Late-stage Clinical Development Research Articles

Safety, Tolerability, and Immunogenicity of the InvaplexAR-DetoxShigella Vaccine Co-Administered with the dmLT Adjuvant in Dutch and Zambian Adults: Study Protocol for a Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation Phase Ia/b Clinical Trial.

Shigella infections remain endemic in places with poor sanitation and are a leading cause of diarrheal mortality globally, as well as a major contributor to gut enteropathy and stunting. There are currently no licensed vaccines for shigellosis but it has been estimated that an effective vaccine could avert 590,000 deaths over a 20-year period. A challenge to effective Shigella vaccine development has been the low immunogenicity and protective efficacy of candidate Shigella vaccines in infants and young children. Additionally, a new vaccine might be less immunogenic in a highly endemic setting compared to a low endemic setting ("vaccine hyporesponsiveness"). The use of a potent adjuvant enhancing both mucosal and systemic immunity might overcome these problems. InvaplexAR-Detox is an injectable Shigella vaccine that uses a novel combination of conserved invasion plasmid antigen proteins and a serotype-specific bacterial lipopolysaccharide attenuated for safe intramuscular administration. The adjuvant dmLT has been shown to enhance Shigella immune responses in mice, has safely been administered intramuscularly, and was shown to enhance immune responses in healthy volunteers when given in combination with other antigens in phase I trials. This article describes the protocol of a study that will be the first to assess the safety, tolerability, and immunogenicity of InvaplexAR-Detox co-administered with dmLT in healthy adults in low-endemic and high-endemic settings. In a multi-center, randomized, double-blind, and placebo-controlled dose-escalation phase Ia/b trial, the safety, tolerability, and immunogenicity of three intramuscular vaccinations administered 4 weeks apart with 2.5 µg or 10 µg of InvaplexAR-Detox vaccine, alone or in combination with 0.1 µg of the dmLT adjuvant, will first be assessed in a total of 50 healthy Dutch adults (phase Ia) and subsequently in 35 healthy Zambian adults (phase Ib) aged 18-50 years. The primary outcome is safety, and secondary outcomes are humoral and cellular immune responses to the adjuvanted or non-adjuvanted vaccine. This trial is part of the ShigaPlexIM project that aims to advance the early clinical development of an injectable Shigella vaccine and to make the vaccine available for late-stage clinical development. This trial addresses the issue of hyporesponsiveness in an early stage of clinical development by testing the vaccine and adjuvant in an endemic setting (Zambia) after the first-in-human administration and the dose-escalation has proven safe and tolerable in a low-endemic setting (Netherlands). Besides strengthening the vaccine pipeline against a major diarrheal disease, another goal of the ShigaPlexIM project is to stimulate capacity building and strengthen global North-South relations in clinical research. EU CT number: 2023-506394-35-02, ClinicalTrials.gov identifier: NCT05961059.

P110 Zasocitinib (TAK-279) exhibits high levels of TYK2 inhibition and no inhibition of JAK 1/3 when compared with licensed TYK2 and JAK inhibitors

Abstract Zasocitinib (TAK-279) is an oral, allosteric, highly selective, tyrosine kinase 2 (TYK2) inhibitor in late-stage clinical development for the treatment of immune-mediated inflammatory diseases, including psoriasis. Zasocitinib was developed using AI-assisted compound design strategy to create a TYK2 inhibitor with next-generation selectivity and >1 million-fold greater affinity for TYK2 than for Janus kinase (JAK) 1/2/3. This study compared the potency and selectivity of zasocitinib for TYK2 vs. JAK1/3 with licensed TYK2/JAK inhibitors. The inhibitory constants (Kis) of zasocitinib and deucravacitinib for JAK1 and TYK2 Janus homology 2 (JH2) domains were determined using a homogeneous time-resolved fluorescence assay. Fresh whole-blood cultures from 12 to 13 healthy volunteers characterized concentration–response (percentage inhibition) curves for TYK2- (IL-12/18 IFN-γ) and JAK1/3- (IL-2 pSTAT5) dependent pathways for zasocitinib and licensed TYK2/JAK inhibitors. Statistical modelling determined the relationship between concentration and percentage inhibition, and half-maximal inhibitory concentration (IC50) values were estimated. Drug plasma concentrations at clinically relevant/approved doses were simulated using published population pharmacokinetic models. Time over plasma concentrations >IC50 and percentage daily inhibition were compared between drugs for each pathway. The Kis of zasocitinib and deucravacitinib for the JAK1 JH2 domain were >15 000 and 1 nM, respectively. The Kis of zasocitinib and deucravacitinib for the TYK2 JH2 domain were 0.0087 and 0.0115 nM, respectively. Simulated plasma concentrations were above TYK2 IC50 for 24 h for zasocitinib 30 mg once daily (QD) vs. 3 h for deucravacitinib 6 mg QD, and 0 h for baricitinib 4 mg QD, tofacitinib 10 mg twice daily and upadacitinib 30 mg QD. TYK2 percentage daily inhibition was 91% for zasocitinib 30 mg and 23% for deucravacitinib 6 mg. Baricitinib 4 mg, upadacitinib 30 mg and tofacitinib 10 mg showed minimal TYK2 inhibition (0–8%). Simulated plasma concentrations of zasocitinib 30 mg and deucravacitinib 6 mg did not reach JAK1/3 IC50; those of baricitinib 4 mg, upadacitinib 30 mg and tofacitinib 10 mg were above JAK1/3 IC50 for 24 h. JAK1/3 percentage daily inhibition was 0% for zasocitinib 30 mg and 3% for deucravacitinib 6 mg vs. 91–97% for baricitinib 4 mg, upadacitinib 30 mg and tofacitinib 10 mg. Selective TYK2 inhibition offers a distinct cytokine receptor inhibition profile. Zasocitinib showed greater and longer selective inhibition of TYK2-mediated signalling vs. deucravacitinib at its clinical dosage, without affecting JAK1/3-mediated signalling.

