Scientific considerations in the regulatory approval of generic (or biosimilar) version of enoxaparin sodium - A lifesaving carbohydrate polymer.

Enoxaparin sodium (Clexane®/Klexane®/Lovenox®) is one amongst the few drugs that have assumed a central role as drug of treatment and/or prevention against thromboembolic complications during COVID-19. The increase in demand resulting in many generic (or biosimilar) versions entering the market has increased the risks of quality and safety (including immunogenicity) related issues. Under the circumstances, development of stringent regulatory approaches has received much attention as investigation of new drug delivery systems for improved therapeutic activity. As one of the measures to increase quality testing and ensure uninterrupted supply of this life-saving drug globally, determination of enoxaparin molecular weight (MW) has been added in the United States Pharmacopoeia (USP) monograph for enoxaparin sodium. In addition, the presence of a unique 1,6-anhydro-ring structure at the reducing end of about 15-25% of the poly (oligo) saccharide chains of the generic (or biosimilar) product has been set as a mandatory requirement. This article presents an overview of the scientific considerations in the quality manufacturing and testing of the generic (or biosimilar) enoxaparin for regulatory review and approval. In certain cases of strong analytical similarity (structural and functional), abandonment of in vivo testing in animals and humans represents a major advancement in the approval of generic (or biosimilar) version of innovator enoxaparin sodium (lovenox®, injections).

Commercial Low Molecular Weight Heparins - Patent Ecosystem and Technology Paradigm for Quality Characterization.

Heparin is a subject of ever-growing interest for laboratory researchers and pharmaceutical industry. One of the driving factors is its critical life-saving drug status, which during the COVID-19 pandemic has assumed a central role in disease treatment and/or prevention. Apart, heparin is one amongst few drugs enjoying a "demand constant" status. In 2020, heparin market size was valued to US$6.5 bn., and given the ongoing stability in the COVID-19 health crisis, it is expected to reach US$11.43 bn. by 2027 with yearly growth rate momentum (CAGR) of 3.9% during the forecast period (Pepi et al., Mol Cell Proteomics 20:100,025, 2021). As patent is a limited monopoly, every year, many patents on low molecular weight heparin (LMWH; a chemically or enzymatically degraded product of unfractionated heparin) are losing market exclusivity worldwide, inviting the generic/biosimilar drug manufacturers to capture market share with cheaper drug products. By tracking patent expiration, drugs in patent litigation, regulatory setbacks for innovator companies (such as those seeking data exclusivity or patent term extension), or other unexpected events affecting market demand and competition, generics can make investment decisions in manufacturing off-patent LMWH drug products of commercial significance. However, given the US Food and Drug Administration (FDA), European Medicine Agency (EMA), Drug Regulatory Authority of Pakistan (DRAP), and other regulatory authorities scientifically rigorous standards for generic/biosimilar LMWH drug products marketing approval, the market is secured and momentous for drug makers that could demonstrate through scientific and clinical dataset that the generic/biosimilar LMWH drug product is of the same quality and purity as the innovator drug product. This study presents an overview of the patent landscape of commercially available LMWHs and advanced analytical techniques for their structural and biochemical characterization for quality control and quality assurance during manufacturing and post-marketing. The study also covers FDA, EMA, Health Canada, and DRAP's current approaches to evaluating the generic/biosimilar LMWH drug products for quality, safety including immunogenicity, and efficacy.

Biosimilars: A Comparative Study of Regulatory, Safety and Pharmacovigilance Monograph in the Developed and Developing Economies.

Epitomizing one of the rapidly maturing segments of pharmaceutical industry, biologics gestalt has severely implicated treatment algorithms of many life-threatening diseases especially in oncology, immunology, diabetes, and irresistible infections through integration of biologics in the clinical practice guidelines. As of 2021, the impact is expected to gain resilience as more patents on new biological drugs (such as Erbitux, Avastin, Orencis) are going off. Growing acceptance, trusting on stringent risk-benefits assessment, cost-effectiveness, and potential for return on investment, drive the global market of biosimilars is expected to remain steadfast in the following years; hence knowing about regulatory requirements for approval, opportunities, and barriers to biosimilars uptake in the biggest markets of USA, European Union, Canada, and Asia-Pacific (India and Pakistan) is warranted for development of effective biosimilars marketing strategies. This article reviews the biosimilars development from the beginning (historic) to the end (development & marketing approval perspectives) and then tries to present a clear picture on areas that are still uncertain concerning the biosimilars landscape especially the biologics effect on immunogenicity, the provocative issue of interchangeability, and extrapolation of indications.

