Can We Predict the Toxicity and Response to Thiopurines in Inflammatory Bowel Diseases?

Antibiotics influence the risk of anti-drug antibody formation during anti-TNF therapy in Chinese inflammatory bowel disease patients

Aims: The formation of anti-drug antibodies (ADAs) during anti-tumor necrosis factor (anti-TNF) therapy is reported to lead to reducing serum drug levels, which may bring about a loss of response to treatment. Previous research has suggested an association between specific antibiotic classes and ADA formation during anti-TNF therapy. However, there are few studies specifically examining this association in Chinese inflammatory bowel disease (IBD) patients. Therefore, our study aimed to evaluate the possible effect of antibiotic use on ADA formation to anti-TNF therapy in Chinese patients with IBD. Methods: A total of 166 patients with IBD, including 149 with Crohn's disease (CD) and 17 with ulcerative colitis (UC), were included in this retrospective analysis. These patients were initially treated with anti-TNF therapy (infliximab or adalimumab) after January 2018 and reviewed with available ADA levels before October 2023. After univariable analysis of all the variables, a multivariate Cox proportional hazards model was used to assess the association between antibiotic use and ADA development. Results: Among 166 IBD patients treated with infliximab (108/166, 65.1%) or adalimumab (58/166, 34.9%), 31 patients (18.7%) were measured as positive ADA levels. Cox proportional hazard model demonstrated an increased risk of ADA formation in IBD patients who used β-lactam-β-lactamase inhibitor combinations (BL-BLIs) (HR = 5.143, 95%CI 1.136-23.270, p = 0.033), or nitroimidazoles (HR = 4.635, 95%CI 1.641-13.089, p = 0.004) during 12 months before the ADA test. On the contrary, a reduced risk was noted in patients treated with fluoroquinolones (HR = 0.258, 95% CI 0.072-0.924, p = 0.037). Moreover, the median serum infliximab or adalimumab concentration in patients with positive ADA levels was significantly lower than that in patients with negative ADA levels (infliximab: 0.30 vs. 1.85 μg/mL, p < 0.0001; adalimumab: 0.45 vs. 7.55 μg/mL, p = 0.0121). Conclusion: ADA development is associated with various antibiotic classes. BL-BLIs and nitroimidazoles might increase the risk of ADA formation during anti-TNF therapy in Chinese IBD patients, while the treatment with fluoroquinolones could probably reduce such risk. There were certain limitations in the retrospective analysis of the study, therefore, the results are just for reference, and other studies are needed to further confirm our findings.

The Role of Low-Dose Oral Methotrexate in Increasing Anti-TNF Drug Levels and Reducing Immunogenicity in IBD

Concomitant immunomodulation is utilised in combination with anti-TNF therapy for IBD primarily to increase drug levels and prevent anti-drug antibody formation. Whilst thiopurines have traditionally been the immunomodulator of choice in IBD populations, there are concerns regarding the long-term safety of the prolonged use of these agents: particularly an association with lymphoproliferative disorders. Given this, we have explored the existing literature on the use of low-dose oral methotrexate as an alternative immunomodulator for this indication. Although there is a lack of data directly comparing the efficacies of methotrexate and thiopurines as concomitant immunomodulators, the available literature supports the use of methotrexate in improving the pharmacokinetics of anti-TNF agents. Furthermore, low-dose oral methotrexate regimens appear to have comparable efficacies to higher-dose parenteral administration and are better tolerated. We suggest that clinicians should consider the use of low-dose oral methotrexate as an alternative to thiopurines when the primary purpose of concomitant immunomodulation is to improve anti-TNF pharmacokinetics.

Development and validation of a novel HPLC-UV method for simultaneous determination of azathioprine metabolites in human red blood cells

A rapid, specific and accurate high-performance liquid chromatography with tunable ultraviolet detection method was developed to simultaneously determine azathioprine metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methyl mercaptopurine riboside (6-MMPr) in human red blood cells. Erythrocyte lysate sample was precipitated by perchloric acid under the protection of dithiothreitol, with 6-TGN and 6-MMPr being acid hydrolyzed to produce 6-thioguanine (6-TG) and 6-methymercaptopurine (6-MMP). A Waters Cortecs C₁₈ column (2.1 × 150 mm, 2.7 μm) was used for chromatographic separation with a water (containing 0.01 mol/L ammonium acetate and 0.2% acetic acid)/methanol linear gradient at a flow rate of 0.45 mL/min in a 5.5 min. UV detection wavelengths were 340 nm for 6-TG, 303 nm for 6-MMP and the IS (5-bromouracil). The calibration curves fitted a least squares model (weighed 1/x ²) from 0.15 to 15 μmol/L for 6-TG (r ²  = 0.9999) and from 1 to 100 μmol/L for 6-MMP (r ²  = 0.9998). This method was validated according to the FDA bioanalytical method validation guidance and ICH M10 bioanalytical method validation and study sample analysis guidance for industry, and successfully utilized in ten IBD patients receiving azathioprine therapy.