Telomerase in Cancer Therapeutics.

While silent in normal differentiated human tissues, telomerase is reactivated in most human cancers. Thus, telomerase is an almost universal oncology target. This update describes preclinical and clinical advancements using a variety of approaches to target telomerase. These include direct telomerase inhibitors, G-quadruplex DNA-interacting ligands, telomerase-based vaccine platforms, telomerase promoter-driven attenuated viruses, and telomerase-mediated telomere targeting approaches. While imetelstat has been recently approved by the Food and Drug Administration (FDA), several other approaches are in late-stage clinical development. The pros and cons of the major approaches will be reviewed.

Epicutaneous immunotherapy for the treatment of peanut allergy.

Peanut allergy treatment options remain limited, but novel approaches are being studied, including epicutaneous immunotherapy (EPIT). EPIT uses the cutaneous immune system to promote tolerance to food allergens. Viaskin™ Peanut, an approach to EPIT in late-stage clinical development uses an occlusive patch with a condensation chamber that enables natural epidermal water loss to solubilize dry antigen on the patch, which is then absorbed and captured by skin Langerhans cells. This form of EPIT does not require disruption of the skin barrier, thus avoiding a proinflammatory cytokine response by targeting the nonvascularized epidermis and limiting systemic allergen exposure. Extensive preclinical research suggests that Viaskin Peanut has a distinct mechanism of desensitization, including the potential for disease modification, driven by a unique population of regulatory T cells. Numerous clinical studies of Viaskin Peanut have demonstrated desensitization and reductions in reaction severity, particularly in children aged 1 through 11 years, as well as a favorable safety profile with mostly mild-to-moderate skin reactions that were observed to decrease over time. EPIT with Viaskin Peanut may be a potential therapeutic option for peanut allergy that is clinically practical with long-term efficacy and tolerability.

Rethinking the necessity of long-term toxicity studies for biotherapeutics using weight of evidence assessment

The registration of biotherapeutics for chronic indications requires 6-month toxicity studies. However, extensive experience has shown that the non-clinical safety profiles of biotherapeutics are generally predictable. This suggests that conducting multiple studies, especially a 6-month study may not be necessary. In a meta-analysis of biologics developed for non-oncology indications over last 25 years at Pfizer, we compared organ system findings between short-term (1–3 month) and long-term (6-month) animal studies. Our goal was to determine if there were differences in the safety profiles between the two study durations and their relevance to human risk assessment. Our analysis revealed that most clinically relevant toxicities could be detected in shorter-term studies (87%; 26/30 programs). This suggests either an undifferentiated safety profile between short-and long-term studies, or anticipated toxicities based on the modality, such as immunogenicity or exaggerated pharmacology. However, for 4 out of 30 programs (13%), long-term studies did identify either potential new toxicities or more severe manifestation of exaggerated pharmacology, leading to modifications in clinical trial designs and human risk assessment. Our experience suggests that 3-month toxicity studies may be sufficient to support late-stage clinical development for a majority of standard biotherapeutic programs. This pragmatic and science-based approach aligns with the goal of advancing 3R's initiatives in nonclinical safety assessment.

Insights on estetrol, the native estrogen: from contraception to hormone replacement therapy.

