Promising Results In Preclinical Trials Research Articles

Poxvirus Vaccines: Past, Present, and Future.

Smallpox was a significant cause of mortality for over three thousand years, amounting to 10% of deaths yearly. Edward Jenner discovered smallpox vaccination in 1796, which rapidly became a smallpox infection preventive practice throughout the world and eradicated smallpox infection by 1980. After smallpox eradication, monkeypox vaccines have been used primarily in research and in outbreaks in Africa, where the disease is endemic. In the present, the vaccines are being used for people who work with animals or in high-risk areas, as well as for healthcare workers treating patients with monkeypox. Among all orthopoxviruses (OPXV), monkeypox viral (MPXV) infection occurs mainly in cynomolgus monkeys, natural reservoirs, and occasionally causes severe multi-organ infection in humans, who were the incidental hosts. The first case of the present epidemic of MXPV was identified on May 7, 2022, and rapidly increased the number of cases. In this regard, the WHO declared the outbreak, an international public health emergency on July 23, 2022. The first monkeypox vaccine was developed in the 1960s by the US Army and was based on the vaccinia virus, which is also used in smallpox vaccines. In recent years, newer monkeypox vaccines have been developed based on other viruses such as Modified Vaccinia Ankara (MVA). These newer vaccines are safer and can provide longer-lasting immunity with fewer side effects. For the future, there is ongoing research to improve the current vaccines and to develop new ones. One notable advance has been the development of a recombinant vaccine that uses a genetically modified vaccinia virus to express monkeypox antigens. This vaccine has shown promising results in pre-clinical trials and is currently undergoing further testing in clinical trials. Another recent development has been the use of a DNA vaccine, which delivers genetic material encoding monkeypox antigens directly into cells. This type of vaccine has shown effectiveness in animal studies and is also undergoing clinical testing in humans. Overall, these recent advances in monkeypox vaccine development hold promise for protecting individuals against this potentially serious disease.

Abstract 17599: Sotatercept for the Treatment of Pulmonary Arterial Hypertension: A Systematic Review and Single-Arm Meta-Analysis

Introduction: Pulmonary arterial hypertension (PAH) is associated with progressive clinical worsening and a 50% 5-year survival rate with current PAH therapies. Sotatercept is a first-in-class fusion protein with promising results in preclinical trials, but clinical evidence on its role in treating PAH remains limited. Hypothesis: Sotatercept may provide clinical benefits for patients with symptomatic PAH. Aims: To assess the efficacy of sotatercept in addition to background PAH therapy in this population. Methods: We searched PubMed, Embase, Cochrane and Clinicaltrials.gov in April 2023 for clinical trials assessing efficacy outcomes of sotatercept in patients with PAH. Using a random-effects model, we performed a single-arm meta-analysis of proportions for binary outcomes and applied generic inverse variance weighting formulas to pool arithmetic means and least squares means for continuous outcomes. Statistical analyses were performed using Review Manager 5.4.1 and R software 4.2.2. Results: We included three clinical trials comprising 254 patients with WHO functional class II or III PAH. At 24 weeks, only 2% of patients on sotatercept experienced symptoms of clinical worsening (95% CI 1 to 5; Fig. 1A). Sotatercept was also associated with a reduction in pulmonary vascular resistance (mean change from baseline -199.92 dyn·sec·cm -5 ; 95% CI -256.83 to -143.0; Fig. 1B), while improving 6-minute walk distance (mean change from baseline 45.86 m; 95% CI 28.54 to 63.18; Fig. 1C). Conclusions: These findings suggest that sotatercept may improve exercise capacity while decelerating clinical worsening and attenuating pulmonary vascular resistance in patients with mild to moderate PAH.

Focused ultrasound for treatment of peripheral brain tumors.

Malignant brain tumors are the leading cause of cancer-related death in children and remain a significant cause of morbidity and mortality throughout all demographics. Central nervous system (CNS) tumors are classically treated with surgical resection and radiotherapy in addition to adjuvant chemotherapy. However, the therapeutic efficacy of chemotherapeutic agents is limited due to the blood-brain barrier (BBB). Magnetic resonance guided focused ultrasound (MRgFUS) is a new and promising intervention for CNS tumors, which has shown success in preclinical trials. High-intensity focused ultrasound (HIFU) has the capacity to serve as a direct therapeutic agent in the form of thermoablation and mechanical destruction of the tumor. Low-intensity focused ultrasound (LIFU) has been shown to disrupt the BBB and enhance the uptake of therapeutic agents in the brain and CNS. The authors present a review of MRgFUS in the treatment of CNS tumors. This treatment method has shown promising results in preclinical trials including minimal adverse effects, increased infiltration of the therapeutic agents into the CNS, decreased tumor progression, and improved survival rates.