Association of genetic polymorphism of NUDT15, TPMT and ITPA gene in the toxicity and efficacy of azathioprine-based regimen in Egyptian inflammatory bowel disease patients

Background

Inflammatory Bowel disease (IBD) is a chronic progressive condition that prompts generous physical and mental morbidity. Choosing the best kind of management and medication dosage prevents new episodes of high disease activity during therapy because of adverse drug reactions (ADRs). This can lead to cessation or inefficacy of the treatment, or complete non-responsiveness to specific medications. Pharmacogenetics (PGx) is a well-established aspect in IBD. One of the exemplary instances of PGx is thiopurines, which are frequently utilized as IBD therapy. This study aimed to evaluate specific gene polymorphism involved in the toxicity and efficacy of Azathioprine (AZA) use in the management in Egyptian patients and to find the correlation between the polymorphism of Nudix Hydrolase15 (NUDT15) gene (rs116855232), The Thiopurine methyltransferase (TPMT) gene (rs1800460) and Inosine Triphosphatase (ITPA) gene (rs1127354) which are involved in the metabolism of the medications utilized in IBD management.

Methods

This prospective study was performed in 150 patients with IBD. All patients were treated with 2 mg/kg per day AZA (Imuran, GlaxoSmithKline®) for at least 3 months at therapeutic doses to induce remission. Subsequent treatment of AZA. The minimum follow-up period for those who did not experience ADR was one year. Among the studied patients, one hundred twenty-nine patients were treated with combination regimen of steroids (oral prednisone 1 mg/kg/day).

Also, treatment failure was considered among the patients who could not tolerate AZA side effects, or there was no improvement after dose modification.

Results

The most identifiable adverse effect among the studied population was anemia followed by leukopenia and myelosuppression. SNPs genotype TPMT (rs1800460) and ITPA gene (rs1127354) were significantly related to adverse effects among IBD patients receiving Azathioprine treatment. There was a lack of any variants in the NUDT15 genotype among the Egyptian population.

Conclusion

Further research is required in to clarify the relationship between NUDT15 PGx and AZA-ADRs. The effect of NUDT15 PGx on toxicity and ADRs as yet necessitates to be elucidated. Studies with a larger sample size and involving different ethnicities are also necessary.

Personalize, participate, predict, and prevent: 4Ps in inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a complex, immune-mediated, disorder which leads to several gastrointestinal and systemic manifestations determining a poor quality of life, disability, and other negative health outcomes. Our knowledge of this condition has greatly improved over the last few decades, and a comprehensive management should take into account both biological (i.e., disease-related, patient-related) and non-biological (i.e., socioeconomic, cultural, environmental, behavioral) factors which contribute to the disease phenotype. From this point of view, the so called 4P medicine framework, including personalization, prediction, prevention, and participation could be useful for tailoring ad hoc interventions in IBD patients. In this review, we discuss the cutting-edge issues regarding personalization in special settings (i.e., pregnancy, oncology, infectious diseases), patient participation (i.e., how to communicate, disability, tackling stigma and resilience, quality of care), disease prediction (i.e., faecal markers, response to treatments), and prevention (i.e., dysplasia through endoscopy, infections through vaccinations, and post-surgical recurrence). Finally, we provide an outlook discussing the unmet needs for implementing this conceptual framework in clinical practice.

Role of Pharmacogenomics in the Efficacy and Safety of Thiopurines in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Thiopurines' toxicity often leads to dose reduction or discontinuation. This systematic review aims to synthesize the evidence on the effect of genotype-based dosing of thiopurines on treatment efficacy and safety in inflammatory bowel disease (objective #1), and the association between genotype status and the efficacy and safety profile (objective #2).

