A model-based tool for guiding infliximab induction dosing to maximise long-term deep remission in children with inflammatory bowel diseases

BACKGROUND AND AIMS

Adequate infliximab concentrations during induction treatment are predictive for deep remission (corticosteroid-free clinical and endoscopic remission) at six months in children with inflammatory bowel diseases (IBD). Under standard infliximab induction dosing, children often have low infliximab trough concentrations. Model-informed precision dosing (MIPD) (i.e., model-based therapeutic drug monitoring) is advocated as a promising infliximab dosing strategy. We aimed to develop and validate an MIPD framework for guiding paediatric infliximab induction treatment.

METHODS

Data from 31 children with IBD (4-18years) receiving standard infliximab induction dosing (5mg/kg at week [w]0, w2, and w6) were repurposed. Eight paediatric population pharmacokinetic models were evaluated. Modelling and simulation were used to identify exposure targets, an optimal sampling strategy, and develop a multi-model prediction algorithm for implementation into an MIPD software tool. A role for infliximab clearance monitoring was evaluated.

RESULTS

A 7.5mg/L infliximab concentration target at w12 was associated with 64% probability of deep remission at six months. With standard dosing, less than 80% of simulated children <40kg attained this target. The w12 target was most accurately and precisely achieved by implementing MIPD at w6 using the w6 infliximab concentration (rapid assay required). The multi-model algorithm outperformed single models when optimising the w6 dose based on both w2 and w4 concentrations. MIPD using only the w2 concentration resulted in biased and imprecise predictions. Infliximab clearances at w6 and w12 were predictive for deep remission.

CONCLUSIONS

A freely available, multi-model MIPD tool facilitates infliximab induction dosing and improves deep remission rates in children with IBD.

Acute Severe Ulcerative Colitis: Optimal Strategies for Drug Therapy

Acute severe ulcerative colitis (ASUC) is a life-threatening medical emergency with considerable morbidity (30% to 40%). Patients with ASUC require hospitalization for prompt medical treatment, and colectomy is considered if medical therapy fails. Corticosteroids remain the primary initial therapy, although one-third of patients do not respond to treatment. Clinical data have indicated that cyclosporine, tacrolimus, and infliximab can be used to treat patients with ASUC who do not respond to intravenous corticosteroids. The effectiveness and safety of sequential therapy have recently been reported; however, the data are not convincing. Importantly, timely decision-making with rescue therapy or surgical treatment is critical to manage ASUC without compromising the health or safety of the patients. In addition, risk stratification and the use of predictive clinical parameters have improved the clinical outcome.of ASUC. Multidisciplinary teams that include inflammatory bowel disease experts, colorectal surgeons, and other medical staff contribute to the better management of patients with ASUC. In this review, we introduce current evidence and present a clinical approach to manage ASUC.

An ameliorated anti-hTNF-α therapy for arthritis via carrier-free macromolecular nanoparticles consisted of infliximab

Infliximab (INF) is intravenously used for the clinical treatment of rheumatoid arthritis. However, it can cause serious side effects, which are mainly associated with systemic exposure and high doses. Here, we developed a modified hydrophobic ion-pairing complexes (INF HIPC) through the sequential introduction of bovine lactoferrin (BLF) and hyaluronic acid (HA) with opposite charges into the INF solution. INF and BLF were found to be not only integrally responsible for the structural integrity of HIPC but also were determined to have respective biological activities by binding human tumor necrosis factor-alpha (hTNF-α) or promoting the proliferation of osteoblasts. The INF HIPC had good stability, high drug-loading efficiency, and long-term retention effects. Whether via knee joint injection or intravenous injection, INF HIPC resulted in lower hTNF-α levels and less cartilage destruction than INFs in the transgenic mouse model. At the same time, INF HIPC could reduce toxicity based on body weight changes in transgenic mice. Our findings provide a simple and promising avenue to develop advanced delivery systems for other antibodies and macromolecules.

A pediatric case of infliximab-resistant ulcerative colitis successfully treated using vedolizumab

Pediatric ulcerative colitis is likely to be more severe than adult ulcerative colitis. Failure to thrive should be considered during therapy. A 10-year-old boy was diagnosed with ulcerative colitis based on his clinical presentation and colonoscopy and biopsy results. The administration of 5-aminosalicylic acid and prednisolone resulted in remission ; however, the symptoms reappeared after the discontinuation of prednisolone. Then, infliximab was administered ; however, the patient was resistant to it and appeared to be dependent on prednisolone. Vedolizumab, a monoclonal antibody against ?4?7 integrin, was administered, which resulted in rapid remission. A steady decrease in prednisolone followed, and remission was maintained even after prednisolone discontinuation. Vedolizumab may be effective in pediatric patients with moderate-to-severe refractory ulcerative colitis. Vedolizumab prevents lymphocytes from binding to MAdCAM-1, which is selectively expressed in the gastrointestinal submucosa, leading to the mitigation of the systemic side effects of immunosuppression, such as infections. In Japan, vedolizumab use is not yet approved for use in children, but its effectiveness and safety in children is expected to be investigated in the future. J. Med. Invest. 70 : 294-297, February, 2023.

Diagnostic work-up and treatment in patients with pyoderma gangrenosum: retrospective analysis of US insurance claims-based data

Pyoderma gangrenosum (PG) is a rare, and often challenging to diagnose, inflammatory disorder with relatively high rates of morbidity and mortality. Central to the diagnosis of PG is histologic evaluation and exclusion of other entities. Large-scale studies investigating the proportion of patients receiving a thorough diagnostic work-up, as well as prevalence studies regarding comorbidities and systemic treatment in PG using claims-based data, are sparse. Our objective was to identify patients diagnosed with PG and describe the diagnostic work-up and prevalence of common comorbidities and therapies in this population using claims-based data in a retrospective cohort study. In order to better understand practices of diagnostic work-up, we captured rates of skin biopsy, tissue culture, and/or surgical debridement prior to initial diagnosis. We also identified the prevalence of PG-associated comorbidities and initial immunosuppressive therapy given for PG. Of the 565 patients diagnosed with PG, 9.4% underwent skin biopsy, 8% tissue culture, and 1.4% both skin biopsy AND tissue culture prior to diagnosis. Inflammatory bowel disease was the most prevalent comorbidity (16.3%). The most common treatment administered was systemic corticosteroids (17%). Although practice guidelines explicitly delineate histology and exclusion of infection as important diagnostic criteria, only a minority of patients in this study underwent skin biopsy and/or tissue culture prior to receiving a diagnosis of PG, suggesting that patients may receive a diagnosis of PG without having tissue evaluation. Such discordance between practice guidelines and "real-world" practice inevitably increases the risk for misdiagnosis of PG and misdirected treatment with immunosuppressants for presumptive PG in cases of PG mimickers. Moreover, comorbidities associated with PG may occur, or be identified in, a lower proportion of patients as compared with what is reported in the existing literature. Study limitations include a population restricted to < 65 years with commercial insurance and the reliance upon ICD diagnostic coding to capture the population.

Smoking Is Not an Independent Risk Factor for Surgery in Patients with Crohn's Disease on Biologic Therapy

Introduction

The development and course of inflammatory bowel disease appear to be influenced by environmental factors. Particularly, smoking has been shown to assume a harmful role in Crohn's disease (CD) and a protective role in ulcerative colitis. This study aims to examine the effect of smoking on need for surgery in patients with moderate to severe CD receiving biologic therapy.

Methods

This was a retrospective study of adult patients with CD at a University Medical Center over a 20-year period.

Results

A total of 251 patients were included (mean age 36.0 ± 15.0; 70.1% males; current, former, and nonsmokers: 44.2%, 11.6%, and 43.8%, respectively). Mean duration on biologics was 5.0 ± 3.1 years (>2/3 received anti-TNFs, followed by ustekinumab in 25.9%) and a third of patients (29.5%) received more than one biologic. Disease-related surgeries (abdominal, perianal, or both) occurred in 97 patients (38.6%): 50 patients had surgeries prior to starting biologics only, 41 had some surgeries after, and 6 had insufficient information. There was no significant difference in surgeries between ever-smokers (current or previous) versus nonsmokers in the overall study group. On logistic regression, the odds of having any CD surgery were higher in patients with longer disease duration (OR = 1.05, 95% CI = 1.01, 1.09) and in those receiving more than one biologic (OR = 2.31, 95% CI = 1.16, 4.59). However, among patients who had surgery prior to biologic therapy, smokers were more likely to have perianal surgery compared to nonsmokers (OR = 10.6, 95% CI = 2.0, 57.4; p = 0.006).

Conclusion

In biologic-naive CD patients requiring surgery, smoking is an independent predictor of perianal surgery. Smoking, however, is not an independent risk factor for surgery in this cohort after starting biologics. The risk of surgery in those patients is primarily associated with disease duration and the use of more than one biologic.

