Assessing human carcinogenicity risk of agrochemicals without the rodent cancer bioassay.

The rodent cancer bioassays are conducted for agrochemical safety assessment yet they often do not inform regulatory decision-making. As part of a collaborative effort, the Rethinking Carcinogenicity Assessment for Agrochemicals Project (ReCAAP) developed a reporting framework to guide a weight of evidence (WOE)-based carcinogenicity assessment that demonstrates how to fulfill the regulatory requirements for chronic risk estimation without the need to conduct lifetime rodent bioassays. The framework is the result of a multi-stakeholder collaboration that worked through an iterative process of writing case studies (in the form of waivers), technical peer reviews of waivers, and an incorporation of key learnings back into the framework to be tested in subsequent case study development. The example waivers used to develop the framework were written retrospectively for registered agrochemical active substances for which the necessary data and information could be obtained through risk assessment documents or data evaluation records from the US EPA. This exercise was critical to the development of a framework, but it lacked authenticity in that the stakeholders reviewing the waiver already knew the outcome of the rodent cancer bioassay(s). Syngenta expanded the evaluation of the ReCAAP reporting framework by writing waivers for three prospective case studies for new active substances where the data packages had not yet been submitted for registration. The prospective waivers followed the established framework considering ADME, potential exposure, subchronic toxicity, genotoxicity, immunosuppression, hormone perturbation, mode of action (MOA), and all relevant information available for read-across using a WOE assessment. The point of departure was estimated from the available data, excluding the cancer bioassay results, with a proposed use for the chronic dietary risk assessment. The read-across assessments compared data from reliable registered chemical analogues to strengthen the prediction of chronic toxicity and/or tumorigenic potential. The prospective case studies represent a range of scenarios, from a new molecule in a well-established chemical class with a known MOA to a molecule with a new pesticidal MOA (pMOA) and limited read-across to related molecules. This effort represents an important step in establishing criteria for a WOE-based carcinogenicity assessment without the rodent cancer bioassay(s) while ensuring a health protective chronic dietary risk assessment.

Ozanimod Differentially Impacts Circulating Lymphocyte Subsets in Patients with Moderately to Severely Active Crohn's Disease.

BACKGROUND: Ozanimod showed efficacy and safety in the phase 2 STEPSTONE study conducted in patients with moderately to severely active Crohn's disease. AIMS: This analysis assessed the effects of ozanimod on circulating lymphocytes in Crohn's disease. METHODS: Patients received ozanimod 0.92 mg for 12 weeks. Lymphocyte subtypes were evaluated using multicolor flow analysis on blood samples collected before treatment and on Week 12. Absolute lymphocyte count changes were analyzed by Wilcoxon signed rank tests. Disease activity changes and efficacy outcomes were evaluated at Week 12, and associations with lymphocyte subtype levels were assessed using Spearman's correlation and logistic regression. RESULTS: Reductions in median total T, Th, and cytotoxic T cells occurred at Week 12 (45.4%-76.8%), with reductions in most subtypes of 47.5% to 91.3% (P < 0.001). CD8+ terminally differentiated effector memory cells were largely unaffected (median change, - 19%; P = 0.44). Reductions in median total B cells occurred at Week 12 (76.7%), with reductions in subtypes of 71.4% to 81.7% (P < 0.001). Natural killer and monocyte cell counts were unchanged. Greater baseline levels and changes in nonswitched memory B cells were significantly associated with clinical, endoscopic, and histologic efficacy (P < 0.05, all comparisons). CONCLUSIONS: Ozanimod reduced circulating levels of all B-cell and most T-cell subsets but not monocytes or natural killer cells. Key subsets relevant to immune surveillance were not reduced, supporting the low risk of infection and malignancy with ozanimod in chronic inflammatory diseases. Levels of nonswitched memory B cells were associated with efficacy, providing a potential marker for ozanimod response. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02531113, EudraCT: 2015-002025-19.