METHODS

The Cochrane Library, MEDLINE, and EMBASE were searched in August 2021. A total of 80 studies (19,859 individuals) were included. Meta-analyses for mortality, different types of adverse events (AEs), withdrawal due to AE, change in disease activity and clinical remission were performed following mainly a fixed-effects model. PROSPERO registration: CRD42020148130.

RESULTS

Genotype-based dosing was associated to a significantly lower incidence of hematologic AEs (risk ratio=0.71; 95% CI: 0.56-0.90; I2: 47%; 4 randomized controlled trials; moderate quality), which may be attributable to nudix hydrolase 15 (NUDT15) testing more than to thiopurine methyltransferase (TPMT) genotyping. No differences were found in other outcomes. Mutations in TPMT and NUDT15 genes were associated to a higher probability of serious AEs [odds ratio (OR) TPMT=4.98; OR NUDT15=11.44], hematologic AEs (OR TPMT=3.18), and serious hematologic AEs (OR TPMT=7.88; OR NUDT15=12.83). TPMT was also associated with a higher risk of withdrawals due to AEs (OR=3.38), and NUDT15 with gastrointestinal AEs (OR=2.04). Mutations in the ITPA gene did not lead to significant differences. Evidence of an association between other genes and clinical outcomes is still scarce.

CONCLUSIONS

Mutations in TPMT and NUDT15 genes predispose patients to suffer thiopurine-induced toxicity, and genotype-guided treatment has been shown to contribute to the prevention of thiopurine-induced toxicity, especially in the case of NUDT15 in Asians.

Implementation of NUDT15 Genotyping to Prevent Azathioprine-Induced Leukopenia for Patients With Autoimmune Disorders in Chinese Population

Azathioprine (AZA) is commonly used for many autoimmune disorders; however, the limitation of its clinical use is due to potential toxicities, including severe leukopenia. Recent studies have identified genetic NUDT15 variants strongly associated with AZA-induced leukopenia in Asian patients. This study aimed to investigate the strength of above genetic association and evaluate the usefulness of prospective screening of the NUDT15 variants to prevent AZA-induced leukopenia in Chinese patients. AZA-induced leukopenia in patients with autoimmune disorders were enrolled from multiple medical centers in Taiwan/China between 2012 and 2017 to determine the strength of genetic association of NUDT15 or TPMT variants by whole exome sequencing (WES). Furthermore, a prospective study was conducted between 2018 and 2021 to investigate the incidence of AZA-induced leukopenia with and without genetic screening. The WES result showed the genetic variants of NUDT15 R139C (rs116855232) (P = 3.7 × 10^-25 , odds ratio (OR) = 21.7, 95% confidence interval (95% CI) = 12.1-38.8) and NUDT15 rs746071566 (P = 4.2 × 10^-9 , OR = 7.1, 95% CI = 3.7-13.7), but not TPMT, were associated with AZA-induced leukopenia and NUDT15 R139C variant shows the highest sensitivity with 92.5%. Furthermore, the targeted screening of 1,013 participants for NUDT15 R139C enabled those identified as carriers to use alternative immunosuppressants. This strategy resulted in a significant decrease in the incidence of AZA-induced leukopenia compared with historical incidence (incidence rate = from 7.6% decreased to 0.4%; P = 9.3 × 10^-20 ). In conclusion, the NUDT15 R139C variant was strongly associated with AZA-induced leukopenia in Chinese patients. The genetic screening of NUDT15 R139C followed by use of alternative immunosuppressants in identified carriers effectively decreased the incidence of AZA leukopenia for patients with autoimmune disorders.

Nudix Hydroxylase 15 Mutations Strongly Predict Thiopurine-Induced Leukopenia Across Different Asian Ethnicities: Implications for Screening in a Diverse Population

Background and Aims

Thiopurines, which are immunosuppressive drugs for maintaining remission for inflammatory bowel disease, are known to cause myelotoxicity in patients with Nudix Hydroxylase 15 (NUDT15) genetic variants in some Asian countries with monoethnic populations. We aimed to investigate the association of NUDT15 variants with leukopenia in a multiethnic population in Southeast Asia.

Methods

Patients with a confirmed diagnosis of inflammatory bowel disease were recruited. We collected demographic and clinical characteristics and whole blood counts before and after initiating thiopurines. Thiopurine S-methyltransferase (TPMT) and NUDT15 genotypes were analyzed with the single nucleotide polymorphisms (SNPs) genotyping assay. Leukopenia was defined as a white blood cell (WBC) count < 3,000/μl.

