Nutritional aspects in autoimmune diseases undergoing hematopoietic stem cell transplantation: overview and recommendations on behalf of the EBMT ADWP and Nurses Group.

Autoimmune diseases (ADs) represent a heterogeneous group of conditions affecting 5-10% of the global population. In recent decades, hematopoietic stem cell transplant (HSCT), mainly autologous, has been successfully adopted to treat patients affected by severe/refractory ADs. In this context malnutrition has a detrimental impact on relapse, mortality, infection rate, engraftment, long-term survival, and prolongation of hospitalization. However, in this population, the management of nutrition should be improved since nutritional assessment is partially performed in routine clinical practice. A panel of nurses and physicians from the European Society for Blood and Marrow Transplantation (EBMT) reviewed all available evidence based on current literature and expert practices from centers with extensive experience in HSCT for ADs, on the nutritional management of ADs patients during HSCT procedure. In this context, adequate nutritional status predicts a better response to treatment and improves quality of life. Herein, a systematic and comprehensive monitoring of nutritional status before, during and after HSCT, with adequate nutritional support in the case of ADs patients, in addition to assessing the dietary requirements associated with HSCT has been covered. Moreover, given the singularity of each AD, the underlying disease should be considered for an appropriate approach. The management and evaluation of nutritional status must be carried out by a multidisciplinary team to assess the needs, monitor the effectiveness of each intervention, and prevent complications, especially in complex situations as patients affected by ADs.

Deriving acceptable limits for non-mutagenic impurities in medicinal products - Durational adjustments.

ICH Q3A/B guidelines are not intended to be applied to drug substance or product used during the clinical research phase of development and durationally adjusted qualification thresholds are not included. A central tenet of ICH Q3A is that lifetime exposure to 1 mg/day of an unqualified NMI is not a safety concern. An analysis of in vivo toxicology data from 4878 unique chemicals with established NO(A)ELs was conducted to determine whether durationally adjusted qualification limits can be supported. Although not a recommendation of ICH Q3A/B, a conservative approach was taken and allometric scaling was used in the analysis. Following allometric scaling of the 5th percentile of the distribution of NO(A)ELs from available chronic toxicology studies, it was reconfirmed that there is a safety basis for the 1 mg/day qualification threshold in ICH Q3A. Additionally, allometric scaling of the 5th percentile of the distribution of NO(A)ELs from sub-acute and sub-chronic toxicology studies could support acceptable limits of 20 and 5 mg/day for an unqualified NMI for dosing durations of less than or greater than one month, respectively. This analysis supports durationally adjusted NMI qualification thresholds for pharmaceuticals that protect patient safety and contribute to 3Rs efforts for qualifying impurities using NAMs.

Analysis of Non-Mutagenic Substances in the Context of Drug Impurity Assessment - Few are Potent Toxicants.

ICH Q3A/B guidelines provide qualification thresholds for impurities or degradation products in new drug substances and products. However, the guidelines note that certain impurities / degradation products may warrant further safety evaluation for being unusually potent or toxic. The purpose of this study was to confirm that especially toxic non-mutagenic compounds are rare and to identify classes of compounds that could warrant lower qualification thresholds. A total of 2,815 compounds were evaluated, of which 2,213 were assessed as non-mutagenic. For the purpose of this analysis, compounds were considered potent when the point of departure was ≤ 0.2 mg/kg/day based on the qualification threshold (1 mg/day or 0.02 mg/kg/day for a 50 kg human) in a new drug substance, with an additional 10-fold margin. Only 54 of the entire set (2.4%) would be considered potent based on this conservative potency analysis, confirming that the existing ICH Q3A/B qualification thresholds are appropriate for the majority of impurities. If the Q3A/B threshold, without the additional 10-fold margin is used, 14 compounds (0.6%) are considered "highly potent". Very few non-mutagenic structural classes were identified, including organothiophosphates and derivatives, polychlorinated benzenes and polychlorinated polycyclic aliphatics, that correlate with potential high potency, consistent with prior publications.

Haploidentical Transplant with Post-Transplant Cyclophosphamide for Acute Myeloid Leukaemia and Myelodysplastic Syndromes Patients: The Role of Previous Lines of Therapy.