Efficacy and Safety of Approximately 3 Years of Continuous Ozanimod in Moderately to Severely Active Ulcerative Colitis: Interim Analysis of the True North Open-label Extension.

BACKGROUNDS AND AIMS: This interim analysis from the True North open-label extension [OLE] study examines efficacy and safety of approximately 3 years of continuous ozanimod treatment in patients with moderately to severely active ulcerative colitis. METHODS: Clinical responders after 52 weeks of ozanimod during the phase 3 True North study, who continued treatment in the OLE, were evaluated. Efficacy, including endoscopic and histological endpoints, was assessed during the OLE for approximately 2 additional years through OLE Week 94, using observed case [OC] and nonresponder imputation [NRI] analyses. Adverse events were monitored from True North baseline through OLE data cutoff and expressed as exposure-adjusted incidence rates. RESULTS: This analysis included 131 patients; 54% had achieved corticosteroid-free remission at True North Week 52. In OC analyses, clinical response, clinical remission, and corticosteroid-free remission were achieved by 91.4%, 69.1%, and 67.9% of patients, respectively, at OLE Week 94 [146 weeks of total treatment]. Similarly, endoscopic improvement, histological remission, and mucosal healing were achieved by 73.3%, 67.3%, and 56.3% of patients, respectively, at OLE Week 94. Efficacy rates were lower using NRI analyses, but maintenance of efficacy was demonstrated through OLE Week 94. No new safety signals emerged from this analysis. Serious infections, malignancy, cardiovascular events, and hepatic events occurred infrequently. CONCLUSIONS: Among patients who achieved clinical response after 1 year of ozanimod treatment during True North, a high percentage sustained clinical and mucosal efficacy over 2 additional years in the OLE. No new safety signals were observed with long-term ozanimod use.

Etrasimod as induction and maintenance therapy for ulcerative colitis (ELEVATE): two randomised, double-blind, placebo-controlled, phase 3 studies.

BACKGROUND: Etrasimod, a once-daily, oral, sphingosine 1-phosphate (S1P) receptor modulator that selectively activates S1P receptor subtypes 1, 4, and 5, with no detectable activity on S1P2,3, is in development for the treatment of immune-mediated diseases, including ulcerative colitis. In these two phase 3 trials, we aimed to evaluate the safety and efficacy of etrasimod in adult patients with moderately to severely active ulcerative colitis. METHODS: In two independent randomised, multicentre, double-blind, placebo-controlled, phase 3 trials, ELEVATE UC 52 and ELEVATE UC 12, adults with active moderate-to-severe ulcerative colitis and an inadequate or loss of response or intolerance to at least one approved ulcerative colitis therapy were randomly assigned (2:1) to once-daily oral etrasimod 2 mg or placebo. Patients in ELEVATE UC 52 were enrolled from 315 centres in 40 countries. Patients in ELEVATE UC 12 were enrolled from 407 centres in 37 countries. Randomisation was stratified by previous exposure to biologicals or Janus kinase inhibitor therapy (yes vs no), baseline corticosteroid use (yes vs no), and baseline disease activity (modified Mayo score [MMS]; 4-6 vs 7-9). ELEVATE UC 52 comprised a 12-week induction period followed by a 40-week maintenance period with a treat-through design. ELEVATE UC 12 independently assessed induction at week 12. The primary efficacy endpoints were the proportion of patients with clinical remission at weeks 12 and 52 in ELEVATE UC 52 and week 12 in ELEVATE UC 12. Safety was evaluated in both trials. ELEVATE UC 52 and ELEVATE UC 12 were registered with ClinicalTrials.gov, NCT03945188 and NCT03996369, respectively. FINDINGS: Patients in ELEVATE UC 52 were enrolled between June 13, 2019, and Jan 28, 2021. Patients in ELEVATE UC 12 were enrolled between Sept 15, 2020, and Aug 12, 2021. ELEVATE UC 52 and ELEVATE UC 12 screened 821 patients and 606 patients, respectively, with 433 and 354 subsequently undergoing random assignment. The full analysis set of ELEVATE UC 52 comprised 289 patients assigned to etrasimod and 144 to placebo. In ELEVATE UC 12, 238 patients were assigned to etrasimod and 116 to placebo. In ELEVATE UC 52, a significantly greater proportion of patients in the etrasimod group achieved clinical remission compared with patients in the placebo group at completion of the 12-week induction period (74 [27%] of 274 patients vs ten [7%] of 135 patients; p<0·0001) and at week 52 (88 [32%] of 274 patients vs nine [7%] of 135 patients; p<0·0001). In ELEVATE UC 12, 55 (25%) of 222 patients in the etrasimod group had clinical remission compared with 17 (15%) of 112 patients in the placebo group at the end of the 12-week induction period (p=0·026). Adverse events were reported in 206 (71%) of 289 patients in the etrasimod group and 81 (56%) of 144 patients in the placebo group in ELEVATE UC 52 and 112 (47%) of 238 patients in the etrasimod group and 54 (47%) of 116 patients in the placebo group in ELEVATE UC 12. No deaths or malignancies were reported. INTERPRETATION: Etrasimod was effective and well tolerated as an induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. Etrasimod is a treatment option with a unique combination of attributes that might address the persistent unmet needs of patients with ulcerative colitis. FUNDING: Arena Pharmaceuticals.