A Novel Case of Multicentric Reticulohistiocytosis Associated with Renal Cell Carcinoma Successfully Treated with Infliximab and Methotrexate

Multicentric reticulohistiocytosis (MRH) is categorized as a rare non-Langerhans cell histiocytosis most commonly seen in women in the fourth to fifth decade of life. This systemic inflammatory condition affects multiple organ systems and can result in severe joint destruction which can progress to arthritis mutilans. To date, various underlying malignancies have been discovered in patients with MRH including breast, gastric, thymic, hepatic, and melanoma. There has been 1 case of underlying renal cell carcinoma reported in a patient diagnosed with MRH. Additionally, there is no consistently recognized treatment for MRH described in the literature. The rarity of the disease contributes to the difficulty in defining a standardized treatment. We present the case of a patient with extensive joint and skin involvement who was successfully treated with infliximab and methotrexate, experienced clinical improvement, and was later diagnosed with clear cell renal cell carcinoma. The synergistic effects of infliximab and methotrexate, in combination with the low side-effect profile, appear to be promising in the setting of MRH and in our patient resulted in the resolution of symptoms and cutaneous manifestations. We suggest this regimen as an effective combination therapy. We emphasize thorough and continuous screening for underlying malignancy associated with MRH, despite clinical improvement or negative malignancy work-up upon initial diagnosis.

Gluteal and Presacral Abscess Due to Crohn's Disease with Multiple Fistulas

The abscess is a common complication of Crohn's disease (CD), with the perianal form more frequent than gluteal or presacral which is relatively rare. There are few case reports of gluteal abscess combined with presacral abscess caused by CD and the treatment has not been established. A 21-year-old male was admitted with right buttock and lower back pain with a duration of 3 months. He had a history of CD in the small intestine diagnosed 10 months previously. He had poor compliance and had not returned for follow-up care during the previous 6 months. Abdominopelvic CT indicated newly developed multiple abscess pockets in right gluteal region, including piriformis muscle and presacral space. Additionally, fistula tracts between small bowel loops and presacral space were observed. Patient's CD was moderate activity (273.12 on the Crohn's Disease Activity Index [CDAI]). Treatment was started with piperacillin/ tazobactam antibiotic but patient developed a fever and abscess extent was aggravated. Therefore, surgical incision and drainage was performed and 4 Penrose drains were inserted. Patient's pain and fever were resolved following surgery. Infliximab was then administered for the remaining fistulas. After the induction regimen, multiple fistula tracts improved and patient went into remission (CDAI was -0.12).

Early Infliximab Clearance Predicts Remission in Children with Crohn's Disease

BACKGROUND AND AIMS

Children with Crohn's disease have lower response rates to infliximab, lower infliximab levels, and higher infliximab clearance on weight-based dosing than adults. We hypothesize infliximab clearance is a predictive of later outcomes on infliximab in children with Crohn's disease.

METHODS

In this single-center retrospective study, data were collected from charts on diagnosis, anthropometry, routine labs, infliximab therapeutic drug monitoring, infliximab dosing, disease activity, and other treatments. With these data we generated a population pharmacokinetic model using non-linear mixed effects modeling and calculated infliximab clearance for each patient over time. Patients were classified as in remission, responder-only or non-responder at 5, 10 and 16 months. Regression and ROC analyses were used to assess for early predictors of remission and response to infliximab.

RESULTS

Eighty-five subjects were included, with a median follow-up of 22.3 months (IQR 10.1-36.8). Our pharmacokinetic model showed infliximab clearance was positively associated with CRP and weight, while negatively associated with albumin. In regression analyses, early infliximab clearance was the only significant, consistent predictor of remission. A 0.1 L/day increase in infliximab clearance predicted remission with an OR between 0.179 and 0.426. Differences in dosing did not account for differences in outcome. Infliximab clearance alone had moderate predictive accuracy of remission, with an AUC between 0.682 and 0.738.

CONCLUSIONS

Early infliximab clearance is strongly associated with remission in children with Crohn's disease. It may be useful as a marker of response in proactive therapeutic drug monitoring to guide early dose optimization and/or changes in treatment for betterment of long-term outcomes.

Multidisciplinary treatment of a patient with severe immune checkpoint inhibitor-induced colitis: A case report

BACKGROUND

Immune checkpoint inhibitors (ICIs) are a new class of antitumor drugs that have been approved to treat a variety of malignant tumors. However, the occurrence of immune related adverse events (irAEs) has become an important reason for terminating treatment. ICIs sometimes lead to diarrhea and colitis, with severe enterocolitis potentially causing the hemorrhage of the lower gastrointestinal tract and colonic perforation. ICI-associated colitis is primarily treated with glucorticosteroids and/or agents targeting tumor necrosis factor-α. Here, we describe a case of severe ICI-associated colitis due to anti-programmed cell death ligand 1 (PD-L1) (durvalumab) treatment for small cell lung cancer with liver metastasis. The patient exhibited a poor response to rescuable therapy, and eventually received a laparoscopic subtotal colectomy and ileostomy. The data presented here will contribute to optimizing current treatment strategies for patients with severe ICI-associated colitis.

CASE SUMMARY

A 71-year-old man was admitted for a second course of anti-PD-L1 + IP (durvalumab + irinotecan + cisplatin) treatment to manage lung cancer with liver metastasis, diagnosed 1 mo previously. Four days after the second dose, the patient developed abdominal pain and bloody diarrhea. Due to the anti-PD-L1 medication history and colonoscopy findings of the patient, he was diagnosed with a colitis associated with ICI treatment. After treatment with sufficient glucocorticoids and two courses of infliximab, the patient developed severe lower gastrointestinal bleeding. After adequate assessment, the patient was treated by laparoscopic surgery, and was discharged in stable condition.

CONCLUSION

The early screening and hierarchical management of irAEs need the joint participation of a multidisciplinary team. For ICI-related colitis with ineffective medical treatment, timely surgical intervention could prevent the death of patients.

Anti-drug antibodies and rheumatoid factor level in patients with rheumatoid arthritis using the infliximab biosimilar CT-P13

BACKGROUND

This study evaluated the existence of anti-drug antibodies (ADAs) before and 52 weeks after switching from intravenous infliximab (IFX) to intravenous CT-P13 in patients with rheumatoid arthritis (RA).

METHODS

We performed a prospective observational study. Twenty-eight patients (7 males and 21 females) received intravenous CT-P13 after intravenous IFX, and the clinical data were collected from medical records. Rheumatoid factor (RF) and anti-CCP antibody were examined at baseline. At baseline and 52 weeks after the start of CT-P13 treatment, the Disease Activity Score based on the 28-joint count and the levels of C-reactive protein, matrix metalloproteinase-3, and ADA, as well as the erythrocyte sedimentation rate were evaluated. ADAs were measured using an enzyme-linked immunosorbent assay kit.

RESULTS

Seven (25%) and 6 (21.4%) cases were positive for ADAs at baseline and 52 weeks after, respectively. One case became newly positive for ADAs at week 52. Two of the ADA-positive cases became ADA-negative 52 weeks after. The ADA-positive group showed significantly higher RF values at baseline than the ADA-negative group (p = 0.03). No difference was observed between the ADA-positive group and the ADA-negative group regarding other clinical parameters.

CONCLUSIONS

The positive rate of ADAs did not increase after switching from intravenous IFX to intravenous CT-P13. Among the patients with ADAs, a high level of RF was observed at baseline.

Management of the Hospitalized Patient with Acute Colitis

Acute severe ulcerative colitis is a rapidly progressive severe form of colitis that can occur in 20-30% patients with ulcerative colitis. Early recognition, hospitalization at centers with experience and expertise and multidisciplinary treatment is the cornerstone of appropriate management of this condition. After excluding infections and other differentials, patients should be started on parenteral corticosteroids to control inflammation. ASUC patients are at high risk for thromboembolic complications and hence DVT prophylaxis is ideally started as soon as possible in the emergency room and continued throughout hospitalization. Objective criteria should be applied to assess improvement and identify patients who are unlikely to improve without second line/rescue therapy as early as 72 hours on steroid therapy. Infliximab and cyclosporine are the most used options for second line therapy and should be administered under direction by gastroenterologists. Disease progression despite aggressive treatment or non-response to second line therapy, complications such as megacolon, perforation, hemorrhage can occur requiring colectomy as a salvage option in those patients.

Cerebral venous thrombosis in adolescence: Looking beyond the obvious

Behçet's disease (BD) is a rare systemic vasculitis with multisystemic involvement. Neurological involvement, called neuro-Behçet's disease (NBD), mostly involves the central nervous system and cerebral venous thrombosis (CVT) is the predominant neurological manifestation in the pediatric age. A 12-year-old female with a past medical history of a CVT, without an identifiable etiology, was admitted with a five-day right fronto-orbital headache. Neuroimage showed a subacute thrombosis of a right superficial sylvian vein, with indirect signs of intracranial hypertension and no imaging signs of vasculitis. Prothrombotic screening and immunologic study were normal. She was started on acetazolamide and hypocoagulation with progressively improving. She had a history of frequent oral aphthae and an episode of a genital ulcer three months before admission. Pathergy test was negative. HLA-B51 was positive. She was diagnosed with NBD and started therapy with colchicine and infliximab. After discharge, the patient remains without symptoms, hypocoagulated, and on infliximab regimen, without complications to report. This case, only diagnosed in the second episode of CVT, is paradigmatic of the difficulty in establishing the diagnosis of BD.

Ischemic stroke in neurosarcoidosis: A retrospective cohort analysis

BACKGROUND

Cerebrovascular disease is rarely reported in neurosarcoidosis and constitutes one of its least well-described forms, though recognition for it has grown in the last decade with recent studies estimating a higher frequency of occurrence than previously known.