Estetrol (E4) is a natural estrogen that has recently emerged as new option for contraception and hormone replacement therapy (HRT). Unlike other estrogens, E4 primarily stimulates nuclear estrogen receptor alpha (ERα) and does not activate membrane ERα. For this reason, this novel estrogen has tissue-specific effects across various organs such as liver, vascular endothelium, mammary glands, brain, vagina, and uterus. The selective activation of the nuclear ERα results in distinct pharmacological properties that contribute to its unique therapeutic profile. Moreover, E4 shows minimal interaction with the hepatic cytochrome P450 enzyme system, leading to a favorable pharmacokinetic profile and a reduced potential for drug-drug interactions. Currently, E4 is commercially available in combination with drospirenone as a combined oral contraceptive and its application in HRT is undergoing late-stage clinical development. Many studies have demonstrated that E4 has a lower impact on hemostatic and metabolic parameters compared to other estrogens, potentially reducing the risk of adverse effects commonly associated with hormonal therapies such as thromboembolic events or dyslipidemia. Beyond its role in contraception and HRT, E4 shows promising therapeutic potential in other medical fields, including neuroprotection in neonatal hypoxic-ischemic encephalopathy, enhancement of hematopoietic stem cell transplantation outcomes and prostate cancer management. This review synthesizes the latest evidence on E4 primarily focusing on its pharmacological characteristics and clinical applications. The findings suggest that E4 versatility and peculiar mechanism of action may represent an important therapeutic option for a broad spectrum of medical conditions.

On the Application of Artificial Intelligence/Machine Learning (AI/ML) in Late-Stage Clinical Development.

Whereas AI/ML methods were considered experimental tools in clinical development for some time, nowadays they are widely available. However, stakeholders in the health care industry still need to answer the question which role these methods can realistically play and what standards should be adhered to. Clinical research in late-stage clinical development has particular requirements in terms of robustness, transparency and traceability. These standards should also be adhered to when applying AI/ML methods. Currently there is some formal regulatory guidance available, but this is more directed at settings where a device or medical software is investigated. Here we focus on the application of AI/ML methods in late-stage clinical drug development, i.e. in a setting where currently less guidance is available. This is done via first summarizing available regulatory guidance and work done by regulatory statisticians followed by the presentation of an industry application where the influence of extensive sets of baseline characteristics on the treatment effect can be investigated by applying ML-methods in a standardized manner with intuitive graphical displays leveraging explainable AI methods. The paper aims at stimulating discussions on the role such analyses can play in general rather than advocating for a particular AI/ML-method or indication where such methods could be meaningful.

A Framework for Best Practices and Readiness in the Advent of Anti-Amyloid Therapy for Early Alzheimer's Disease in Asia.

Advances in biomarker-based diagnostic modalities, recent approval of anti-amyloid monoclonal antibodies for early Alzheimer's disease (AD; mild cognitive impairment or mild dementia due to AD) and late-stage clinical development of other disease-modifying therapies for AD necessitate a significant paradigm shift in the early detection, diagnosis and management of AD. Anti-amyloid monoclonal antibodies target the underlying pathophysiological mechanisms of AD and have demonstrated a significant reduction in the rate of clinical decline in cognitive and functional outcome measures in patients with early AD. With growing recognition of the benefit of early interventions in AD, an increasing number of people may seek diagnosis for their subjective cognitive problems in an already busy medical system. Various factors such as limited examination time, lack of expertise for cognitive assessment and limited access to specialized tests can impact diagnostic accuracy and timely detection of AD. To overcome these challenges, a new model of care will be required. In this paper, we provide practical guidance for institutional readiness for anti-amyloid therapies for early AD in Asia, in terms of best practices for identifying eligible patients and diagnosing them appropriately, safe administration of anti-amyloid monoclonal antibodies and monitoring of treatment, managing potential adverse events such as infusion reactions and amyloid-related imaging abnormalities, and cross-disciplinary collaboration. Education and training will be the cornerstone for the establishment of new pathways of care for the identification of patients with early AD and delivery of anti-amyloid therapies in a safe and efficient manner to eligible patients.

FDA Breakthrough Therapy Designation Reduced Late-Stage Drug Development Time.

The Food and Drug Administration's (FDA's) breakthrough therapy designation (BTD) program was created to increase patient access to safe and effective therapies by supporting the efficient clinical development of qualifying, clinically meaningful therapies. Using a new data set of key development milestones for drugs approved between 2006 and 2020, including both BTD drugs and a set of comparator drugs identified by FDA experts, we estimated the BTD program's impact on time spent in late-stage clinical development, measured as the elapsed time between a drug's end-of-Phase-II meeting with regulators and its approval for marketing. Our analysis suggests that the BTD program lowers late-stage clinical development time by 30percent. Our findings provide insight into future regulatory and innovation policies aimed at driving efficiency in medical product development to ensure timely patient access to the most clinically meaningful therapies.

Highly pure DNA-encoded chemical libraries by dual-linker solid-phase synthesis.

