Assessing the risk to health care staff from long-term exposure to anticancer drugs--the case of monoclonal antibodies

Clinical Oncology Society of Australia Position Statement: 2022 update to the safe handling of monoclonal antibodies in healthcare settings

AIM

The aims were to (a) review the scientific literature on occupational risk, including exposure mechanisms and risk assessment, with regards to handling monoclonal antibodies (mABs) in healthcare settings; and (b) update the recommendations in the Clinical Oncology Society of Australia (COSA) safe handling of monoclonal antibodies in healthcare settings position statement, published in 2013.

METHODS

A literature search was conducted between April 24, 2022, and July 3, 2022, to identify evidence relating to occupational exposure and handling of mABs in healthcare settings. Evidence in the literature was compared to the Position Statement published in 2013, and any potential additions, deletions, or revisions were discussed by the authors, and then agreed changes were made.

RESULTS

Thirty-nine references were included in this update, comprising of the 2013 Position Statement itself and 10 of its references, as well as 28 new references. The risks to healthcare workers in the preparation and administration of mABs arise from four distinct exposure mechanisms: dermal, mucosal, inhalation, and oral. Updates included recommendations on using protective eyewear during the preparation and administration of mABs, developing a local institutional risk assessment tool and handling recommendations, considerations for using closed system transfer devices, and to have awareness of the nomenclature change from 2021 for new mABs.

CONCLUSION

Practitioners should follow the 14 recommendations to lower occupational risk when handling mABs. Another Position Statement update should occur in 5-10 years to ensure the currency of recommendations.

Developing a flowchart to evaluate the use of Closed System Drug-Transfer Devices with monoclonal antibodies: Focus on the clinical trial setting

OBJECTIVE

Available guidelines are ambiguous about safe handling monoclonal antibodies (MABs) and whether or not to use a Closed System Drug-Transfer Device (CSTD). In this article we want to describe a standardized working method on handling MABs in a clinical trial setting.

DATA SOURCES

The current workflow at the clinical trial unit of the Ghent University Hospital was critically analyzed, after which an extensive literature review was performed using the National Institute for Occupational Safety and Health Working Group guidelines and the database PubMed (Keywords: monoclonal antibodies, closed system transfer devices, safety guidelines, safe handling, management, administration, (bio)compatibility, volume loss, contamination, clinical trial unit. Period: 2020-2022).

DATA SUMMARY

Literature data are ambiguous. CSTDs can reduce cross-contamination and minimize exposure to potential hazardous drugs for healthcare professionals. However, in recent years more questions have been raised about their in-use compatibility and their impact on final product quality. This makes the debate on implementing CSTDs a hot topic in daily pharmacy practice and demands a holistic and standardized approach when deciding whether or not to use a CSTD when handling MABs. In a clinical trial setting, where safety data are frequently not available and the compatibility of CSTDs and investigational product is often unknown, this poses additional challenges that need to be taken into account.

CONCLUSION

We developed a flowchart which standardizes the use of a CSTD when handling MABs. It allows other healthcare professionals and clinical trial sponsors to define and evaluate the necessary criteria when standardizing the position of a CSTD in their safe handling procedures.

Development and validation of a method for airborne monoclonal antibodies to quantify workplace exposure

Modern therapy strategies are based on patient-specific treatment where the drug and dose are optimally adapted to the patient's needs. In recent drugs, monoclonal antibodies (mAbs) are increasingly used as active ingredients. Their patient-specific formulations are not part of the pharmaceutical industry's manufacturing process but are prepared from concentrates by pharmaceutical personnel. During the manufacturing process, however, active pharmaceutical ingredients are released in trace amounts or, in the case of accidents and spills, also in high concentrations. Regardless of the source of entry, mAbs can become airborne, be inhaled, and cause undesirable side-effects such as sensitization. To assess the risk for pharmaceutical personnel, a personal air sampling method was developed and validated for bevacizumab, cetuximab, daratumumab, omalizumab, rituximab and trastuzumab. The method is based on the combination of high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The analytical method achieves a limit of detection of 0.30-8.8 ng mL^-1, recoveries of 83-96 % (intra-day assay) and 75-89 % (inter-day assay), with no detectable carry-over. A polycarbonate filter proved suitable for sampling airborne monoclonal antibodies, as it achieved 80-104 % recovery across all mAbs. It also showed concentration-independent desorption efficiency. The sampling duration can be up to 480 min without negatively affecting the recovery. MAbs are stable on the polycarbonate filter at 5 °C for 3 days (recovery: 94 % ± 5 %) and at - 20 °C for 14 days (recovery: 97 % ± 4 %). Our method demonstrated that there is a potential for release when handling monoclonal antibodies. However, this can be reduced below the limit of detection by using pressure equalization systems (spikes).

