Immune checkpoint inhibitor-related cholangiopathy: Novel clinicopathological description of a multi-centre cohort.

BACKGROUND AND AIMS: Cholestatic liver dysfunction is common in immune-related hepatitis (irH) during treatment with immune checkpoint inhibitors (CPI) for malignancy. We investigated the spectrum of bile duct injury and associated natural history in this cohort. METHOD: Clinical, laboratory, radiological and histopathological data in patients with evidence of bile duct injury during CPI treatment from 2018 to 2020 was collected in three tertiary hospitals. RESULTS: In this study, ten patients with confirmed bile duct disease were identified. Pembrolizumab was most commonly implicated (8/10). Median CPI cycles prior to bile duct injury was 6. Median alanine aminotransferase and alkaline phosphatase were 225 U/L and 1549 U/L respectively. Clinical jaundice was seen in 6/10 and radiological evidence of bile duct pathology in 8/10. Of five patients, who had liver biopsy, three cases (including two cases with normal MRCP) showed primary sclerosing cholangitis (PSC) like changes with periductal fibrosis. All patients were treated first-line with prednisolone following cessation of CPI, three with mycophenolate mofetil and one with tacrolimus, with clinical response in four patients. Five patients died after a mean follow-up of 27 weeks; cause of death was primarily related to progression of malignancy. CONCLUSION: Within this heterogeneous cohort, we identified that CPI-related cholangiopathy responded poorly to immunosuppression and potentially progressed to bile duct loss. Thorough radiological and histological assessment is recommended, as identification of the cholangiopathy-associated phenotype may permit more informed advice regarding prognosis. Further data is required to determine detailed immunological characterisation in order to identify individuals at an increased risk of developing cholangiopathy.

Combined anti-PD-1 and anti-CTLA-4 checkpoint blockade: Treatment of melanoma and immune mechanisms of action.

Cytotoxic T-lymphocyte associated protein-4 (CTLA-4) and the Programmed Death Receptor 1 (PD-1) are immune checkpoint molecules that are well-established targets of antibody immunotherapies for the management of malignant melanoma. The monoclonal antibodies, Ipilimumab, Pembrolizumab, and Nivolumab, designed to interfere with T cell inhibitory signals to activate immune responses against tumors, were originally approved as monotherapy. Treatment with a combination of immune checkpoint inhibitors may improve outcomes compared to monotherapy in certain patient groups and these clinical benefits may be derived from unique immune mechanisms of action. However, treatment with checkpoint inhibitor combinations also present significant clinical challenges and increased rates of immune-related adverse events. In this review, we discuss the potential mechanisms attributed to single and combined checkpoint inhibitor immunotherapies and clinical experience with their use.

18F FDG PET/CT and Novel Molecular Imaging for Directing Immunotherapy in Cancer.

Immunotherapy has transformed the treatment landscape of many cancers, with durable responses in disease previously associated with a poor prognosis. Patient selection remains a challenge, with predictive biomarkers an urgent unmet clinical need. Current predictive biomarkers, including programmed death-ligand 1 (PD-L1) (measured with immunohistochemistry), are imperfect. Promising biomarkers, including tumor mutation burden and tumor infiltrating lymphocyte density, fail to consistently predict response and have yet to translate to routine clinical practice. Heterogeneity of immune response within and between lesions presents a further challenge where fluorine 18 fluorodeoxyglucose PET/CT has a potential role in assessing response, stratifying treatment, and detecting and monitoring immune-related toxicities. Novel radiopharmaceuticals also present a unique opportunity to define the immune tumor microenvironment to better predict which patients may respond to therapy, for example by means of in vivo whole-body PD-L1 and CD8+ T cell expression imaging. In addition, longitudinal molecular imaging may help further define dynamic changes, particularly in cases of immunotherapy resistance, helping to direct a more personalized therapeutic approach. This review highlights current and emerging applications of molecular imaging to stratify, predict, and monitor molecular dynamics and treatment response in areas of clinical need.

Differences between immunotherapy-induced and primary hypophysitis-a multicenter retrospective study.