METHODS

Patients with ischemic stroke were included if the mechanism was directly attributable to sarcoidosis of the CNS. Patients were excluded if an alternative stroke etiology was of equal or higher likelihood than CNS sarcoidosis.

RESULTS

Neurologic disease was the initial presenting manifestation of sarcoidosis in 8/11 (72.7%), and ischemic stroke was an inaugural manifestation of sarcoidosis in 4/11 (36.4%). Small vessel disease was the predominant ischemia subtype (10/11, 90.9%) with pontine perforating vessels (6/11, 54.5%) and lenticulostriate arteries (3/11, 27.3%) being the vasculature most often affected. Vessels with a more rostral supratentorial distribution were uncommonly affected. Common neuroinflammatory accompaniments included leptomeningitis (10/11, 90.9%) and cranial nerve disease (3/11, 27.3%). Recurrent strokes occurred in 8/11 (72.7%), and recurrent neuroinflammation occurred in 7/11 (63.6%). Antiplatelet drugs were used in 6/11 (54.5%) patients. Most (10/11, 90.9%) required at least two lines of immunosuppression to achieve inflammatory disease remission in this context; infliximab was the most successfully employed immunosuppressant (7/8 treatment courses, 87.5%). Recurrent strokes occurred in 8/11 (72.7%) patients, and a second inflammatory attack occurred in 7/11 (63.6%) patients. The presenting median modified Rankin Scale score of 4.0 improved to 2.0 over a median period of follow-up of 52.0 months.

CONCLUSION

Ischemic strokes in neurosarcoidosis occur in a caudal-to-rostral distribution, tend to affect small caliber blood vessels that lack collateral blood flow, and typically associate with inflammatory leptomeningeal disease. The risk for relapse in the forms of stroke or neuroinflammation are high in this neurosarcoidosis phenotype.

Risk Prediction and Comparative Efficacy of Anti-TNF vs Thiopurines, for Preventing Postoperative Recurrence in Crohn's Disease: A Pooled Analysis of 6 Trials

BACKGROUND & AIMS

The superiority of anti-TNF-α agents to thiopurines for the prevention of postoperative recurrence of Crohn's disease (CD) after ileocolonic resection remains controversial. In this meta-analysis of individual participant data (IPD), the effect of both strategies was compared and assessed after risk stratification.

METHODS

After a systematic literature search, IPD were requested from randomized controlled trials investigating thiopurines and/or anti-TNF-α agents after ileocolonic resection. Primary outcome was endoscopic recurrence (ER) (Rutgeerts score ≥i2) and secondary outcomes were clinical recurrence (Harvey-Bradshaw Index/Crohn's Disease Activity Index score) and severe ER (Rutgeerts score ≥i3). A fixed effect network meta-analysis was performed. Subgroup effects were assessed and a prediction model was established using Poisson regression models, including sex, smoking, Montreal classification, CD duration, history of prior resection and previous exposure to anti-TNF-α or thiopurines.

RESULTS

In the meta-analysis of IPD, 645 participants from 6 studies were included. In the total population, a superior effect was demonstrated for anti-TNF-α compared with thiopurine prophylaxis for ER (relative risk [RR], 0.52; 95% confidence interval [CI], 0.33-0.80), clinical recurrence (RR, 0.50; 95% CI, 0.26-0.96), and severe ER (RR, 0.41; 95% CI, 0.21-0.79). No differential subgroup effects were found for ER. In Poisson regression analysis, previous exposure to anti-TNF-α and penetrating disease behavior were associated with ER risk. The advantage of anti-TNF-α agents as compared with thiopurines was observed in low- and high-risk groups.

CONCLUSIONS

Anti-TNF-α is superior to thiopurine prophylaxis for the prevention of endoscopic and clinical postoperative CD recurrence after ileocolonic resection. The advantage of anti-TNF-α agents was confirmed in subgroup analysis and after risk stratification.

Efficacy of Infliximab for the Treatment of Oral Manifestation of Crohn's Disease

Oral manifestations of IBD can be specific or nonspecific, due to intestinal malabsorption or induced by pharmacological treatments. Oral manifestations may precede the diagnosis of IBD or interfere with timely diagnosis and treatment. The paradigm of treatment for oral lesions in patients with IBD is based on treating and controlling the intestinal manifestations of the underlying disease as well as local methods of treatment can be used. Here, we report a case of a patient with the oral manifestation of IBD, who responded to treatment with infliximab. The patient was admitted with complaints of long-term nonhealing ulcers of the lips and oral cavity, odynophagia, and there were no intestinal manifestations at that time. The appearance of the disease in 2008 with lesions of the oral cavity, however, Crohn's disease was diagnosed in 2016. The patient began therapy with azathioprine and prednisolone, and later developed hormone dependence and osteoporosis. In 2020, against the background of immunosuppressive therapy, the patient has an exacerbation, especially increased symptoms from the lesion of the oral cavity. In 2020 was started therapy with vedolizumab, with slight improvement. Due to the ineffectiveness of the latter's therapy, therapy with monoclonal antibodies (infliximab) was started in February 2021. Currently, patient is in clinical, laboratory, and endoscopic remission.

Tumor necrosis factor-α inhibition restores matrix formation by human adipose-derived stem cells in the late stage of chondrogenic differentiation

BACKGROUND

Cartilage tissue engineering is a promising strategy for treating cartilage damage. Matrix formation by adipose-derived stem cells (ADSCs), which are one type of seed cell used for cartilage tissue engineering, decreases in the late stage of induced chondrogenic differentiation in vitro, which seriously limits research on ADSCs and their application.

AIM

To improve the chondrogenic differentiation efficiency of ADSCs in vitro, and optimize the existing chondrogenic induction protocol.

METHODS

Tumor necrosis factor-alpha (TNF-α) inhibitor was added to chondrogenic culture medium, and then Western blotting, enzyme linked immunosorbent assay, immunofluorescence and toluidine blue staining were used to detect the cartilage matrix secretion and the expression of key proteins of nuclear factor kappa-B (NF-κB) signaling pathway.

RESULTS

In this study, we found that the levels of TNF-α and matrix metalloproteinase 3 were increased during the chondrogenic differentiation of ADSCs. TNF-α then bound to its receptor and activated the NF-κB pathway, leading to a decrease in cartilage matrix synthesis and secretion. Blocking TNF-α with its inhibitors etanercept (1 μg/mL) or infliximab (10 μg/mL) significantly restored matrix formation.

CONCLUSION

Therefore, this study developed a combination of ADSC therapy and targeted anti-inflammatory drugs to optimize the chondrogenesis of ADSCs, and this approach could be very beneficial for translating ADSC-based approaches to treat cartilage damage.

克罗恩病患儿英夫利西单抗维持治疗前血药浓度与疾病转归的关系

OBJECTIVES

To study the association between infliximab trough level (IFX-TL) prior to maintenance treatment and disease outcome in children with Crohn's disease (CD).

METHODS

A retrospective analysis was performed on 35 children with CD who received induction therapy with infliximab (IFX) and the measurement of IFX-TL before maintenance treatment from August 2018 to November 2021. Clinical data and laboratory markers at baseline and before maintenance treatment were collected, and the association between outcome and IFX-TL was analyzed.

RESULTS

The clinical remission group, endoscopic remission group, and combined remission group had a significantly higher IFX-TL level than the corresponding non-remission groups (P<0.05), and there was no significant difference in the IFX-TL level between the biological remission and non-biological remission groups (P>0.05). The receiver operating characteristic (ROC) curve showed that IFX-TL had an area under the ROC curve of 0.959 (95%CI: 0.894-1) in predicting clinical remission, with a sensitivity of 90% and a specificity of 100% at the optimal cutoff value of 2.3 µg/mL (P<0.001).

CONCLUSIONS

Among children with CD receiving infliximab induction therapy, the children achieving clinical and endoscopic remission before maintenance treatment tend to have a higher level of IFX-TL. IFX-TL has a certain predictive value for clinical remission.

The effect of adjunctive infliximab treatment on future cardiovascular disease risk in patients with bipolar disorder

INTRODUCTION

Bipolar disorder (BD) is characterized by a pro-inflammatory biotype, and is a major cause of cardiovascular disease (CVD), consequently causing elevated rates of morbidity and mortality among individuals with BD.

METHODS

The present study is based on a 12-week clinical trial assessing the antidepressant effects of adjunctive infliximab treatment in BD. Generalized estimating equation (GEE) models were used to evaluate CVD risk in people with BD following adjunctive infliximab treatment at baseline and week 12. Participants (baseline: n = 40; endpoint: 33) were randomized for an infliximab-treatment or placebo group. CVD-risk was calculated using Framingham risk scores (FRS), mean arterial blood pressure (MAP) and total cholesterol (TC).

RESULTS

There was no main effect of treatment on FRS in infliximab-treated participants compared to controls (p = 0.408). Similarly, there were no significant differences in MAP between the infliximab-treated and control group (p = 0.796). The effect of treatment on TC was not significant (p = 0.130), however, an evaluation across time suggested the main effect of the group was significant at week 0 (p = 0.01), but not week 12 (p = 0.219).

LIMITATIONS

Cardiovascular disease was not an outcome of the original clinical trial, and our participant group did not have a high CVD-risk at baseline.

CONCLUSION

There were no significant treatment effects of infliximab on FRS, MAP and TC. The current study highlights the complexity of immune-system targets that influence CVD in psychiatric populations. Future studies should include a large scale, combinatorial omnibus biomarker approach to evaluate the immune and vascular link in BD.