Background: Allogeneic haematopoietic stem-cell transplant is an option, potentially curative, for high-risk acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) patients. Post-transplant cyclophosphamide administration allows for the selection of haploidentical donors in patients who are eligible for the procedure but do not have a fully matched donor since it can overcome the HLA barrier. There is still an active debate on whether intensifying the conditioning regimen is necessary with haploidentical donors when peripheral blood stem cells are used as the graft source. Herein, we report our decennial experience of haploidentical stem-cell transplant using peripheral blood stem cells (haplo-PBSC) at King's College Hospital. Objectives: The primary objective was to evaluate overall survival (OS) following haplo-PBSC. Secondary objectives were total OS for patients with less than two previous lines of therapy, OS according to cytomegalovirus (CMV) reactivation, incidence of transplant-related mortality (TRM), graft-versus-host disease (GVHD) and GVHD-relapse-free survival (GRFS). Results: One-year and three-year total OS were 62% and 43%, respectively, with a median OS of 22 months. One-year and three-year OS for patients with ≤2 and those with >2 previous lines of therapy were 72% and 55%, and 60% and 22%, respectively (p-value=0.04). The median OS in patients with >2 previous and ≤2 lines of therapy was 16 and 49 months, respectively. Cumulative incidence (CI) of relapse was 25% with a median time to relapse of 5 months (range 1 - 38 months). Conclusions: Haploidentical haematopoietic stem-cell transplant is potentially curative in chemosensitive AML and MDS and offers a high rate of prolonged remission. Our cohort further confirms the role of consolidative haploidentical transplant in patients in complete remission and highlights that patients with heavily pre-treated disease may not benefit from this strategy.

Germline predisposition traits in allogeneic hematopoietic stem-cell transplantation for myelodysplastic syndromes: a survey-based study and position paper on behalf of the Chronic Malignancies Working Party of the EBMT.

The recent application of whole exome or whole genome sequencing unveiled a plethora of germline variants predisposing to myeloid disorders, particularly myelodysplastic neoplasms. The presence of such variants in patients with myelodysplastic syndromes has important clinical repercussions for haematopoietic stem-cell transplantation, from donor selection and conditioning regimen to graft-versus-host disease prophylaxis and genetic counselling for relatives. No international guidelines exist to harmonise management approaches to this particular clinical scenario. Moreover, the application of germline testing, and how this informs clinical decisions, differs according to the expertise of individual clinical practices and according to different countries, health-care systems, and legislations. Leveraging the global span of the European Society for Blood and Marrow Transplantation (EBMT) network, we took a snapshot of the current European situation on these matters by disseminating an electronic survey to EBMT centres experienced in myelodysplastic syndromes transplantation. An international group of haematologists, transplantation physicians, paediatricians, nurses, and experts in molecular biology and constitutional genetics with experience in myelodysplastic syndromes contributed to this Position Paper. The panel met during multiple online meetings to discuss the results of the EBMT survey and to establish suggested harmonised guidelines for such clinical situations, which are presented here.

Assessing the utility of common arguments used in expert review of in silico predictions as part of ICH M7 assessments.

Expert review of two predictions, made by complementary (quantitative) structure-activity relationship models, to an overall conclusion is a key component of using in silico tools to assess the mutagenic potential of impurities as part of the ICH M7 guideline. In lieu of a specified protocol, numerous publications have presented best practise guides, often indicating the occurrence of common prediction scenarios and the evidence required to resolve them. A semi-automated expert review tool has been implemented in Lhasa Limited's Nexus platform following collation of these common arguments and assignment to the associated prediction scenarios made by Derek Nexus and Sarah Nexus. Using datasets primarily donated by pharmaceutical companies, an automated analysis of the frequency these prediction scenarios occur, and the likelihood of the associated arguments assigning the correct resolution, could then be conducted. This article highlights that a relatively small number of common arguments may be used to accurately resolve many prediction scenarios to a single conclusion. The use of a standardised method of argumentation and assessment of evidence for a given impurity is proposed to improve the efficiency and consistency of expert review as part of an ICH M7 submission.

