and release kinetics. SLNB offered significant protection to murine splenic lymphocytes against 4 Gy ionizing radiation (IR) induced apoptosis. Oral administration of SLNB exhibited ~70% protection to mice against whole body irradiation (WBI 7.5 Gy) induced mortality. Oral relative bioavailability of BCL was enhanced by over ~300% after entrapment in the SLNB as compared to BCL. Oral dosing of SLNB resulted in transient increase in neutrophil abundance in peripheral blood. Interestingly, we observed that treatment of human lung cancer cells (A549) with radioprotective dose of SLNB exhibited radio-sensitization as evinced by decrease in survival and clonogenic potential. Contrary to antioxidant nature of baicalein in normal cells, SLNB treatment induced significant increase in cellular ROS levels in A549 cells probably due to higher uptake and inhibition of TrxR. Thus, a pharmaceutically acceptable SLNB exhibited improved bioavailability, better radioprotection to normal cells and sensitized cancer cells to radiation induced killing as compared to BCL suggesting its possible utility as an adjuvant during cancer radiotherapy.

Comparative proteomic analysis of serum from nonhuman primates administered BIO 300: a promising radiation countermeasure

Hematopoietic acute radiation syndrome (H-ARS) and delayed effects of acute radiation exposure (DEARE) are detrimental health effects that occur after exposure to high doses of ionizing radiation. BIO 300, a synthetic genistein nanosuspension, was previously proven safe and effective against H-ARS when administered (via the oral (po) or intramuscular (im) route) prior to exposure to lethal doses of total-body radiation. In this study, we evaluated the proteomic changes in serum of nonhuman primates (NHP) after administering BIO 300 by different routes (po and im). We utilized nanoflow-ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (NanoUPLC-MS/MS) methods for comprehensive global profiling and quantification of serum proteins. The results corroborate previous findings that suggest a very similar metabolic profile following both routes of drug administration. Furthermore, we observed minor alterations in protein levels, 2 hours after drug administration, which relates to the C_max of BIO 300 for both routes of administration. Taken together, this assessment may provide an insight into the mechanism of radioprotection of BIO 300 and a reasonable illustration of the pharmacodynamics of this radiation countermeasure.

Radioprotection and Radiomitigation: From the Bench to Clinical Practice

The development of protective agents against harmful radiations has been a subject of investigation for decades. However, effective (ideal) radioprotectors and radiomitigators remain an unsolved problem. Because ionizing radiation-induced cellular damage is primarily attributed to free radicals, radical scavengers are promising as potential radioprotectors. Early development of such agents focused on thiol synthetic compounds, e.g., amifostine (2-(3-aminopropylamino) ethylsulfanylphosphonic acid), approved as a radioprotector by the Food and Drug Administration (FDA, USA) but for limited clinical indications and not for nonclinical uses. To date, no new chemical entity has been approved by the FDA as a radiation countermeasure for acute radiation syndrome (ARS). All FDA-approved radiation countermeasures (filgrastim, a recombinant DNA form of the naturally occurring granulocyte colony-stimulating factor, G-CSF; pegfilgrastim, a PEGylated form of the recombinant human G-CSF; sargramostim, a recombinant granulocyte macrophage colony-stimulating factor, GM-CSF) are classified as radiomitigators. No radioprotector that can be administered prior to exposure has been approved for ARS. This differentiates radioprotectors (reduce direct damage caused by radiation) and radiomitigators (minimize toxicity even after radiation has been delivered). Molecules under development with the aim of reaching clinical practice and other nonclinical applications are discussed. Assays to evaluate the biological effects of ionizing radiations are also analyzed.

Effects of genistein on lipopolysaccharide-induced injury of mouse alveolar epithelial cells and its mechanism

Alveolar and bronchial epithelial cells have critical functions in acute respiratory distress syndrome progress. Genistein could protect the lungs from acute lung injury, however, whether genistein protects the alveolar epithelial cells from LPS-induced injury was less studied. Spectrophotometric method 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and enzyme-linked immunosorbent assay (ELISA) were performed to detect cell viability and levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. Flow cytometry and western blot assay were performed to detect cells apoptosis and protein levels. In LPS-induced model of mouse lung epithelial (MLE)-12 cells, PBEF (proinflammatory cytokine) expression, and cell apoptosis were increased and cell viability was decreased, whereas NF-κB was activated and expression levels of TNF-α, IL-1β, and IL-6 were increased. However, genistein partly reversed the effect of LPS, and it plays a protective role in lung injury by reducing expression of PBEF, inhibiting the activation of NF-κB and alleviating inflammatory response of cells.