OBJECTIVE: Immune checkpoint inhibitors can cause various immune-related adverse events including secondary hypophysitis. We compared clinical characteristics of immunotherapy-induced hypophysitis (IIH) and primary hypophysitis (PH) DESIGN: Retrospective multicenter cohort study including 56 patients with IIH and 60 patients with PH. METHODS: All patients underwent extensive endocrine testing. Data on age, gender, symptoms, endocrine dysfunction, MRI, immunotherapeutic agents and autoimmune diseases were collected. RESULTS: Median time of follow-up was 18 months in IIH and 69 months in PH. The median time from initiation of immunotherapy to IIH diagnosis was 3 months. IIH affected males more frequently than PH (p < 0.001) and led to more impaired pituitary axes in males (p < 0.001). The distribution of deficient adenohypophysial axes was comparable between both entities, however, central hypocortisolism was more frequent (p < 0.001) and diabetes insipidus considerably less frequent in IIH (p < 0.001). Symptoms were similar except that visual impairment occurred more rarely in IIH (p < 0.001). 20 % of IIH patients reported no symptoms at all. Regarding MRI, pituitary stalk thickening was less frequent in IIH (p = 0.009). Concomitant autoimmune diseases were more prevalent in PH patients before the diagnosis of hypophysitis (p = 0.003) and more frequent in IIH during follow-up (p = 0.002). CONCLUSIONS: Clinically, IIH and PH present with similar symptoms. Diabetes insipidus very rarely occurs in IIH. Central hypocortisolism, in contrast, is a typical feature of IIH. Preexisting autoimmunity seems not to be indicative of developing IIH.

A rapidly expanding cutaneous tumour in the context of a Janus kinase inhibitor agent following allogeneic stem cell transplant.

Ruxolitinib is a selective, Janus kinase (JAK)1 and JAK2 inhibitor, which is effective in management of chronic graft-versus-host disease (cGvHD). However, the ensuing immunosuppressive effects can give rise to aggressive cutaneous tumours, including Merkel cell carcinoma. We present this case to highlight the development of cutaneous tumours with ruxolitinib, an increasingly used therapy, and the challenge of managing such tumours in the context of refractory cGvHD. Click here for the corresponding questions to this CME article.

Safety and immunogenicity of one versus two doses of the COVID-19 vaccine BNT162b2 for patients with cancer: interim analysis of a prospective observational study.

BACKGROUND: The efficacy and safety profiles of vaccines against SARS-CoV-2 in patients with cancer is unknown. We aimed to assess the safety and immunogenicity of the BNT162b2 (Pfizer-BioNTech) vaccine in patients with cancer. METHODS: For this prospective observational study, we recruited patients with cancer and healthy controls (mostly health-care workers) from three London hospitals between Dec 8, 2020, and Feb 18, 2021. Participants who were vaccinated between Dec 8 and Dec 29, 2020, received two 30 µg doses of BNT162b2 administered intramuscularly 21 days apart; patients vaccinated after this date received only one 30 µg dose with a planned follow-up boost at 12 weeks. Blood samples were taken before vaccination and at 3 weeks and 5 weeks after the first vaccination. Where possible, serial nasopharyngeal real-time RT-PCR (rRT-PCR) swab tests were done every 10 days or in cases of symptomatic COVID-19. The coprimary endpoints were seroconversion to SARS-CoV-2 spike (S) protein in patients with cancer following the first vaccination with the BNT162b2 vaccine and the effect of vaccine boosting after 21 days on seroconversion. All participants with available data were included in the safety and immunogenicity analyses. Ongoing follow-up is underway for further blood sampling after the delayed (12-week) vaccine boost. This study is registered with the NHS Health Research Authority and Health and Care Research Wales (REC ID 20/HRA/2031). FINDINGS: 151 patients with cancer (95 patients with solid cancer and 56 patients with haematological cancer) and 54 healthy controls were enrolled. For this interim data analysis of the safety and immunogenicity of vaccinated patients with cancer, samples and data obtained up to March 19, 2021, were analysed. After exclusion of 17 patients who had been exposed to SARS-CoV-2 (detected by either antibody seroconversion or a positive rRT-PCR COVID-19 swab test) from the immunogenicity analysis, the proportion of positive anti-S IgG titres at approximately 21 days following a single vaccine inoculum across the three cohorts were 32 (94%; 95% CI 81-98) of 34 healthy controls; 21 (38%; 26-51) of 56 patients with solid cancer, and eight (18%; 10-32) of 44 patients with haematological cancer. 16 healthy controls, 25 patients with solid cancer, and six patients with haematological cancer received a second dose on day 21. Of the patients with available blood samples 2 weeks following a 21-day vaccine boost, and excluding 17 participants with evidence of previous natural SARS-CoV-2 exposure, 18 (95%; 95% CI 75-99) of 19 patients with solid cancer, 12 (100%; 76-100) of 12 healthy controls, and three (60%; 23-88) of five patients with haematological cancers were seropositive, compared with ten (30%; 17-47) of 33, 18 (86%; 65-95) of 21, and four (11%; 4-25) of 36, respectively, who did not receive a boost. The vaccine was well tolerated; no toxicities were reported in 75 (54%) of 140 patients with cancer following the first dose of BNT162b2, and in 22 (71%) of 31 patients with cancer following the second dose. Similarly, no toxicities were reported in 15 (38%) of 40 healthy controls after the first dose and in five (31%) of 16 after the second dose. Injection-site pain within 7 days following the first dose was the most commonly reported local reaction (23 [35%] of 65 patients with cancer; 12 [48%] of 25 healthy controls). No vaccine-related deaths were reported. INTERPRETATION: In patients with cancer, one dose of the BNT162b2 vaccine yields poor efficacy. Immunogenicity increased significantly in patients with solid cancer within 2 weeks of a vaccine boost at day 21 after the first dose. These data support prioritisation of patients with cancer for an early (day 21) second dose of the BNT162b2 vaccine. FUNDING: King's College London, Cancer Research UK, Wellcome Trust, Rosetrees Trust, and Francis Crick Institute.