Myeloablative Dose of Busulfan and Fludarabine Combined with In Vivo T Cell Depletion Is Safe and Effective Conditioning for Acute Myeloid Leukemia and Myelodysplastic Syndrome Patients.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative strategy for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). The prediction of transplantation-related mortality (TRM) using the Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) score and an arbitrary upper age limit of 55 years for administering myeloablative conditioning (MAC) are common strategies to ensure a safe procedure. The use of reduced-toxicity conditioning regimens is an additional approach to providing safe and effective myeloablation. Herein we report the outcome of AML and MDS patients conditioned with fludarabine and a myeloablative dose of busulfan (FB4) stratified by age and HCT-CI score. The primary objective was overall survival (OS) for patients age ≥55 years. Secondary objectives were total OS, TRM, graft-versus-host disease (GVHD), and GVHD, relapse-free survival (GRFS). The 2 year OS was 72% in patients age <55 and 51% in patients age ≥55. In patients age ≥55 with an HCT-CI <2, the estimated 2 year OS was 64%, with median OS not reached. In those with HCT-CI ≥2, the 2-year OS was 43%, with a median OS of 14 months. The total cumulative incidence of relapse was 30% regardless of age or HCT-CI score. FB4 conditioning regimen offers a high rate of prolonged remission with a relapse rate similar to that reported in previous studies. These positive outcomes suggest that this conditioning platform can be offered to patients age ≥55 years in the absence of comorbidities, and that age should not be the sole determinant of conditioning intensity.

The European Society for Blood and Marrow Transplantation (EBMT) roadmap and perspectives to improve nutritional care in patients undergoing hematopoietic stem cell transplantation on behalf of the Cellular Therapy and Immunobiology Working Party (CTIWP) and the Nurses Group (NG) of the EBMT.

Malnutrition is the most common comorbidity during the continuum of hematopoietic stem cell transplant (HSCT) and negatively impacts clinical outcomes, response to therapy, quality of life, and costs. The intensive conditioning regimen administered before transplant causes inflammatory damages to the gastrointestinal system, which themselves contribute to trigger graft versus host disease (GvHD) in the allogeneic setting. GvHD and other post-transplant complications such as infections adversely affect food intake and gut absorption of nutrients. Consequently, patients exhibit signs of malnutrition such as weight loss and muscle wasting, thus triggering a "vicious circle" that favours additional complications. Among HSCT centres, there is marked variability in nutritional care, from screening for malnutrition to nutritional intervention. The present paper, elaborated by the Cellular Therapy and Immunobiology Working Party and the Nurses Group of the European Society for Blood and Marrow Transplantation, aims at defining a roadmap that identifies the main nutritional critical issues in the field of HSCT. This document will be propaedeutic to the development of clinical algorithms to counteract risk factors of malnutrition, based on scientific evidence and shared among HSCT centres, and thus maximize transplant outcomes.

Fludarabine-Melphalan-Campath, Followed by Unmanipulated Peripheral-Blood Haematopoietic Stem Cells, Can Still Cure Lymphoma.

Background: The second decade of this millennium was characterized by a widespread availability of chimeric antigen receptor T-cell (CAR-T) therapies to treat relapsed and refractory lymphomas. As expected, the role and indication of allogeneic haematopoietic stem cell transplant (allo-HSCT) in the management of lymphoma changed. Currently, a non-neglectable proportion of patients will be considered candidate for an allo-HSCT, and the debate of which transplant platform should be offered is still active. Objectives: to report the outcome of patients affected with relapsed/refractory lymphoma and transplanted following reduced intensity conditioning at King's College Hospital, London, between January 2009 and April 2021. Methods: Conditioning was with 150mg/m2 of fludarabine and melphalan of 140mg/m2. The graft was unmanipulated G-CSF mobilized peripheral blood haematopoietic stem cells (PBSC). Graft-versus-host disease (GVHD) prophylaxis consisted of pre-transplant Campath at the total dose of 60 mg in unrelated donors and 30 mg in fully matched sibling donors and ciclosporin. Results: One-year and five years OS were 87% and 79.9%, respectively, and median OS was not reached. The cumulative incidence of relapse was 16%. The incidence of acute GVHD was 48% (only grade I/II); no cases of grade III/IV were diagnosed. Chronic GVHD occurred in 39% of patients. TRM was 12%, with no cases developed within day 100 and 18 months after the procedure. Conclusions: The outcomes of heavily pretreated lymphoma patients are favorable, with median OS and survival not reached after a median of 49 months. In conclusion, even if some lymphoma subgroups cannot be treated (yet) with advanced cellular therapies, this study confirms the role of allo-HSCT as a safe and curative strategy.

Acceptable intakes (AIs) for 11 small molecule N-nitrosamines (NAs).

