Micropharma (Canada)

ABSTRACT Protollin, a nasal adjuvant, was evaluated in a randomized double-blind phase 1 study of 16 early Alzheimer’s disease (AD) patients to determine safety and to assess its immunomodulatory effects. In a double-blind dose escalation study, subjects received nasal Protollin at doses of 0.1mg, 0.5mg, 1.0mg, and 1.5mg or placebo twice over a two-week period. Treatment was well-tolerated with minimal side effects. Transcriptomic and single-cell analyses demonstrated that prior to treatment, AD blood monocytes had downregulation of phagocytosis-related genes and an increased pro-inflammatory signature. These AD monocyte abnormalities were reversed by nasal Protollin beginning at a dose of 1.0mg. Protollin induced a robust phagocytic gene signature, including upregulation of CD36 , ITGAL , LYST , and FCGR1A . A similar phagocytic signature was observed in brain- infiltrating amyloid-clearing monocytes in an APP Tg mouse model treated with nasal Protollin. Protollin treatment decreased the expression of costimulatory molecules on monocytes and decreased CD8+ T cell activation and cytotoxicity. Our results provide the basis for a phase 2 study of nasal Protollin in subjects with AD in which nasal Protollin at a dose of 1.0 mg will be administered weekly over 6 months to modulate peripheral immunity and clear amyloid from the brain. ClinicalTrials.gov registration no NCT07187141 .

Bone metastases are a significant clinical problem in many major cancers, especially in breast and prostate cancer where 70-90% of advanced patients develop bone metastases. Myeloma bone disease is associated with similar clinical problems than bone metastases, including increased risk of fractures and bone pain that decrease the quality of life. Current cancer therapies can only partially decrease tumor growth, resulting in only 5% of bone metastatic patients being alive 5 years after the diagnosis. Bone metastases are therefore a high unmet medical need with a high demand for effective therapies. Lack of appropriate preclinical bone metastasis models that would exhibit the same clinical features that are observed in bone metastatic patients has made it difficult to advance therapy development at early stages. This study describes the establishment of three preclinical bone metastasis models, a breast cancer model using 4T1 mouse triple-negative breast cancer cells in BALB/c mice, a prostate cancer model using RM-1 mouse androgen-insensitive prostate cancer cells in C57BL/6 mice, and a multiple myeloma model using human RPMI 8226 cells in immunodeficient NPG mice. The cancer cells were inoculated intratibially into the bone marrow to model tumor growth in bone. Tumor growth was monitored by bioluminescence imaging (BLI), cancer-induced bone changes by X-ray imaging, and bone pain by Von Frey filaments (mechanical allodynia). In the 4T1 breast cancer model, 100% of the mice had bone metastases at day 7, and maximum study duration was 21 days. Osteolytic bone lesions were clearly observed and bone pain was detected at day 7. In the RM-1 prostate cancer model, 83% of the mice had bone metastases at day 7, and 100% of the mice at day 14, and maximum study duration was 28 days. Bone pain was observed at day 7, and osteolytic-mixed bone metastases were visible at day 14. In the RPMI 8226 multiple myeloma model, 100% tumor take rate was detected at day 7. Osteolytic bone metastases were visible at day 21, and maximum study duration was 100 days. We have established a clinically relevant Bone Metastasis Technology Platform (BMTP©) that currently includes preclinical bone metastasis models for breast and prostate cancer and multiple myeloma. These models have clinical features that are similar to those observed in bone metastatic patients. In preclinical models established in BMTP, tumor burden is monitored by BLI, the type and extent of cancer-induced bone loss is visualized by X-ray imaging, and bone pain is analyzed to provide a clinically relevant readout about the quality of life. We conclude that BMTP is a clinically relevant translational tool for evaluating efficacy of cancer therapies on bone metastasizing cancers. Citation Format: Tiina E. Kähkönen, Jie Wen, Ru Yang, Yuyang Xu, Michael Zhang, Jussi M. Halleen. Bone Metastasis Technology Platform: Establishing clinically relevant bone metastasis models for breast and prostate cancer and multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3927.

