Impact of Early Access Reform on Oncology Innovation in France: Approvals, Patients, and Costs.

BACKGROUND: An ambitious reform of the early access (EA) process was set up in July 2021 in France, aiming to simplify procedures and accelerate access to innovative drugs. OBJECTIVE: This study analyzes the characteristics of oncology drug approvals through the EA process and its impact on real-life data for oncology patients. METHODS: The number and characteristics of EA demands concerning oncology drugs submitted to the National Health Authority (HAS, Haute Autorité de Santé) were reviewed until 31 December 2022. A longitudinal retrospective study on patients treated with an EA oncology drug between 1 January 2019 and 31 December 2022 was also performed using the French nationwide claims database (Systeme National des Données de Santé [SNDS]) to assess the impact of the reform on the number of indications and patients, and the costs. RESULTS: Among 110 published decisions, the HAS granted 88 (80%) EA indications within 70 days of assessment on average, including 46 (52%) in oncology (67% in solid tumors and 33% in hematological malignancies). Approved indications were mostly supported by randomized phase III trials (67%), whereas refused EA relied more on non-randomized (57%) trials. Overall survival was the primary endpoint of 28% of EA approvals versus none of denied EAs. In the SNDS data, the annual number of patients with cancer treated with an EA drug increased from 3137 patients in 2019 to 18,341 in 2022 (+ 484%), whereas the number of indications rose from 12 to 62, mainly in oncohematology (n = 17), lung (n = 12), digestive (n = 9) and breast cancer (n = 9). Reimbursement costs for EA treatments surged from €42 to €526 million (+ 1159%). CONCLUSION: The French EA reform contributed to enabling rapid access to innovations in a wide range of indications for oncology patients. However, the findings highlight ongoing challenges in financial sustainability, warranting continued evaluation and adjustments.

Early morning immune checkpoint blockade and overall survival of patients with metastatic cancer: An In-depth chronotherapeutic study.

INTRODUCTION: Recent retrospective studies suggest potential large patient's benefit through proper timing of immune checkpoint blockers (ICB). The association between ICB treatment timing and patient survival, neoplastic response and toxicities was investigated, together with interactions with performance status (PS) and sex. METHODS: A cohort of patients with metastatic or locally advanced solid tumors, who received pembrolizumab, nivolumab, atezolizumab, durvalumab, or avelumab, alone or with concomitant chemotherapy, between November 2015 and March 2021, at the Centre Leon Bérard (France), was retrospectively studied. RESULTS: 361 patients were investigated (80% non-small cell lung cancer patients, mean [SD] age: 63 [11] years, 39% of women, 83% PS0-1 at first infusion, 19% received concomitant chemotherapy). ICB were administered from 07:25 to 17:21 and optimal morning/afternoon cut-off was 11:37. Morning infusions were associated with increased OS as compared to afternoon (median 30.3 vs 15.9 months, p = 0.0024; HR 1.56 [1.17-2.1], p = 0.003). A strong PS-timing interaction was found (PS0-1 patients, HR=1.53 [1.10-2.12], p = 0.011; PS2-3 patients, HR=0.50 [0.25-0.97], p = 0.042). Morning PS0-1 patients displayed increased OS (median 36.7 vs 21.3 months, p = 0.023), partial/complete response rate (58% vs 41%, p = 0.027), and grade1-3 toxicities (49% vs 34%, p = 0.028). Mortality risk ratio between infusions at worst time-of-day, estimated at 13:36 [12:48-14:23], and in early morning was equal to 4.8 ([2.3-10.1], p = 0.008). Timing differences in toxicities resulted significant only in female patients (women vs men: p < 0.001 vs 0.4). CONCLUSIONS: Early morning ICB infusion was associated with increased OS, response, and toxicities in patients with PS0-1 as compared to later infusions within the day. Prospective randomized trials are needed to confirm this retrospective study.

Pharmacokinetic Consideration of Venetoclax in Acute Myeloid Leukemia Patients: A Potential Candidate for TDM? A Short Communication.