A patent-based consideration of latest platforms in the art of directed evolution: a decade long untold story.

Directed (or in vitro) evolution of proteins and metabolic pathways requires tools for creating genetic diversity and identifying protein variants with new or improved functional properties. Besides simplicity, reliability, speed, versatility, universal applicability and economy of the technique, the new science of synthetic biology requires improved means for construction of smart and high-quality mutant libraries to better navigate the sequence diversity. In vitro CRISPR/Cas9-mediated mutagenic (ICM) system and machine-learning (ML)-assisted approaches to directed evolution are now in the field to achieve the goal. This review describes the gene diversification strategies, screening and selection methods, in silico (computer-aided), Cas9-mediated and ML-based approaches to mutagenesis, developed especially in the last decade, and their patent position. The objective behind is to emphasize researchers the need for noting which mutagenesis, screening or selection method is patented and then selecting a suitable restriction-free approach to sequence diversity. Techniques and evolved products subject to patent rights need commercial license if their use is for purposes other than private or experimental research.

Forty years of directed evolution and its continuously evolving technology toolbox: A review of the patent landscape.

Generating functional protein variants with novel or improved characteristics has been a goal of the biotechnology industry and life sciences, for decades. Rational design and directed evolution are two major pathways to achieve the desired ends. While rational protein design approach has made substantial progress, the idea of using a method based on cycles of mutagenesis and natural selection to develop novel binding proteins, enzymes and structures has attracted great attention. Laboratory evolution of proteins/enzymes requires new tools and analytical approaches to create genetic diversity and identifying variants with desired traits. In this pursuit, construction of sufficiently large libraries of target molecules to search for improved variants and the need for new protocols to alter the properties of target molecules has been a continuing challenge in the directed evolution experiments. This review will discuss the in vivo and in vitro gene diversification tools, library screening or selection approaches, and artificial intelligence/machine-learning-based strategies to mutagenesis developed in the last 40 years to accelerate the natural process of evolution in creating new functional protein variants, optimization of microbial strains, and transformation of enzymes into industrial machines. Analyzing patent position over these techniques and mechanisms also constitutes an integral and distinctive part of this review. The aim is to provide an up-to-date resource/technology toolbox for research-based and pharmaceutical companies to discover the boundaries of competitor's intellectual property (IP) portfolio, their freedom-to-operate in the relevant IP landscape, and the need for patent due diligence analysis to rule out whether use of a particular patented mutagenesis method, library screening/selection technique falls outside the safe harbor of experimental use exemption. While so doing, we have referred to some recent cases that emphasize the significance of selecting a suitable gene diversification strategy in directed evolution experiments.

Surgical salvage after failed irradiation for vestibular schwannoma.

OBJECTIVES/HYPOTHESIS: Compare vestibular schwannoma (VS) surgical outcome between patients with prior irradiation and those not previously treated. STUDY DESIGN: Retrospective review with matched control group. METHODS: Review of tumor adherence to the facial nerve, facial nerve grade, and complications in 38 patients with radiotherapy as a primary procedure before VS surgical removal and a matched random sample of 38 patients with primary surgery. The majority of the irradiated group had gamma knife radiation therapy. Mean time from irradiation to surgical salvage was 3.3 years (SD = 3.2), with a minimum of 5.2 months and a maximum of 15.8 years. Most (89.5%) patients in each group underwent a translabyrinthine approach. Mean tumor size at surgery was 2.6 cm in each group. RESULTS: The irradiated group had more moderate to severe adherence of tumor than the controls (89% vs. 63%, P < or = .01). They also had a lower rate of good facial function (House-Brackmann grade I/II) (37% vs. 70%) and a higher rate of poor function (grades V or VI) (50% vs. 18%) at follow-up (P < or = .019). Results were similar when including only those with good preoperative function (50% vs. 72% and 32% vs. 15%) but did not achieve statistical significance. Surgical time and complications did not differ. CONCLUSION: Patients who have undergone irradiation for VS and require surgical salvage may have a more difficult surgery and poorer outcomes than those not previously irradiated. When making their initial choice of treatment, patients should be counseled that surgery might be more difficult after failed stereotactic irradiation.