Results

In this study, 19 (18.6%) of the 102 patients who had adequate thiopurine therapy experienced leukopenia, 11 patients (57.9%) had NUDT15 c.415C > T variants, 2 patients (10.5%) had NUDT15 c.52G > A variants while one (5.3%) had a TPMT variation. Individually, NUDT15 c.415C > T had a sensitivity and specificity of 57.9% and 94.0% (odds ratio [OR] = 21.45, 95% CI 5.94–77.41, p < 0.001), respectively, for predicting thiopurine-induced leukopenia, while NUDT15 c.52G > A was only observed in patients with leukopenia. As compared with patients with wild-type NUDT15, both NUDT15 variations had a combined sensitivity and specificity of 68.4% and 94%, respectively (OR = 33.80, 95% CI 8.99–127.05, p < 0.001), for predicting thiopurine-induced leukopenia as well as a shorter onset to leukopenia (median onset [months] 2.0 vs. 5.5; p = 0.045). Sub-group analysis showed that both NUDT15 variations were strongly associated with leukopenia among the Chinese and Indians but not among the Malays.

Conclusion

Nudix Hydroxylase 15 variants strongly predicted thiopurine-induced leukopenia across a multiethnic Southeast Asian population, particularly among the Chinese and Indians.

Effect of NUDT15 polymorphisms on early hematological safety of low-dose azathioprine in Chinese patients with pemphigus vulgaris: A prospective cohort study

Azathioprine (AZA) is the preferred immunosuppressant for treating pemphigus vulgaris (PV), with discontinuation mainly attributed to hematological adverse events (AE). Reportedly, nucleoside diphosphate‐linked moiety X‐type motif 15 (NUDT15) polymorphisms have been strongly associated with thiopurine‐induced leukopenia. To investigate hematological AE of low‐dose AZA based on NUDT15 genotypes among patients with PV, a prospective cohort study was conducted in patients with PV, followed‐up for the first 8 weeks after AZA administration. All patients were divided into wild homozygous and heterozygous NUDT15 groups. Both groups initiated AZA at low dose (50 mg/day) and continued with different dose‐escalating approaches. Bone marrow suppression was considered the principal outcome. Overall, 62 patients with PV were enrolled (48 in the wild homozygous NUDT15 group vs. 14 in the heterozygous NUDT15 group). Except for median maintenance doses of AZA, no statistically significant differences were observed between the two groups in terms of age, sex, white blood cells, neutrophil count, platelet count, hemoglobin level, median final doses of corticosteroids (mg prednisone equivalent), pemphigus disease area index, and anti‐desmoglein 1/3 autoantibodies. In both groups, patients presented similar hematological AE and treatment responses after administration of different low‐dose AZA treatment strategies. Low‐dose AZA based on NUDT15 genotypes can reduce the risk of early hematological AE among patients with PV.

Insights into the cellular pharmacokinetics and pharmacodynamics of thiopurine antimetabolites in a model of human intestinal cells

Thiopurines, immunomodulating drugs used in the management of different chronic autoimmune conditions and as anti-leukemic agents, may exert in some cases gastrointestinal toxicity. Moreover, since these agents are administered orally, they are absorbed across the gastrointestinal tract epithelium. On these premises, cellular and molecular events occurring in intestinal cells may be important to understand thiopurine effects. However, quantitative information on the biotransformation of thiopurines in intestinal tissues is still limited. To shed light on biotransformation processes specific of the intestinal tissue, in this study thiopurine metabolites concentrations were analyzed by an in vitro model of human healthy colon, the HCEC cell line, upon exposure to cytotoxic concentrations of azathioprine or mercaptopurine; the investigation was carried out using an innovative mass spectrometry method, that allowed the simultaneous quantification of 11 mono-, di-, and triphosphate thionucleotides. Among the 11 metabolites evaluated, TIMP, TGMP, TGDP, TGTP, MeTIMP, MeTIDP and MeTITP were detectable in HCEC cells treated with azathioprine or mercaptopurine, considering two different incubation times before the addition of the drugs (4 and 48 h). Different associations between metabolites concentrations and cytotoxicity were detected. In particular, the cytotoxicity was dependent on the TGMP, TGDP, TGTP and MeTITP concentrations after the 4 h incubation before the addition of thiopurines. This may be an indication that, to study the association between thiopurine metabolite concentrations and the cytotoxicity activity in vitro, short growth times before treatment should be used. Moreover, for the first time our findings highlight the strong correlation between cytotoxicity and thiopurine pharmacokinetics in HCEC intestinal cells in vitro suggesting that these cells could be a suitable in vitro model for studying thiopurine intestinal cytotoxicity.

