Berotralstat (BCX7353) is a novel oral prophylactic treatment for hereditary angioedema: Review of phase II and III studies

Fluorine in the pharmaceutical industry: Synthetic approaches and application of clinically approved fluorine-enriched anti-infectious medications

The strategic integration of fluorine atoms into anti-infectious agents has become a cornerstone in the field of medicinal chemistry, owing to the unique influence of fluorine on the chemical and biological properties of pharmaceuticals. This review examines the synthetic methodologies that enable the incorporation of fluorine into anti-infectious drugs, and the resultant clinical applications of these fluorine-enriched compounds. With a focus on clinically approved medications, the discussion extends to the molecular mechanisms. It further outlines the specific effects of fluorination, which contribute to the heightened efficacy of anti-infective therapies. By presenting a comprehensive analysis of current drugs and their developmental pathways, this review underscores the continuing evolution and significance of fluorine in advancing anti-infectious treatment options. The insights offered extend valuable guidance for future drug design and the development of next-generation anti-infectious agents.

Once-Daily Oral Berotralstat for Long-Term Prophylaxis of Hereditary Angioedema: The Open-Label Extension of the APeX-2 Randomized Trial

BACKGROUND

Berotralstat is a first-line, once-daily oral plasma kallikrein inhibitor approved for prophylaxis of hereditary angioedema (HAE) attacks in patients 12 years or older.

OBJECTIVE

This analysis examined the safety and effectiveness of long-term prophylaxis with berotralstat.

METHODS

APeX-2 was a phase 3, parallel-group, multicenter trial in patients with HAE caused by C1-inhibitor deficiency (NCT03485911). Part 1 was a randomized, double-blind, placebo-controlled evaluation of 150 and 110 mg of berotralstat over 24 weeks. In part 2, berotralstat-treated patients continued the same treatment, and placebo-treated patients were re-randomized to 150 or 110 mg of berotralstat for 24 weeks. In part 3, all patients were treated with open-label berotralstat at 150 mg, which could be continued for up to an additional 4 years. In part 3, the primary endpoint was long-term safety and tolerability. Secondary endpoints included HAE attack rates and quality of life (QoL).

RESULTS

Eighty-one patients entered part 3. Treatment-emergent adverse events (TEAEs) occurred in 82.7% of patients, with most being mild or moderate in severity. The most common TEAEs were nasopharyngitis, urinary tract infection, abdominal pain, arthralgia, coronavirus infection, and diarrhea. Drug-related TEAEs occurred in 14.8% of patients, but none were serious. For patients who completed 96 weeks of berotralstat treatment (n = 70), the mean (standard error) change in attack rate from baseline was -2.21 (0.20) attacks/mo. Clinically meaningful improvements in QoL were also observed, with the largest improvements in the functioning domain.

CONCLUSION

Berotralstat was generally well tolerated, provided rapid and sustained reductions in HAE attacks and improved QoL over 96 weeks.

An expert panel's review on patients with hereditary angioedema switching from attenuated androgens to oral prophylactic therapy