Adherence patterns in naïve and prevalent use of infliximab and its biosimilar

Introduction

Although short-term clinical trials have demonstrated that switching from infliximab (INF) bio-originator to its biosimilar is safe with no significant loss of efficacy, there are limited real-world data comparing their patterns of use and adherence.

Methods

Using 2015–2018 IBM Marketscan data, we established 4 cohorts of patients with at least one administration or pharmacy claim for INF bio-originator or biosimilar in 2017, including INF naïve biosimilar users, INF prevalent biosimilar users, INF naïve bio-originator users, and INF prevalent bio-originator users, defined according to their prior use of INF from 2015 to their first INF administration in 2017. The proportion of days covered (PDC) was calculated for patients with at least 6, 12, or 18 months of follow-up time. Factors associated with optimal adherence (PDC > 80%) were evaluated using log-binomial models.

Results

We identified 96 INF naïve biosimilar users, 223 INF prevalent biosimilar users, 2,149 INF naïve bio-originator users, and 10,970 INF prevalent bio-originator users. At the end of 18 months of follow-up, 64% of INF prevalent bio-originators, 48% of INF naïve biosimilars, 41% of INF naïve bio-originators, and 36% of INF prevalent biosimilars had optimal adherence. Depression, previous hospitalization, and greater use of prior biologics were negatively associated with adherence, whereas IBD diagnoses (referent to RA) and age 55–64 (referent to < 35) were positively associated with high adherence.

Conclusion

INF prevalent users had higher adherence in our analyses than INF naïve users. However, further studies with larger sample size are needed to evaluate INF biosimilar users’ adherence.

Effects of Biologic Therapies on the Chance of COVID-19 Infection Among Rheumatoid Arthritis and Lupus Patients During the First Wave of the Pandemic

Background

Patients with rheumatic diseases taking immunosuppressive medications might be at an increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Despite the effectiveness of using combined conventional and biological disease-modifying anti-rheumatic drugs(bDMARDs) in managing rheumatic diseases, there have been concerns that taking biological agents may have an additive effect on getting infected with COVID-19. This study evaluates the impact of taking biological agents on altering the chance of getting infected with SARS-CoV-2 in rheumatoid and lupus patients compared to traditional DMARDs.

Methods

We carried out a cross-sectional survey study from February 2020 to January 2021 on patients diagnosed with lupus and rheumatoid arthritis disease. COVID-19 infection was confirmed by the presence of symptoms and signs of the disease and para-clinical findings such as lymphopenia and elevated C-reactive protein (CRP) and positive chest CT scan or polymerase chain reaction (PCR) of COVID-19.

Results

Out of 591 patients included in this study, 422 (71.4%) had rheumatoid arthritis (RA), and 169 (28.6%) had systemic lupus erythematosus (SLE). Among them, 56 (9.5%) cases were diagnosed with COVID-19 infection. No association was found between age, gender, or type of rheumatological diseases and SARS-CoV-2. There was a significant association between COVID-19 infection and treatment with biological drugs (P-value<0.05) regardless of the type of rheumatologic disease. Interestingly, the analysis revealed that the type of biologic drug also altered the chance of COVID-19 infection; In fact, patients who took TNF inhibitors were significantly at a higher risk of disease than those taking Rituximab (P-value=0.000). Identical results were observed among RA patients (P-value<0.001), however, all 5 (3%) lupus cases treated with Rituximab infected with covid 19.

Conclusion

This study develops a better understanding of the risk of immunosuppressive medications for SARS-CoV-2 infection. Patients treated with conventional and biological medicine had a higher disease risk than those taking exclusively conventional drugs. However, more studies are required to deliberate the relation of the reviewed factors with the severity of COVID-19.

Use of multibiomarker disease activity scores in biosimilarity studies for the treatment of patients with rheumatoid arthritis

Objectives

This exploratory analysis investigated the potential use of the multibiomarker disease activity (MBDA) score to support biosimilarity assessments using data from two randomised controlled trials (RCTs) of biosimilar infliximab (IFX-qbtx) and biosimilar adalimumab (ADL-afzb) versus EU-sourced infliximab (Remicade; IFX-EU) and adalimumab (Humira; ADL-EU) reference products, respectively, both conducted in adult patients with active rheumatoid arthritis.

Methods

In one study, patients (N=650) were randomised 1:1 to IFX-qbtx or IFX-EU (3 mg/kg intravenous at weeks 0, 2 and 6, then every 8 weeks). In the other, patients (N=597) were randomised 1:1 to ADL-afzb or ADL-EU (40 mg subcutaneous every other week). All treatments were given with MTX. Mean values of MBDA scores were calculated at baseline (BL), based on the concentrations of 12 serum proteins using the Vectra disease activity algorithm, and at timepoints throughout treatment period 1 (TP1) of the IFX (weeks 6, 14, 30) and ADL (weeks 6, 12, 26) studies. Data were summarised using descriptive statistics for the intent-to-treat population, without imputation for missing data.

Results

At BL, mean (±SD) MBDA scores were 61.3 (±12.5) and 58.8 (±13.2) for IFX-qbtx (n=236) and IFX-EU (n=248), respectively, and 57.2 (±14.44) and 58.3 (±15.34) for ADL-afzb (n=292) and ADL-EU (n=293), respectively. Mean MBDA scores were highly comparable between IFX-qbtx and IFX-EU and between ADL-afzb and ADL-EU at all measured timepoints during TP1 in each study.

Conclusions

These RCTs are the first to incorporate MBDA score as an exploratory assessment of biosimilarity. MBDA scores may provide objective, quantitative evidence of biosimilarity using an assessment of disease activity that is independent of the potential subjectivity inherent in joint counts, or in patient or physician global assessments.

Trial registration numbers

NCT02222493 and NCT02480153.

Steroid-Free Deep Remission at One Year Does Not Prevent Crohn's Disease Progression: Long-Term Data From the TAILORIX Trial

BACKGROUND & AIMS

Crohn's disease (CD) patients included in the Tailored Treatment With Infliximab for Active Crohn's Disease (TAILORIX) trial started infliximab in combination with an immunosuppressant for 1 year. The aim of the present study was to determine the long-term disease course beyond the study period.

METHODS

We compared the outcomes of patients who did or did not reach the primary end point of the TAILORIX trial, defined as sustained corticosteroid-free clinical remission from weeks 22 through 54, with no ulcers on ileocolonoscopy at week 54. The primary outcome of this follow-up study was the progression-free survival of CD defined by anal or major abdominal surgery, CD-related hospitalization, or the need for a new systemic CD treatment.

RESULTS

The 95 patients (median disease duration, 4.5 mo; interquartile range, 1.0-56.6 mo) analyzed, including 45 (47%) who achieved the primary end point, were followed up for a median duration of 64.2 months (interquartile range, 57.6-69.9 mo) after the end of the study period. There was no significant difference in CD progression-free survival at 1, 3, and 5 years between patients who achieved the TAILORIX primary end point and patients who did not (P = .64). No difference was observed between both groups for each component of CD progression: anal surgery, major abdominal surgery, CD-related hospitalization, or the need for a new systemic CD treatment.

CONCLUSIONS

Achieving a sustained clinical remission off steroids with complete endoscopic remission in this cohort of 95 patients with early CD was not associated with less disease progression. Prospective trials to define the therapeutic goals that change the natural history of CD and prevent complications are needed.

Adalimumab versus Infliximab Treatment Outcome in Ulcerative Colitis: Application of EQ-5D, Visual Analogue Scale, and IBDQ-9 Measures: A Prospective Observational Study

BACKGROUND

Ulcerative colitis (UC) is a chronic global disease, and its incidence and prevalence are increasing worldwide.

OBJECTIVE

Our objective was to compare the secondary outcome of treatment with Infliximab (IFX) and Adalimumab (ADA) in the UC patients.

METHODS

This was a one-year prospective observational study of moderate- to -severe UC patients treated with ADA or IFX. Patients' secondary health outcomes were measured using the EQ-5D 3L, EQ-VAS, and IBDQ-9 tools. T-test, Mann-Whitney, chi-square, and Fisher's exact tests were used to compare health-related quality of life (HRQoL) among UC patients. HRQoL predictor variables were identified by multivariate linear regression and multivariate logistic regression.

RESULTS

A total of 238 UC patients (patients taking IFX: 78, patients taking ADA: 160) with a mean age of 37.66 and a mean disease duration of 9.29 years were enrolled. The EQ-5D index, EQ-VAS, and IBDQ-9 scores of patients taking IFX were 0.65, 55.93 and, 37.42, respectively. Similarly, patients taking ADA were 0.68, 59.27 and, 36.61, respectively. The highest problem reports were in P/D: 86.1% and A/D: 73.5%. The main independent predictors of HRQoL were: education over 12 years (β = 0.054 [EQ-5D index], β = 13.63 [EQ-VAS], OR: 0.28 [MO], OR: 0.07 [SC]), education between 6-12 years (β = 11.23 [EQ-VAS]), and having "other chronic diseases" (β = -0.074 [EQ-5D index], β = -5.29 [IBDQ-9], OR: 2.84 [UA], OR: 3.80 [A/D]).

CONCLUSION

There was no significant difference between the effect of ADA and IFX on secondary health outcomes in patients with moderate-to-severe UC.