Low levels of N-nitrosamines (NAs) were detected in pharmaceuticals and, as a result, health authorities (HAs) have published acceptable intakes (AIs) in pharmaceuticals to limit potential carcinogenic risk. The rationales behind the AIs have not been provided to understand the process for selecting a TD50 or read-across analog. In this manuscript we evaluated the toxicity data for eleven common NAs in a comprehensive and transparent process consistent with ICH M7. This evaluation included substances which had datasets that were robust, limited but sufficient, and substances with insufficient experimental animal carcinogenicity data. In the case of robust or limited but sufficient carcinogenicity information, AIs were calculated based on published or derived TD50s from the most sensitive organ site. In the case of insufficient carcinogenicity information, available carcinogenicity data and structure activity relationships (SARs) were applied to categorical-based AIs of 1500 ng/day, 150 ng/day or 18 ng/day; however additional data (such as biological or additional computational modelling) could inform an alternative AI. This approach advances the methodology used to derive AIs for NAs.

Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a refined classification from the European society for blood and marrow transplantation (EBMT).

Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). A new definition for diagnosis, and a severity grading system for SOS/VOD in adult patients, was reported a few years ago on behalf of the European Society for Blood and Marrow Transplantation (EBMT). The aim of this work is to update knowledge regarding diagnosis and severity assessment of SOS/VOD in adult patients, and also its pathophysiology and treatment. In particular, we now propose to refine the previous classification and distinguish probable, clinical and proven SOS/VOD at diagnosis. We also provide an accurate definition of multiorgan dysfunction (MOD) for SOS/VOD severity grading based on Sequential Organ Failure Assessment (SOFA) score.

Benchmarking of survival outcomes following Haematopoietic Stem Cell Transplantation (HSCT): an update of the ongoing project of the European Society for Blood and Marrow Transplantation (EBMT) and Joint Accreditation Committee of ISCT and EBMT (JACIE).

From 2016 EBMT and JACIE developed an international risk-adapted benchmarking program of haematopoietic stem cell transplant (HSCT) outcome to provide individual EBMT Centers with a means of quality-assuring the HSCT process and meeting FACT-JACIE accreditation requirements relating to 1-year survival outcomes. Informed by previous experience from Europe, North America and Australasia, the Clinical Outcomes Group (COG) established criteria for patient and Center selection, and a set of key clinical variables within a dedicated statistical model adapted to the capabilities of the EBMT Registry. The first phase of the project was launched in 2019 to test the acceptability of the benchmarking model through assessment of Centers' performance for 1-year data completeness and survival outcomes of autologous and allogeneic HSCT covering 2013-2016. A second phase was delivered in July 2021 covering 2015-2019 and including survival outcomes. Reports of individual Center performance were shared directly with local principal investigators and their responses were assimilated. The experience thus far has supported the feasibility, acceptability and reliability of the system as well as identifying its limitations. We provide a summary of experience and learning so far in this 'work in progress', as well as highlighting future challenges of delivering a modern, robust, data-complete, risk-adapted benchmarking program across new EBMT Registry systems.

Practice harmonization workshops of EBMT: an expert-based approach to generate practical and contemporary guidelines within the arena of hematopoietic cell transplantation and cellular therapy.

For hematopoietic cell transplantation (HCT) and cellular therapy (CT), clinical patient care is localized, and practices may differ between countries and from center to center even within the same country. Historically, international guidelines were not always adapted to the changing daily clinical practice and practical topics there were not always addressed. In the absence of well-established guidelines, centers tended to develop local procedures/policies, frequently with limited communication with other centers. To try to harmonize localized clinical practices for malignant and non-malignant hematological disorders within EBMT scope, the practice harmonization and guidelines (PH&G) committee of the EBMT will co-ordinate workshops with topic-specific experts from interested centers. Each workshop will discuss a specific issue and write guidelines/recommendations that practically addresses the topic under review. To provide clear, practical and user-friendly guidelines when international consensus is lacking, the EBMT PH&G committee plans to develop European guidelines by HCT and CT physicians for peers' use. Here, we define how workshops will be conducted and guidelines/recommendations produced, approved and published. Ultimately, there is an aspiration for some topics, where there is sufficient evidence base to be considered for systematic reviews, which are a more robust and future-proofed basis for guidelines/recommendations than consensus opinion.

Sexual function of adult long-term survivors and their partners after allogeneic hematopoietic cell transplantation in Europe (S-FAST): a study from the Transplant Complications Working Party and Nurses Group of the EBMT.