Background: Hereditary angioedema (HAE) is a rare condition marked by swelling episodes in various body parts, including the extremities, upper airway, face, intestinal tract, and genitals. Long-term prophylaxis (LTP), prescribed to control recurring HAE attacks, is integral to its management. Previously, attenuated androgens (AAs) were the only oral LTP options. However, in 2020, berotralstat, an oral plasma kallikrein inhibitor, was approved in the United States. A 2018 survey of adults with HAE type I or type II showed that almost all the patients who used prophylactic HAE medication preferred oral treatment (98%) and felt that it fit their lifestyle better than injectable treatment (96%). Still, guidelines lack consensus on transitioning patients from AAs to alternative oral prophylactic therapy. Objective: This paper aims to share expert insights and patient feedback on transitioning from AAs to berotralstat, an alternative oral prophylactic therapy, from the perspective of clinicians with extensive experience in treating patients with HAE. Methods: A panel of five HAE specialists convened for a virtual half-day roundtable discussion in April 2023. Results: Discussions about transitioning from AAs to berotralstat were prompted by routine consultations, patient inquiries based on independent research, ineffective current treatment, or worsening AA-related adverse effects. For patients who switched from AAs, the physicians reported that the decision was influenced by the alternative therapy's ability to prevent HAE attacks, its safety, and the once-daily administration schedule. All expert panel members identified fewer AA-related adverse effects; better quality of life; and less severe, shorter, and less frequent HAE attacks as clinical or patient goals they hoped to achieve through the treatment switch. Conclusion: The emergence of new, highly specific LTP drugs for HAE calls for the development of comprehensive recommendations and guidelines for transitioning from AAs to alternative oral prophylactic therapy. The expert panel highlighted key factors to consider during the development of such guidelines.

Synthesis and Structural Characterization of Macrocyclic Plasmin Inhibitors

Two series of macrocyclic plasmin inhibitors with a C-terminal benzylamine group were synthesized. The substitution of the N-terminal phenylsulfonyl group of a previously described inhibitor provided two analogues with sub-nanomolar inhibition constants. Both compounds possess a high selectivity against all other tested trypsin-like serine proteases. Furthermore, a new approach was used to selectively introduce asymmetric linker segments. Two of these compounds inhibit plasmin with K_i values close to 2 nM. For the first time, four crystal structures of these macrocyclic inhibitors could be determined in complex with a Ser195Ala microplasmin mutant. The macrocyclic core segment of the inhibitors binds to the open active site of plasmin without any steric hindrance. This binding mode is incompatible with other trypsin-like serine proteases containing a sterically demanding 99-hairpin loop. The crystal structures obtained experimentally explain the excellent selectivity of this inhibitor type as previously hypothesized.

[Hereditary angioedema and its new treatments: An update]

Hereditary angioedema, with or without deficient C1 inhibitor level or function, is a rare disease characterized by recurrent attacks of noninflammatory subcutaneous and/or submucosal edema. It may be life-threatening and substantially affects quality of life. Attacks may be spontaneous or induced, in a setting of emotional stress, by infections or physical trauma, in particular. As the key mediator is bradykinin, this angioedema does not respond to the usual treatments of mast cell-mediated angioedema (antihistamines, corticosteroids, adrenaline), which is much more frequent. Therapeutic management of hereditary angioedema first consists in treating severe attacks with a selective B2 bradykinin receptor antagonist or a C1 inhibitor concentrate. The latter or an attenuated androgen (danazol) can be used for short-term prophylaxis. Therapeutic solutions conventionally proposed for long-term prophylaxis (danazol, antifibrinolytics [tranexamic acid], C1 inhibitor concentrate) vary in efficacy and/or pose problems of safety or ease of use. Kallikrein inhibitors (subcutaneous lanadelumab, oral berotralstat) recently made available as disease-modifying treatment constitute an important advance in long-term prophylaxis of hereditary angioedema attacks. The advent of these new drugs is accompanied by a new ambition for patients: optimize control of the disease and thereby minimize its impact on quality of life.

The international WAO/EAACI guideline for the management of hereditary angioedema – The 2021 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2), by providing guidance on common and important clinical issues, such as: 1) How should HAE be diagnosed? 2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? 3) What are the goals of treatment? 4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast feeding women? 5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update

Hereditary angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1 inhibitor (type 1) and HAE with dysfunctional C1 inhibitor (type 2), by providing guidance on common and important clinical issues, such as: (1) How should HAE be diagnosed? (2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? (3) What are the goals of treatment? (4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast-feeding women? and (5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