A simple approach to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings

Background

Several drugs for human use possess genotoxic properties as a necessary consequence of their intended therapeutic effect (e.g. antineoplastics). Health workers may be exposed to these chemicals in various occupational settings such as dose preparation and administration. To date, there are no quantitative risk assessment models to estimate the cancer risk of health workers due to the handling of genotoxic drugs. We therefore developed a quantitative risk assessment model to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings based on the threshold of toxicological concern (TTC) concept. This model was used to evaluate the cancer risk of health workers due to the handling of genotoxic drugs in modern health care facilities.

Methods

We modified the threshold of toxicological concern (TTC) concept to fit the purpose of occupational cancer risk assessment. The risk model underlying ICH guideline M7 (R1): “assessment and control of DNA reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk” was used as a starting point for our model. We conducted a short review of studies on the occupational exposure of health workers to genotoxic drugs. These occupational exposure data were compared to the acceptable exposure levels resulting from our TTC based risk model.

Results

Based on the threshold of toxicological concern (TTC) concept, we defined an acceptable daily intake (ADI) of 4 μg/day as threshold of no concern for the exposure of health workers to genotoxic drugs. Regarding the dermal exposure of health workers to genotoxic drugs, we derived a corresponding acceptable surface contamination level (ASCL) of 20 ng/cm². Both ADI and ASCL are usually not exceeded in modern healthcare settings. Current safety precautions provide sufficient protection to health workers.

Conclusions

The application of our model indicates that workers in modern healthcare facilities are not at risk of developing work related cancer above widely accepted cancer risk levels due to the occupational exposure to genotoxic drugs. Hence, the present study may assist employers and public authorities to make informed decisions concerning the need for (further) protective measures and during risk communication to health workers.

Considerations for setting occupational exposure limits for novel pharmaceutical modalities

In order to develop new and effective medicines, pharmaceutical companies must be modality agnostic. As science reveals an enhanced understanding of biological processes, new therapeutic modalities are becoming important in developing breakthrough therapies to treat both rare and common diseases. As these new modalities progress, concern and uncertainty arise regarding their safe handling by the researchers developing them, employees manufacturing them and nurses administering them. This manuscript reviews the available literature for emerging modalities (including oligonucleotides, monoclonal antibodies, fusion proteins and bispecific antibodies, antibody-drug conjugates, peptides, vaccines, genetically modified organisms, and several others) and provides considerations for occupational health and safety-oriented hazard identification and risk assessments to enable timely, consistent and well-informed hazard identification, hazard communication and risk-management decisions. This manuscript also points out instances where historical exposure control banding systems may not be applicable (e.g. oncolytic viruses, biologics) and where other occupational exposure limit systems are more applicable (e.g. Biosafety Levels, Biologic Control Categories).

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Review of toxicology and pharmacology information for novel therapeutic modalities.

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Identification of occupational hazards associated with novel therapeutic modalities.

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Occupational hazards and exposure risks differ across pharmaceutical modalities.

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Occupational exposure control banding systems are not one size fits all.

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Banding system variations offer benefits while enabling proper exposure controls.

Staff sensitisation to therapeutic monoclonal antibodies resulting from workplace exposure: A case report

Monoclonal antibodies were introduced to clinical practice in 1980s and play a vital role in a variety of diseases and clinical interventions including cancer, inflammatory disease, and ophthalmologic disease. There is a lack of substantial research or evidence on the effect of occupational exposure on staff, leading many staff to have significant concerns about what is a safe level of exposure, especially given their increasing availability and use. This report describes a case in which a nurse became sensitised to monoclonal antibodies as a result of preparing and administering them in a clinical area, and the subsequent actions taken in response to the incident to reduce the risk to staff.