Risk of COVID-19 death in cancer patients: an analysis from Guy's Cancer Centre and King's College Hospital in London.

BACKGROUND: Using an updated dataset with more patients and extended follow-up, we further established cancer patient characteristics associated with COVID-19 death. METHODS: Data on all cancer patients with a positive reverse transcription-polymerase chain reaction swab for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) at Guy's Cancer Centre and King's College Hospital between 29 February and 31 July 2020 was used. Cox proportional hazards regression was performed to identify which factors were associated with COVID-19 mortality. RESULTS: Three hundred and six SARS-CoV-2-positive cancer patients were included. Seventy-one had mild/moderate and 29% had severe COVID-19. Seventy-two patients died of COVID-19 (24%), of whom 35 died <7 days. Male sex [hazard ratio (HR): 1.97 (95% confidence interval (CI): 1.15-3.38)], Asian ethnicity [3.42 (1. 59-7.35)], haematological cancer [2.03 (1.16-3.56)] and a cancer diagnosis for >2-5 years [2.81 (1.41-5.59)] or ≥5 years were associated with an increased mortality. Age >60 years and raised C-reactive protein (CRP) were also associated with COVID-19 death. Haematological cancer, a longer-established cancer diagnosis, dyspnoea at diagnosis and raised CRP were indicative of early COVID-19-related death in cancer patients (<7 days from diagnosis). CONCLUSIONS: Findings further substantiate evidence for increased risk of COVID-19 mortality for male and Asian cancer patients, and those with haematological malignancies or a cancer diagnosis >2 years. These factors should be accounted for when making clinical decisions for cancer patients.

One Piece of the Jigsaw for the Cancer Recovery Strategy: Prevalence of COVID-19 in Patients With Cancer.

COVID-19 has forced governments to make drastic changes to healthcare systems. To start making informed decisions about cancer care, we need to understand the scale of COVID-19 infection. Therefore, we introduced swab testing for patients visiting Guy's Cancer Centre. Our Centre is one of the largest UK Cancer Centers at the epicenter of the UK COVID-19 epidemic. The first COVID-19 positive cancer patient was reported on 29 February 2020. We analyzed data from 7-15 May 2020 for COVID-19 tests in our cancer patients. 2,647 patients attended for outpatient, chemotherapy, or radiotherapy appointments. 654 were swabbed for COVID-19 (25%). Of those tested, 9 were positive for COVID-19 (1.38%) of which 7 were asymptomatic. Cancer service providers will need to understand their local cancer population prevalence. The absolute priority is that cancer patients have the confidence to attend hospitals and be reassured that they will be treated in a COVID-19 managed environment.

Setting the scene - a future 'epidemic' of immune-related adverse events in association with checkpoint inhibitor therapy.

Cancer immune therapy with checkpoint inhibitors (CPIs) has changed the landscape of treatment for a growing number of indications. These drugs are associated with a specific mechanism of action that has profound implications for both immunology and inflammatory disease. This article looks to set the scene covering the history of CPI therapy to date and outlining the likely future developments.

Dynamic imaging for CAR-T-cell therapy.

Chimaeric antigen receptor (CAR) therapy is entering the mainstream for the treatment of CD19(+)cancers. As is does we learn more about resistance to therapy and the role, risks and management of toxicity. In solid tumour CAR therapy research the route to the clinic is less smooth with a wealth of challenges facing translating this, potentially hugely valuable, therapeutic option for patients. As we strive to understand our successes, and navigate the challenges, having a clear understanding of how adoptively transferred CAR-T-cells behavein vivoand in human trials is invaluable. Harnessing reporter gene imaging to enable detection and tracking of small numbers of CAR-T-cells after adoptive transfer is one way by which we can accomplish this. The compatibility of certain reporter gene systems with tracers available routinely in the clinic makes this approach highly useful for future appraisal of CAR-T-cell success in humans.

Lifileucel, an Autologous Tumor-Infiltrating Lymphocyte Monotherapy, in Patients with Advanced Non-Small Cell Lung Cancer Resistant to Immune Checkpoint Inhibitors.

