Identification of Target Golimumab Levels in Maintenance Therapy of Crohn's Disease and Ulcerative Colitis Associated With Mucosal Healing

Higher Ustekinumab Levels in Maintenance Therapy are Associated with Greater Mucosal Healing and Mucosal Response in Crohn's Disease: An Experience of 2 IBD Centers

BACKGROUND

Ustekinumab (UST), a human monoclonal antibody that binds the p40 subunit of interleukin 12 (IL-12) and IL-23, is licensed for induction and maintenance therapy of moderate to severe inflammatory bowel disease (IBD). To date, there is limited data published on any potential association between ustekinumab serum trough levels and mucosal healing in order to guide treatment strategies and appropriate dosing.

AIM

This study aims to identify a relationship between maintenance ustekinumab serum trough levels and mucosal healing and/or response in patients with Crohn's disease in an observational cohort study.

METHODS

Ustekinumab serum trough levels and antibody titres were analyzed in patients on maintenance drug using an ELISA drug-tolerant assay. Mucosal response (MR) was defined as ≥50% reduction in fecal calprotectin level (FC) and/or ≥50% reduction in the Simple Endoscopic Score for Crohn's Disease (SES-CD score). Mucosal healing (MH) was defined as FC ≤150 µg/mL and/or global SES-CD score ≤5. Median trough levels were analyzed using the Kruskal-Wallis test, and logistic regression was used to determine sensitivity and specificity of levels predicting mucosal response.

RESULTS

Forty-seven patients on maintenance ustekinumab for Crohn's disease were included in this study. The majority were female (66%), with a median age of 40 years (21-78 years). The majority of patients were biologic-experienced (89.4%, n = 42). Patients with histologically confirmed Crohn's disease represented 100% (n = 47) of the cohort. Over one-third of patients (n = 18, 38.3%) were on higher than standard dosing of 90 mg every 8 weeks. Patients with mucosal healing (n = 30) had significantly higher mean serum ustekinumab levels (5.7 µg/mL, SD 6.4) compared with those with no response (1.1 µg/mL, SD 0.52; n = 7, P < .0001). A serum ustekinumab trough level greater than 2.3 µg/mL was associated with MH, with a sensitivity of 100% and specificity of 90.6% (likelihood ratio 10.7). Similarly, for patients with MR (n = 40), we observed a higher mean serum ustekinumab trough level (5.1 µg/mL, SD 6.1) compared with those with no response (1.1 µg/mL, SD 0.52; n = 7, P < .0001). Furthermore, a serum ustekinumab trough level greater than 2.3 µg/mL was associated with a 10-fold increased likelihood of mucosal response vs mucosal nonresponse (sensitivity 100%, specificity 90.5%, likelihood ratio 10.5).

CONCLUSION

This study demonstrates that higher ustekinumab serum trough levels are associated with a greater likelihood of achieving mucosal healing and mucosal response in patients with Crohn's disease regardless of prior biologic exposure. Further prospective studies are required to correlate target maintenance trough levels and the optimal time to dose-escalate in order to improve patient outcomes.

Association of golimumab trough concentrations during maintenance with clinical, biological, endoscopic and histologic remission in patients with ulcerative colitis

BACKGROUND

Optimal golimumab concentration thresholds for important outcomes during maintenance are lacking.

AIMS

To investigate the association of golimumab trough concentrations during maintenance with key outcomes, including endoscopic and histologic remission, and long-term event-free persistence with golimumab, in patients with UC.

METHODS

This multi-centre, cross-sectional study included patients with UC on golimumab maintenance recruited either in remission or during a flare. Colonoscopy was scheduled, and study-specific rectocolonic biopsies were taken for blind central histologic reading. Samples for golimumab trough concentrations were collected close to colonoscopy.

RESULTS

Fifty-two patients were included. Median golimumab trough concentrations (μg/ml) were significantly higher in patients who had clinical remission (2.01 vs. 0.72, p = 0.047), combined clinical-biochemical remission (PMS ≤2 + faecal calprotectin <250 μg/g) (2.21 vs. 1.47, p = 0.041), endoscopic healing (Mayo endoscopic subscore 0) (2.52 vs. 1.47, p = 0.003), histologic remission (Geboes index ≤2.0) (2.33 vs. 1.50, p = 0.02) and disease clearance (clinical remission endoscopic healing + histologic remission) (2.52 vs. 1.70, p = 0.009), compared with those not meeting these criteria. Golimumab concentrations were significantly higher in patients who avoided golimumab dose escalation/discontinuation during follow-up (2.24 vs. 0.98, p = 0.012). Receiver-operating characteristic analyses identified golimumab thresholds [area under the curve] of 0.85 [0.76], 1.90 [0.76], 2.29 [0.75], 1.79 [0.68], 2.29 [0.72] and 1.56 [0.71] μg/ml as associated with clinical remission, combined remission, endoscopic healing, histologic remission, disease clearance and long-term event-free persistence with golimumab, respectively.

CONCLUSIONS

Golimumab trough concentrations during maintenance are associated with favourable treatment outcomes including endoscopic healing, histologic remission and long-term persistence on golimumab. We identified the optimal golimumab thresholds most closely associated with key outcomes.