Intratympanic steroid injection for treatment of idiopathic sudden hearing loss.

OBJECTIVE: To conduct a clinical trial of intratympanic steroid injection for idiopathic sudden sensorineural hearing loss in subjects who failed oral steroid therapy. STUDY DESIGN AND SETTING: Open-label methylprednisolone injection clinical trial in a tertiary neurotologic referral center. Twenty subjects (14 males; 6 females) received 4 injections within a 2-week period (4 days apart). Hearing, dizziness, and tinnitus were evaluated before and after treatment. RESULTS: There were no serious unexpected adverse events and 2 types of expected adverse events (tympanic membrane perforation, nausea after injection). No increases in dizziness or tinnitus lasting longer than 24 hours were observed after injections. One of 20 (5%) improved to near-normal hearing. In addition, there was statistically significant improvement in 4-frequency pure-tone average and speech discrimination score at 1 month after treatment. CONCLUSION: Four intratympanic injections of methylprednisolone improved pure-tone average or speech discrimination scores for a subset of sudden hearing loss subjects that failed to benefit from oral steroids. SIGNIFICANCE: A clinical trial of intratympanic injections for idiopathic sudden hearing loss was successfully completed and promising results were found.

MRI evaluation of neurofibromatosis 2 patients: a standardized approach for accuracy in interpretation.

OBJECTIVE: To determine the level of agreement between local radiologists' and an experienced neuroradiologist's measurements of vestibular schwannomas. STUDY DESIGN: Prospective study with uniform magnetic resonance acquisition protocol parameters and reporting instructions across 30 magnetic resonance imaging facilities worldwide. SETTING: Multicenter natural history study of neurofibromatosis Type 2. SUBJECTS: One hundred fifteen magnetic resonance imaging examinations of 57 neurofibromatosis Type 2 patients older than 5 years of age. INTERVENTIONS: Thin-slice, postcontrast cranial magnetic resonance imaging. MAIN OUTCOME MEASURES: Spearman's rho interobserver association coefficient of vestibular schwannoma linear measurements. RESULTS: The local and experienced radiologist measurements and identification of tumors agreement was fair (kappa = 0.77). Discordant interpretations were adjudicated by another experienced neuroradiologist. CONCLUSION: The least interobserver variability was found in measurements of thin-slice postcontrast magnetic resonance imaging scans obtained at neurofibromatosis Type 2 centers in patients without previous operations and moderately sized tumors. If the schwannoma was difficult to assess, because of magnetic resonance imaging acquisition protocol, postoperative changes, or tumors smaller than 5 mm in greatest diameter, the neuroradiologist provided a more thorough assessment. The authors suggest uniform reporting criteria for vestibular schwannoma assessments to ensure clinically relevant information is communicated regarding vestibular schwannoma size.

Oral steroid regimens for idiopathic sudden sensorineural hearing loss.

OBJECTIVE: To determine hearing recovery in patients with idiopathic sudden hearing loss treated with varying amounts of oral steroids. STUDY DESIGN AND SETTING: A retrospective chart review (n = 75) in a tertiary care clinic examined sudden hearing loss patients treated with 1 60-mg prednisone taper, 1 course of steroid less than a 60-mg taper, or any 2 courses of oral steroid. RESULTS: Overall, 35% of the patients recovered a clinically significant amount of hearing. Recovery was associated with immediate treatment (within 2 weeks from onset), better hearing at the onset of treatment, and treatment with the higher dose of prednisone in patients with just 1 additional symptom (dizziness or tinnitus). Patients tended to continue to experience some recovery in hearing up to 4 months after treatment. CONCLUSION: Immediate treatment of patients with unilateral idiopathic sudden hearing loss and additional symptoms (dizziness or tinnitus) with a 14-day course of 60 mg prednisone (with taper) is recommended. EBM RATING: B-3.