Crohn's disease shared decision making intervention leads to more patients choosing combination therapy: a cluster randomised controlled trial.

BACKGROUND: Crohn's disease requires effective patient-clinician communication for successful illness and medication management. Shared decision making (SDM) has been suggested to improve communication around early intensive therapy. However, effective evidence-based SDM interventions for Crohn's disease are lacking, and the impact of SDM on Crohn's disease decision making and choice of therapy is unclear. AIM: To test the impact of SDM on choice of therapy, quality of the decision and provider trust compared to standard Crohn's disease care. METHODS: We conducted a multi-site cluster randomised controlled trial in 14 diverse gastroenterology practices in the US. RESULTS: A total of 158 adult patients with Crohn's disease within 15 years of their diagnosis, with no prior Crohn's disease complications, and who were candidates to receive immunomodulators or biologics, participated in the study. Among these, 99 received the intervention and 59 received standard care. Demographics were similar between groups, although there were more women assigned to standard care, and a slightly shorter disease duration among those in the intervention group. Participants in the intervention group more frequently chose combination therapy (25% versus 5% control, p < 0.001), had a significantly lower decisional conflict (p < 0.05) and had greater trust in their provider (p < 0.05). CONCLUSIONS: With rapidly expanding medication choices for Crohn's disease and slow uptake of early intensive therapy, SDM can personalise treatment strategies and has the potential to move the field of Crohn's disease management forward with an ultimate goal of consistently treating this disease early and intensively in appropriate patients. TRIAL REGISTRATION: Evaluating a Shared Decision Making Program for Crohn's Disease, ClinicalTrials.gov Identifier NCT02084290 https://clinicaltrials.gov/ct2/show/NCT02084290.

Towards achieving a modern science-based paradigm for agrochemical carcinogenicity assessment.

The rodent cancer bioassay has been the standard approach to fulfill regulatory requirements for assessing human carcinogenic potential of agrochemicals, food additives, industrial chemicals, and pharmaceuticals. Decades of research have described the limitations of the rodent cancer bioassay leading to international initiatives to seek alternatives and establish approaches that modernize carcinogenicity assessment. Biologically relevant approaches can provide mechanistic information and increased efficiency for evaluating hazard and risk of chemical carcinogenicity to humans. The application of human-relevant mechanistic understanding to support new approaches to carcinogenicity assessment will be invaluable for regulatory decision-making. The present work outlines the challenges and opportunities that authorities should consider as they come together to build a roadmap that leads to global acceptance and incorporation of fit-for-purpose, scientifically defensible new approaches for human-relevant carcinogenicity assessment of agrochemicals.

Ozanimod as a novel oral small molecule therapy for the treatment of Crohn's disease: The YELLOWSTONE clinical trial program.