The first drugs discovered using DNA-encoded chemical library (DEL) screens have entered late-stage clinical development. However, DEL technology as a whole still suffers from poor chemical purity resulting in suboptimal performance. In this work, we report a technique to overcome this issue through self-purifying release of the DEL after magnetic bead-based synthesis. Both the first and last building blocks of each assembled library member were linked to the beads by tethers that could be cleaved by mutually orthogonal chemistry. Sequential cleavage of the first and last tether, with washing in between, ensured that the final library comprises only the fully complete compounds. The outstanding purity attained by this approach enables a direct correlation of chemical display and encoding, allows for an increased chemical reaction scope, and facilitates the use of more diversity elements while achieving greatly improved signal-to-noise ratios in selections.

Cholesteryl Ester Transfer Protein Inhibitors and Cardiovascular Outcomes: A Systematic Review and Meta-Analysis.

Atherosclerosis is a multi-factorial disease, and low-density lipoprotein cholesterol (LDL-C) is a critical risk factor in developing atherosclerotic cardiovascular disease (ASCVD). Cholesteryl-ester transfer-protein (CETP), synthesized by the liver, regulates LDL-C and high-density lipoprotein cholesterol (HDL-C) through the bidirectional transfer of lipids. The novelty of CETP inhibitors (CETPis) has granted new focus towards increasing HDL-C, besides lowering LDL-C strategies. To date, five CETPis that are projected to improve lipid profiles, torcetrapib, dalcetrapib, evacetrapib, anacetrapib, and obicetrapib, have reached late-stage clinical development for ASCVD risk reduction. Early trials failed to reduce atherosclerotic cardiovascular occurrences. Given the advent of some recent large-scale clinical trials (ACCELERATE, HPS3/TIMI55-REVEAL Collaborative Group), conducting a meta-analysis is essential to investigate CETPis' efficacy. We conducted a thorough search of randomized controlled trials (RCTs) that commenced between 2003 and 2023; CETPi versus placebo studies with a ≥6-month follow-up and defined outcomes were eligible. major adverse cardiovascular events (MACEs), cardiovascular disease (CVD)-related mortality, all-cause mortality. stroke, revascularization, hospitalization due to acute coronary syndrome, myocardial infarction (MI). Nine RCTs revealed that the use of a CETPi significantly reduced CVD-related mortality (RR = 0.89; 95% CI: 0.81-0.98; p = 0.02; I2 = 0%); the same studies also reduced the risk of MI (RR = 0.92; 95% CI: 0.86-0.98; p = 0.01; I2 = 0%), which was primarily attributed to anacetrapib. The use of a CETPi did not reduce the likelihood any other outcomes. Our meta-analysis shows, for the first time, that CETPis are associated with reduced CVD-related mortality and MI.

Abstract PS08-06: A Phase Ib/II Study to Assess the Safety and Efficacy of PM8002 (Anti-PD-L1 x VEGF-A Bispecific Antibody) in Combination with Nab-Paclitaxel for First Line Treatment of Locally Advanced or Metastatic Triple-Negative Breast Cancer