Sarcoidosis

Sarcoidosis is a systemic autoimmune disease that is associated with the development of non-caseating granulomas. The disease especially affects the lymph nodes, lungs, skin and eyes. It is an infrequent but not rare disease, especially in northern Europe, the United States and India. Sarcoidosis affects more women and is diagnosed between the ages of 30 and 50. Etiopathogenically, it is closely linked to environmental factors, especially occupational exposures. Clinically, it stands out for a wide variety of presentation phenotypes (casual diagnosis, involvement of a single organ or systemic presentation). The diagnosis of sarcoidosis is complex and requires the integration of clinical, analytical, radiological, and histolopathogical data carried out by multidisciplinary clinical units. The evolution of the disease is variable, as is the indication for systemic treatment, based on the use of corticosteroids as first-line option, the use of immunosuppressants as second-line therapy, and anti-TNF agents in severe and/or refractory cases.

Trends in medication use and treatment patterns in Chinese patients with inflammatory bowel disease

BACKGROUND

Medications for inflammatory bowel disease (IBD) have changed dramatically over time. However, no study on long-term medication profiles has been conducted in the Chinese population.

AIM

To evaluate temporal changes in medication use and treatment patterns for Chinese patients with IBD.

METHODS

A multicenter retrospective cohort study was conducted among Chinese patients newly diagnosed with Crohn’s disease (CD) and ulcerative colitis (UC) between January 1999 and December 2019. Baseline characteristics and drug prescriptions were collected. Trends in medication use and therapeutic patterns were analyzed.

RESULTS

In total, 3610 patients were analyzed. During follow-up, 5-aminosalicylates (5-ASA) and corticosteroids (CS) prescriptions gradually decreased, accompanied by a notable increase in immunosuppressants (IMS) and infliximab (IFX) prescriptions in patients with CD. Prescription rates of 5-ASA and CS were stable, whereas IMS and IFX slightly increased since 2007 in patients with UC. Subgroup (n = 957) analyses showed a switch from conventional medications to IFX in patients with CD, while 5-ASA and CS were still steadily prescribed in patients with UC. Logistic regression analyses revealed that surgical history, disease behavior, and disease location were associated with initial therapeutic strategies in patients with CD. However, medications before diagnosis, disease location, and diagnostic year might affect initial strategies in patients with UC.

CONCLUSION

Long-term treatment strategies analyses has provided unique insight into the switch from conventional drugs to IFX in Chinese patients with CD.

Tumor necrosis factor alpha (TNF-α) blockage reduces acute inflammation and delayed wound healing in oral ulcer of rats

Oral traumatic ulcers (OTU) are common in dental routine, and the control of proinflammatory cytokines, such as the tumor necrosis factor-alpha (TNF-α), may interfere with OTU repair. Our aim was to evaluate the role of TNF-α in the healing process of OTU in rats. Wistar male rats were divided into six groups: a control-group (treated with 0.1 mL/kg of saline) and five groups treated with anti-TNF-α infliximab (INF) at 1, 3, 5, 7, and 10 mg/kg immediately before OTU production. The animals were weighed (day 0) and euthanized on days 1, 3, 7, 14 and 21 after ulceration. The ulcers were clinically measured, and the mucosa samples were histologically (scores 0-4), histochemically (collagen assay (pircrosirius)), histomorphometrically (cell counting), and immunohistochemically (TNF-α, α-smooth-muscle-actin (α-SMA), monocyte-chemoattractive-protein-1 (MCP-1), interleukin-8 (IL-8), and fibroblast-growth-factor (FGF)) analyzed. The Evans blue assay was used to measure the vascular permeability. ANOVA-1-2-way/Bonferroni, Kruskal-Wallis/Dunn, and correlation analyses were performed (GraphPad Prism 5.0, p < 0.05). High doses of INF reduced the OTU area (p = 0.043), body mass loss (p = 0.023), vascular permeability (p < 0.001), and reduced delayed histologic scores (p < 0.05), polymorphonuclear (p < 0.001) and mononuclear (p < 0.001) cells, blood vessel counting (p = 0.006), and total (p < 0.001), type-I (p = 0.018), and type-III (p < 0.001) collagen. INF treatment reduced TNF-α immunostaining and delayed MPC-1, FGF, and α-SMA expression, with little/none influence in IL-8 immunostaining. TNF-α blockage by INF reduced acute inflammation in OTU but delayed cell migration and wound healing.

A randomized, double-blind, placebo-controlled 12-week trial of infliximab in patients with juvenile-onset spondyloarthritis

Objective

To assess the efficacy and safety of infliximab versus placebo in the treatment of patients with juvenile-onset spondyloarthritis (JoSpA).

Methods

Phase III, randomized, double-blind, placebo-controlled trial of 12 weeks that included patients ≤ 18 years old with JoSpA not responding to nonsteroidal anti-inflammatory drugs, sulfasalazine, or methotrexate. Patients were randomly assigned 1:1 to the infusion of infliximab 5mg/kg or placebo; completers entered then an open-label extension (OLE) period of 42 weeks. The primary endpoint was the number of active joints. Secondary outcomes included the assessment of disease activity, tender entheses, spinal mobility, serum C-reactive protein (CRP), the Bath Ankylosing Spondylitis Disease Activity and Functional Index, and the Childhood Health Assessment Questionnaire (CHAQ).

Results

We randomized 12 patients to infliximab and 14 to placebo. No significant differences were found between groups at baseline. At week 12, the mean number of active joints was 1.4 (SD 2.4) in the infliximab group and 4.1 (SD 3.0) in the placebo group (p = 0.0002). A repeated-measures mixed model analysis that included all endpoints in the study demonstrated sustained favourable outcomes of infliximab for active joints, tender joints, swollen joints, and tender enthesis counts, as well as for CHAQ and CRP (p < 0.01). Adverse events were more frequent in the infliximab group, including infections and infusion reactions, but none of them was serious.

Conclusion

Infliximab is efficacious for patients with JoSpA with an inadequate response to conventional treatment. No serious adverse events with the use of infliximab were observed.

Clinical observations on infliximab treatment of infantile onset Takayasu arteritis

BACKGROUND

There is insufficient evidence on the clinical effectiveness and safety of infliximab (IFX) treatment of Takayasu arteritis (TA) in infants.

METHODS

We evaluated the therapeutic effectiveness and safety of IFX in a retrospective case series of 10 infantile TA patients. Observations included assessment of clinical symptoms, laboratory testing, and vascular imaging.

RESULTS

Fever was the presenting symptom for 8 of 10 infants with TA. During acute episodes, leucocyte and inflammatory indices were significantly increased. Vascular imaging showed the most commonly involved arteries to be carotid arteries, abdominal aortas, and coronary arteries (9 cases, 90%). Two weeks after initiating IFX treatment, leukocyte and platelet counts decreased and hemoglobin levels increased. There were statistically significant clinical improvements 6 weeks after starting treatment compared with before treatment (p < 0.05). Inflammatory indices decreased 2 weeks after starting IFX treatment compared with before treatment (p < 0.05). Vascular lesions began to recover within 1.5-3 months of initiating IFX therapy, and involved vessels significantly recovered within 13 months. Some arteries remained stenotic, with intimal thickening and uneven lumen wall thicknesses. The only adverse event was a treatment-responsive allergic reaction during IFX infusion in one infant.

CONCLUSIONS

Fever was the main manifestation of illness and was often accompanied by significantly increased inflammatory indices. IFX treatment was apparently effective and reduced or eliminated need for glucocorticoids. IFX had a reasonably good safety profile.

Short interruptions of TNF-inhibitor treatment can be associated with treatment failure in patients with immune-mediated diseases

INTRODUCTION

The prevalence of immune-mediated diseases has increased in the past decades and despite the use of biological treatments all patients do not achieve remission. The aim of this study was to characterise the reasons for short interruptions during treatment with two commonly used TNF-inhibitors infliximab and adalimumab and to analyse the possible effects of the interruptions on immunisation and switching the treatment.

MATERIAL AND METHODS

This case-control study was based on retrospective analyses of patient records and a questionnaire survey to clinicians. A total of 370 patients (194 immunised cases and 172 non-immunised controls, 4 excluded) were enrolled from eight hospitals around Finland. Eleven different diagnoses were represented, and the largest patient groups were those with inflammatory bowel or rheumatic diseases.

RESULTS

Treatment interruptions were associated with immunisation in patients using infliximab (p < .001) or adalimumab (p < .000001). Patients with treatment interruptions were more likely to have been treated with more than one biological agent compared to those without treatment interruptions. This was particularly prominent among patients with a rheumatic disease (p < .00001). The most frequent reason for a treatment interruption among the cases was an infection, whereas among the control patients it was remission. The median length of one interruption was one month (interquartile range 1-3 months).

CONCLUSION

Our results suggest that the interruptions of the treatment with TNF-inhibitors expose patients to immunisation and increase the need for drug switching. These findings stress the importance of careful judgement of the need for a short interruption in the biological treatment in clinical work, especially during non-severe infections.

How has the disease course of pediatric ulcerative colitis changed throughout the biologics era? A comparison with the IBSEN study

BACKGROUND

In Korea, infliximab was approved for use in children with ulcerative colitis (UC) in October 2012.

AIM

To compare the clinical course of UC before and after the introduction of biological agents, and to compare with the IBSEN study.