Development of a flowchart for risk assessment and allocation of preparation of monoclonal antibodies

Monoclonal antibodies have expanded as a novel class of therapeutic agents. In contrast to appropriate guidelines for safe handling of cytotoxics, there are no real standards for the safe handling of monoclonal antibodies. Many questions have arisen whether monoclonal antibodies have to be prepared under controlled circumstances or can be prepared on the ward. We developed a flowchart which provides recommendations for the classification of monoclonal antibodies according to their toxicity profile and takes practical and financial issues into account. It allows oncology pharmacists worldwide to define which monoclonal antibodies can/must be prepared in pharmacy aseptic facilities and which monoclonal antibodies can be prepared on the ward.

Safe handling of monoclonal antibodies: Too large to be hazardous?

It has been argued that the larger molecular weight of hazardous monoclonal antibodies may prevent their dermal absorption via occupational exposure. However, this assertion does not seem to be supported by direct evidence. Although the larger molecular weight may render monoclonal antibodies less probable to achieve therapeutic systemic level through dermal absorption, the concern in occupational health is whether these drugs can possibly attain a detectable level through repeated dermal exposure. Currently, there is no direct evidence to support a particular molecular weight above which a drug cannot achieve a detectable level following repeated occupational exposure. Therefore, the precautionary principle would dictate that repeated exposure of healthcare workers to hazardous monoclonal antibodies should be kept to a minimum.

Surface wipe sampling for antineoplastic (chemotherapy) and other hazardous drug residue in healthcare settings: Methodology and recommendations

Surface wipe sampling for various hazardous agents has been employed in many occupational settings over the years for various reasons such as evaluation of potential dermal exposure and health risk, source determination, quality or cleanliness, compliance, and others. Wipe sampling for surface residue of antineoplastic and other hazardous drugs in healthcare settings is currently the method of choice to determine surface contamination of the workplace with these drugs. The purpose of this article is to review published studies of wipe sampling for antineoplastic and other hazardous drugs, to summarize the methods in use by various organizations and researchers, and to provide some basic guidance for conducting surface wipe sampling for these drugs in healthcare settings.  Recommendations on wipe sampling methodology from several government agencies and organizations were reviewed. Published reports on wipe sampling for hazardous drugs in numerous studies were also examined. The critical elements of a wipe sampling program and related limitations were reviewed and summarized.  Recommendations and guidance are presented concerning the purposes of wipe sampling for antineoplastic and other hazardous drugs in the healthcare setting, technical factors and variables, sampling strategy, materials required, and limitations. The reporting and interpretation of wipe sample results is also discussed.  It is recommended that all healthcare settings where antineoplastic and other hazardous drugs are handled consider wipe sampling as part of a comprehensive hazardous drug "safe handling" program. Although no standards exist for acceptable or allowable surface concentrations for these drugs in the healthcare setting, wipe sampling may be used as a method to characterize potential occupational dermal exposure risk and to evaluate the effectiveness of implemented controls and the overall safety program. A comprehensive safe-handling program for antineoplastic drugs may utilize wipe sampling as a screening tool to evaluate environmental contamination and strive to reduce contamination levels as much as possible, using the industrial hygiene hierarchy of controls.

Safe handling and administration of MABS: the guidance

While monoclonal antibodies (MABs) are not as hazardous as cytotoxic drugs, there is concern among health professionals about the potential risks and the limited evidence about this. Guidance on the safe use of MABs is mainly to be found in national documents covering all systemic anti-cancer therapies, with the only consensus guidelines specifically on MABs coming from Australia. This article therefore summarises the existing guidance relating to MABs.

A survey of manufacturing and handling practices for monoclonal antibodies by pharmacy, nursing and medical personnel

INTRODUCTION

There is a paucity of data available to assess the occupational health and safety risk associated with exposure to monoclonal antibodies. Industry standards and published guidelines are conflicting or outdated. Guidelines offer contrary recommendations based on an array of methodological approaches. This survey aimed to describe current practices, beliefs and attitudes relating to the handling of monoclonal antibodies by Australian medical, nursing and pharmacy clinicians.

METHODS

An electronic survey was distributed between June and September 2013. Respondents were surveyed on three focus areas: institutional guideline availability and content, current practices and attitudes. Demographic data relating to respondent and primary place of practice were also collected.