Abstract Background: PD-L1 and VEGF play important roles in immune evasion and pro-tumor angiogenesis promoting cancer growth and metastasis. PM8002 is a bispecific antibody targeting PD-L1 and VEGF-A for treating cancer. Here, we present results from a Phase Ib/II study of PM8002 in combination with nab-paclitaxel in patients with locally-advanced or metastatic triple-negative breast cancer (TNBC). Methods: 42 patients with locally-advanced or metastatic TNBC (without prior systemic treatment) were enrolled in this Phase Ib/II study to test the safety and efficacy of PM8002 in combination with nab-paclitaxel. The first 6 patients were enrolled during Phase Ib with safety as the primary endpoint, and the remaining patients were enrolled during Phase II with objective response rate (ORR) as the primary endpoint. Each treatment cycle lasts 28 days. All patients received PM8002 at 20 mg/kg (Q2W) and nab-paclitaxel at 100 mg/m2 on the 1st, 8th, and 15th days of each cycle until unacceptable toxicity or disease progression were observed. Tumor responses were evaluated every 8 weeks according to RECIST 1.1. Safety was evaluated according to CTCAE 5.0. Nab-paclitaxel dose was reduced according to toxicity, while PM8002 dose was kept consistent according to body weight. PD-L1 expression in tumors was tested, and subgroup analysis of ORR data stratified by PD-L1 expression was also included. Results: As of June 30, 2023, 42 patients were treated and evaluated at least once for treatment efficacy. The median duration of drug exposure was 4.6 months (min, max: 2.0, 7.6). The best overall ORR was 76.2% (32/42), including 1 complete response (CR) and 31 partial responses (PRs) with 29 objective responses occurring at the patient's first evaluation. The confirmed ORR was 57.2% (24/42) and the overall disease control rate (DCR) was 95.2% (40/42). The median time to response (TTR) was 1.9 months (95% CI:1.8~2.0) and the median best percentage change from baseline for target lesions was -47.2% (Q1, Q3: -56.9%, -33.5%). Among 13 patients with PD-L1 combined positive scores (CPS) < 1, the best ORR and DCR were 69.2% (9/13) and 100.0% (13/13), respectively. Among 25 patients with PD-L1 CPS ≥1, the best ORR and DCR were 80.0% (20/25) and 96.0% (24/25), respectively. Among 9 patients with PD-L1 CPS ≥10, the best ORR and DCR were both 100.0% (9/9). At the cut-off date of data analysis, 38 patients were still on treatment with a median progression-free survival (mPFS) of 7.4 months (95% CI: 7.4~NA); 38 patients were censored due to no disease progression or death. The incidence of treatment-related adverse events (TRAEs) was 95.2%, of which 26.2% were Grade 3 or 4; no Grade 5 TRAEs were observed. The incidence of drug-related TRAEs related to PM8002 was 92.9%, of which 23.8% were Grade 3 or 4. The incidence of drug-related TRAEs related to nab-paclitaxel was 95.2%, of which 26.2% were Grade 3 or 4. 1 patient (2.4%) reduced nab-paclitaxel dose due to diarrhea. 1 patient (2.4%) discontinued PM8002 and nab-paclitaxel treatment due to diarrhea. The most common TRAEs related to PM8002 and nab-paclitaxel included neutropenia (69.0%), leukocytopenia (59.5%), anemia (52.4%) and proteinuria (26.2%). The incidence of immune-related adverse events (irAEs) was 11.9%, which included hyperthyroidism, hypothyroidism, and rash. No ≥ Grade 3 irAEs were observed. AEs related to targeting VEGF were also analyzed, including hypertension 19.0% (4.8% at Grade 1, 11.9% at Grade 2, and 2.4% at Grade 3) and proteinuria 26.2% (9.5% at Grade 1, and 16.7% at Grade 2). Conclusions: Rapid, deep, and durable tumor responses were observed for the combination of PM8002 and nab-paclitaxel in patients with first line TNBC. PM8002 did not enhance toxicity that is typically observed for nab-paclitaxel. This Phase II study is still ongoing with plans for entering late-stage clinical development for solid tumors. Citation Format: Jiong Wu, Jian Zhang, Zhongsheng Tong, Qingyuan Zhang, Yong-Sheng Wang, Qiao Cheng, Xin Chen, Zhihua Li, Yongmei Yin. A Phase Ib/II Study to Assess the Safety and Efficacy of PM8002 (Anti-PD-L1 x VEGF-A Bispecific Antibody) in Combination with Nab-Paclitaxel for First Line Treatment of Locally Advanced or Metastatic Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS08-06.

Successes and pitfalls in orphan drug development for sickle cell disease

AbstractSickle cell disease (SCD) is a hereditary red cell disorder with a large disease burden at a global level. In the United States and Europe, medicines may qualify for orphan designation (OD), a regulatory status that provides incentives to boost development. We evaluated the development of new therapies for SCD using data for OD granted in the United States and Europe over the last 2 decades (2000-2021). We analyzed their characteristics, pathophysiological targets, trends, and OD sponsors. We then investigated the approval outcomes, including the phase success rate and reasons for discontinuation across different variables. We identified 57 ODs for SCD: 43 (75.4%) small molecules, 32 (56.1%) for oral administration, and 36 (63.1%) for chronic use to prevent SCD complications. At the end of the study (2021), development of 34 of 57 ODs was completed. Four ODs were approved with a success rate of 11.8%. Products targeting upstream causative events of SCD pathophysiology had a 1.8 higher success rate compared with products targeting disease consequences. Large companies showed a fourfold higher success rate compared with small-medium enterprises. Failures in clinical development were mainly seen in phase 3 for a lack of efficacy on vaso-occlusive crisis as the primary study end point, likely related to variable definitions and heterogeneity of pain scoring and treatment. Both advances in SCD knowledge and regulatory incentives paved the way for new therapies for SCD. Our finding of high failure rates in late-stage clinical development signals the need for better early-stage predictive models, also in the context of meaningful clinical end points.