Randomized double-blinded, placebo-controlled clinical trial of famciclovir for reduction of Ménière's disease symptoms.

OBJECTIVE: To conduct a clinical trial of famciclovir for symptom control in Meniere's disease. STUDY DESIGN AND SETTING: Randomized, double-blinded placebo-controlled clinical trial in a tertiary referral center, with 12 subjects in the active treatment arm and 11 subjects in the placebo arm. RESULTS: There were no serious adverse events. Twenty-five percent of the famciclovir group and 18% of the placebo group showed a reduction in number of vertigo spells, the primary efficacy endpoint. This difference was not statistically significant. All subjects improved in dizziness and health-related quality of life. There was a trend for the famciclovir arm to have less fluctuation in hearing relative to the placebo arm. CONCLUSION: No dramatic effects of famciclovir were found on vertigo or dizziness. Some promising effects on reduction of the fluctuation in hearing were observed. SIGNIFICANCE: Famciclovir may suppress the fluctuation of hearing in Meniere's disease, but had a minimal effect on vertigo or dizziness symptoms in this study. The probable multifactorial etiology in Meniere's disease requires that further studies be conducted to determine the effects of antiviral medications. EBM RATING: A.

Vestibular schwannoma growth rates in neurofibromatosis type 2 natural history consortium subjects.

OBJECTIVE: To determine the amount of growth in vestibular schwannomas in Neurofibromatosis type 2 (NF2) patients from diagnosis through short-term (up to 2 yr) and long-term (up to 4 yr) follow-up. STUDY DESIGN: Retrospective magnetic resonance imaging (MRI) films were obtained on subjects enrolled in the NF2 Natural History study and examined for changes in vestibular schwannoma size over time. SETTING: Data were collected from nine foreign and domestic NF2 centers, including hospital-based, academic, and tertiary care centers. SUBJECTS: NF2 patients with MRI data and at least one follow-up examination within 9 months to 2 years of diagnosis were included; n=56 patients with 84 lesions for evaluation of growth. INTERVENTION: Routine, clinically obtained, magnetic resonance images were digitized and measured using image management software. Short-term follow-up was defined as up to 2 years (n=84 lesions), and long-term follow-up was defined as 3 to 4 years (n=29 lesions). OUTCOME MEASURES: Vestibular schwannoma size was assessed using anterior-posterior, medial-lateral, and greatest diameter linear measurements. RESULTS: Vestibular schwannomas increased in size (at least 5 mm) in 8% of the vestibular schwannomas across short-term follow-up. At long-term follow-up, 13% of the tumors had increased in size. On average, schwannomas increased in greatest diameter 1.3 mm per year across short-term follow-up. CONCLUSION: Slightly greater than 1 in 10 diagnosed NF2-related vestibular schwannomas increased in size by at least 5 mm by 4 years of follow-up, if still untreated at that time.

Hearing changes after diagnosis in neurofibromatosis type 2.

OBJECTIVE: Describe the changes in hearing ability and progression of disease over time in subjects with neurofibromatosis Type 2 enrolled in a multicenter natural history study of vestibular schwannomas in neurofibromatosis Type 2. STUDY DESIGN: Retrospective clinical study. SETTING: International neurofibromatosis Type 2 tertiary care centers. PATIENTS: Study participants had a clinical diagnosis of neurofibromatosis Type 2, at least one untreated vestibular schwannoma, and were at least 5 years old. Sixty-three subjects (108 ears) with audiology data at either short-term follow-up (7 mo-2 yr) or long-term follow-up (3-5 yr) after diagnosis were examined in this study. MAIN OUTCOME MEASURES: Changes in four-frequency pure-tone average and speech discrimination score before any treatment intervention for both follow-up intervals. RESULTS: Within 2 years of the diagnosis of neurofibromatosis Type 2, 27% of the ears experienced a significant loss in pure-tone average relative to diagnosis, and 73% of the ears experienced no significant change in hearing. CONCLUSION: Newly diagnosed neurofibromatosis Type 2 patients who do not require immediate treatment of both vestibular schwannomas are likely to have stable hearing in the unoperated ear(s) for approximately 1 to 2 years.