Treatment of Breast Cancer-Related Lymphedema With Topical Tacrolimus: A Prospective, Open-Label, Single-Arm, Phase II Pilot Trial.

Breast cancer-related lymphedema (BCRL) is a chronic, progressive side effect of breast cancer treatment, occurring in one-third of patients treated with axillary lymph node dissection and nodal radiotherapy. Cluster of differentiation 4-positive (CD4+) cells plays a key role in BCRL by facilitating inflammation and inhibiting lymphangiogenesis. Tacrolimus is an anti-inflammatory and immunosuppressive macrolide that targets CD4+ cells. Treatment of lymphedema with topical tacrolimus has revealed promising results in preclinical trials. This clinical trial was aimed at evaluating the feasibility, safety, and effect of tacrolimus in women with stage I or II BCRL, according to the International Society of Lymphology. We conducted this open-label, single-arm, phase II pilot trial from September 2020 to April 2021. Eighteen women with BCRL stage I or II BCRL were treated with topical tacrolimus for 6 months and followed up at 3 and 6 months. The primary outcome was arm volume, and secondary outcomes were the lymphedema index (L-Dex), health-related quality of life (HRQoL), lymph flow and function, and safety and feasibility of the trial design. The mean lymphedema arm volume and L-Dex reduced significantly by 130.44 ± 210.13 mL (p < 0.05; relative reduction: 3.6%) and 3.54 ± 4.98 (p < 0.05), respectively, and health-related quality of life scores was improved significantly (p < 0.05). According to the MD Anderson scale, in terms of lymph flow and function, three patients (16.7%) showed improvement, while none showed worsening. Lymph flow or function showed no change according to the Arm Dermal Backflow scale. In this trial, treatment with tacrolimus was safe and feasible in women with stage I or II BCRL. Tacrolimus alleviated BCRL in terms of improved arm volume, L-Dex, and HRQoL. Assessments of lymph flow and function were positive, although inconclusive. Larger randomized controlled trials are required to verify these findings. ClinicalTrials.gov Identifier: NCT04541290.

Neuroprotective Strategies in Glaucoma - Translation to Clinical Trials

Neuroprotection in glaucoma is any medical treatment by which decline in visual function can be slowed or prevented by supporting the health and survival of neural cells, independent of lowering of intraocular pressure (IOP). This is achieved by targeting mechanisms to inhibit or delay retinal ganglion cell death and promote cell survival pathways. Despite demonstrating promising results in preclinical trials, many neuroprotective strategies have failed to show success in subsequent clinical trials. Of the clinical trials performed, many have been hampered by slow disease progression and questions surrounding biomarker sensitivity. Adaptive clinical trial design, enriched populations and the use of state-of-the-art clinical endpoints are required to improve assessment of therapeutic efficacy. We review the neuroprotective strategies in glaucoma that have been investigated in clinical trials, and appraise experimental designs, the strength of the original hypotheses and preceding work to examine why so few candidates have successfully translated into clinical research.

Suicide gene therapy for caner: HSVtkGV and possible delivery systems

Genotherapeutic drugs are promising group of drugs for oncologic and familiar genetic disorders which are limitedly marketed at present. Anti-cancer gene therapy, using gene killer and enzyme prodrug system demonstrates promising results in preclinical trials. 2 types of carriers are used to deliver genes in a living organism — viral and non-viral, both of them have advantages and disadvantages.

Development of a Synthesis of Kinase Inhibitor AKN028

The novel tyrosine kinase inhibitor AKN028 has demonstrated promising results in preclinical trials. An expedient protocol for the synthesis of the compound at kilogram scale is described, including an SNAr reaction with high regioselectivity and a Suzuki coupling. Furthermore, an efficient method for purification and removal of residual palladium is described.

How to feed patients with gastrointestinal mucositis.

