FDA Approvals of Biologics in 2022

A target affinity enrichment workflow to characterize critical post-translational modifications within therapeutic antibodies

The therapeutic efficacy of a monoclonal antibody (mAb) relies on tight and specific binding to its intended target. This interaction may be abrogated or influenced by antibody fragmentation and/or post-translational modifications (PTMs) on or near the paratope. PTMs with reduced target affinity are considered impactful to drug quality and should be well-characterized during pharmaceutical development. The task of identifying and characterizing these PTMs can be facilitated by employing a strategy which utilizes semi-preparative affinity chromatography using an immobilized ligand target. Here, we present a proof-of-concept application of this strategy for a therapeutic antibody targeting a Type I cytokine receptor. Briefly, a sub-molar equivalent of the therapeutic antibody was applied to a column containing the immobilized receptor target. Fractions containing antibody variants with differential affinity to target were collected and evaluated by a panel of extended characterization assays, including size, charge, target-binding affinity, and cell-based potency. This approach specifically targets variants based on ligand affinity and enabled the identification of novel and specific PTMs, including Fab glycosylation, which were shown to be impactful to drug quality and could be considered critical quality attributes (CQAs). Furthermore, characterization of affinity-enriched fractions using assays that are orthogonal and complimentary to those used for release could guide or support the development of such assays which are sufficiently sensitive to detect these PTMs during product release.

Analytical Methodologies for Anti-Infective Orphan Drugs: A Comprehensive Review of FDA Approvals (2013-2023) Part 1

Most orphan diseases, which affect small patient populations, are chronic, incurable and often lead to early death. Due to small market size, orphan drugs developed to address these diseases receive little attention from the pharmaceutical industry. This lack of interest also applies to the development of analytical methods, which are crucial for drug analysis and quality control. Analysis of orphan drugs faces challenges, including a lack of reference standard and an inadequate number of samples for testing. In addition, constant adjustment of analytical techniques is demanded due to the lengthy development process. Financial constraints further hinder the advancement of analytical techniques since orphan drugs represents a narrow niche market and the pharmaceutical industry often focuses on research with greater impact, causing orphan drugs to be deprioritized. This review summarizes the analytical methods developed for US FDA-approved anti-infective orphan drugs (except antivirals) in the period between 2013 to 2023, covering in depth small molecules and broadly biologics in numerous dosage forms and biological samples. It covers the most common reported analytical methods, such as liquid chromatography, TLC, spectroscopy, and electrochemical analysis. This review highlights the crucial need for the continuous development of new analytical techniques to support the development and quality control of orphan drugs.

Food and Drug Administration (FDA) Approvals of Biological Drugs in 2023

An increase in total drug (small molecules and biologics) approvals by the Food and Drug Administration (FDA) was seen in 2023 compared with the previous year. Cancer remained the disease most targeted by monoclonal antibodies (mAbs), followed by autoimmune conditions. Our data reveal the prevalence of approvals for biologics even during years when the total number of authorizations was low, such as in 2022. Over half the drugs that received the green light in 2023 benefited from expedited programs, as the incidence of many diseases increased. In addition, over half of the biologics approved received Orphan Drug Designation from the FDA. This narrative review delves into details of the most significant approvals in 2023, including mAbs, enzymes, and proteins, explaining their mechanisms of action, differences from previous drugs, placebo, and standards of care, and outcomes in clinical trials. Given the varying number of drugs authorized annually by the U.S. health authority, this review also examines the limits of external influences over the FDA's decisions and independence regarding drug approvals and withdrawals.

Leucine as a Moisture-Protective Excipient in Spray-Dried Protein/Trehalose Formulation

The incorporation of leucine (Leu), a hydrophobic amino acid, into pharmaceutically relevant particles via spray-drying can improve the physicochemical and particulate properties, stability, and ultimately bioavailability of the final product. More specifically, Leu has been proposed to form a shell on the surface of spray-dried (SD) particles. The aim of this study was to explore the potential of Leu in the SD protein/trehalose (Tre) formulation to control the water uptake and moisture-induced recrystallization of amorphous Tre, using lysozyme (LZM) as a model protein. LZM/Tre (1:1, w/w) was dissolved in water with varied amounts of Leu (0 - 40%, w/w) and processed by spray-drying. The solid form, residual moisture content (RMC), hygroscopicity, and morphology of SD LZM/Tre/Leu powders were evaluated, before and after storage under 22°C/55% RH conditions for 90 and 180 days. The X-ray powder diffraction results showed that Leu was in crystalline form when the amount of Leu in the formulation was at least 20% (w/w). Thermo-gravimetric analysis and scanning electron microscopy results showed that 0%, 5%, and 10% (w/w) Leu formulations led to comparable RMC and raisin-like round particles. In contrast, higher Leu contents resulted in a lower RMC and increased surface corrugation of the SD particles. Dynamic vapor sorption analysis showed that partial recrystallization of amorphous Tre to crystalline Tre·dihydrate occurred in the 0% Leu formulation. However, adding as little as 5% (w/w) Leu inhibited this recrystallization during the water sorption/desorption cycle. In addition, after storage, the formulations with higher Leu contents showed reduced water uptake. Instead of observing recrystallization of amorphous Tre in 0%, 5%, and 10% (w/w) Leu formulations, recrystallization of amorphous Leu was noted in the 5% and 10% (w/w) Leu formulations after storage. In summary, our study demonstrated that the addition of Leu has the potential to reduce water uptake and inhibit moisture-induced recrystallization of amorphous Tre in the SD protein/Tre powder system.