METHODS

Patients under 18 years of age, who were diagnosed with UC and followed from January 2003 to October 2020, were included in the study. Group A (n = 48) was followed for at least 2 years between January 2003 and October 2012, and Group B (n = 62) was followed for at least 2 years between November 2012 and October 2020. We compared endoscopic remission, drug composition, relapse rate, steroid-free period, and the quality of life of each group. We plotted the clinical course of the included patients using the pediatric UC activity index score, and compared our patients with those in the IBSEN study.

RESULTS

After 2 years of treatment, colonoscopy evaluation revealed different outcomes in the two treatment groups. Remission was confirmed in 14 patients (29.2%) of Group A, and in 31 patients (50.0%) of Group B (P < 0.012). The median cumulative corticosteroid-free period was 3.0 years in Group A and 4.4 years in Group B. Steroid-free period of Group B was significantly longer than that of Group A (P < 0.001). There was a statistically significant difference between the two groups in evaluation of the relapse rate during the observation period (P < 0.001). The plotted clinical course graphs of Group A showed similar proportions to the graphs in the IBSEN study. However, in Group B, the proportion of patients corresponding to curve 1 (remission or mild severity after initial high activity) was high at 76% (47/62).

CONCLUSION

The incidence of relapse has decreased and the steroid-free period has increased after the introduction of the biological agent. The clinical course also showed a different pattern from that of IBSEN study. The active use of biological agents may change the long-term disease course in moderate to severe pediatric UC.

A novel clinical radiomics nomogram at baseline to predict mucosal healing in Crohn's disease patients treated with infliximab

OBJECTIVES

Mucosal healing (MH) is currently the gold standard in Crohn's disease (CD) management. Noninvasive assessment of MH in CD patients is increasingly a concern of clinicians.

METHODS

This retrospective study included 106 patients with confirmed CD who were divided into a training cohort (n = 73) and a testing cohort (n = 33). Patient demographics were evaluated to establish a clinical model. Radiomics features were extracted from computed tomography enterography (CTE) images. A radiomics signature was constructed, and a radiomics score (Rad-score) was calculated by using the radiomics signature-based formula. A clinical radiomics nomogram was then built by incorporating the Rad-score and significant clinical features. The diagnostic performance of the three models was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 106 patients with CD, 37 exhibited MH after 26 weeks of infliximab (IFX) treatment. The area under the ROC curve (AUC) of the clinical radiomics nomogram for distinguishing MH from non-MH, which was based on the disease duration and Rad-score, was 0.880 (95% confidence interval [CI]: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort. Decision curve analysis (DCA) confirmed the clinical utility of the clinical radiomics nomogram.

CONCLUSIONS

This is a preliminary study suggesting that this CTE-based radiomics model has potential value for predicting MH in CD patients. A nomogram constructed by combining radiomics signatures and clinical features can help clinicians select appropriate therapeutic strategies for CD patients.

KEY POINTS

• The disease duration (odds ratio (OR) = 0.969, 95% confidence interval (CI) = 0.943-0.995, p = 0.021) was an independent predictor of MH in the clinical model. • The AUC of the radiomics model constructed by the five radiomics features was 0.846 (95% CI: 0.759-0.921) in the training cohort and 0.817 (95% CI: 0.665-0.945) in the testing cohort for differentiating MH from non-MH. • The AUC of the clinical radiomics nomogram was 0.880 (95% CI: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort for distinguishing MH from non-MH.

Production of an anti-TNFα antibody in murine myeloma cells by perfusion culture

Infliximab is a mouse/human chimeric IgG1 monoclonal antibody which recognizes the proinflammatory cytokine, tumor necrosis factor α (TNFα), and inhibits receptor interactions, thereby decreasing inflammation and autoimmune response in patients. This monoclonal antibody has been successfully used to treat rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. However, the high treatment cost limits patient access to this biotherapy. One alternative to this problem is the use of biosimilars. In this work, we describe the stable expression and physicochemical characterization of an anti-TNFα antibody. While infliximab is produced in recombinant murine SP2/0 cells, our anti-TNFα IgG antibody was expressed in recombinant murine NS0 myeloma cells. The best anti-TNFα antibody-expressing clone was selected from three clone candidates based on the stability of IgG expression levels, specific productivity as well as TNFα-binding activity compared to commercial infliximab. Our results indicate that the selected cell clone, culture medium, and fermentation mode allowed for the production of an anti-TNFα antibody with similar characteristics to the reference commercially available product. An optimization of the selected culture medium by metabolomics may increase the volumetric productivity of the process to satisfy the demand for this product. Further experiments should be performed to evaluate the biological properties of this anti-TNFα antibody. KEY POINTS: • An anti-TNFα antibody was produced in NS0 cells using perfusion culture. • A proprietary chemically defined culture medium was used to replace commercially available protein-free medium. • The purified anti-TNFα antibody was comparable to the reference marketed product.

Comparative Efficacy and Rapidity of Action for Infliximab vs Ustekinumab in Biologic Naïve Crohn's Disease

BACKGROUND & AIMS

Comparative effectiveness has become increasingly important to help position therapies for inflammatory bowel disease. We compared the efficacy and rapidity of onset of action of infliximab vs ustekinumab induction therapy for moderate to severe biologic-naïve Crohn's disease (CD) using patient-level data from randomized controlled trials.

METHODS

This was a post hoc analysis of 2 large CD clinical trial programs that included data on 420 biologic-naïve CD patients. Differences in proportions of patients achieving week 6 clinical remission, clinical response, and normalization of calprotectin were compared. Multivariate logistic regression was used to adjust for confounders. Sensitivity analysis was conducted using propensity scores to create a cohort of matched participants with similar distribution of baseline covariates.

RESULTS

At week 6, a comparable number of patients achieved clinical remission with infliximab compared with patients treated with ustekinumab (44.9% vs 37.9%; adjusted odds ratio [aOR], 1.22; 95% CI, 0.79-1.89). Similarly, at week 6 the clinical response rates were not significantly different (58.4% infliximab vs 54.9% ustekinumab; aOR, 1.25; 95% CI, 0.82-1.90). No significant difference was observed between treatment groups for achieving a week 6 fecal calprotectin level less than 250 mcg/L in those with increased values at baseline (42.3% infliximab vs 34.7% ustekinumab; aOR, 1.34; 95% CI, 0.79-2.28). Similar results were seen for all analyses performed within the propensity matched cohort.

CONCLUSIONS

Based on this post hoc analysis, infliximab and ustekinumab appear to have similar efficacy and speed of onset in patients with CD who are biologic-naïve.

High Anti-Infliximab Antibody Titers Do Not Impact Response to Subsequent Adalimumab Treatment in Inflammatory Bowel Diseases

BACKGROUND

While the role of anti-drug antibodies in mediating loss of response to infliximab (IFX) is known, it is possible that there are different clinical implications for high compared to low titers of antibodies to infliximab (ATI). The impact of ATI titer on efficacy of subsequent anti-TNF treatment has not been established previously.

METHODS

This is a multicenter retrospective cohort study of individuals with IBD who discontinued infliximab due to development of ATI and were subsequently switched to adalimumab therapy. IFX anti-drug antibody titer level was measured using Mayo or Esoterix assays. We examined clinical and endoscopic response to adalimumab at 3 months, 12 months, and 2 years.

RESULTS

Our study included 90 patients (69 CD, 17 UC, 4 CD of the ileoanal pouch) with IBD. The median antibody titer levels for the Esoterix (208 u/mL) or Mayo clinic laboratory (236 u/mL) were similar (p > 0. 50). Patients with high ATI titers (median 824 u/ml, IQR 405-1250 u/ml) were as likely to respond to adalimumab as those with low titers (median 76u/ml, IQR 41-129 u/ml). At 3 months and 12 months, the rates of clinical response/remission to adalimumab therapy were 78% and 77%, respectively, among those with high ATI titers and 81% and 84% among those with low ATI titers (p = 0.81 and 0.62, respectively). In patients who initiated a different therapeutic mechanism after adalimumab, the response rates were similar to that observed with adalimumab.

CONCLUSIONS

The presence of high titers of anti-drug antibodies to IFX is not predictive of treatment failure with adalimumab.

Comparative Efficacy for Infliximab Vs Vedolizumab in Biologic Naive Ulcerative Colitis

BACKGROUND & AIMS

Comparative effectiveness studies are needed to help position therapies for ulcerative colitis (UC). We compared the efficacy of infliximab vs vedolizumab for moderate to severe biologic-naïve UC using patient-level data from clinical trial program data sets.

METHODS

This was a post hoc analysis of 3 UC clinical trial programs that included data on 795 biologic-naïve UC patients. Differences in proportions of patients achieving week 6 clinical remission (CR) and response, and 1-year CR, corticosteroid-free CR, and endoscopic remission (ER), are reported. Multivariate logistic regression was used to adjust for potential confounders. As a sensitivity analysis, propensity scores were calculated and a cohort of matched participants with similar distribution of baseline covariates was created. All analyses were intention-to-treat.