Gastrointestinal mucositis is a frequent side effect of systemic anticancer treatment and radiotherapy. The occurrence endangers body resources by decreasing food intake and absorption. This review highlights new developments in treatment and prevention. Recent clinical practice guidelines recommend supplying adequate amounts of energy and nutrients to cancer patients undergoing anticancer treatments. This requires repeated screening for risk of malnutrition and in at-risk patients, assessment of food intake and nutritional status, followed by nutritional interventions targeted at individual deficiencies and tolerance to oral, enteral or parenteral feeding. Recent preclinical data report beneficial effects of stimulating the sensor for cell damage signals TRPA1, blocking histamine H2 receptors or supplying probiotics. In a recent clinical trial, amifostine reduced gastrointestinal symptoms and was well tolerated. Probiotics are studied in ongoing clinical trials and glucagon-like peptide 2 analogues are considered for future trials. Due to limited options available today, it has been suggested to also consider several plant-based complementary therapies. Although options for prevention and treatment of chemotherapy or radiotherapy-induced gastrointestinal mucositis today are still limited, inadequate energy and nutrient intake should trigger nutritional interventions, including counselling, oral nutritional supplements, tube feeding and parenteral nutrition. To prevent gastrointestinal mucositis, several new agents have shown promising results in preclinical trials.

Targeting Macrophages in Cancer: From Bench to Bedside.

Macrophages are a major component of the tumor microenvironment and orchestrate various aspects of immunity. Within tumors, macrophages can reversibly alter their endotype in response to environmental cues, including hypoxia and stimuli derived from other immune cells, as well as the extracellular matrix. Depending on their activation status, macrophages can exert dual influences on tumorigenesis by either antagonizing the cytotoxic activity immune cells or by enhancing antitumor responses. In most solid cancers, increased infiltration with tumor-associated macrophages (TAMs) has long been associated with poor patient prognosis, highlighting their value as potential diagnostic and prognostic biomarkers in cancer. A number of macrophage-centered approaches to anticancer therapy have been investigated, and include strategies to block their tumor-promoting activities or exploit their antitumor effector functions. Integrating therapeutic strategies to target TAMs to complement conventional therapies has yielded promising results in preclinical trials and warrants further investigation to determine its translational benefit in human cancer patients. In this review, we discuss the molecular mechanisms underlying the pro-tumorigenic programming of macrophages and provide a comprehensive update of macrophage-targeted therapies for the treatment of solid cancers.

Amyotrophic lateral sclerosis: clinical perspectives

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in adults. It is a rapidly advancing neurodegenerative disease leading to progressive paralysis and death, with a mean time of survival from onset of symptoms to death of 2-5 years. The pathophys- iology of ALS remains poorly understood. The only US Food and Drug Administration-approved therapy for ALS is riluzole, a glutamatergic neurotransmission inhibitor, with modest benefits on survival. Many other agents have shown promising results in preclinical trials, but have yet to show benefit in human clinical trials. This review gives an overview of drugs that have been studied in clinical trials and their reported outcomes. This also includes more recent treatment strategies, including antisense oligonucleotides (ASOs) and stem cells. ASOs have the potential to target genes known to cause ALS by silencing their function. Many clinical trials are under way using these therapies. Different kinds of stem cells have been used in an attempt to either replace the lost motor neurons or to improve their metabolic supply and thus prolong their death. Given the limited therapeutic treatment options to date, the most important approach to improve the patient's quality of life remains symptom-based management. Additionally, we give an overview of the current treatment offered in multidisciplinary clinics.

Histone methylases as novel drug targets: developing inhibitors of EZH2.

Post-translational modifications of histones (so-called epigenetic modifications) play a major role in transcriptional control and normal development, and are tightly regulated. Disruption of their control is a frequent event in disease. In particular, the methylation of lysine 27 on histone H3 (H3K27), induced by the methylase EZH2, emerges as a key control of gene expression and a major regulator of cell physiology. The identification of driver mutations in EZH2 has already led to new prognostic and therapeutic advances, and new classes of potent and specific inhibitors for EZH2 show promising results in preclinical trials. This review examines the roles of histone lysine methylases and demethylases in cells and focuses on the recent knowledge and developments about EZH2.

Glioblastoma multiforme: State of the art and future therapeutics.

Background:Glioblastoma multiforme (GBM) is the most common and lethal primary malignancy of the central nervous system (CNS). Despite the proven benefit of surgical resection and aggressive treatment with chemo- and radiotherapy, the prognosis remains very poor. Recent advances of our understanding of the biology and pathophysiology of GBM have allowed the development of a wide array of novel therapeutic approaches, which have been developed. These novel approaches include molecularly targeted therapies, immunotherapies, and gene therapy.Methods:We offer a brief review of the current standard of care, and a survey of novel therapeutic approaches for treatment of GBM.Results:Despite promising results in preclinical trials, many of these therapies have demonstrated limited therapeutic efficacy in human clinical trials. Thus, although survival of patients with GBM continues to slowly improve, treatment of GBM remains extremely challenging.Conclusion:Continued research and development of targeted therapies, based on a detailed understanding of molecular pathogenesis can reasonably be expected to yield improved outcomes for patients with GBM.