Azathioprine-induced alopecia: rare adverse event early marker of myelotoxicity

Azathioprine is a drug widely used to treat patients with inflammatory bowel disease, with not an inconsiderable frequency of adverse events. Among these, myelotoxicity is one of the most serious. For some time, the existence of specific genetic variations of the gene encoding thiopurine-methyltransferase that affect enzymatic activity and produce alterations in thiopurine metabolism that translate into a higher frequency of adverse events in these patients has been known. It has recently been observed that patients carrying certain genetic variations in the nudix hydrolase gene also present a higher rate of adverse events induced by azathioprine, mainly related to leukopenia and alopecia, the latter behaving as an early clinical marker of myelotoxicity. These genetic variants are more common in the Asian population. We present the case of a European patient with azathioprine-induced alopecia and leukopenia whose genetic analysis confirmed that she had one of the genetic alterations associated with the appearance of these adverse events.

Use of thiopurines is not a risk factor for post-ERC pancreatitis in patients with primary sclerosing cholangitis

INTRODUCTION

Risk of post-ERC pancreatitis (PEP) in patients with primary sclerosing cholangitis (PSC) is 1-7.8%. PSC is often associated with inflammatory bowel disease and autoimmune hepatitis, which are usually treated with thiopurines. The role of thiopurines in PEP risk is still unclear.

AIMS AND METHODS

We evaluated the thiopurine use in PEP. The data of 354 PSC patients who underwent 985 ERCs between 2009 and 2018 were collected. 177 patients treated with thiopurines (study group, SG) and 177 controls (CG) were matched with a propensity score (PSM). Odds ratios (ORs) with 95% confidence interval (95% CI) were calculated. Multivariable logistic regression analysis and generalized linear mixed model were performed. The P-value <0.05 was significant.

RESULTS

In matched data, 472 ERCs were performed in SG and 513 in CG. Thiopurines were used in 373/472 (79.0%) ERCs in SG. The PEP rate was 5.3% in SG and 5.7% in CG (p = 0.889). Unintentional pancreatic duct cannulation (OR 1.28, 95%CI 1.07-1.51, p = 0.004), and periampullary diverticulum (OR 4.87, 95%CI 1.72-11.98, p = 0.001) increased the risk of PEP.

CONCLUSION

Prior or present thiopurine use did not increase the risk of PEP.

Thiopurines in Inflammatory Bowel Disease. How to Optimize Thiopurines in the Biologic Era?

Thiopurines have been a cornerstone in the treatment of inflammatory bowel disease (IBD). Although they have been used for more than 50 years, there are still some unsolved issues about their efficacy and, also, some safety concerns, mainly the risk of myelosuppression and life-threatening lymphoproliferative disorders. Furthermore, the development of biological therapy raises the question whether there is still a role for thiopurines in the IBD treatment algorithm. On the other hand, limited cost and wide availability make thiopurines a reasonable option in settings of limited resources and increasing prevalence of IBD. In fact, there is a growing interest in optimizing thiopurine therapy, since pharmacogenomic findings suggest that a personalized approach based on the genotyping of some molecules involved in its metabolism could be useful to prevent side effects. Polymorphisms of thiopurine methyltransferase enzyme (TPMT) that result in low enzymatic activity have been associated with an increased risk of myelotoxicity, especially in Caucasians; however, in Asians it is assumed that the variants of nudix hydrolase 15 (NUDT15) are more relevant in the development of toxicity. Age is also important, since in elderly patients the risk of complications seems to be increased. Moreover, the primo-infection of Epstein Barr virus and cytomegalovirus under thiopurine treatment has been associated with severe lymphoproliferative disorders. In addition to assessing individual characteristics that may influence thiopurines treatment outcomes, this review also discusses other strategies to optimize the therapy. Low-dose thiopurines combined with allopurinol can be used in hypermethylators and in thiopurine-related hepatotoxicity. The measurement of metabolites could be useful to assess compliance, identify patients at risk of adverse events and also facilitating the management of refractory patients. Thioguanine is also a rescue therapy in patients with toxicity related to conventional thiopurine therapy. Finally, the current indications for thiopurines in monotherapy or in combination with biologics, as well as the optimal duration of treatment, are also reviewed.