BACKGROUND: Ozanimod, an oral sphingosine 1-phosphate receptor modulator currently approved for the treatment of moderately to severely active ulcerative colitis and relapsing multiple sclerosis, showed clinical, endoscopic, and histological benefit in the phase 2 STEPSTONE trial for Crohn's disease (CD). We aim to describe the trial design of the YELLOWSTONE phase 3 program evaluating the safety and efficacy of ozanimod in patients with moderately to severely active CD. METHODS: The YELLOWSTONE program consists of phase 3, randomized, double-blind, placebo-controlled induction (NCT03440372 and NCT03440385) and maintenance (NCT03464097) trials and an open-label extension (OLE) study (NCT03467958). Patients with inadequate response or intolerance to ≥1 CD treatment are randomized to receive daily ozanimod 0.92 mg (equivalent to ozanimod HCl 1 mg) or placebo for 12 weeks during induction. Those who respond to ozanimod are rerandomized to continue ozanimod or placebo maintenance therapy for 52 weeks. Patients who do not meet criteria for maintenance, experience relapse during maintenance, or complete maintenance or ≥ 1 year of STEPSTONE are eligible for open-label treatment for up to 234 weeks. Efficacy endpoints include clinical, endoscopic, and histologic outcomes. RESULTS: Expected 2023 (induction studies), 2024 (maintenance study), and 2026 (OLE). CONCLUSION: YELLOWSTONE will provide pivotal phase 3 data on the safety and efficacy of ozanimod in patients with moderately to severely active CD using state-of-the-art methods, including centrally read endoscopic and histologic measurements, along with subjective assessments of symptom control based on the Crohn's Disease Activity Index. These studies could enable approval of ozanimod as a new CD therapy. CLINICAL TRIAL REGISTRATION NUMBERS: NCT03440372, NCT03440385, NCT03464097, NCT03467958.

A new approach to the classification of carcinogenicity.

Concern over substances that may cause cancer has led to various classification schemes to recognize carcinogenic threats and provide a basis to manage those threats. The least useful schemes have a binary choice that declares a substance carcinogenic or not. This overly simplistic approach ignores the complexity of cancer causation by considering neither how the substance causes cancer, nor the potency of that mode of action. Consequently, substances are classified simply as "carcinogenic", compromising the opportunity to properly manage these kinds of substances. It will likely be very difficult, if not impossible, to incorporate New Approach Methodologies (NAMs) into binary schemes. In this paper we propose a new approach cancer classification scheme that segregates substances by both mode of action and potency into three categories and, as a consequence, provides useful guidance in the regulation and management of substances with carcinogenic potential. Examples are given, including aflatoxin (category A), trichlorethylene (category B), and titanium dioxide (category C), which demonstrate the clear differentiation among these substances that generate appropriate levels of concern and management options.

Rethinking chronic toxicity and carcinogenicity assessment for agrochemicals project (ReCAAP): A reporting framework to support a weight of evidence safety assessment without long-term rodent bioassays.

Rodent cancer bioassays have been long-required studies for regulatory assessment of human cancer hazard and risk. These studies use hundreds of animals, are resource intensive, and certain aspects of these studies have limited human relevance. The past 10 years have seen an exponential growth of new technologies with the potential to effectively evaluate human cancer hazard and risk while reducing, refining, or replacing animal use. To streamline and facilitate uptake of new technologies, a workgroup comprised of scientists from government, academia, non-governmental organizations, and industry stakeholders developed a framework for waiver rationales of rodent cancer bioassays for consideration in agrochemical safety assessment. The workgroup used an iterative approach, incorporating regulatory agency feedback, and identifying critical information to be considered in a risk assessment-based weight of evidence determination of the need for rodent cancer bioassays. The reporting framework described herein was developed to support a chronic toxicity and carcinogenicity study waiver rationale, which includes information on use pattern(s), exposure scenario(s), pesticidal mode-of-action, physicochemical properties, metabolism, toxicokinetics, toxicological data including mechanistic data, and chemical read-across from similar registered pesticides. The framework could also be applied to endpoints other than chronic toxicity and carcinogenicity, and for chemicals other than agrochemicals.

