Ipilimumab-induced colitis: a rare but serious side effect

Local Administration of GITR Agonistic Antibody Induces a Stronger Antitumor Immunity than Systemic Delivery

An anti-glucocorticoid induced TNF receptor (GITR) agonistic antibody (Ab) induces an antitumor immunity with both stimulation of effector T cells and inhibition of regulatory T cell activity. To enhance GITR Ab-mediated tumor immunity, we focused on the intratumoral route, since a tumor-localized high concentration of Ab would confer activation of only tumor-infiltrating T cells. First, in a murine colon cancer model, we showed that the intratumoral delivery of Ab significantly increased the number of effector T cells infiltrated into tumors, and suppressed tumor growth more effectively than the intraperitoneal and intravenous injections did. Then, we found that the injection of Ab into the peritumoral area induced a systemic antitumor immunity at a similar level to the intratumoral injection. Therefore, we hypothesized that the transfer of locally administrated Ab into tumor-draining lymph nodes (TDLNs) plays an important role in inducing an effective immunity. In fact, intratumorally or peritumorally injected Ab was detected in TDLNs, and resection of Ab-injected TDLNs significantly reduced GITR Ab-mediated systemic tumor immunity. Intratumoral injection showed less number of auto-reactive T cells in the spleen than the intraperitoneal injection did. Intratumoral delivery of GITR Ab is a promising approach to induce an effective immunity compared to the systemic delivery.

Management of challenging immune-related gastrointestinal adverse events associated with immune checkpoint inhibitors

Immune-related gastrointestinal toxicities (irGI) are well-known adverse events (AEs) with immune checkpoint inhibitors. The aim of this review was to present clinical data from 82 cases to provide information to clinicians who face real-world challenges among their patients with irGI AEs. The findings of this review support the use of the current management guidelines. By analyzing the treatment courses and outcomes of all cases identified, our review recommends that recurrent cases be treated carefully regardless of the grade of diarrhea at the onset of events. Earlier gastroenterology consultation and computed tomography/endoscopy diagnosis are essential, especially when an irGI AE recurs or worsens during steroid tapering. We would also suggest earlier decision to add immunosuppressant agents, particularly for recurrent cases.

Ipilimumab in melanoma

INTRODUCTION

The treatment of melanoma is evolving rapidly over the past few years. Patients with BRAFv600 mutations can be treated with a combination of a BRAF-inhibitor and an MEK-inhibitor. Patients with BRAF wild-type tumors and BRAFv600 mutated tumors can be treated with immunotherapy i.e. check point inhibitors.

AREAS COVERED

We conducted a comprehensive review of the literature on the efficacy and predictive markers, safety, and pharmacoeconomics of ipilimumab in melanoma Expert commentary: Ipilimumab was the first check point inhibitor reaching the clinic, gaining FDA and EMA approval for metastatic melanoma in 2011. Ipilimumab was also approved by FDA in the adjuvant setting for patients with high risk, stage III melanoma. The anti-PD1 directed antibodies pembrolizumab and nivolumab are superior to single agent ipilimumab, which is no longer considered the standard first line treatment in metastatic melanoma. The addition ipilimumab to nivolumab is associated with a higher response rate and a better PFS, particularly in patients with PD-L1 negative tumors, albeit at the cost of a steep increase in grade 3-4 adverse event rate. Definitive survival data on this combination are pending and the selection of patients potentially requiring the combination and its pharmacoeconomic implications are to be elucidated.

[Ipilimumab-induced colitis: A new challenge for gastroenterologists]

Many drugs can produce enterocolitis and they should always be included in the differential diagnosis of this clinical picture. Entities such as antibiotic-associated colitis and neutropenic colitis have been known for some time and recently a new type of drug-induced colitis has emerged due to monoclonal antibodies. Ipimumab is a humanized monoclonal antibody against the CTLA4 molecule that is involved in the maturation and regulation of T lymphocyte activation. This drug causes immune activation and has an immune-mediated antitumor effect with excellent results in tumours such as melanoma. However, several immune-related adverse effects may occur in different organs. The most frequently involved site is the gastrointestinal tract, with adverse effects ranging from mild diarrhoea to colitis with systemic involvement, intestinal perforation, and even death. Although no similarities have been found in the pathogenesis with inflammatory bowel disease, treatments have been used in correlation with its autoimmunological profile: anti-TNF alpha corticosteroids have shown clinical efficacy in moderate to severe disease. However the use of anti-TNF treatment has not been defined and the safety profile is unknown. The inclusion of these new therapies in the treatment of several tumours requires familiarity with these entities and their management should be approached as a new challenge for the gastroenterologist. For that reason, we conducted a review of ipilimumab-induced colitis, evaluating essential features of its symptoms, diagnosis and treatment.