Abstract 1245: The histone methyltransferase KMT2D mediates subtype-specific transcriptional regulation and therapeutic response in prostate cancer

Abstract Primary prostate cancer is characterized by its dependence on androgen receptor (AR) and often has hyperactive PI3K signaling, most frequently through loss of PTEN. PI3K/AKT pathway inhibitors are in late-stage clinical development in combination with anti-AR therapy. Androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, but the development of castration-resistant prostate cancer (CRPC) eventually occurs. CRPC remains largely dependent on AR for growth with a subset of CRPC that lose AR dependence. There is an urgent need to study the molecular pathways leading to AR activation and the loss of AR reliance in order to identify therapeutic targets. KMT2D is a histone methyltransferase and an important regulator of gene expression. Here we found that KMT2D establishes the chromatin competence necessary for the recruitment of AR and FOXA1 transcription factors (TFs) to activate AR-dependent transcription in AR-high prostate models. In AR-low models such as the stem cell-like (SCL) subtype, KMT2D controls residual AR-FOXA1 gene expression programs and AP-1 TFs such as FOSL1, a driver of the SCL subtype. In SCL, single cell RNA-seq and single cell chromatin assays confirm a key role for KMT2D in the maintenance of a mixed lineage cell state through the regulation of AP-1 and FOXA1 TFs. Combined suppression of PI3K/AKT and KMT2D reduces cell proliferation in prostate cancer cells and patient derived organoids, providing a rationale for epigenetically informed combination therapies with PI3K/AKT inhibitors in PTEN-deficient prostate cancer. Together, these data establish KMT2D as a major mediator of subtype-specific chromatin accessibility and transcriptomic landscape in CRPC, required for prostate cancer growth and therapeutic response. Citation Format: Srushti Kittane, Erik Ladewig, Taibo Li, Jillian Love, Amaia Arruabarrena-Aristorena, Xinyu Guo, Mirna Sallaku, Liliana Garcia-Martinez, Ryan Blawski, Javier Carmona Sanz, Christopher Simpkins, Wanlu Chen, Bujamin Vokshi, Peihua Zhao, Nachiket Kelkar, Laura Baldino, Ingrid Kalemi, Pau Castel, Emiliano Cocco, Lluis Morey, Charles Sawyers, Hongkai Ji, Maurizio Scaltriti, Alexis Battle, Christina Leslie, Wouter Karthaus, Eneda Toska. The histone methyltransferase KMT2D mediates subtype-specific transcriptional regulation and therapeutic response in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1245.

Development of a robust cell-based potency assay for a coxsackievirus A21 oncolytic virotherapy

Oncolytic viruses (OV) are part of a burgeoning field of investigational oncolytic therapy (OT), in which lytic viruses dissolve advanced tumors productively and specifically. One such OT is a Coxsackievirus A21 (CVA21) based OV that is currently under clinical evaluation. A tissue culture infectious dose (TCID50) assay was used for CVA21 potency release and stability testing in early clinical development. The titer measured in this method was an extrapolated value from cytopathic effect (CPE) observed during the serial dilution but doesn't represent direct viral killing of cells. Moreover, the assay was not deemed to be optimal to carry into late phase clinical development due to limitations in assay precision, turn-around time, and sample throughput. To address these points, we developed a plaque assay to measure viral plaque forming units to measure the potency value for drug substance (DS), drug product (DP) and virus seed (master and working) stocks. In this manuscript, we describe the steps taken to develop this plaque assay for the late-stage clinical development, which include the assay qualification, validation, and robustness protocols, and describe statistical methods for data analysis. Moreover, the method was validated for linearity, accuracy, precision, and specificity. Furthermore, the plaque assay quantifies OV infectivity with better precision (32% vs 58%), with higher sample throughput (22 samples/week vs 3 samples/week) and shorter assay turnaround time (4 days vs 7 days) than the TCID50 method. This assay development strategy can provide guidance for the development of robust cell-based potency methods for OVs and other infectious viral products.

“Why has this new vaccine come and for what reasons?” key antecedents and questions for acceptance of a future maternal GBS vaccine: Perspectives of pregnant women, lactating women, and community members in Kenya

ABSTRACT Group B streptococcus (GBS) is a leading global cause of neonatal sepsis and meningitis, stillbirth, and puerperal sepsis. While intrapartum antibiotic prophylaxis (IAP) is a currently available GBS disease prevention strategy, IAP is programmatically complex to implement, precluding use in low- and middle-income countries. In Kenya, 2% of stillbirths are attributable to GBS infection. Two maternal GBS vaccines are in late-stage clinical development. However, licensure of a maternal GBS vaccine does not translate into reduction of disease. We conducted 28 in-depth interviews with pregnant people, lactating people, and community members across two counties in Kenya to better understand the attitudes and informational needs of primary vaccine beneficiaries. We identified two emerging themes from the data. The first focused on antecedents to maternal GBS vaccine acceptability. The most common antecedents focused on the vaccine’s ability to protect the baby and/or the mother, followed by community sensitization before the vaccine was available. The second key theme focused on questions that would need to be addressed before someone could accept a maternal GBS vaccine. Three key categories of questions were identified, including vaccine safety compared to vaccine benefits, who gets the vaccine, and how the vaccine works. Realizing the potential benefits of a future GBS maternal vaccine will require a multifactorial approach, including ensuring that communities are aware of GBS-related harms as well as the safety and effectiveness of a maternal GBS vaccine. Our study contributes to informing this multifactorial approach by elucidating the attitudes and concerns of key populations.