The codification of hazard and its impact on the hazard versus risk controversy.

The long running controversy about the relative merits of hazard-based versus risk-based approaches has been investigated. There are three levels of hazard codification: level 1 divides chemicals into dichotomous bands of hazardous and non-hazardous; level 2 divides chemicals into bands of hazard based on severity and/or potency; and level 3 places each chemical on a continuum of hazard based on severity and/or potency. Any system which imposes compartments onto a continuum will give rise to issues at the boundaries, especially with only two compartments. Level 1 schemes are only justifiable if there is no variation in severity, or potency or if there is no threshold. This is the assumption implicit in GHS/EU classification for carcinogenicity, reproductive toxicity and mutagenicity. However, this assumption has been challenged. Codification level 2 hazard assessments offer a range of choices and reduce the built-in conflict inherent in the level 1 process. Level 3 assessments allow a full range of choices between the extremes and reduce the built-in conflict even more. The underlying reason for the controversy between hazard and risk is the use of level 1 hazard codification schemes in situations where there are ranges of severity and potency which require the use of level 2 or level 3 hazard codification. There is not a major difference between level 2 and level 3 codification, and they can both be used to select appropriate risk management options. Existing level 1 codification schemes should be reviewed and developed into level 2 schemes where appropriate.

Long-Term Efficacy and Safety of Ozanimod in Moderately to Severely Active Ulcerative Colitis: Results From the Open-Label Extension of the Randomized, Phase 2 TOUCHSTONE Study.

BACKGROUND AND AIMS: This analysis examined the long-term safety and efficacy of ozanimod in patients with moderately to severely active ulcerative colitis [UC] with ≥ 4 years of follow-up in the phase 2 TOUCHSTONE open-label extension [OLE]. METHODS: Patients receiving placebo or ozanimod HCl 0.5 mg or 1 mg during the double-blind period could enter the OLE [ozanimod HCl 1 mg daily]. Partial Mayo score [pMS] clinical response and remission were assessed through OLE week 200 and summarized descriptively using observed cases [OC] and non-responder imputation [NRI]. Endoscopy was required at OLE week 56 and the end of treatment. Parameters associated with endoscopy were summarized at weeks 56 and 104 [OC], and week 56 [NRI]. C-reactive protein and faecal calprotectin were assessed. Adverse events were monitored throughout the study. RESULTS: Of 197 patients receiving double-blind treatment, 170 entered the OLE. Discontinuation rates were 28% at year 1 and 15-18% annually through year 4. Partial Mayo measures indicated clinical response and remission rates at OLE week 200 of 93.3% and 82.7%, respectively, using OC and 41% and 37% with the more conservative NRI analysis. At weeks 56 and 104, respectively, histological remission rates were 46.3% and 38.5%, and endoscopic improvement rates were 46.4% and 46.5% [OC]. No new safety signals were identified during ≥ 4 years of follow-up. CONCLUSIONS: There was a high rate of continued study participation and long-term benefit with ozanimod HCl 1 mg daily based on clinical, histological and biomarker measures in patients with moderately to severely active UC in the TOUCHSTONE OLE. [NCT02531126].

Therapeutic Drug Monitoring of Tumor Necrosis Factor Antagonists in Crohn Disease: A Theoretical Construct to Apply Pharmacokinetics and Guidelines to Clinical Practice.