Abstract Disclosure: G. Schang: Employee; Self; 35Pharma. M. De Molliens: Employee; Self; 35Pharma. E. Brule: Employee; Self; 35Pharma. C. Chauvet: Employee; Self; 35Pharma. J. Denis: Employee; Self; 35Pharma. A. Sours: Employee; Self; 35Pharma. V. Ganesh: Employee; Self; 35Pharma. G. Tremblay: Employee; Self; 35Pharma. J. Schoelermann: Employee; Self; 35Pharma. M. O'Connor: Employee; Self; 35Pharma. Introduction: Novel anti-obesity medications including incretin mimetics have revolutionized the pharmacotherapy of obesity and type 2 diabetes, leading to unprecedented weight loss and clinically meaningful improvement of glucose metabolism and cardiometabolic health. However, incretins reduce body mass in a non-selective manner; both fat mass and lean mass are lost with incretin treatment. In obese patients treated with incretins, undesirable loss of lean body mass (LBM) can account for up to 40% of overall weight loss. Loss of LBM negatively impacts resting metabolic rate, leading to a weight loss plateau and often unsustainable results. Furthermore, individuals with sarcopenia, characterized by low muscle mass and strength, are at greater risk for heart failure. The preservation, or even increase, of LBM is therefore a desirable treatment goal for obesity pharmacotherapy and overall cardiometabolic health. Activins and growth differentiation factors (GDFs), which are members of the TGF-beta superfamily, are validated targets controlling body composition and metabolism. Specifically, blockade of activins and GDFs has anabolic effects in metabolically active tissues such as skeletal muscle and brown adipose tissue, while reducing white adipose tissue mass. Therefore, specific and selective blockade of activins and GDFs represents a novel anti-obesity treatment strategy which can act orthogonally to current anti-obesity medications. HS235 is an activin receptor ectodomain-based (ActR) Fc-fusion protein that has been rationally designed to attain optimal inhibition of ligands controlling body composition in obesity. Methods: A structure-assisted rational molecular engineering approach coupled with cell-based potency screening was employed to design HS235. To validate the anti-obesogenic potential of HS235, diet-induced obese (DIO) mice were injected with HS235, an incretin mimetic, or a combination of both. Fat mass, LBM, muscle weights, and biomarker readouts were assessed at the end of study. Results: In cell-based assays, HS235 potently and selectively neutralized activins and GDFs implicated in body composition. This translated to complete in vivo target engagement and pharmacodynamic response. In a DIO mouse model, both HS235 and the incretin mimetic significantly improved metabolic parameters and decreased fat mass, but only HS235 increased LBM, while incretin-based treatment led to LBM loss. Importantly, the addition of HS235 to the incretin mimetic lead to a synergistic fat mass loss and prevented loss of LBM. Conclusion: Potent and selective inhibition of activins and GDFs by HS235 represents a novel LBM preserving weight loss strategy orthogonal to incretin mimetics. Collectively, these data support the development of HS235 as a novel anti-obesity agent to complement currently approved incretin-based medications to improve quality of weight loss. Presentation: 6/3/2024