BACKGROUND: Venetoclax (VNX)-based regimens have demonstrated significantly favorable outcomes in patients with acute myeloid leukemia (AML) and are now becoming the standard treatment. Tyrosine kinase inhibitors are administered at a fixed dose, irrespective of body surface area or weight. For such orally targeted therapies, real-world data have highlighted a larger pharmacokinetic (PK) interindividual variability (IIV) than expected. Even if VNX PKs have been well characterized and described in the literature, only 1 clinical trial-based PK study has been conducted in patients with AML. This study aimed to evaluate the PK of VNX in AML patients. MATERIAL AND METHODS: We retrospectively analyzed all patients treated with a combination of VNX-azacitidine between January and July 2022 at our center, using at least 1 available VNX blood sample. Based on a previously published population PK model, individual PK parameters were estimated to evaluate the exposure and IIV. RESULTS: and Discussion. Twenty patients received VNX in combination with azacitidine, according to the PK data. A total of 93 plasma concentrations were collected. The dose of VNX was 400 mg, except in 7 patients who received concomitant posaconazole (VNX 70 mg). The patients' weight ranged from 49 kg to 108 kg (mean = 78 kg). Mean individual clearance was 13.5 ± 9.4 L/h with mean individual daily area under the concentration-time curves of 35.8 mg.h/L with significant IIV (coefficient of variation = 41.1%). Ten patients were still alive (8 in complete response), but all experienced at least 1 hematological toxicity of grade ≥ 3. CONCLUSIONS: Based on the observed large PK variability in the data from our real-world AML patients, the risk of drug interactions and the recommended fixed-dosage regimen of VNX therapeutic drug monitoring may be useful.

A novel injectable radiopaque hydrogel with potent properties for multicolor CT imaging in the context of brain and cartilage regenerative therapy.

Cell therapy is promising to treat many conditions, including neurological and osteoarticular diseases. Encapsulation of cells within hydrogels facilitates cell delivery and can improve therapeutic effects. However, much work remains to be done to align treatment strategies with specific diseases. The development of imaging tools that enable monitoring cells and hydrogel independently is key to achieving this goal. Our objective herein is to longitudinally study an iodine-labeled hydrogel, incorporating gold-labeled stem cells, by bicolor CT imaging after in vivo injection in rodent brains or knees. To this aim, an injectable self-healing hyaluronic acid (HA) hydrogel with long-persistent radiopacity was formed by the covalent grafting of a clinical contrast agent on HA. The labeling conditions were tuned to achieve sufficient X-ray signal and to maintain the mechanical and self-healing properties as well as injectability of the original HA scaffold. The efficient delivery of both cells and hydrogel at the targeted sites was demonstrated by synchrotron K-edge subtraction-CT. The iodine labeling enabled to monitor the hydrogel biodistribution in vivo up to 3 days post-administration, which represents a technological first in the field of molecular CT imaging agents. This tool may foster the translation of combined cell-hydrogel therapies into the clinics.

In vitro reconstitution of kallikrein-kinin system and progress curve analysis.

Human kallikrein-kinin system (KKS) is a proteolytic cascade with two serine-protease zymogen couples (Factor XII and prekallikrein (PK) and their activated forms, FXIIa, PKa, respectively), releasing bradykinin by cleavage of native high-molecular-weight kininogen (nHK) into cleaved HK. For KKS investigation in human plasma, this cascade is usually triggered on ice eventually by mixing with purified proteins. It has been established that purified FXIIa, PK, and nHK required a fixed order and timing for mixing protein on ice to ensure reproducibility of testing, we investigated the activation kinetics of both enzymes. The activation process of this in vitro minimal reconstitution of KKS was studied by progress curve analysis, in condition of high enzyme/substrate ratio and by using on natural rather than peptide substrates. FXIIa and PKa were found five-times less active on ice than at 37°C: kcat = 0.133 ± 0.034 and 0.0119 ± 0.0027 s-1, KM = 672 ± 150 and 115 ± 24 nM, respectively. The progress curve analysis of our in vitro KKS reconstitutions differed from a Michaelis-Menten mathematical simulation by a faster initial rate and a slower late rate. These two features were also observed ex vivo by using dextran sulfate-activated plasma and could reinforce the hypothesis of a maximal local effect (bradykinin release) and a minimal systemic consequence (PK preservation) in KKS activation process. Analyzing the complete curve of cold KKS activation would provide valuable information for ex vivo investigation of KKS in samples from patients presenting with hereditary angioedema and other inflammatory conditions.

Dual role of histone variant H3.3B in spermatogenesis: positive regulation of piRNA transcription and implication in X-chromosome inactivation.