RESULTS

At week 6, comparable proportions of patients achieved clinical response and CR with infliximab vs vedolizumab (clinical response, 60.5% [138 of 228] vs 60.0% [340 of 567]; P = .884; and CR, 39.9% [91 of 228] vs 38.6% [219 of 567]; P = .736). Similar proportions of patients achieved 1-year CR with infliximab vs vedolizumab (39.9% [91 of 228] vs 38.6% [219 of 567]; adjusted odds ratio [aOR], 1.02; 95% CI, 0.74-1.40). Infliximab-treated patients had significantly higher rates of 1-year ER (36.0% [82 of 228] vs 25.6% [145 of 567]; aOR, 1.60; 95% CI, 1.12-2.28) and corticosteroid-free CR (29.5% [23 of 78] vs 15.0% [38 of 254]; aOR, 2.36; 95% CI, 1.27-4.39). Similar results were observed in the propensity score matched cohort.

CONCLUSIONS

Although infliximab and vedolizumab have similar efficacy in clinical symptom improvement, infliximab had higher rates of 1-year corticosteroid-free CR and ER in treatment of biologic-naïve UC.

Effectiveness and Durability of COVID-19 Vaccination in 9447 Patients With IBD: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

The serological responses after severe acute respiratory syndrome coronavirus 2 vaccination may be attenuated in immunocompromised individuals. The study aimed to systematically evaluate the seroconversion rates after complete vaccination for coronavirus disease 2019 (COVID-19) in patients with inflammatory bowel disease (IBD).

METHODS

Electronic databases were searched to identify studies reporting response to COVID-19 vaccination in IBD. Pooled seroconversion rates after complete vaccination were calculated. Subgroup analysis for vaccine types was also performed. Pooled seroconversion rates for various drugs or classes were also estimated. The pooled rates of breakthrough infections in vaccinated IBD patients were estimated. The pooled neutralization rates after complete vaccination were also estimated. The studies reporting durability of titers were systematically assessed.

RESULTS

A total of 46 studies were included. The pooled seroconversion rate for complete vaccination (31 studies, 9447 patients) was 0.96 (95% confidence interval [CI], 0.94-0.97; I2 = 90%). When compared with healthy control subjects, the pooled relative risk of seroconversion was lower (0.98; 95% CI, 0.98-0.99; I2 = 39%). The pooled seroconversion rates were statistically similar among various drug classes. The pooled positivity of neutralization assays (8 studies, 771 participants) was 0.80 (95% CI, 0.70-0.87; I2 = 82%). The pooled relative risk of breakthrough infections in vaccinated IBD patients was similar to vaccinated control subjects (0.60; 95% CI, 0.25-1.42; I2 = 79%). Most studies suggested that titers fall after 4 weeks of COVID-19 vaccination, and the decay was higher in patients on anti-tumor necrosis factor alone or combination with immunomodulators. An additional dose of COVID-19 vaccine elicited serological response in most nonresponders to complete vaccination.

CONCLUSIONS

Complete COVID-19 vaccination is associated with seroconversion in most patients with IBD. The decay in titers over time necessitates consideration of additional doses in these patients.

Acute hepatitis B virus infection despite vaccination in a patient treated by infliximab: a case report

Background

Despite an effective vaccine, hepatitis B remains a major global health problem due to its significant morbidity and mortality. Vaccination in immunosuppressed patients such as those treated for an inflammatory bowel disease (IBD) can be less effective. This case describes an uncommon original diagnosis of an acute hepatitis B infection occurring in a vaccinated but immunocompromised IBD patient under long-term infliximab treatment. A low anti-HBs titer and the presence of HBsAg escape mutations are possible hypotheses to explain this unexpected infection.

Case presentation

A 28-year-old Caucasian male, regularly followed-up for a Crohn’s disease treated by infliximab, was regularly screened for sexually transmissible infections because of at-risk behaviors. Despite a correct immunization scheme against hepatitis B virus (HBV), an active HBV infection was diagnosed during one of those screenings. Retrospective testing of a sample collected 6 months earlier was in favor of an evolution from an acute hepatitis B toward a chronic hepatitis B. The patient has always had a low anti-HBs antibody levels (near the threshold of 10 IU/L) possibly explaining his infection. In addition, HBV sequencing revealed a genotype A2 HBV strain, carrying the sD144A substitution on the S protein, known as a potential immune escape variant. Dual therapy combining tenofovir disoproxil fumarate and emtricitabine, active against HBV but also efficient as an HIV pre-exposure prophylaxis, was initiated. Ten months after treatment initiation, all surrogate biochemical and virological endpoints for HBV functional cure were achieved. Treatment and periodical monitoring are being maintained.

Conclusion

Emphasis should be placed on HBV screening, vaccination and regular monitoring of patients under long-term immunosuppressive therapy, particularly those with at-risk behaviors.

Efficacy and safety of adalimumab in comparison to infliximab for Crohn's disease: A systematic review and meta-analysis

BACKGROUND

Adalimumab (ADA) and infliximab (IFX) are the cornerstones of the treatment of Crohn’s disease (CD). It remains controversial whether there is a difference in the effectiveness and safety between IFX and ADA for CD.

AIM

To perform a meta-analysis to compare the effectiveness and safety of ADA and IFX in CD.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched. Cohort studies were considered for inclusion. The primary outcomes were induction of response and remission, maintenance of response and remission, and secondary loss of response. Adverse events were secondary outcomes.

RESULTS

Fourteen cohort studies were included. There was no apparent difference between the two agents in the induction response [odds ratio (OR): 1.27, 95% confidence interval (CI): 0.93-1.74, P = 0.14] and remission (OR: 1.11, 95%CI: 0.78–1.57, P = 0.57), maintenance response (OR: 1.08, 95%CI: 0.76–1.53, P = 0.67) and remission (OR: 1.26, 95%CI: 0.87–1.82, P = 0.22), and secondary loss of response (OR: 1.01, 95%CI: 0.65–1.55, P = 0.97). Subgroup analysis revealed ADA and IFX had similar rates of response, remission, and loss of response either in anti-tumor necrosis factor-α naïve or non-naïve patients. Further, there was a similar result regardless of whether CD patients were treated with optimized therapy, including dose intensification, shortening interval, and combination immunomodulators. However, ADA had a fewer overall adverse events than IFX (OR: 0.62, 95%CI: 0.42–0.91, P = 0.02).

CONCLUSION

ADA and IFX have similar clinical benefits for anti-tumor necrosis factor-α naïve or non-naïve CD patients. Overall adverse events rate is higher in patients in the IFX group.

Model Informed Precision Dosing Tool Forecasts Trough Infliximab and Associates with Disease Status and Tumor Necrosis Factor-Alpha Levels of Inflammatory Bowel Diseases

Background: Substantial inter-and intra-individual variability of Infliximab (IFX) pharmacokinetics necessitates tailored dosing approaches. Here, we evaluated the performances of a Model Informed Precision Dosing (MIPD) Tool in forecasting trough Infliximab (IFX) levels in association with disease status and circulating TNF-α in patients with Inflammatory Bowel Diseases (IBD). Methods: Consented patients undergoing every 8-week maintenance therapy with IFX were enrolled. Midcycle specimens were collected, IFX, antibodies to IFX, albumin were determined and analyzed with weight using nonlinear mixed effect models coupled with Bayesian data assimilation to forecast trough levels. Accuracy of forecasted as compared to observed trough IFX levels were evaluated using Demings’s regression. Association between IFX levels, CRP-based clinical remission and TNF-α levels were analyzed using logistic regression and linear mixed effect models. Results: In 41 patients receiving IFX (median dose = 5.3 mg/Kg), median IFX levels decreased from 13.0 to 3.9 µg/mL from mid to end of cycle time points, respectively. Midcycle IFX levels forecasted trough with Deming’s slope = 0.90 and R2 = 0.87. Observed end cycle and forecasted trough levels above 5 µg/mL associated with CRP-based clinical remission (OR = 7.2 CI95%: 1.7−30.2; OR = 21.0 CI95%: 3.4−127.9, respectively) (p < 0.01). Median TNF-α levels increased from 4.6 to 8.0 pg/mL from mid to end of cycle time points, respectively (p < 0.01). CRP and TNF-α levels associated independently and additively to decreased IFX levels (p < 0.01). Conclusions: These data establish the value of our MIPD tool in forecasting trough IFX levels in patients with IBD. Serum TNF-α and CRP are reflective of inflammatory burden which impacts exposure.

Lower Relapses Rate With Infliximab Versus Adalimumab in Sight-Threatening Uveitis: A Multicenter Study of 330 Patients

PURPOSE

To compare the relapse rate of sight-threatening noninfectious uveitis (NIU) in patients treated with infliximab (IFX) or adalimumab (ADA).

DESIGN

Observational retrospective multicenter study.

METHODS

A total of 330 patients (median age, 36 years; interquartile range, 27-54), 45.2% men) with sight-threatening NIU (ie, retinal vasculitis and/or macular edema) treated with anti-tumor necrosis factor [TNF]-α agents (IFX intravenously at 5 mg/kg at weeks 0, 2, 6, and every 4 to 6 weeks or ADA subcutaneously at 80 mg, then 40 mg every 2 weeks). Data were obtained retrospectively from patients' medical records. Main outcome measures were relapse rate, complete response of NIU, corticosteroid sparing effect, and safety.