Predictors and Early Markers of Response to Biological Therapies in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are chronic conditions that primarily affect the gastrointestinal tract, with a complex pathogenesis; they are characterized by a significant heterogeneity of clinical presentations and of inflammatory pathways that sustain intestinal damage. After the introduction of the first biological therapies, the pipeline of therapies for IBD has been constantly expanding, and a significant number of new molecules is expected in the next few years. Evidence from clinical trials and real-life experiences has taught us that up to 40% of patients do not respond to a specific drug. Unfortunately, to date, clinicians lack a valid tool that can predict each patient’s response to therapies and that could help them in choosing what drug to administer. Several candidate biomarkers have been investigated so far, with conflicting results: clinical, genetic, immunological, pharmacokinetic and microbial markers have been tested, but no ideal marker has been identified so far. Based on recent evidence, multiparametric models seemingly hold the greatest potential for predicting response to therapy. In this narrative review, we aim to summarize the current knowledge on predictors and early markers of response to biological therapies in IBD.

Personalized Medicine of Monoclonal Antibodies in Inflammatory Bowel Disease: Pharmacogenetics, Therapeutic Drug Monitoring, and Beyond

The pharmacotherapy of inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) has experienced significant progress with the advent of monoclonal antibodies (mABs). As therapeutic proteins, mABs display peculiar pharmacokinetic characteristics that differentiate them from chemical drugs, such as aminosalicylates, antimetabolites (i.e., azathioprine, 6-mercaptopurine, and methotrexate), and immunosuppressants (corticosteroids and cyclosporine). However, clinical trials have demonstrated that biologic agents may suffer from a pharmacokinetic variability that could influence the desired clinical outcome, beyond primary resistance phenomena. Therefore, therapeutic drug monitoring (TDM) protocols have been elaborated and applied to adaptation drug doses according to the desired plasma concentrations of mABs. This activity is aimed at maximizing the beneficial effects of mABs while sparing patients from toxicities. However, some aspects of TDM are still under discussion, including time-changing therapeutic ranges, proactive and reactive approaches, the performance and availability of instrumental platforms, the widely varying individual characteristics of patients, the severity of the disease, and the coadministration of immunomodulatory drugs. Facing these issues, personalized medicine in IBD may benefit from a combined approach, made by TDM protocols and pharmacogenetic analyses in a timeline that necessarily considers the frailty of patients, the chronic administration of drugs, and the possible worsening of the disease. Therefore, the present review presents and discusses the activities of TDM protocols using mABs in light of the most recent results, with special attention on the integration of other actions aimed at exploiting the most effective and safe therapeutic effects of drugs prescribed in IBD patients.

Therapeutic thresholds for golimumab serum concentrations during induction and maintenance therapy in ulcerative colitis: results from the GO-LEVEL study

BACKGROUND

Significant associations between serum golimumab concentrations and favourable outcomes have been observed during both induction and maintenance therapy in ulcerative colitis (UC). However, data regarding optimal therapeutic serum golimumab concentration thresholds are limited.

AIMS

To identify optimal serum golimumab concentration thresholds during induction and maintenance treatment with golimumab.

METHODS

GO-LEVEL was an open label, phase IV study that included a prospective cohort of UC patients commencing golimumab, as well as a cross-sectional cohort receiving maintenance treatment. Patients commencing induction for active UC (defined as a simple clinical colitis activity index [SCCAI] >5 in addition to a raised faecal calprotectin [FC] >59μg/g or, raised C-reactive protein [CRP] [>5mg/L] or, Mayo endoscopic disease activity 2 or 3) were evaluated at weeks 6, 10 and 14. Patients receiving maintenance therapy were recruited either at the point of flare or during remission. Combined clinical-biochemical remission was defined as SCCAI ≤2 and FC <250μg/g. Serum golimumab concentrations were measured using a commercially available ELISA (LISATRACKER, Theradiag).

RESULTS

Thirty-nine patients were included in the induction cohort, of whom 15 (38%) achieved combined clinical-biochemical remission at week 6. The median serum golimumab concentration of those in combined clinical-biochemical remission was significantly higher than those who were not (5.0 vs 3.1 μg/mL, respectively, P = 0.03). Receiver operating characteristic (ROC) curve analysis demonstrated 3.8 μg/mL as the optimal threshold (sensitivity 0.71, specificity 0.65, area under curve [AUC] 0.72, positive predictive value [PPV] 0.59 and negative predictive value [NPV] 0.79). Sixty-three patients were included in the maintenance cohort; 31 (49%) were in combined remission, 32 (51%) were not. The median serum golimumab concentration of those in combined remission was significantly higher (2.9 vs 2.1 μg/mL, respectively, P = 0.01). ROC curve analysis demonstrated 2.4 μg/mL as the optimal threshold (sensitivity 0.68, specificity 0.66, AUC 0.68, PPV 0.65 and NPV 0.66).

CONCLUSIONS

GO-LEVEL (NCT03124121) offers further evidence regarding golimumab's exposure-response relationship. Clinicians may consider using therapeutic drug monitoring to optimise golimumab dosing aiming to achieve our suggested therapeutic thresholds of 3.8 μg/mL at week 6 and 2.4 μg/mL during maintenance.