Therapeutic drug monitoring (TDM) is the measurement of drug and antidrug antibody concentrations in individuals to guide treatment decisions. In patients with Crohn disease (CD), TDM, used either reactively or proactively, is emerging as a valuable tool for optimization of tumor necrosis factor (TNF) antagonist therapy. Reactive TDM is carried out in response to treatment failure, whereas proactive TDM involves the periodic monitoring of patients responding to TNF antagonist therapy to allow treatment optimization. In patients with CD, most of the available data for TDM relate to the first-to-market TNF antagonist infliximab and, to a lesser extent, to adalimumab and certolizumab pegol. Several gastroenterology associations, including the American Gastroenterology Association, have endorsed the use of reactive TDM in patients with active CD. However, fewer recommendations currently exist for the use of proactive TDM, although several new prospective randomized controlled trials evaluating proactive TDM strategies have been published. In this review, the current evidence for reactive and proactive TDM is discussed, and a proactive treatment algorithm for certolizumab pegol based on previously published threshold concentrations is proposed.

A comprehensive view on mechanistic approaches for cancer risk assessment of non-genotoxic agrochemicals.

Currently the only methods for non-genotoxic carcinogenic hazard assessment accepted by most regulatory authorities are lifetime carcinogenicity studies. However, these involve the use of large numbers of animals and the relevance of their predictive power and results has been scientifically challenged. With increased availability of innovative test methods and enhanced understanding of carcinogenic processes, it is believed that tumour formation can now be better predicted using mechanistic information. A workshop organised by the European Partnership on Alternative Approaches to Animal Testing brought together experts to discuss an alternative, mechanism-based approach for cancer risk assessment of agrochemicals. Data from a toolbox of test methods for detecting modes of action (MOAs) underlying non-genotoxic carcinogenicity are combined with information from subchronic toxicity studies in a weight-of-evidence approach to identify carcinogenic potential of a test substance. The workshop included interactive sessions to discuss the approach using case studies. These showed that fine-tuning is needed, to build confidence in the proposed approach, to ensure scientific correctness, and to address different regulatory needs. This novel approach was considered realistic, and its regulatory acceptance and implementation can be facilitated in the coming years through continued dialogue between all stakeholders and building confidence in alternative approaches.

Ozanimod induction therapy for patients with moderate to severe Crohn's disease: a single-arm, phase 2, prospective observer-blinded endpoint study.

BACKGROUND: Although treatment of Crohn's disease has improved with development of tumour necrosis factor antagonists, fewer than 50% of patients have sustained benefit. Durable maintenance therapy with orally administered alternative treatments remains an unmet need. We aimed to evaluate the effects of ozanimod, an oral agent selectively targeting sphingosine-1-phosphate receptor subtypes 1 and 5, on endoscopic disease activity in Crohn's disease. METHODS: STEPSTONE was a phase 2, uncontrolled, multicentre trial in adults with moderately to severely active Crohn's disease recruited at 28 hospital and community research centres in Canada, the USA, Hungary, Poland, and Ukraine. All patients began treatment with a 7-day dose escalation (4 days on ozanimod 0·25 mg daily followed by 3 days at 0·5 mg daily). Patients then received ozanimod 1·0 mg oral capsule daily for a further 11 weeks, for a 12-week induction period, followed by a 100-week extension. The primary endpoint was change in Simple Endoscopic Score for Crohn's Disease (SES-CD) from baseline to week 12, as determined by a blinded central reader. Data are reported for the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02531113 and EudraCT, number 2015-002025-19, and is completed. FINDINGS: 69 patients were enrolled between Nov 17, 2015, and Aug 18, 2016. At week 12, the mean change from baseline in SES-CD was -2·2 (SD 6·0); 16 (23·2%, 95% CI 13·9-34·9) patients experienced endoscopic response. A reduction from baseline in Crohn's Disease Activity Index (CDAI) score also was observed (mean change -130·4 [SD 103·9]). Clinical remission (CDAI <150 points) was shown in 27 (39·1%, 95% CI 27·6-51·6) patients and response (CDAI decrease from baseline ≥100) in 39 (56·5%, 95% CI 44·0-68·4) of patients. The mean change from baseline in two-item patient-reported outcome (PRO2, stool frequency, abdominal pain scores) score was -66·1 (SD 65·4). Mean change from baseline in Geboes Histology Activity Score (GHAS) was -5·9 (SD 11·0) and in Robart's Histopathology Index (RHI) -10·6 (25·1). Adverse events were most frequently those attributed to Crohn's disease, most commonly Crohn's disease (flare) in 18 (26%) patients. The most commonly reported serious treatment-related adverse events were Crohn's disease (six [9%]) and abdominal abscess (two [3%]). INTERPRETATION: Endoscopic, histological, and clinical improvements were seen within 12 weeks of initiating ozanimod therapy in patients with moderately to severely active Crohn's disease. Phase 3 placebo-controlled trials have been initiated. FUNDING: Celgene Corporation.