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants associated with a wide variety of adverse human health outcomes. PCB 126 and PCB 153 are among the most prevalent congeners associated with human exposure. Emerging studies have suggested that PCB exposure leads to lower gut microbial diversity although their effects on microbial production of health promoting short-chain fatty acids (SCFAs) has been scarcely studied. Blue potatoes are rich in anthocyanins (ACNs), which is a class of polyphenols that promote the growth of beneficial intestinal bacteria such as Bifidobacterium and Lactobacillus and increase the generation of SCFAs. A batch-culture, pH-controlled, stirred system containing human fecal microbial communities was utilized to assess whether human gut microbiota composition and SCFA production are affected by: (a) PCB 126 and PCB 153 exposure; and (b) ACN-rich digests in the presence and absence of the PCB congeners. Anthocyanin-rich blue potato meals (11.03 g) were digested over 12 h with and without PCB 126 (0.5 mM) and PCB 153 (0.5 mM) using an in vitro simulated gut digestion model involving upper gastrointestinal digestion followed by metabolism by human fecal microbiota. Fecal digests were collected for analysis of gut microbial and SCFA profiles. Polychlorinated biphenyl-exposed fecal samples showed a significant (p < 0.05) decrease in species richness and a significantly (p < 0.05) different microbial community structure. PCB treatment was associated with an increased (p < 0.05) relative abundance of Akkermansia, Eggerthella, and Bifidobacterium and a decreased (p < 0.05) relative abundance of Veillonella, Streptococcus, and Holdemanella. ACN digests counteracted the altered abundances of Akkermansia and Bifidobacterium seen with the PCB treatment. PCB exposure was associated with a significant (p < 0.05) decrease in total SCFA and acetate concentrations. ACN digests were associated with significantly (p < 0.05) higher SCFA and acetate concentrations in the presence and absence of PCBs. Human fecal matter exposed to PCB 126 and PCB 153 led to decreased abundance and altered gut microbiota profiles as well as lowered SCFA and acetate levels. Importantly, this study showed that prebiotic ACN-rich potatoes counteract PCB-mediated disruptions in human gut microbiota profiles and SCFA production.

Abstract Prostate cancer is the most common cancer, and the second leading cause of cancer death, among men in the United States. Metastatic castration-resistant prostate cancer (mCRPC) is an advanced stage of disease in which patients ultimately fail androgen-deprivation therapies and exhibit a poor survival rate. Recently, prostate-specific membrane antigen (PSMA) has been validated as a prostate cancer tumor antigen with its over-expression in prostate tumors and low level of expression in select normal tissues. Using an expanded genetic code to create Engineered Precision Biologics (EPBs), Ambrx has developed ARX517, an anti-PSMA targeted next-generation antibody drug conjugate (ADC), for treatment of mCRPC patients. ARX517 is composed of a humanized anti-PSMA antibody site-specifically conjugated to drug linker AS269 (a potent tubulin inhibitor), yielding a drug-to-antibody ratio of 2. After binding to PSMA expressed on the surface of tumor cells, ARX517 is internalized and delivers a cytotoxic payload which inhibits tubulin polymerization and induces cellular apoptosis. In vitro testing of ARX517 in prostate cancer cell lines with variable PSMA expression demonstrated highly specific and potent sub-nanomolar activity in cells with high PSMA expression. To minimize premature payload release, ARX517 employs a non-cleavable PEG linker and stable oxime conjugation chemistry to enhance stability in circulation. ARX517 exhibited a long terminal half-life and high serum exposure in mice. The serum stability of ARX517 should effectively deliver more payload to target tumor cells, and in multiple CDX and PDX prostate cancer models, ARX517 showed dose-dependent anti-tumor activity in both enzalutamide-sensitive and enzalutamide-resistant models. Repeat dose toxicokinetic studies in non-human primates demonstrated ARX517 was tolerated at exposures well above therapeutic exposures in mouse pharmacology studies, indicating a wide therapeutic index. In summary, ARX517 elicited highly specific, potent cell killing in cell lines with high PSMA expression, inhibited tumor growth in enzalutamide-sensitive and enzalutamide-resistant CDX and PDX models, demonstrated a tolerable safety profile in cynomolgus monkeys, and has a clear therapeutic index based on preclinical serum exposure data. The strong preclinical data and recent clinical validation of PSMA as a mCRPC target provide rationale for evaluation of ARX517 as a potential prostate cancer treatment. ARX517 is currently in a Phase 1 dose escalation trial (ARX517-2011 [NCT04662580]) in the United States. Citation Format: Lillian Skidmore, David Mills, Ji Young Kim, Prathap Shastri, Nick A. Knudsen, Jeff Steen, Jay Nelson, Ying Buechler, Feng Tian, Shawn Zhang. Preclinical characterization of ARX517, a next-generation anti-PSMA antibody drug conjugate for the treatment of metastatic castration-resistant prostate cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3997.