Reassessing potential economic value and health impact of effective Shigella vaccines.

The gram-negative bacterium Shigella is a leading cause of diarrheal morbidity and mortality in children in low- and middle-income countries. Several promising vaccine candidates are in late stages of clinical development against this increasingly antibiotic-resistant pathogen. However, considering the increasingly crowded and costly paediatric immunization schedule, and likely advent of other important new vaccines, it is unclear whether introduction of a Shigella vaccine would represent a high priority for international agencies or health ministries in low- and middle-income countries. To determine whether there is a compelling public health value proposition for a Shigella vaccine, we used the World Health Organization's Full Value of Vaccine Assessment analytic framework and formulated five broad scientific, policy, economic and commercial-related propositions regarding the development of a Shigella vaccine. We also explored the current regulatory, clinical, policy and commercial challenges to a Shigella-containing combination vaccine development and adoption. Through a series of literature reviews, expert consultations, social science field studies and model-based analyses, we addressed each of these propositions. As described in a series of separate publications that are synthesized here, we concluded that the economic and public health value of a Shigella vaccine may be greater than previously recognized, particularly if it is found to also be effective against less severe forms of diarrheal disease and childhood stunting. The decision by pharmaceutical companies to develop a standalone vaccine or a multipathogen combination will be a key factor in determining its relative prioritization by various stakeholders in low- and middle-income countries.

Semaglutide reduces tumor burden in the GAN diet-induced obese and biopsy-confirmed mouse model of NASH-HCC with advanced fibrosis

Non-alcoholic steatohepatitis (NASH) is emerging as a major cause of hepatocellular carcinoma (HCC), however, it is not resolved if compounds in late-stage clinical development for NASH may have additional therapeutic benefits in NASH-driven HCC (NASH-HCC). Here, we profiled monotherapy with semaglutide (glucagon-like-receptor-1 receptor agonist) and lanifibranor (pan-peroxisome proliferator-activated receptor agonist) in a diet-induced obese (DIO) mouse model of NASH-HCC. Disease progression was characterized in male C57BL/6 J mice fed the GAN (Gubra Amylin NASH) diet high in fat, fructose and cholesterol for 12–72 weeks (n = 15 per group). Other GAN DIO-NASH-HCC mice fed the GAN diet for 54 weeks and with biopsy-confirmed NASH (NAFLD Activity Score ≥ 5) and advanced fibrosis (stage F3) received vehicle (n = 16), semaglutide (30 nmol/kg, s.c., n = 15), or lanifibranor (30 mg/kg, p.o., n = 15) once daily for 14 weeks. GAN DIO-NASH-HCC mice demonstrated progressive NASH, fibrosis and HCC burden. Tumors presented with histological and molecular signatures of poor prognostic HCC. Consistent with clinical trial outcomes in NASH patients, both lanifibranor and semaglutide improved NASH while only lanifibranor reduced fibrosis in GAN DIO-NASH-HCC mice. Notably, only semaglutide reduced tumor burden in GAN DIO-NASH-HCC mice. In conclusion, the GAN DIO-NASH-HCC mouse is a clinical translational model of NASH-HCC. Semaglutide improves both NASH and tumor burden in GAN DIO-NASH-HCC mice, highlighting the suitability of this preclinical model for profiling novel drug therapies targeting NASH-HCC.

Pharmacodynamics of zoliflodacin plus doxycycline combination therapy against Neisseria gonorrhoeae in a gonococcal hollow-fiber infection model.