RESULTS

A total of 222 clinicians completed the survey, with representation from all targeted professional groups and from a variety of geographic locations. 92% of respondents reported that their institution prepared or administered monoclonal antibodies, with 87% specifically handling anti-cancer monoclonal antibodies. Monoclonal antibodies were mostly prepared onsite (84-90%) and mostly within pharmacy clean-rooms (75%) and using cytotoxic cabinets (61%). 43% of respondents reported access to institutional monoclonal antibody handling guidelines with risk reduction strategies including training and education (71%), spill and waste management (71%), procedures for transportation (57%) and restricted handling (50%). Nurses had a stronger preference towards pharmacy manufacturing than both doctors and pharmacists for a range of clinical scenarios. 95% of all respondents identified that professional or regulatory body guidelines are an important resource when considering handling practices.

CONCLUSION

Monoclonal antibodies are most commonly handled according to cytotoxic drug standards and often in the absence of formal guidelines.

A review of the evidence for occupational exposure risks to novel anticancer agents – A focus on monoclonal antibodies

Introduction

Evidence of occupational exposure risks to novel anticancer agents is limited and yet to be formally evaluated from the Australian healthcare perspective.

Methods

From March to September 2013 medical databases, organizational policies, drug monographs, and the World Wide Web were searched for evidence relating to occupational exposure to monoclonal antibodies, fusion proteins, gene therapies, and other unclassified novel anticancer agents.

Results

Australian legislation, national and international guidelines, and drug company information excluded novel agents or provided inconsistent risk assessments and safe handling recommendations. Monoclonal antibody guidelines reported conflicting information and were often divergent with available evidence and pharmacologic rationale demonstrating minimal internalisation ability and occupational exposure risk. Despite similar physiochemical, pharmacologic, and internalisation properties to monoclonal antibodies, fusion proteins were included in only a minority of guidelines. Clinical directives for the safe handling of gene therapies and live vaccines were limited, where available focusing on prevention against exposure and cross-contamination. Although mechanistically different, novel small molecule agents (proteasome inhibitors), possess similar physiochemical and internalisation properties to traditional cytotoxic agents warranting cytotoxic classification and handling.

Conclusion

Novel agents are rapidly emerging into clinical practice, and healthcare personnel have few resources to evaluate risk and provide safety recommendations. Novel agents possess differing physical, molecular and pharmacological profiles compared to traditional cytotoxic anticancer agents. Evaluation of occupational exposure risk should consider both toxicity and internalisation. Evidence-based guidance able to direct safe handling practices for novel anticancer agents across a variety of clinical settings is urgently required.

Bioavailability of therapeutic proteins by inhalation--worker safety aspects

A literature review and analysis of inhalation bioavailability data for large therapeutic proteins was conducted in order to develop a practical estimate of the inhalation bioavailability of these drugs. This value is incorporated into equations used to derive occupational exposure limits(OELs) to protect biopharmaceutical manufacturing workers from systemic effects. Descriptive statistics implies that a value of 0.05, or 5% is an accurate estimate for large therapeutic proteins (molecular weight ≥ 40kDa). This estimate is confirmed by pharmacokinetic modeling of data from a human daily repeat-dose inhalation study of immunoglobulin G. In conclusion, we recommend using 5% bioavailability by inhalation when developing OELs for large therapeutic proteins.

Cancer stem cells: the development of new cancer therapeutics

INTRODUCTION

Cancer stem cells (CSCs) are a subpopulation of tumor cells with indefinite proliferative potential that drive the growth of tumors. CSCs seem to provide a suitable explanation for several intriguing aspects of cancer pathophysiology.

AREAS COVERED

An explosion of therapeutic options for cancer treatment that selectively target CSCs has been recorded in the recent years. These include the targeting of cell-surface proteins, various activated signalling pathways, different molecules of the stem cell niche and various drug resistance mechanisms. Importantly, approaching cancer research by investigating the pathogenesis of these intriguing cancer cells is increasing the knowledge of the pathophysiology of the disease, emphasizing certain molecular mechanisms that have been partially neglected.

EXPERT OPINION

The characterization of the molecular phenotype of these cancer stem-like cells, associated with an accurate definition of their typical derangement in cell differentiation, can represent a fundamental advance in terms of diagnosis and therapy of cancer. Preliminary results seem to be promising but further studies are required to define the therapeutic index of this new anticancer treatment. Moreover, understanding the pathogenetic mechanisms of CSCs can expand the therapeutic applications of normal adult stem cells by reducing the risk of uncontrolled tumorigenic stem cell differentiation.