Sexual dysfunction after allogeneic hematopoietic cell transplantation (allo-HCT) is a common long-term complication. We conducted a European multicenter cross-sectional study of adult allo-HCT recipients who had survived >2 years and their partners to investigate sexual functioning after HCT and to evaluate whether discussion about sexual functioning between the transplant team and the survivor and partner was perceived to have taken place. In total, 136 survivors (77 males, 59 females) and 81 partners (34 males, 47 females) participated. Median age was 56 and 54 years in male and female survivors, respectively. Forty-seven percent of male and 65% of female survivors and 57% of male and 59% of female partners reported clinically relevant sexual problems. Sixty-two percent of survivors and 79% of partners reported that sexual functioning had not been discussed with them during transplant. Standardized sexual functioning scores were correlated with self-reported health status in survivors (rho = 0.24, p = 0.009). The high prevalence of sexual dysfunction warrants additional studies focusing on the impact of changes in sexuality for patients as well as their partners. Future studies should also investigate which methods that are effective in preventing or treating sexual problems after allo-HCT.

Strategies for Assessing Acceptable Intakes for Novel N-Nitrosamines Derived from Active Pharmaceutical Ingredients.

The detection of N-nitrosamines, derived from solvents and reagents and, on occasion, the active pharmaceutical ingredient (API) at higher than acceptable levels in drug products, has led regulators to request a detailed review for their presence in all medicinal products. In the absence of rodent carcinogenicity data for novel N-nitrosamines derived from amine-containing APIs, a conservative class limit of 18 ng/day (based on the most carcinogenic N-nitrosamines) or the derivation of acceptable intakes (AIs) using structurally related surrogates with robust rodent carcinogenicity data is recommended. The guidance has implications for the pharmaceutical industry given the vast number of marketed amine-containing drugs. In this perspective, the rate-limiting step in N-nitrosamine carcinogenicity, involving cytochrome P450-mediated α-carbon hydroxylation to yield DNA-reactive diazonium or carbonium ion intermediates, is discussed with reference to the selection of read-across analogs to derive AIs. Risk-mitigation strategies for managing putative N-nitrosamines in the preclinical discovery setting are also presented.

The EBMT Immune Effector Cell Nursing Guidelines on CAR-T Therapy: A Framework for Patient Care and Managing Common Toxicities.

Chimeric antigen receptor T-cell (CAR T) therapy is a new and rapidly developing field. Centers across the world are gaining more experience using these innovative anti-cancer treatments, transitioning from the 'bench' to the 'bedside', giving benefit to an increasing number of patients. For those with some refractory hematological malignancies, CAR-T may offer a treatment option that was not available a few years ago.CAR-T therapy is an immune effector cell and precision/personalized medicine treatment which is tailored to the individual patient and associated with a variety of unique adverse events and toxicities that necessitate specialist nursing/medical vigilance in an appropriate clinical setting. Subtle unrecognized signs and symptoms can result in rapid deterioration and, possibly, life threatening cardiorespiratory and/or neurological sequelae.These guidelines have been prepared for nurses working in cellular therapy in inpatient, outpatient and ambulatory settings. Many nurses will encounter cellular therapy recipients indirectly, during the referral process, following discharge, and when patients are repatriated back to local centers. The aim of these guidelines is to provide all nurses with a practice framework to enable recognition, monitoring and grading of CAR-T therapy-associated toxicities, and to support and nurse these highly complex patients with confidence.They have been developed under the auspices of several bodies of the European society for Blood and Marrow Transplantation (EBMT), by experienced health professionals, and will be a valuable resource to all practitioners working in cellular therapy.

Access to and affordability of CAR T-cell therapy in multiple myeloma: an EBMT position paper.

Chimeric antigen receptor (CAR) T-cell therapy is a promising immunotherapeutic approach in the treatment of multiple myeloma, and the recent approval of the first two CAR T-cell products could result in improved outcomes. However, it remains a complex and expensive technology, which poses challenges to health-care systems and society in general, especially in times of crises. This potentially accelerates pre-existing inequalities as access to CAR T-cell therapy varies, both between countries, depending on the level of economic development, and within countries, due to structural disparities in access to quality health care-a parameter strongly correlated with socioeconomic status, ethnicity, and lifestyle. Here, we identify two important issues: affordability and access to CAR T-cell treatment. This consensus statement from clinical investigators, clinicians, nurses, and patients from the European Society for Blood and Marrow Transplantation (EBMT) proposes solutions as part of an innovative collaborative strategy to make CAR T-cell therapy accessible to all patients with multiple myeloma.