Mechanism and therapeutic window of a genistein nanosuspension to protect against hematopoietic-acute radiation syndrome

There are no FDA-approved drugs that can be administered prior to ionizing radiation exposure to prevent hematopoietic-acute radiation syndrome (H-ARS). A suspension of synthetic genistein nanoparticles was previously shown to be an effective radioprotectant against H-ARS when administered prior to exposure to a lethal dose of total body radiation. Here we aimed to determine the time to protection and the duration of protection when the genistein nanosuspension was administered by intramuscular injection, and we also investigated the drug's mechanism of action. A single intramuscular injection of the genistein nanosuspension was an effective radioprotectant when given prophylactically 48 h to 12 h before irradiation, with maximum effectiveness occurring when administered 24 h before. No survival advantage was observed in animals administered only a single dose of drug after irradiation. The dose reduction factor of the genistein nanosuspension was determined by comparing the survival of treated and untreated animals following different doses of total body irradiation. As genistein is a selective estrogen receptor beta agonist, we also explored whether this was a central component of its radioprotective mechanism of action. Mice that received an intramuscular injection of an estrogen receptor antagonist (ICI 182,780) prior to administration of the genistein nanosuspension had significantly lower survival following total body irradiation compared with animals only receiving the nanosuspension (P < 0.01). These data define the time to and duration of radioprotection following a single intramuscular injection of the genistein nanosuspension and identify its likely mechanism of action.

Acute Proteomic Changes in the Lung After WTLI in a Mouse Model: Identification of Potential Initiating Events for Delayed Effects of Acute Radiation Exposure

Radiation-induced lung injury is a delayed effect of acute radiation exposure resulting in pulmonary pneumonitis and fibrosis. Molecular mechanisms that lead to radiation-induced lung injury remain incompletely understood. Using a murine model of whole-thorax lung irradiation, C57BL/6J mice were irradiated at 8, 10, 12, and 14 Gy and assayed at day 1, 3, and 6 postexposure and compared to nonirradiated (sham) controls. Tryptic digests of lung tissues were analyzed by liquid chromatography-tandem mass spectrometry on a Waters nanoLC instrument coupled to a Thermo Scientific Q Exactive hybrid quadrupole-orbitrap mass spectrometer. Pathway and gene ontology analysis were performed with Qiagen Ingenuity, Panther GO, and DAVID databases. A number of trends were identified in the proteomic data, including protein changes greater than 10 fold, protein changes that were consistently up regulated or down regulated at all time points and dose levels interrogated, time and dose dependency of protein changes, canonical pathways affected by irradiation, changes in proteins that serve as upstream regulators, and proteins involved in key processes including inflammation, radiation, and retinoic acid signaling. The proteomic profiling conducted here represents an untargeted systems biology approach to identify acute molecular events that could potentially be initiating events for radiation-induced lung injury.

Pharmacokinetic and Metabolomic Studies with BIO 300, a Nanosuspension of Genistein, in a Nonhuman Primate Model

Genistein is a naturally occurring phytoestrogen isoflavone and is the active drug ingredient in BIO 300, a radiation countermeasure under advanced development for acute radiation syndrome (H-ARS) and for the delayed effects of acute radiation exposure (DEARE). Here we have assessed the pharmacokinetics (PK) and safety of BIO 300 in the nonhuman primate (NHP). In addition, we analyzed serum samples from animals receiving a single dose of BIO 300 for global metabolomic changes using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS). We present a comparison of how either intramuscularly (im) or orally (po) administered BIO 300 changed the metabolomic profile. We observed transient alterations in phenylalanine, tyrosine, glycerophosphocholine, and glycerophosphoserine which reverted back to near-normal levels 7 days after drug administration. We found a significant overlap in the metabolite profile changes induced by each route of administration; with the po route showing fewer metabolic alterations. Taken together, our results suggest that the administration of BIO 300 results in metabolic shifts that could provide an overall advantage to combat radiation injury. This initial assessment also highlights the utility of metabolomics and lipidomics to determine the underlying physiological mechanisms involved in the radioprotective efficacy of BIO 300.

Decreasing the Toxicity of Radiation Therapy: Radioprotectors and Radiomitigators Being Developed by the National Cancer Institute Through Small Business Innovation Research Contracts

PURPOSE

The use of radioprotectors and radiomitigators could improve the therapeutic index of radiation therapy. With the intention of accelerating translation of radiation-effect modulators (radioprotectors and mitigators), the Radiation Research Program and SBIR (Small Business Innovation Research) Development Center within the National Cancer Institute issued 4 Requests for Proposals (RFPs) from 2010 to 2013. Twelve SBIR contract awards in total were made in response to the 4 RFPs from September 2011 through September 2014. Here, we provide an update on the status of SBIR contract projects for the development of radiation-effect modulators.

METHODS AND MATERIALS

To assess the status of research and development efforts under the 4 RFPs on radiation-effect modulators, we searched PubMed for research articles, google.com for published abstracts, clinicaltrials.gov for ongoing or completed clinical trials, and company websites for press releases and other news. All information obtained and reported here is publicly available and thus protects the intellectual property of the investigators and companies.