An HDAC in the Cytoplasm, not the Nucleus, Plays a Pathogenic Role in Huntington's Disease

​TheThe gene for Huntington's disease (HD) was discovered in 1993 and ever since has been puzzling researchers intent on understanding its effects. The mutation, an expanded CAG repeat, is translated into an extended polyglutamine tract in the huntingtin protein (HTT), which leads to protein misfolding, accumulation of sticky protein aggregates in both cytoplasm and nucleus, and degeneration of neurons, first in the brain's striatum and later in the cortex and elsewhere. There are no disease-altering treatments and no single hypothesis of disease pathogenesis. In a new study, Michal Mielcarek, Gillian Bates, and colleagues elucidate a key role for the transcription regulator histone deactylase 4 (HDAC4)—not within the nucleus as you might expect, but instead in the cytoplasm. HDAC4 acts in the cytoplasm of brain cells to exacerbate the Huntington's disease (HD) pathogenic process. Reduction of HDAC4 levels ameliorates cytoplasmic-related HD phenotypes and improves survival, but does not change gene transcription. One prominent feature of HD molecular pathology is a global transcriptional dysregulation, likely driven in part by reduced histone acetylation. To counterbalance that effect, researchers have investigated whether inhibiting HDACs might be therapeutic, and one HDAC inhibitor has produced promising results in preclinical trials in models of HD. There are 11 different mammalian HDACs, and in order to better characterize their individual contributions to HD, the authors examined the effects of partially or completely knocking out each one. They found that reducing HDAC4 by 50% in a mouse model of HD reduced neuronal dysfunction of striatal neurons and delayed loss of motor function of the mice, allowing them to perform a balancing task at 12 weeks of age as well as untreated mice who were a month younger. Treatment also extended lifespan by about 20%, a significant improvement in this aggressive disease model of HD. Antibodies against HDAC4 and either mutant or wild-type HTT indicated that HDAC4 bound to mutant HTT in either soluble or aggregated form, but not to normal protein. Like HTT, HDAC4 includes a polyglutamine region, and it is likely that its interaction with mutant HTT is through the reciprocal attractions between these regions. Reducing HDAC4 reduced the total burden of HTT aggregates throughout the brain while increasing the amount of soluble HTT, indicating that treatment delayed the aggregation process. The work thereby finds a novel route to modulating the toxicity of HTT. HDAC4 remains sequestered in the cytoplasm until it is called upon to shuttle into the nucleus to take part in regulating transcription. Co-labeling HDAC4 and mutant HTT indicated that they localized together in the cytoplasm, but not the nucleus, and that reducing HDAC4 reduced aggregation in the cytoplasm while leaving the number of nuclear aggregates unchanged. This ability of the work to separate cytoplasmic pathologies from nuclear ones is an important advance in this field. Surprisingly, reducing HDAC4 had no effect on the widespread transcriptional dysregulation that led HD researchers to consider HDAC inhibitors in the first place. It did, however, have one potentially important effect on gene expression: it largely restored the levels of brain-derived neurotrophic factor, a growth factor that neurons need for survival and that is known to be lost in HD. This effect is likely mediated through a cytoplasmic, not nuclear, mechanism, based on previous work on this pathway in HD; further work will be needed to understand it in detail. These results have several implications for understanding and treating HD. There is no shortage of hypotheses of pathogenic mechanisms in HD, and this new mechanism is unlikely to be the sole cause of neuronal damage. But the discovery of a strictly cytoplasmic pathogenic effect of mutant HTT is new and will likely bring more attention to the cytoplasm as a site for further research. The demonstration that shifting the balance of mutant protein from aggregated to soluble forms has a beneficial effect further informs a long-standing debate in disorders of protein misfolding, about whether aggregates are toxic or protective, and will likely accelerate exploration of therapies to promote disaggregation. As mentioned, there are currently no disease-modifying therapeutics available for HD. The discovery that reducing HDAC4 has therapeutic effects in the HD model tested here—which happens to be a gold standard model in which most therapeutics fail when tested—will spur efforts to mimic this effect with small molecules to obstruct the interaction of HDAC4 and mutant HTT, or antisense therapies designed to prevent production of HDAC4 protein. Mielcarek M, Landles C, Weiss A, Bradaia A, Seredenina T, et al (2013). HDAC4 Reduction: A Novel Therapeutic Strategy to Target Cytoplasmic Huntingtin and Ameliorate Neurodegeneration. doi:10.1371/journal.pbio.1001717

Preclinical Approach to Sensitize Multiple Myeloma Cells: Combination of the MEK Inhibitor PD0325901 with ABT-737 or Mevinolin.