Antimicrobial resistance in the sexually transmitted bacterium Neisseria gonorrhoeae is compromising the management and control of gonorrhea globally. Optimized use and enhanced stewardship of current antimicrobials and development of novel antimicrobials are imperative. The first in class zoliflodacin (spiropyrimidinetrione, DNA Gyrase B inhibitor) is a promising novel antimicrobial in late-stage clinical development for gonorrhea treatment, i.e., the phase III randomized controlled clinical trial (ClinicalTrials.gov Identifier: NCT03959527) was recently finalized, and zoliflodacin showed non-inferiority compared to the recommended ceftriaxone plus azithromycin dual therapy. Doxycycline, the first-line treatment for chlamydia and empiric treatment for non-gonococcal urethritis, will be frequently given together with zoliflodacin because gonorrhea and chlamydia coinfections are common. In a previous static in vitro study, it was indicated that doxycycline/tetracycline inhibited the gonococcal killing of zoliflodacin in 6-h time-kill curve analysis. In this study, our dynamic in vitro hollow-fiber infection model (HFIM) was used to investigate combination therapies with zoliflodacin and doxycycline. Dose-range experiments using the three gonococcal strains WHO F (susceptible to relevant therapeutic antimicrobials), WHO X (extensively drug-resistant, including ceftriaxone-resistant; zoliflodacin-susceptible), and SE600/18 (zoliflodacin-susceptible strain with GyrB S467N substitution) were conducted simulating combination therapy with a single oral dose of zoliflodacin 0.5-4g combined with a doxycycline daily oral dose of 200mg administered as 100mg twice a day, for 7days (standard dose for chlamydia treatment). Comparing combination therapy of zoliflodacin (0.5-4g single dose) plus doxycycline (200mg divided into 100mg twice a day orally, for 7days) to zoliflodacin monotherapy (0.5-4g single dose) showed that combination therapy was slightly more effective than monotherapy in the killing of N. gonorrhoeae and suppressing emergence of zoliflodacin resistance. Accordingly, WHO F was eradicated by only 0.5g single dose of zoliflodacin in combination with doxycycline, and WHO X and SE600/18 were both eradicated by a 2g single dose of zoliflodacin in combination with doxycycline; no zoliflodacin-resistant populations occurred during the 7-day experiment when using this zoliflodacin dose. When using suboptimal (0.5-1g) zoliflodacin doses together with doxycycline, gonococcal mutants with increased zoliflodacin MICs, due to GyrB D429N and the novel GyrB T472P, emerged, but both the mutants had an impaired biofitness. The present study shows the high efficacy of zoliflodacin plus doxycycline combination therapy using a dynamic HFIM that more accurately and comprehensively simulate gonococcal infection and their treatment, i.e., compared to static in vitro models, such as short-time checkerboard experiments or time-kill curve analysis. Based on our dynamic in vitro HFIM work, zoliflodacin plus doxycycline for the treatment of both gonorrhea and chlamydia can be an effective combination.

FRI378 Estetrol Prolongs Anagen In Healthy Female Scalp Hair Follicles By Positively Modulating Dermal Papilla Functions And Generation Of Progenitor Stem Cells Ex Vivo

Abstract Disclosure: C. Gerard: None. A. La Riche: None. S. Altendorf: None. V. Dion: None. L. Epping: None. T. Bíro: None. G. Dixon: None. M. Bertolini: None. The human hair follicle (HF) is a neuroendocrine mini-organ that responds to, but also generates, a wide range of hormones, which affect hair cycle and HF biology. HF functions are profoundly regulated by several intrafollicular neuroendocrine axes like the HF-equivalent of the hypothalamic-pituitary-adrenal and thyroid axes, as well as by local prolactin secretion. In this regard, estrogens exert a direct role in hair cycle regulation, since estrogen receptors are prominently expressed in the epithelium of scalp HFs. It has been shown that postmenopausal women increasingly experience female pattern hair loss (FPHL) due to the decrease in ovarian estrogen secretion. Conversely, elevated estrogen levels were found to correlate with enhanced numbers of anagen HFs during pregnancy. Estetrol (E4) is a natural estrogen produced by the fetal liver during pregnancy. E4 was recently approved as the estrogenic component of a new combined oral contraceptive and is currently in the late stage of clinical development for its use as a menopausal hormone therapy. In this study, we aimed to assess the capacity of E4 to regulate hair growth.Frontotemporal, full-length microdissected HFs from 4 healthy female donors (> 50 years) were exposed to different concentrations of E4 (300nM, 3µM and 30µM) ex vivo. Subsequently, hair cycle staging, hair matrix keratinocyte proliferation (Ki-67), dermal papilla (DP) inductivity (versican expression and alkaline phosphatase activity), fibroblast emigration (cell density in the DP, the dermal cup (DC) and the DP stalk), and the percentage of HFs stem cell (HFSC) progenitors (CD34+) was assessed by quantitative (immuno-)histomorphometry. E4 treatment led to a tendential (300nM and 30µM) or significant (3µM) increase in the number of anagen (growing) HFs, further supported by enhanced hair matrix keratinocyte proliferation. Although neither size nor cell density of DP was affected by the treatment with E4, a significant lower number of cells was detected in the DP stalk and DC, indicating less DP fibroblast emigration. Additionally, E4 treatment stimulated DP fibroblast inductivity as evidenced by a tendential up-regulation of versican expression and alkaline phosphatase activity in the DP, the latter even significantly in only anagen HFs. Moreover, application of 3µM E4 positively affected the generation of stem cell progeny by significantly increasing the percentage of CD34+ cells in the suprabulbar outer root sheath. Taken together, our data suggest that treatment with E4 boosts anagen maintenance, reduces DP fibroblast emigration, stimulates DP inductivity and promotes the expansion of HFSC progeny. Thus, these findings point at a potential role of E4 to prevent catagen development and changes known to be involved in HF miniaturization, and further encourage the exploration of E4 as possible treatment strategy for hair loss disorders such as FPHL. Presentation: Friday, June 16, 2023