The histone variant H3.3 is encoded by two distinct genes, H3f3a and H3f3b, exhibiting identical amino-acid sequence. H3.3 is required for spermatogenesis, but the molecular mechanism of its spermatogenic function remains obscure. Here, we have studied the role of each one of H3.3A and H3.3B proteins in spermatogenesis. We have generated transgenic conditional knock-out/knock-in (cKO/KI) epitope-tagged FLAG-FLAG-HA-H3.3B (H3.3BHA) and FLAG-FLAG-HA-H3.3A (H3.3AHA) mouse lines. We show that H3.3B, but not H3.3A, is required for spermatogenesis and male fertility. Analysis of the molecular mechanism unveils that the absence of H3.3B led to alterations in the meiotic/post-meiotic transition. Genome-wide RNA-seq reveals that the depletion of H3.3B in meiotic cells is associated with increased expression of the whole sex X and Y chromosomes as well as of both RLTR10B and RLTR10B2 retrotransposons. In contrast, the absence of H3.3B resulted in down-regulation of the expression of piRNA clusters. ChIP-seq experiments uncover that RLTR10B and RLTR10B2 retrotransposons, the whole sex chromosomes and the piRNA clusters are markedly enriched of H3.3. Taken together, our data dissect the molecular mechanism of H3.3B functions during spermatogenesis and demonstrate that H3.3B, depending on its chromatin localization, is involved in either up-regulation or down-regulation of expression of defined large chromatin regions.

Survival and risk of COVID-19 after SARS-COV-2 vaccination in a series of 2391 cancer patients.

BACKGROUND: Patients with cancer are at high risk of severe or lethal COVID-19. The impact of SARS-COV-2 vaccination on the risk of developing COVID-19 was investigated in an exhaustive series of patients from a comprehensive cancer center. METHODS: This is a study of the exhaustive population of 2391 cancer patients who were prescribed SARS-COV-2 vaccination until 09/21. Patient characteristics, documented SARS-COV-2 infection with RT-PCR, and survival were collected. The primary endpoint was the rate of COVID-19 after vaccination. Secondary endpoints included risk factors to develop COVID-19 after vaccination, with a comparison with the cohort of vaccinated health care workers (HCW), and risk factors for death. RESULTS: From January to September 2021, among 2391 patients with cancer under active treatment in whom a SARS-COV-2 vaccine was prescribed, 659 (28%), 1498 (63%) and 139 (6%) received 1, 2, and 3 doses, respectively. Ninety five patients received a single dose of vaccine after a previous COVID-19. Two thousand two hundred eighty five health care workers (HCW) received one (N = 17, 0.7%), 2-3 (N = 2026, 88.7%) vaccine doses and one dose after COVID-19 (N = 242, 10.6%). With a median follow-up of 142 and 199 days for patients and HCW, respectively. Thirty nine (1.6%) patients and 35 (1.5%) HCW developed COVID-19 after vaccination. Six of 39 cancer patients and no HCW died because ofCOVID-19 within 50 days after diagnosis. Independent risk factors for COVID-19 in vaccinated patients were age, single dose of vaccine without previous COVID-19 and anti-CD20 treatment in the last three months. Independent risk factors for death included metastatic disease, gender, cancer type, but also documented COVID-19 before vaccination. CONCLUSIONS: Patients receiving two or more doses of COVID-19 vaccine have reduced risk of COVID-19. The risk of death of vaccinated cancer patients presenting COVID-19 remains high. COVID-19 before vaccination is associated with an increased overall risk of death.

Mouse Models of Osteoarthritis: A Summary of Models and Outcomes Assessment.

Osteoarthritis (OA) is a multidimensional health problem and a common chronic disease. It has a substantial impact on patient quality of life and is a common cause of pain and mobility issues in older adults. The functional limitations, lack of curative treatments, and cost to society all demonstrate the need for translational and clinical research. The use of OA models in mice is important for achieving a better understanding of the disease. Models with clinical relevance are needed to achieve 2 main goals: to assess the impact of the OA disease (pain and function) and to study the efficacy of potential treatments. However, few OA models include practical strategies for functional assessment of the mice. OA signs in mice incorporate complex interrelations between pain and dysfunction. The current review provides a comprehensive compilation of mouse models of OA and animal evaluations that include static and dynamic clinical assessment of the mice, merging evaluation of pain and function by using automatic and noninvasive techniques. These new techniques allow simultaneous recording of spontaneous activity from thousands of home cages and also monitor environment conditions. Technologies such as videography and computational approaches can also be used to improve pain assessment in rodents but these new tools must first be validated experimentally. An example of a new tool is the digital ventilated cage, which is an automated home-cage monitor that records spontaneous activity in the cages.

Identification of human gene research articles with wrongly identified nucleotide sequences.