Chemical carcinogenicity revisited 2: Current knowledge of carcinogenesis shows that categorization as a carcinogen or non-carcinogen is not scientifically credible.

Developments in the understanding of the etiology of cancer have undermined the 1970s concept that chemicals are either "carcinogens" or "non-carcinogens". The capacity to induce cancer should not be classified in an inflexible binary manner as present (carcinogen) or absent (non-carcinogen). Chemicals may induce cancer by three categories of mode of action: direct interaction with DNA or DNA replication including DNA repair and epigenetics; receptor-mediated induction of cell division; and non-specific induction of cell division. The long-term rodent bioassay is neither appropriate nor efficient to evaluate carcinogenic potential for humans and to inform risk management decisions. It is of questionable predicitiveness, expensive, time consuming, and uses hundreds of animals. Although it has been embedded in practice for over 50 years, it has only been used to evaluate less than 5% of chemicals that are in use. Furthermore, it is not reproducible because of the probabilisitic nature of the process it is evaluating combined with dose limiting toxicity, dose selection, and study design. The modes of action that lead to the induction of tumors are already considered under other hazardous property categories in classification (Mutagenicity/Genotoxicity and Target Organ Toxicity); a separate category for Carcinogenicity is not required and provides no additional public health protection.

Chemical carcinogenicity revisited 1: A unified theory of carcinogenicity based on contemporary knowledge.

Developments in the understanding of the etiology of cancer have profound implications for the way the carcinogenicity of chemicals is addressed. This paper proposes a unified theory of carcinogenesis that will illuminate better ways to evaluate and regulate chemicals. In the last four decades, we have come to understand that for a cell and a group of cells to begin the process of unrestrained growth that is defined as cancer, there must be changes in DNA that reprogram the cell from normal to abnormal. Cancer is the consequence of DNA coding errors that arise either directly from mutagenic events or indirectly from cell proliferation especially if sustained. Chemicals that act via direct interaction with DNA can induce cancer because they cause mutations which can be carried forward in dividing cells. Chemicals that act via non-genotoxic mechanisms must be dosed to maintain a proliferative environment so that the steps toward neoplasia have time to occur. Chemicals that induce increased cellular proliferation can be divided into two categories: those which act by a cellular receptor to induce cellular proliferation, and those which act via non-specific mechanisms such as cytotoxicity. This knowledge has implications for testing chemicals for carcinogenic potential and risk management.

Chemical carcinogenicity revisited 3: Risk assessment of carcinogenic potential based on the current state of knowledge of carcinogenesis in humans.

Over 50 years, we have learned a great deal about the biology that underpins cancer but our approach to testing chemicals for carcinogenic potential has not kept up. Only a small number of chemicals has been tested in animal-intensive, time consuming, and expensive long-term bioassays in rodents. We now recommend a transition from the bioassay to a decision-tree matrix that can be applied to a broader range of chemicals, with better predictivity, based on the premise that cancer is the consequence of DNA coding errors that arise either directly from mutagenic events or indirectly from sustained cell proliferation. The first step is in silico and in vitro assessment for mutagenic (DNA reactive) activity. If mutagenic, it is assumed to be carcinogenic unless evidence indicates otherwise. If the chemical does not show mutagenic potential, the next step is assessment of potential human exposure compared to the threshold for toxicological concern (TTC). If potential human exposure exceeds the TTC, then testing is done to look for effects associated with the key characteristics that are precursors to the carcinogenic process, such as increased cell proliferation, immunosuppression, or significant estrogenic activity. Protection of human health is achieved by limiting exposures to below NOEALs for these precursor effects. The decision tree matrix is animal-sparing, cost effective, and in step with our growing knowledge of the process of cancer formation.