Usefulness of Measuring Thiopurine Metabolites in Children with Inflammatory Bowel Disease and Autoimmunological Hepatitis, Treated with Azathioprine

Introduction

Thiopurines, such as azathioprine (AZA) and 6-mercaptopurine (6-MP), are immunomodulatory agents, used for the maintenance of remission in children with inflammatory bowel disease (IBD)—Crohn's disease (CD) and ulcerative colitis (UC), as well as with autoimmunological hepatitis (AIH). Measurements of thiopurine metabolites may allow identifying patients at risk for toxicity and nonadherence. It can also provide an explanation for the ineffectiveness of the treatment, observed in some patients. Patients and Methods. A retrospective analysis was carried out of sixty-eight patients (thirty-six patients with CD, eighteen with UC, and fourteen with AIH), treated with AZA. Thiopurine metabolites, 6-thioguanine nucleotide (6-TGN) and 6-methylmercaptopurine (6-MMP), were assayed by high-performance liquid chromatography (HPLC), and the AZA dose was adjusted when 6-TGN concentration was known.

Result

Only twenty-five (41%) children had therapeutic 6-TGN concentrations, ten (16%) subjects had suboptimal 6-TGN concentrations, and twenty-six subjects (43%) had 6-TGN concentrations above the recommended therapeutic range. 6-MMP was not above the therapeutic range in any case. Seven subjects revealed undetectable 6-TGN and 6-MMP levels, indicating nonadherence. The mean AZA dose after the 6-TGN concentration-related adjustment did not differ, in comparison to the initial dose, either in IBD or AIH groups. The mean AZA dose was lower in AIH than in IBD. The subjects with an optimal 6-TGN level presented with a higher ratio of remission (88%) than the under- or overdosed patients (60% and 69%), respectively (Chi − square test = 3.87, p < 0.05).

Conclusion

Timely measurements of thiopurine metabolites can be a useful tool to identify nonadherent patients before a decision is taken to switch to another drug. We may also spot the patients who receive either too low or too high doses, compensating dose deviations in an appropriate way. The patients with optimal 6-TGN levels presented a higher percentage of remission than the under- or overdosed patients. In most patients, both initial and adjusted AZA doses, lower than suggested in guidelines, appeared to be sufficient to maintain remission.

Pharmacogenetics of inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) show large variability in disease course, and also treatment response. The variability in treatment response has led to many initiatives in search of genetic markers to optimize treatment and avoid severe side effects. This has been very successful for thiopurines, one of the drugs used to induce and maintain remission in IBD. However, for the newer treatment options for IBD, like biologicals, the search for genetic predictors has not yielded any candidate biomarkers with clinical utility. In this review, a summary of recent advances in pharmacogenetics focusing on thiopurines and anti-TNF agents is given.

Defining the Path Forward for Biomarkers to Address Unmet Needs in Inflammatory Bowel Diseases

Despite major advances in the inflammatory bowel diseases field, biomarkers to enable personalized and effective management are inadequate. Disease course and treatment response are highly variable, with some patients experiencing mild disease progression, whereas other patients experience severe or complicated disease. Periodic endoscopy is performed to assess disease activity; as a result, it takes months to ascertain whether a treatment is having a positive impact on disease progression. Minimally invasive biomarkers for prognosis of disease course, prediction of treatment response, monitoring of disease activity, and accurate diagnosis based on improved disease phenotyping and classification could improve outcomes and accelerate the development of novel therapeutics. Rapidly developing technologies have great potential in this regard; however, the discovery, validation, and qualification of biomarkers will require partnerships including academia, industry, funders, and regulators. The Crohn's & Colitis Foundation launched the IBD Biomarker Summit to bring together key stakeholders to identify and prioritize critical unmet needs; prioritize promising technologies and consortium approaches to address these needs; and propose harmonization approaches to improve comparability of data across studies. Here, we summarize the outcomes of the 2018 and 2019 meetings, including consensus-based unmet needs in the clinical and drug development context. We highlight ongoing consortium efforts and promising technologies with the potential to address these needs in the near term. Finally, we summarize actionable recommendations for harmonization, including data collection tools for improved consistency in disease phenotyping; standardization of informed consenting; and development of guidelines for sample management and assay validation. Taken together, these outcomes demonstrate that there is an exceptional alignment of priorities across stakeholders for a coordinated effort to address unmet needs of patients with inflammatory bowel diseases through biomarker science.