Nucleotide sequence reagents underpin molecular techniques that have been applied across hundreds of thousands of publications. We have previously reported wrongly identified nucleotide sequence reagents in human research publications and described a semi-automated screening tool Seek & Blastn to fact-check their claimed status. We applied Seek & Blastn to screen >11,700 publications across five literature corpora, including all original publications in Gene from 2007 to 2018 and all original open-access publications in Oncology Reports from 2014 to 2018. After manually checking Seek & Blastn outputs for >3,400 human research articles, we identified 712 articles across 78 journals that described at least one wrongly identified nucleotide sequence. Verifying the claimed identities of >13,700 sequences highlighted 1,535 wrongly identified sequences, most of which were claimed targeting reagents for the analysis of 365 human protein-coding genes and 120 non-coding RNAs. The 712 problematic articles have received >17,000 citations, including citations by human clinical trials. Given our estimate that approximately one-quarter of problematic articles may misinform the future development of human therapies, urgent measures are required to address unreliable gene research articles.

Rituximab in combination with adapted-dose of ifosfamide and etoposide as salvage treatment in elderly refractory/relapsed diffuse large B-cell lymphoma patients non-candidate for high dose therapy: a retrospective study.

We retrospectively reviewed for 72 relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) patients ineligible for autologous stem-cell transplantation (ASCT) treated between 2004 and 2017, efficacy and safety profile of rituximab (375 mg/m2) in combination with etoposide (300 mg/m2) and ifosfamide (1500 mg/m2) at 2, 3, or 4-week intervals. Median age was 79 years (range, 64-92). The median number of previous line was 1 (range 1-8). Patients received a median of six cycles (1-12). Fourteen patients (19%) presented partial and 14 complete responses (19%). Among the 369 cycles, nine patients developed febrile neutropenia (13%), 14 a grade 3-4 neutropenia (19%), 7 a grade 3-4 thrombocytopenia (10%) without grade 3-4 non-hematological toxicity. With a median follow up of 7.8 months, the median progression-free survival, overall survival, and duration of response were 4.4 months, 9.4 months, and 12 months, respectively. This regimen represents a therapeutic option in R/R DLBCL patients ineligible to ASCT.

[Reducing the exposure of patients and healthcare teams to cytotoxins]. / Réduire l'exposition des patients et des équipes soignantes aux cytotoxiques.

In order to prevent human and environmental risks related to the handling of cytotoxins and cytostatics, health care institutions are implementing precautionary measures. Information and training actions for health professionals, nurses, orderlies and pharmacy assistants are also part of the system. Example with a team in Lyon.

Mediation of Interleukin-23 and Tumor Necrosis Factor-Driven Reactive Arthritis by Chlamydia-Infected Macrophages in SKG Mice.

OBJECTIVE: ZAP-70W163C BALB/c (SKG) mice develop reactive arthritis (ReA) following infection with Chlamydia muridarum. Since intracellular pathogens enhance their replicative fitness in stressed host cells, we examined how myeloid cells infected with C muridarum drive arthritis. METHODS: SKG, Il17a-deficient SKG, and BALB/c female mice were infected with C muridarum or C muridarum luciferase in the genitals. C muridarum dissemination was assessed by in vivo imaging or genomic DNA amplification. Macrophages were depleted using clodronate liposomes. Anti-tumor necrosis factor (anti-TNF) and anti-interleukin-23p19 (anti-IL-23p19) were administered after infection or arthritis onset. Gene expression of Hspa5, Tgtp1, Il23a, Il17a, Il12b, and Tnf was compared in SKG mice and BALB/c mice. RESULTS: One week following infection with C muridarum, macrophages and neutrophils were observed to have infiltrated the uteri of mice and were also shown to have carried C muridarum DNA to the spleen. C muridarum load was higher in SKG mice than in BALB/c mice. Macrophage depletion was shown to reduce C muridarum load and prevent development of arthritis. Compared with BALB/c mice, expression of Il23a and Il17a was increased in the uterine and splenic neutrophils of SKG mice. The presence of anti-IL-23p19 during infection or Il17a deficiency suppressed arthritis. Tnf was overexpressed in the joints of SKG mice within 1 week postinfection, and persisted beyond the first week. TNF inhibition during infection or at arthritis onset suppressed the development of arthritis. Levels of endoplasmic reticulum stress were constitutively increased in the joints of SKG mice but were induced, in conjunction with immunity-related GTPase, by C muridarum infection in the uterus. CONCLUSION: C muridarum load is higher in SKG mice than in BALB/c mice. Whereas proinflammatory IL-23 produced by neutrophils contributes to the initiation of C muridarum-mediated ReA, macrophage depletion reduces C muridarum dissemination to other tissues, tissue burden, and the development of arthritis. TNF inhibition was also shown to suppress arthritis development. Our data suggest that enhanced bacterial dissemination in macrophages of SKG mice drives the TNF production needed for persistent arthritis.