A modular map of Bradykinin-mediated inflammatory signaling network

Bradykinin, a member of the kallikrein-kinin system (KKS), is associated with an inflammatory response pathway with diverse vascular permeability functions, including thrombosis and blood coagulation. In majority, bradykinin signals through Bradykinin Receptor B2 (B2R). B2R is a G protein-coupled receptor (GPCR) coupled to G protein family such as Gα_qs, Gα_q/Gα_11, Gα_i1, and Gβ1_γ2_. B2R stimulation leads to the activation of a signaling cascade of downstream molecules such as phospholipases, protein kinase C, Ras/Raf-1/MAPK, and PI3K/AKT and secondary messengers such as inositol-1,4,5-trisphosphate, diacylglycerol and Ca²⁺ ions. These secondary messengers modulate the production of nitric oxide or prostaglandins. Bradykinin-mediated signaling is implicated in inflammation, chronic pain, vasculopathy, neuropathy, obesity, diabetes, and cancer. Despite the biomedical importance of bradykinin, a resource of bradykinin-mediated signaling pathway is currently not available. Here, we developed a pathway resource of signaling events mediated by bradykinin. By employing data mining strategies in the published literature, we describe an integrated pathway reaction map of bradykinin consisting of 233 reactions. Bradykinin signaling pathway events included 25 enzyme catalysis reactions, 12 translocations, 83 activation/inhibition reactions, 11 molecular associations, 45 protein expression and 57 gene regulation events. The pathway map is made publicly available on the WikiPathways Database with the ID URL: https://www.wikipathways.org/index.php/Pathway:WP5132. The bradykinin-mediated signaling pathway map will facilitate the identification of novel candidates as therapeutic targets for diseases associated with dysregulated bradykinin signaling.

Small molecule drugs for atopic dermatitis, rheumatoid arthritis, and hereditary angioedema

OBJECTIVE

To review recent trends in the development of targeted small molecule drugs (SMDs) for the treatment of immunologically driven disorders, including atopic dermatitis, rheumatoid arthritis, and hereditary angioedema.

DATA SOURCES

Data sources included peer-reviewed published literature from the PubMed database, published abstracts from scientific and medical meetings, and medication information from the Drugs@FDA database.

STUDY SELECTIONS

Articles with primary or retrospective trial results, articles with patient or physician survey results, articles providing expert perspectives, and commentary on chronic immunologic disorders, Food and Drug Administration package inserts, and abstracts from scientific meetings were selected.

RESULTS

Targeted biological therapies have greatly improved response rates and symptom relief for patients with long-term immunologically driven disorders over the past 2 decades. However, recent advances in the understanding of molecular pathways involved in the pathogenesis of these disorders have led to the development of novel targeted SMDs, such as tofacitinib and berotralstat, that can be delivered orally or topically. Few head-to-head studies that compare the safety and efficacy of biologics to SMDs in immunologically driven disorders exist, although some studies suggest that oral and topical modes of administration are preferred by patients and may improve patient quality of life over time.

CONCLUSION

Scientific advances have led to an increase in the development of targeted SMDs for the treatment of chronic immunologic disorders, which may revolutionize the management of these diseases. Head-to-head studies and real-world evidence are needed to fully compare treatment attributes between biologics and SMDs, including safety, efficacy, adherence, impact on quality of life, and cost-effectiveness.

Angioedema and Fatty Acids

Angioedema is a life-threatening emergency event that is associated with bradykinin and histamine-mediated cascades. Although bradykinin-mediated angioedema currently has specific therapeutic options, angioedema is sometimes intractable with current treatments, especially histamine-mediated angioedema, suggesting that some other mediators might contribute to the development of angioedema. Fatty acids are an essential fuel and cell component, and act as a mediator in physiological and pathological human diseases. Recent updates of studies revealed that these fatty acids are involved in vascular permeability and vasodilation, in addition to bradykinin and histamine-mediated reactions. This review summarizes each fatty acid’s function and the specific receptor signaling responses in blood vessels, and focuses on the possible pathogenetic role of fatty acids in angioedema.