The comparability tales: A phase-appropriate roadmap for CGT drug product development.

Cell and gene therapies (CGTs) have revolutionized patient outcomes and provided care options for previously untreatable conditions. The clinical and commercial progress of CGT therapies is hindered by chemistry, manufacturing, and control (CMC) challenges. This article summarizes recommendations from the 2023 Annual Meeting CMC sessions wherein speakers advocated for science-driven comparability strategies, proactive risk assessments, clearer regulatory guidance, and a shift from retrospective to prospective studies. Planning for manufacturing changes, statistical approaches, and consideration of multiple product versions also emerged as crucial elements to help sponsors navigate CMC hurdles for successful CGT clinical and commercial development.

Flow-through cell-based in vitro release method for triamcinolone acetonide poly (lactic-co-glycolic) acid microspheres.

The main objective of the current research was to develop a compendial flow-through cell apparatus based in vitro release testing method for sustained-release triamcinolone acetonide-loaded poly (lactic-co-glycolic) acid (PLGA) microspheres. Media-based and instrument-based parameters, such as surfactant type, concentration, media volume, flow rate, and testing temperature, were investigated. In addition, a detailed exploration was performed to reveal polymer degradation encompassing pore formation, channeling, and triamcinolone acetonide release from microspheres using freeze-fracture scanning electron microscopy. The developed USP apparatus 4 method demonstrated more than 85% drug release from the microspheres in 12 days and showcased reproducibility between different microsphere batches. Large medium volume (15 times saturation solubility) at low surfactant concentration was identified as a critical media-based parameter, with potential application in testing of other sensitive poorly soluble drugs. At 35 °C, drug release via pore channeling to the surface was evident, whereas at 39 °C, drug release slowed due to polymer plasticization. It was demonstrated here for the first time that elevated temperature-accelerated testing does not work for all PLGA-based microsphere products.

Physical and Chemical Compatibility of Extended-Release Triamcinolone Acetonide (TA-ER) with Common Local Anesthetics.

INTRODUCTION: Intra-articular (IA) corticosteroids are used extensively for the treatment of patients with knee osteoarthritis pain. In clinical practice, local anesthetics are frequently combined with corticosteroids prior to IA injection to provide rapid-onset analgesia. From this common practice there is no evidence to suggest that the addition of local anesthetics to corticosteroid preparations, including triamcinolone acetonide (TA), alters the physical properties or efficacy of the corticosteroid. Triamcinolone acetonide extended-release (TA-ER, formerly FX006) is a novel, microsphere-based TA formulation that demonstrated analgesic efficacy in phase 2 and 3 randomized controlled trials. METHODS: The current study assessed the compatibility of TA-ER and lidocaine, ropivacaine, and/or bupivacaine in vitro. The TA-ER and local anesthetic mixtures were assayed for changes in syringeability, pH, particle size, percentage free drug, purity, and appearance compared with TA-ER alone. RESULTS: By these measures, the combination of local anesthetics with TA-ER did not negatively impact the chemical or physical properties of TA-ER when compared to TA-ER controls. CONCLUSION: These results demonstrate that lidocaine, bupivacaine, and ropivacaine are physically and chemically compatible with TA-ER, suggesting that local anesthetic solutions can be added to TA-ER preparations in clinical practice without adversely affecting TA-ER in vitro product characteristics. FUNDING: Flexion Therapeutics, Inc.

The high-fat high-fructose hamster as an animal model for niacin's biological activities in humans.

OBJECTIVE: Niacin has been used for more than 50 years to treat dyslipidemia, yet the mechanisms underlying its lipid-modifying effects remain unknown, a situation stemming at least in part from a lack of validated animal models. The objective of this study was to determine if the dyslipidemic hamster could serve as such a model. MATERIALS/METHODS: Dyslipidemia was induced in Golden Syrian hamsters by feeding them a high-fat, high-cholesterol, and high-fructose (HF/HF) diet. The effect of high-dose niacin treatment for 18 days and 28 days on plasma lipid levels and gene expression was measured. RESULTS: Niacin treatment produced significant decreases in plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and free fatty acids (FFA), but had no measureable effect on high-density lipoprotein cholesterol (HDL-C) in the dyslipidemic hamster. Niacin treatment also produced significant increases in hepatic adenosine ATP-Binding Cassette A1 (ABCA1) mRNA, ABCA1 protein, apolipoprotein A-I (Apo A-I) mRNA, and adipose adiponectin mRNA in these animals. CONCLUSIONS: With the exception of HDL-C, the lipid effects of niacin treatment in the dyslipidemic hamster closely parallel those observed in humans. Moreover, the effects of niacin treatment on gene expression of hepatic proteins related to HDL metabolism are similar to those observed in human cells in culture. The HF/HF-fed hamster could therefore serve as an animal model for niacin's lowering of proatherogenic lipids and mechanisms of action relative to lipid metabolism.

Design and synthesis of boronic acid inhibitors of endothelial lipase.

Endothelial lipase (EL) and lipoprotein lipase (LPL) are homologous lipases that act on plasma lipoproteins. EL is predominantly a phospholipase and appears to be a key regulator of plasma HDL-C. LPL is mainly a triglyceride lipase regulating (V)LDL levels. The existing biological data indicate that inhibitors selective for EL over LPL should have anti-atherogenic activity, mainly through increasing plasma HDL-C levels. We report here the synthesis of alkyl, aryl, or acyl-substituted phenylboronic acids that inhibit EL. Many of the inhibitors evaluated proved to be nearly equally potent against both EL and LPL, but several exhibited moderate to good selectivity for EL.

Standardized assessment of NAb responses elicited in rhesus monkeys immunized with single- or multi-clade HIV-1 envelope immunogens.

The genetic diversity of HIV-1 envelope glycoproteins (Env) remains a major obstacle to the development of an antibody-based AIDS vaccine. The present studies examine the breadth and magnitude of neutralizing antibody (NAb) responses in rhesus monkeys after immunization with DNA prime-recombinant adenovirus (rAd) boost vaccines encoding either single or multiple genetically distant Env immunogens, and subsequently challenged with a pathogenic simian-human immunodeficiency virus (SHIV-89.6P). Using a standardized multi-tier panel of reference Env pseudoviruses for NAb assessment, we show that monkeys immunized with a mixture of Env immunogens (clades A, B, and C) exhibited a greater breadth of NAb activity against neutralization-sensitive Tier 1 viruses following both vaccination and challenge compared to monkeys immunized with a single Env immunogen (clade B or C). However, all groups of Env-vaccinated monkeys demonstrated only limited neutralizing activity against Tier 2 pseudoviruses, which are more characteristic of the neutralization sensitivity of circulating HIV-1. Notably, the development of a post-challenge NAb response against SHIV-89.6P was similar in monkeys receiving either clade B, clade C, or clade A+B+C Env immunogens, suggesting cross-clade priming of NAb responses. In addition, vaccines encoding Env immunogens heterologous to SHIV-89.6P primed for a rapid anamnestic NAb response following infection compared to vaccines lacking an Env component. These results show that DNA/rAd immunization with multiple diverse Env immunogens is a viable approach for enhancing the breadth of NAb responses against HIV-1, and suggest that Env immunogens can prime for anamnestic NAb responses against a heterologous challenge virus.