Calcified cartilage revealed in whole joint by X-ray phase contrast imaging.

Objective: X-ray Phase Contrast Imaging (PCI) is an emerging modality that will be in the next few years available in a wider range of preclinical set-ups. In this study, we compare this imaging technique with conventional preclinical modalities in an osteoarthritis mouse model. Method: Phase contrast technique was performed on 6 post-mortem, monoiodoacetate-induced osteoarthritis knees and 6 control knees. The mice knees were then imaged using magnetic resonance imaging and conventional micro computed tomography. Examples of imaging surrogate markers are reported: local distances within the articular space, cartilage surface roughness, calcified cartilage thickness, number, volume and locations of osteophytes. Results: Thanks to PCI, we can show in 3D calcified cartilage without contrast agent by a non-invasive technique. The phase contrast images reveal more details than conventional imaging techniques, especially at smaller scales, with for instance a higher number of micro-calcifications detected (57, 314 and 329 for MRI, conventional micro-CT and phase contrast imaging respectively). Calcified cartilage thickness was measured with a significant difference (p â€‹< â€‹0.01) between the control (23.4 â€‹± â€‹17.2 â€‹µm) and the osteoarthritis induced animal (46.9 â€‹± â€‹19.0 â€‹µm). Conclusions: X-ray phase contrast imaging outperforms the conventional imaging modalities for assessing the different tissue types (soft and hard). This new imaging modality seems to bring new relevant surrogate markers for following-up small animal models even for low-grade osteoarthritis.

Permeation measurement of 27 chemotherapy drugs after simulated dynamic testing on 15 surgical and examination gloves: A knowledge update.

PURPOSE: Exposure to anticancer drugs is one of the known risks for people working in specialist oncology units. Wearing gloves is a vital form of personal protection. The aim of this study was to assess, in close to real use dynamic conditions, the permeability of 15 surgical and examination gloves made from different materials when exposed to 27 anticancer drugs included in the list from international Guides and Recommendations. METHODS: Gloves were tested by using controlled dynamic conditions replicating flexion and extension movements that mimic typical clinical applications. Tests were performed at 37°C or at 43°C for 30 min and anticancer drugs were tested at the highest concentration used in clinical practice. To determine the permeation rate, the quantification of anticancer drugs was performed with selective and sensitive analytical methods such as inductively coupled plasma-mass spectroscopy and liquid chromatography-mass spectrometry. RESULTS: All the gloves met the EN 16523-1 European standard (1000 ng/(min.cm2)). The penetration rate of busulfan, carmustine and thiotepa exceeded the ASTM D-6978-05 American standard (10 ng/(min.cm2)) with several surgical and/or examination gloves. This standard was met in all of cases when double gloving was used. Breakage of several nitrile gloves was observed in relation with the excipient used by drugs suppliers. CONCLUSIONS: Permeation is a complex multifactorial phenomenon. However, we have suggested that the thickness of the glove and three physicochemical parameters (molecular weight, topological polar surface area and hydrogen bond donor) of the drug were the main parameters affecting permeation.

Semi-automated fact-checking of nucleotide sequence reagents in biomedical research publications: The Seek & Blastn tool.

Nucleotide sequence reagents are verifiable experimental reagents in biomedical publications, because their sequence identities can be independently verified and compared with associated text descriptors. We have previously reported that incorrectly identified nucleotide sequence reagents are characteristic of highly similar human gene knockdown studies, some of which have been retracted from the literature on account of possible research fraud. Because of the throughput limitations of manual verification of nucleotide sequences, we developed a semi-automated fact checking tool, Seek & Blastn, to verify the targeting or non-targeting status of published nucleotide sequence reagents. From previously described and unknown corpora of 48 and 155 publications, respectively, Seek & Blastn correctly extracted 304/342 (88.9%) and 1066/1522 (70.0%) nucleotide sequences and a predicted targeting/ non-targeting status. Seek & Blastn correctly predicted the targeting/ non-targeting status of 293/304 (96.4%) and 988/1066 (92.7%) of the correctly extracted nucleotide sequences. A total of 38/39 (97.4%) or 31/79 (39.2%) Seek & Blastn predictions of incorrect nucleotide sequence reagent use were correct in the two literature corpora. Combined Seek & Blastn and manual analyses identified a list of 91 misidentified nucleotide sequence reagents, which could be built upon through future studies. In summary, incorrect nucleotide sequence reagents represent an under-recognized source of error within the biomedical literature, and fact checking tools such as Seek & Blastn may help to identify papers and manuscripts affected by these errors.