Abstract 1842Poster Board I-868Multiple myeloma (MM) is a plasma cell malignancy incurable with existing conventional therapies. However, the increased understanding of the molecular mechanisms underlying the growth, progression and drug resistance of MM cells is allowing the development of novel therapies based on target-specific drugs. These agents have shown promising results in pre-clinical trials and some are already in early phase of clinical investigation. However, limitations of this approach are represented by the existence of cross-talking signals among different pathways which results in ineffective inhibition of a single pathway. Therefore, targeted therapy based on the multiple inhibition of key signal transduction pathways represents the present focus of translational research. We have already demonstrated (Haematologica 2008;93[suppl.2]:P195) the potent growth-inhibitory effects of the specific MEK inhibitor PD0325901 and the marked pro-apoptotic activity of the Bcl2/BclXL inhibitor ABT-737 (kindly provided by Abbott Laboratories) on MM cell lines and primary CD138+ cells from MM patients at different disease stages (smoldering, diagnosis, relapse, refractory/resistant). Since it has already been reported that the inhibitor of the mevalonate pathway, Mevinolin, strikingly induces apoptosis by regulating different pathways, including the MEK/ERK module, we aimed in the present study to analyze the impact of the simultaneous inhibition of both pathways on apoptosis and cell growth of MM cell lines and primary samples. We exposed the KMS18, KMS27 and ARH-77 MM cell lines to increasing concentrations of PD0325901 (1–100 nM) and ABT-737 (1–100 nM) or Mevinolin (1–100 μM), alone and in combination. When used as single agents the inhibition of cell-growth was dose-dependent, while if used in combination it was synergistic, with combination indexes (CI) of 0.12 and 0.15 for PD0325901 plus ABT-737 and the same plus Mevinolin, respectively (Chou-Talalay method). We then investigated the effects of these agents on apoptosis, as determined by the sub-G1 DNA peak, and found that PD0325901 mainly showed cytostatic effects, while ABT-737 and Mevinolin needed high concentrations to affect apoptosis. The simultaneous exposure to PD0325901 plus ABT-737 or Mevinolin at lower concentrations, induced apoptosis with highly synergistic effects, as demonstrated by a CI of 0.2 (KMS18) and 0.17 (KMS27) for PD0325901 plus ABT-737 and of 0.135 (KMS18) and 0.128 (KMS27) for PD0325901 plus Mevinolin. Similarly, mitochondrial membrane depolarization was greatly induced with the combination approach. Preliminary experiments performed on primary MM samples confirmed the pro-apoptotic synergistic activity of combination strategies. On the contrary, when we used the MEK-inhibitor resistant MM cell line ARH-77, the effects of ABT-737 and Mevinolin were not potentiated by MEK inhibition with PD0325901. In conclusion, we demonstrated that the simultaneous disruption of the MEK/ERK and Bcl2/BclXL or Mevalonate signalling is effective on apoptosis induction and growth inhibition of MM cells at a greater degree than single agent therapy. Additional ongoing studies on primary samples from MM patients at different stages of the disease will help to determine the feasibility and efficacy of these combinations for clinical use. Disclosures:Petrucci:Celgene: Honoraria; Janssen Cilag: Honoraria.

Proof of principle in the selective treatment of cancer by antibody-directed enzyme prodrug therapy: the development of a highly potent prodrug.

Perfectly adept for tumor treatment: With the seco-CBI-Q galactoside 1 a novel highly potent prodrug for the selective treatment of cancer using the ADEPT approach was developed, which shows very promising results in preclinical trials on a human bronchial carcinoma in SCID mice (see picture; lung tissue after (A) and before treatment (B)).

Cell Transplantation for the Treatment of Parkinson's Disease

Cell transplantation is an experimental therapy for Parkinson's disease (PD) and other movement disorders. Several open-label research trials have shown clinically meaningful improvement in parkinsonian signs and symptoms after striatal transplantation of allogeneic fetal ventral mesencephalic (FVM) tissue. However, ethical concerns, variability in surgical techniques, and reports of unusual late complications in a few patients in a clinical trial have limited the use of allogeneic FVM tissue to a few research centers. Research into alternative cell sources such as porcine FVM and allogeneic retinal pigment epithelial cells has shown promising results in preclinical trials, and they are currently being tested in clinical trials. Novel strategies to improve cell survival and to avoid immune rejection of transplants show promising results in preclinical trials. This article focuses on these recent advances and compares the potential clinical utility of these emerging cell therapies for the treatment of advanced PD.