RESULTS

Of the 12 SBIR projects funded, 5 (42%) transitioned successfully from phase 1 to phase 2 SBIR funding, and among the Fast-Track contracts, this rate was 100% (3 of 3). The Internet search identified 3 abstracts and 6 publications related to the aims of the SBIR contracts. One-third of the companies (4 of 12) have successfully launched a total of 8 clinical trials to demonstrate the safety and efficacy of their investigational agents. Two drugs are in clinical trials for their indication as a radioprotector, and 2 drugs are under evaluation for their anticancer properties (an immunomodulator and a small molecule inhibitor).

CONCLUSIONS

The National Cancer Institute's SBIR has provided pivotal funding to small businesses for the development of radioprotectors and radiomitigators, which resulted in multiple early-phase clinical trials. Longer follow-up is needed to determine the full impact of these novel therapeutics that enter clinical practice.

Phase II investigational oral drugs for the treatment of radio/chemotherapy induced oral mucositis

INTRODUCTION

Oral mucositis is a significant unmet clinical need for many cancer patients. The biological complexity of mucositis' pathogenesis provides a number of mechanistic targets suitable as pharmacologic targets. The diversity of targets has stimulated drug development in search of an effective intervention. In this paper, we review a range of agents that are currently being evaluated.

AREAS COVERED

Drugs for management of oral mucositis vary in formulation, route of administration and biological target. Most propose to interrupt the initiation of injury by suppressing activation of the innate immune response or countering oxidative stress, or minimizing downstream inflammatory responses. Overwhelmingly, the population most studied is patients being treated with concomitant chemoradiation for cancers of the head and neck as this is the cohort that most consistently suffers severe mucositis for long periods of time. The Phase 2 pipeline is robust. Preliminary data reported for a number of agents is optimistic. Genomics may be important in interpreting and comparing responses to agents across widely demographically diverse populations.

EXPERT OPINION

Oral mucositis remains a significant toxicity for patients undergoing cancer treatment. Incremental reports of successes have been noted for a number of targeted agents.

BIO 300, a nanosuspension of genistein, mitigates pneumonitis/fibrosis following high-dose radiation exposure in the C57L/J murine model

BACKGROUND AND PURPOSE

BIO 300 nanosuspension (Humanetics Corporation) is being developed as a medical countermeasure (MCM) for the mitigation of the delayed effects of acute radiation exposure, specifically pneumonitis and fibrosis of the lung. The objective of this study was to determine the best dose and treatment duration of BIO 300 to mitigate lung injury and improve the likelihood for survival in C57L/J mice exposed to whole thorax lung irradiation (WTLI).

EXPERIMENTAL APPROACH

Age- and sex-matched C57L/J mice received a single dose of 11.0 or 12.5 Gy WTLI. BIO 300 (200 or 400 mg·kg^-1 , oral gavage) was administered daily starting 24 h post-exposure for a duration of 2, 4, 6 or, in some cases, 10 weeks. Non-treated controls were included for comparison in both sexes. Animals were observed daily for signs of major morbidity. Respiratory function was assessed biweekly. Lungs were collected, weighed and paraffin embedded for histological evaluation post mortem.

KEY RESULTS

BIO 300 administered at an oral dose of 400 mg·kg^-1 for 4 to 6 weeks starting 24 h post-WTLI reduced morbidity associated with WTLI. The improvement in survival correlated with reduced respiratory frequency and enhanced pause. The irradiated lungs of mice treated with BIO 300 (400 mg·kg^-1 ) for 4 to 6 weeks displayed less morphological damage and airway loss due to oedema, congestion and fibrotic scarring than the untreated, irradiated controls.

CONCLUSIONS AND IMPLICATIONS

BIO 300 is a promising MCM candidate to mitigate pneumonitis/fibrosis when administered daily for 4-6 weeks starting 24 h post-exposure.

Targeted Metabolomics Identifies Pharmacodynamic Biomarkers for BIO 300 Mitigation of Radiation-Induced Lung Injury

PURPOSE

Biomarkers serve a number of purposes during drug development including defining the natural history of injury/disease, serving as a secondary endpoint or trigger for intervention, and/or aiding in the selection of an effective dose in humans. BIO 300 is a patent-protected pharmaceutical formulation of nanoparticles of synthetic genistein being developed by Humanetics Corporation. The primary goal of this metabolomic discovery experiment was to identify biomarkers that correlate with radiation-induced lung injury and BIO 300 efficacy for mitigating tissue damage based upon the primary endpoint of survival.

METHODS

High-throughput targeted metabolomics of lung tissue from male C57L/J mice exposed to 12.5 Gy whole thorax lung irradiation, treated daily with 400 mg/kg BIO 300 for either 2 weeks or 6 weeks starting 24 h post radiation exposure, were assayed at 180 d post-radiation to identify potential biomarkers.

RESULTS

A panel of lung metabolites that are responsive to radiation and able to distinguish an efficacious treatment schedule of BIO 300 from a non-efficacious treatment schedule in terms of 180 d survival were identified.

CONCLUSIONS

These metabolites represent potential biomarkers that could be further validated for use in drug development of BIO 300 and in the translation of dose from animal to human.