[Intravenous chemotherapy at home: A pediatric monocentric experience]. / Chimiothérapie intraveineuse à domicile en cancérologie pédiatrique : une expérience monocentrique.

INTRODUCTION: Our home care unit (HCU) developed the administration of IV chemotherapy at home for some pediatric oncologic patients. METHODS: We conducted a retrospective monocentric analysis, leading to identify patients with at least one sequence of chemotherapy at home in 2015. RESULTS: Two hundred and forty four sequences of home chemotherapy have been administered in 2015. We identified two situations for home IV chemotherapy. Pediatric oncologist of day hospital prescribes the sequence. The chemotherapy is delivered at hospital for the first day. HCU takes over for the next days at home. For a sequence replacing a conventional hospitalization, the attending physician examines the patient, and confirm the clinical validation. The pediatric oncologist of HCU checks lab exams, and prescribes the chemotherapy. For both situations, IV chemotherapy is prepared by our hospital pharmacy, delivers at home or at day hospital, and HCU team manages home material and organizes hospitalization. CONCLUSIONS: This kind of organization allows setting up home IV CT for more and more patients. It allows to limit daily hospitalization for some patients living far from the hospital, and whose therapies lead to several hospitalizations.

Histone H3.3 regulates mitotic progression in mouse embryonic fibroblasts.

H3.3 is a histone variant that marks transcription start sites as well as telomeres and heterochromatic sites on the genome. The presence of H3.3 is thought to positively correlate with the transcriptional status of its target genes. Using a conditional genetic strategy against H3.3B, combined with short hairpin RNAs against H3.3A, we essentially depleted all H3.3 gene expression in mouse embryonic fibroblasts. Following nearly complete loss of H3.3 in the cells, our transcriptomic analyses show very little impact on global gene expression or on the localization of histone variant H2A.Z. Instead, fibroblasts displayed slower cell growth and an increase in cell death, coincident with large-scale chromosome misalignment in mitosis and large polylobed or micronuclei in interphase cells. Thus, we conclude that H3.3 may have an important under-explored additional role in chromosome segregation, nuclear structure, and the maintenance of genome integrity.

Kininogen Cleavage Assay: Diagnostic Assistance for Kinin-Mediated Angioedema Conditions.

BACKGROUND: Angioedema without wheals (AE) is a symptom characterised by localised episodes of oedema presumably caused by kinin release from kininogen cleavage. It can result from a hereditary deficiency in C1 Inhibitor (C1Inh), but it can present with normal level of C1Inh. These forms are typically difficult to diagnose although enhanced kinin production is suspected or demonstrated in some cases. OBJECTIVES: We wanted to investigate bradykinin overproduction in all AE condition with normal C1Inh, excluding cases with enhanced kinin catabolism, and to propose this parameter as a disease biomarker. METHODS: We retrospectively investigated high molecular weight kininogen (HK) cleavage pattern, using gel electrophoresis and immunorevelation. Plasma samples were drawn using the same standardised procedure from blood donors or AE patients with normal C1Inh conditions, normal kinin catabolism, and without prophylaxis. RESULTS: Circulating native HK plasma concentrations were similar in the healthy men (interquartile range: 98-175µg/mL, n = 51) and in healthy women (90-176µg/mL, n = 74), while HK cleavage was lower (p<0.001) in men (0-5%) than women (3-9%). Patients exhibited lower native HK concentration (p<10-4; 21-117µg/mL, n = 31 for men; 0-84µg/mL, n = 41 for women) and higher HK cleavage (p<10-4; 10-30% and 14-89%, respectively) than healthy donors. Pathological thresholds were set at: <72µg/mL native HK, >14.4% HK cleavage for men; <38µg/mL; native HK, >33.0% HK cleavage for women, with >98% specificity achieved for all parameters. In plasma from patients undergoing recovery two months after oestrogen/progestin combination withdrawal (n = 13) or two weeks after AE attack (n = 2), HK cleavage was not fully restored, suggesting its use as a post-attack assay. CONCLUSION: As a diagnostic tool, HK cleavage can offer physicians supportive arguments for kinin production in suspected AE cases and improve patient follow-up in clinical trials or prophylactic management.