Sustained Clinical Remission With Vedolizumab in Patients With Moderate-to-Severe Ulcerative Colitis.

BACKGROUND: Sustaining clinical remission is an important treatment goal in moderate-to-severe UC. This post hoc exploratory analysis assessed the long-term efficacy of vedolizumab in the subset of patients with UC in the GEMINI 1 study who were in clinical remission by week 14 after 3 induction doses, administered at weeks 0, 2, and 6. METHODS: Sustained clinical remission (primary endpoint) was evaluated using 2 definitions: (1) a partial Mayo Score (pMS) of ≤2 with no subscore >1 and (2) a rectal bleeding subscore (RBS) of 0 throughout weeks 14, 26, 38, and 52. RESULTS: The proportion of patients in clinical remission at week 14 was significantly higher in patients receiving vedolizumab (n = 620) compared with placebo (n = 149) (pMS: 32.7% vs 20.1% [percentage-point difference (∆) 12.6%; 95% confidence interval [CI], 5.2-20.0]; RBS: 47.3% vs 28.9% [∆18.4%; 95% CI, 10.1-26.7]). Of patients in clinical remission at week 14, a significantly higher proportion of vedolizumab-treated patients achieved sustained clinical remission compared with placebo (pMS: 66.5% vs 26.7%; ∆39.8%; 95% CI, 22.7-56.9; RBS: 56.7% vs 20.9%; ∆35.7%; 95% CI, 22.3-49.1). Findings were consistent in tumor necrosis factor (TNF) antagonist-naive and antagonist-failure patients. CONCLUSION: Compared with placebo, 35%-40% more patients receiving a full induction course of vedolizumab had sustained clinical remission after 52 weeks of therapy. This result was observed irrespective of TNF antagonist treatment history. Clinical remission at week 14 may therefore be a predictor for sustained clinical remission with vedolizumab.

Adherence rates and health care costs in Crohn's disease patients receiving certolizumab pegol with and without home health nurse assistance: results from a retrospective analysis of patient claims and home health nurse data.

BACKGROUND: Patient support programs have a positive effect on adherence to therapy. Certolizumab pegol (CZP) is a tumor necrosis factor antagonist for the treatment of Crohn's disease. OBJECTIVES: To assess, using real-world claims data, whether home health nurse assistance had an effect on patients' adherence to CZP and to measure its impact on health care use and costs. METHODS: A retrospective analysis of medical and pharmacy claims data from the IQVIA Real-World Data Adjudicated Claims Database was conducted using data from January 1, 2007 through September 30, 2015. CZP patients with Crohn's disease were eligible to receive self-administration instructions from a nurse or nurse-administered CZP injections, or both. These services were provided by CIMplicity®, a home health nurse program sponsored by UCB Pharma. Cohorts were based on patients with and without nurse assistance and were matched based on gender and categorical age. Adherence to CZP was determined using the medication possession ratio (MPR) and proportion of days covered (PDC). A Kaplan-Meier analysis was performed to compare time to discontinuation of CZP between the two cohorts. Multivariate regression analyses were performed, adjusting for additional covariates to compare the effect of CZP with and without nurse assistance on hospitalization and total health care costs. RESULTS: Patients with at least 12 months of continuous enrollment post-index date were evaluated for adherence to CZP (n=276 in each cohort). The mean and median PDC and MPR values were higher with nurse assistance than without. Time to discontinuation was significantly longer in patients who received CZP with nurse assistance than without (P=0.0004). Results from the multivariate analyses showed a significant reduction in all-cause hospitalization (-55.8%; P=0.0026) and total health care costs (-14.3%; P=0.0045) with nurse assistance. CONCLUSION: This analysis suggests that home health nurse assistance increases adherence to CZP and reduces health care costs in patients with Crohn's disease.