RESULTS

Main etiologies of uveitis included Behçet disease (27%), idiopathic juvenile arthritis (5.8%), and sarcoidosis (5.5%). The estimated relapse rate at 6 months after introduction of biological agents was 13% (95% CI = 0.009-0.16). IFX was associated with less relapse risk than ADA (hazard ratio [HR] = 0.52, 95% CI = 0.36- 0.77, P = .001). ADA and IFX were comparable in terms of complete response rate of NIU as well as corticosteroid-sparing effect. Behçet disease was associated with higher odds of complete response (HR = 2.04, 95% CI = 1.16 -3.60, P = .01] and lower relapse rate (HR = 0.53, 95% CI = 0.33-0.85, P = .009) than other causes of NIU with anti-TNF-α agents.

CONCLUSIONS

In sight-threatening NIU, IFX seems to be associated with a lower relapse rate than ADA.

Successful prevention of secondary burn progression using infliximab hydrogel: A murine model

INTRODUCTION

Burn injury remains a serious cause of morbidity and mortality worldwide. Severity of burns is determined by the percentage of burned area compared to the body surface area, age of patient, and by the depth of skin and soft tissue involvement; these factors determine management as well as prospective outcomes. The pathophysiology of partial- to full-thickness burn conversion remains poorly understood and is associated with a worse overall prognosis. Recent studies have demonstrated that an altered inflammatory response may play a significant role in this conversion and therefore a reduction in early inflammation is crucial to ultimately decreasing burn severity and morbidity. We hypothesize that the application of a microcapillary gelatin-alginate hydrogel loaded with anti-TNF-α (infliximab) monoclonal antibodies to a partial-thickness burn will reduce inflammation within partially burned skin and prevent further progression to a full-thickness burn.

METHODS

Assembly of the microfluidic hydrogels is achieved by embedding microfibers within a hydrogel scaffold composed of a gelatin-alginate blend, which is then soaked in a solution containing anti-TNF-α antibodies for drug loading. 12 young (2-4 months) and 12 old (>16 months) mice were given partial thickness burns. The treatment cohort received the anti-TNF-α infused hydrogel with an occlusive dressing and the control cohort only received an occlusive dressing. Mice were euthanized at post-burn day 3 and skin samples were taken. Burn depth was evaluated using Vimentin immunostaining.

RESULTS

All mice in the treatment cohort demonstrated decreased conversion of burn from partial to full thickness injury (old = p < 0.01, young = p < 0.001) as compared to the control group. Old mice had greater depth of burn than young mice (p < 0.001). There were greater eosinophils in the treatment cohort for both young and old mice, but it did not reach statistical significance.

CONCLUSION

The application of a novel microcapillary gelatin-alginate hydrogel infused with anti-TNF-α antibody to partial thickness burns in mice showed reduction in partial to full thickness burn secondary progression as compared to controls using this murine model; this promising finding might help decrease the high morbidity and mortality associated with burn injuries.

Emerging role of biosimilars in the clinical care of inflammatory bowel disease patients

The increasing incidence of inflammatory bowel disease (IBD) globally has redirected the healthcare system's focus towards safe and affordable pharmacological interventions. The inception of anti-tumor necrosis factor-α (TNF-α) had resulted in a trend shift from surgical interventions. However, as the patents of approved anti-TNF-α drugs expire, biological copies of the many approved products are in the pipeline. The most commonly used biosimilar for IBD has been infliximab, followed by Adalimumab biosimilars which have been approved in major countries across the world. Although biosimilars are approved on the basis of similarity of their reference product, the lack of real-world evidence of its safety in ulcerative colitis and Crohn’s disease patients has contributed to physicians’ hesitancy. However, biosimilars are expected to reduce treatment costs and provide economic benefits.

Impact of Infliximab-dyyb (Infliximab Biosimilar) on Clinical and Patient-Reported Outcomes: 1-Year Follow-up Results from an Observational Real-World Study Among Patients with Inflammatory Bowel Disease in the US and Canada (the ONWARD Study)

Introduction

To date, there are limited real-world studies published on the use of infliximab-dyyb, a biosimilar to reference product (RP) infliximab approved for the treatment of moderate to severe inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC) in North America. This study examined utilization patterns and the effects of infliximab-dyyb on clinical outcomes, patient-reported outcomes (PROs), and healthcare resource use (HCRU) in IBD patients in a real-world setting.

Methods

In this prospective, observational study, adult IBD patients in the US and Canada were recruited to initiate treatment with infliximab-dyyb and followed for 12 months. Patients included biologic-naïve users of infliximab-dyyb and patients switching from RP infliximab or other biologics to infliximab-dyyb. Partial Mayo (pMAYO) and Harvey Bradshaw Index (HBI) scores measured clinical outcomes for the UC and CD cohorts, respectively. Key PRO measures included the SIBDQ, EQ-VAS, and psychological outcomes. In addition, work productivity, HCRU, and adverse events (AEs) were assessed.

Results

A total of 67 CD and 48 UC patients were enrolled (51% female; mean age 44 years; 87% Caucasian; mean BMI 27.9). Thirty-nine patients were biologic-naïve, 57 switched from RP infliximab, and 19 switched from other biologics. Among UC biologic-naïve users, pMAYO decreased from 5.67 to 1.09 (p < 0.0001) and the remission rate increased from 5.6 to 90.9% (p = 0.0015). For UC patients switching from RP infliximab, pMAYO decreased from 1.38 to 0.29 (p = 0.0103). For CD biologic-naïve users, HBI scores and remission rates did not significantly change. The scores on all the PROs significantly improved from baseline to 12 months. A total of 22 AEs occurred consistent with the known AE profile for infliximab.

Conclusions

Clinical outcomes among biologic-naïve users of infliximab-dyyb improved for UC and were maintained for CD patients. Biologic-naïve users of infliximab-dyyb showed significant improvements in PROs. Patients switching from RP infliximab to infliximab-dyyb maintained their clinical outcomes and PROs.

Trial Registration

ClinicalTrials.gov Registration Number: NCT03801928 (February 23, 2018).

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02104-6.

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.

Long-term clinical and real-world experience with Crohn's disease treated with anti-tumor necrosis factor-α antibodies

Background/Aims

Although anti-tumor necrosis factor (TNF)-α agents are important therapeutic drugs for Crohn’s disease (CD), data regarding their long-term sustained effects are limited. Herein, we evaluated the long-term loss of response (LOR) to anti-TNF-α agents in patients with CD.

Methods

This retrospective study included patients with CD who started treatment with infliximab or adalimumab as a first-line therapeutic approach. The cumulative event-free, retention, and surgery-free rates after the start of biological therapy were analyzed. Secondary LOR was analyzed in patients who achieved corticosteroid-free clinical remission after the start of biological therapy. Cox proportional hazards models were used to analyze the predictive factors of secondary LOR.

Results

The cumulative event-free rates at 1, 2, 5, and 10 years were 83.3%, 75.1%, 37.4%, and 23.3%, respectively. The incidence of LOR was 10.6% per patient-year of follow-up. At 12–14 weeks after the start of biological therapy, the proportion of patients with a C-reactive protein to albumin (CRP/ALB) ratio ≥0.18 was significantly higher in patients with LOR (P<0.001). Multivariate analysis indicates that a CRP/ALB ratio ≥0.18 (hazard ratio [HR], 5.86; 95% confidence interval [CI], 1.56–22.0; P=0.009) and upper gastrointestinal tract inflammation (HR, 3.00; 95% CI, 1.26–7.13; P=0.013) were predictive factors of secondary LOR.

Conclusions

Although anti-TNF-α agents contributed to long-term clinical remission of CD, the annual incidence of secondary LOR was 10.6%. The CRP/ALB ratio at 3 months after the start of biological therapy and upper gastrointestinal tract inflammation were identified as predictive factors of secondary LOR.

Cost-effectiveness analysis of infliximab for the treatment of Kawasaki disease refractory to the initial treatment: A retrospective cohort study

BACKGROUND

Infliximab (IFX) treatment is approved in Japan for health insurance coverage in patients with Kawasaki disease (KD). This study aimed to compare the cost-effectiveness of IFX and other therapeutic strategies for KD refractory to initial treatment, including intravenous immunoglobulin (IVIG), steroids, immunosuppressants, and plasma exchange therapy.

METHODS

This multicenter, retrospective cohort study utilized data from the public medical insurance system of Japan. The target population included those who received treatment for KD between April 2012 and March 2019. Eligibility criteria were as follows: 1) initial onset of KD, 2) age < 15 years at onset, and 3) administration of 3rd line treatment if the 1st line treatment was IVIG alone or 2nd line treatment if the 1st line treatment was a combination of IVIG and steroids, in accordance with Japanese guidelines (2012). Those with KD-related cardiovascular complications before admission and those with congenital cardiac disease were excluded. The primary outcome was cost-effectiveness, which was calculated based on the number of admission events per annum divided by medical expenses per annum (times/10,000 US dollars). The Wilcoxon test was applied to analyze the difference in cost-effectiveness between patients who had received IFX and those who had not.

RESULTS

Among 1267 patients with KD, 25 received IFX treatment, while 206 received another treatment after the disease was designated refractory to initial treatment. The frequency of steroid use during initial IVIG treatment (a predictor of severity) was higher in the non-IFX group than in the IFX group (70.4% vs. 32.0%, p < 0.001) but became comparable after propensity-score matching. Our analysis indicated that IFX was more cost-effective than other treatments [1.04 (0.86, 1.34) vs. 1.38 (1.03, 1.79) (times/10,000 US dollars), p = 0.006].

CONCLUSIONS

IFX treatment may be more cost-effective than non-IFX treatment for patients with KD that is refractory to initial treatment.