Treatment patterns and factors associated with discontinuation of monoclonal antibodies

Background

Biological agents have revolutionized care in specialties such as oncology, immunology, infectious diseases, and genetic disorders, offering targeted actions on specific molecules or select immune cells. Monoclonal antibodies, known for their high specificity and precision, represent one of the most significant and rapidly expanding categories of these agents. Understanding the drug utilization patterns of monoclonal antibodies is crucial to ensure their optimal use, especially given their high cost and potential adverse effects.

Methods

This analytical cross-sectional study was conducted in a secondary hospital in the United Arab Emirates. Patients of either gender receiving monoclonal antibodies at the study site were included. Treatment patterns, utilization, and factors associated with the discontinuation of monoclonal antibodies were assessed.

Results

Hyperlipidemia (136, 39.1%) was the most common indication for monoclonal antibodies, followed by prophylaxis of respiratory syncytial virus infection in congenital heart disease (104, 29.9%) and osteoporosis (42, 12.1%). Evolocumab was the most commonly prescribed monoclonal antibody (135, 38.8%), followed by palivizumab (104, 29.9%), and dupilumab (38, 10.9%). The majority of monoclonal antibodies demonstrated a prescribed daily dose to defined daily dose ratio of 1.0, reflecting their appropriate utilization. One hundred twenty-nine patients (37.0%) discontinued their treatment during the study. Patient's level of education (OR: 0.416, 95% CI: 0.183-0.943, p = 0.036), BMI (OR: 2.358, 95% CI: 1.164-4.777, p = 0.017), number of concomitant medications (OR: 2.457, 95% CI: 1.202-5.025, p = 0.014), and treatment duration (OR: 9.180, 95% CI: 4.909-17.165, p < 0.001) were identified as predictors of discontinuation of monoclonal antibodies.

Conclusion

This study represents the first comprehensive investigation in the United Arab Emirates focused on treatment patterns, utilization, and discontinuation of monoclonal antibodies among the local population. Monoclonal antibodies were prescribed for the management of a wide range of clinical conditions. The study reports appropriate utilization of most monoclonal antibodies and identifies factors such as patient education level, BMI, concomitant medications, and treatment duration as independent predictors of monoclonal antibody treatment discontinuation.

An insight into the pharmacology of cysteine/methionine containing peptide drugs

Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for -SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.

Impact of Excipient Extraction and Buffer Exchange on Recombinant Monoclonal Antibody Stability

The foundation of a biosimilar manufacturer's regulatory filing is the demonstration of analytical and functional similarity between the biosimilar product and the pertinent originator product. The excipients in the formulation may interfere with characterization using typical analytical and functional techniques during this biosimilarity exercise. Consequently, the producers of biosimilar products resort to buffer exchange to isolate the biotherapeutic protein from the drug product formulation. However, the impact that this isolation has on the product stability is not completely known. This study aims to elucidate the extent to which mAb isolation via ultrafiltration-diafiltration-based buffer exchange impacts mAb stability. It has been demonstrated that repeated extraction cycles do result in significant changes in higher-order structure (red-shift of 5.0 nm in fluorescence maxima of buffer exchanged samples) of the mAb and also an increase in formation of basic variants from 19.1 to 26.7% and from 32.3 to 36.9% in extracted innovator and biosimilar Tmab samples, respectively. It was also observed that under certain conditions of tertiary structure disruptions, Tmab could be restabilized depending on formulation composition. Thus, mAb isolation through extraction with buffer exchange impacts the product stability. Based on the observations reported in this paper, we recommend that biosimilar manufacturers take into consideration these effects of excipients on protein stability when performing biosimilarity assessments.

Trends in the Development of Antibody-Drug Conjugates for Cancer Therapy

In cancer treatment, the first-generation, cytotoxic drugs, though effective against cancer cells, also harmed healthy ones. The second-generation targeted cancer cells precisely to inhibit their growth. Enter the third-generation, consisting of immuno-oncology drugs, designed to combat drug resistance and bolster the immune system's defenses. These advanced therapies operate by obstructing the uncontrolled growth and spread of cancer cells through the body, ultimately eliminating them effectively. Within the arsenal of cancer treatment, monoclonal antibodies offer several advantages, including inducing cancer cell apoptosis, precise targeting, prolonged presence in the body, and minimal side effects. A recent development in cancer therapy is Antibody-Drug Conjugates (ADCs), initially developed in the mid-20th century. The second generation of ADCs addressed this issue through innovative antibody modification techniques, such as DAR regulation, amino acid substitutions, incorporation of non-natural amino acids, and enzymatic drug attachment. Currently, a third generation of ADCs is in development. This study presents an overview of 12 available ADCs, reviews 71 recent research papers, and analyzes 128 clinical trial reports. The overarching objective is to gain insights into the prevailing trends in ADC research and development, with a particular focus on emerging frontiers like potential targets, linkers, and drug payloads within the realm of cancer treatment.

Stimuli-Responsive Hydrogels for Protein Delivery

Proteins and peptides are potential therapeutic agents, but their physiochemical properties make their use as drug substances challenging. Hydrogels are hydrophilic polymeric networks that can swell and retain high amounts of water or biological fluids without being dissolved. Due to their biocompatibility, their porous structure, which enables the transport of various peptides and proteins, and their protective effect against degradation, hydrogels have gained prominence as ideal carriers for these molecules' delivery. Particularly, stimuli-responsive hydrogels exhibit physicochemical transitions in response to subtle modifications in the surrounding environment, leading to the controlled release of entrapped proteins or peptides. This review is focused on the application of these hydrogels in protein and peptide delivery, including a brief overview of therapeutic proteins and types of stimuli-responsive polymers.