Safe transfer of pediatric patients from hematopoietic stem cell transplant unit into the pediatric intensive care unit: views of nurses and physicians.

Sufficient communication between hematopoietic stem cell transplantation (HSCT) and pediatric intensive care unit (PICU) teams is pivotal for a successful advanced support in the PICU for HSCT-related complications. We evaluated perceived communication and barriers between both teams with the aim of providing recommendations for improvement. In this cross-sectional survey, a self-designed online questionnaire was distributed among ESPNIC and EBMT members. Data were analyzed using descriptive statistics. Over half of HSCT respondents employed a transfer indication protocol and patient assessment tool, but less structured checklist prior to patient transfer. Nearly all PICU respondents perceived this checklist as improvement for communication. Most HSCT and PICU physicians have daily rounds upon patient transfer while this is mostly missing between nursing teams. Half of both HSCT and PICU nurses indicated that HSCT training for PICU nurses could improve communication and patient transfer. Most respondents indicated that structured meetings between HSCT and PICU nurses could improve communication. Overall there is good communication between HSCT and PICU units, although barriers were noted between members of both teams. Based on our findings, we recommend use of a structured and specific checklist by HSCT teams, HSCT training for PICU personnel, and structured meetings between HSCT and PICU nurses.

Practical and Science-Based Strategy for Establishing Acceptable Intakes for Drug Product N-Nitrosamine Impurities.

The potential for N-nitrosamine impurities in pharmaceutical products presents a challenge for the quality management of medicinal products. N-Nitrosamines are considered cohort-of-concern compounds due to the potent carcinogenicity of many of the structurally simple chemicals within this structural class. In the past 2 years, a number of drug products containing certain active pharmaceutical ingredients have been withdrawn or recalled from the market due to the presence of carcinogenic low-molecular-weight N,N-dialkylnitrosamine impurities. Regulatory authorities have issued guidance to market authorization holders to review all commercial drug substances/products for the potential risk of N-nitrosamine impurities, and in cases where a significant risk of N-nitrosamine impurity is identified, analytical confirmatory testing is required. A key factor to consider prior to analytical testing is the estimation of the daily acceptable intake (AI) of the N-nitrosamine impurity. A significant proportion of N-nitrosamine drug product impurities are unique/complex structures for which the development of low-level analytical methods is challenging. Moreover, these unique/complex impurities may be less potent carcinogens compared to simple nitrosamines. In the present work, our objective was to derive AIs for a large number of complex N-nitrosamines without carcinogenicity data that were identified as potential low-level impurities. The impurities were first cataloged and grouped according to common structural features, with a total of 13 groups defined with distinct structural features. Subsequently, carcinogenicity data were reviewed for structurally related N-nitrosamines relevant to each of the 13 structural groups and group AIs were derived conservatively based on the most potent N-nitrosamine within each group. The 13 structural group AIs were used as the basis for assigning AIs to each of the structurally related complex N-nitrosamine impurities. The AIs of several N-nitrosamine groups were found to be considerably higher than those for the simple N,N-dialkylnitrosamines, which translates to commensurately higher analytical method detection limits.

Calculating qualified non-mutagenic impurity levels: Harmonization of approaches.

The presence of impurities in drugs is unavoidable. As impurities offer no direct benefit to the patient, it is critical that impurities do not compromise patient safety. Current guidelines on the derivation of acceptable impurity levels leave aspects of calculations open for interpretation, resulting in inconsistencies across industry and regulators. To understand current impurity qualification practices from a safety standpoint, regulatory expectations and the safety risk that impurities pose, the IQ DruSafe Impurities Working Group (WG) conducted a pharmaceutical industry-wide survey. Survey results highlighted areas that could benefit from harmonization, including nonclinical species/sex selection and the application of adjustment factors (i.e., body surface area). Recommendations for alignment on these topics is included in this publication. Additionally, the WG collated repeat-dose toxicity information for 181 starting materials and intermediates, reflective of pharmaceutical impurities, to understand the toxicological risks they generally pose in relation to the drug substance (DS) and the assumptions surrounding the calculation of qualified impurity levels. An evaluation of this dataset and the survey were used to harmonize how to calculate a safe limit for an impurity based on toxicology testing of the impurity when present within the DS.