In this phase 2 multicenter study, we evaluated the efficacy and safety of lifileucel (LN-145), an autologous tumor-infiltrating lymphocyte cell therapy, in patients with metastatic non-small cell lung cancer (mNSCLC) who had received prior immunotherapy and progressed on their most recent therapy. The median number of prior systemic therapies was 2 (range, 1-6). Lifileucel was successfully manufactured using tumor tissue from different anatomic sites, predominantly lung. The objective response rate was 21.4% (6/28). Responses occurred in tumors with profiles typically resistant to immunotherapy, such as PD-L1-negative, low tumor mutational burden, and STK11 mutation. Two responses were ongoing at the time of data cutoff, including one complete metabolic response in a PD-L1-negative tumor. Adverse events were generally as expected and manageable. Two patients died of treatment-emergent adverse events: cardiac failure and multiple organ failure. Lifileucel is a potential treatment option for patients with mNSCLC refractory to prior therapy. Significance: Autologous tumor-infiltrating lymphocyte therapy lifileucel was administered to 28 patients with heavily pretreated metastatic non-small cell lung cancer (mNSCLC). Responses were observed in patients with driver mutations, and various tumor mutational burdens and PD-L1 expression, potentially addressing an unmet medical need in patients with mNSCLC refractory to prior therapy. See related commentary by Lotze et al., p. 1366.

Pre-treatment with systemic agents for advanced NSCLC elicits changes in the phenotype of autologous T cell therapy products.

The antitumor activity of adoptive T cell therapies (ACT) is highly dependent on the expansion, persistence, and continued activity of adoptively transferred cells. Clinical studies using ACTs have revealed that products that possess and maintain less differentiated phenotypes, including memory and precursor T cells, show increased antitumor efficacy and superior patient outcomes owing to their increased expansion, persistence, and ability to differentiate into effector progeny that elicit antitumor responses. Strategies that drive the differentiation into memory or precursor-type T cell subsets with high potential for persistence and self-renewal will enhance adoptively transferred T cell maintenance and promote durable antitumor efficacy. Because of the high costs associated with ACT manufacturing, ACTs are often only offered to patients after multiple rounds of systemic therapy. An essential factor to consider in producing autologous ACT medicinal products is the impact of the patient's initial T cell fitness and subtype composition, which will likely differ with age, disease history, and treatment with prior anti-cancer therapies. This study evaluated the impact of systemic anti-cancer therapy for non-small cell lung cancer treatment on the T cell phenotype of the patient at baseline and the quality and characteristics of the genetically modified autologous T cell therapy product after manufacturing.

Proceedings of the inaugural Dark Genome Symposium: November 2022.

In November 2022 the first Dark Genome Symposium was held in Boston, USA. The meeting was hosted by Rome Therapeutics and Enara Bio, two biotechnology companies working on translating our growing understanding of this vast genetic landscape into therapies for human disease. The spirit and ambition of the meeting was one of shared knowledge, looking to strengthen the network of researchers engaged in the field. The meeting opened with a welcome from Rosana Kapeller and Kevin Pojasek followed by a first session of field defining talks from key academics in the space. A series of panels, bringing together academia and industry views, were then convened covering a wide range of pertinent topics. Finally, Richard Young and David Ting gave their views on the future direction and promise for patient impact inherent in the growing understanding of the Dark Genome.

Intratumoral pan-ErbB targeted CAR-T for head and neck squamous cell carcinoma: interim analysis of the T4 immunotherapy study.

BACKGROUND: Locally advanced/recurrent head and neck squamous cell carcinoma (HNSCC) is associated with significant morbidity and mortality. To target upregulated ErbB dimer expression in this cancer, we developed an autologous CD28-based chimeric antigen receptor T-cell (CAR-T) approach named T4 immunotherapy. Patient-derived T-cells are engineered by retroviral transduction to coexpress a panErbB-specific CAR called T1E28ζ and an IL-4-responsive chimeric cytokine receptor, 4αß, which allows IL-4-mediated enrichment of transduced cells during manufacture. These cells elicit preclinical antitumor activity against HNSCC and other carcinomas. In this trial, we used intratumoral delivery to mitigate significant clinical risk of on-target off-tumor toxicity owing to low-level ErbB expression in healthy tissues. METHODS: We undertook a phase 1 dose-escalation 3+3 trial of intratumoral T4 immunotherapy in HNSCC (NCT01818323). CAR T-cell batches were manufactured from 40 to 130 mL of whole blood using a 2-week semiclosed process. A single CAR T-cell treatment, formulated as a fresh product in 1-4 mL of medium, was injected into one or more target lesions. Dose of CAR T-cells was escalated in 5 cohorts from 1×107-1×109 T4+ T-cells, administered without prior lymphodepletion. RESULTS: Despite baseline lymphopenia in most enrolled subjects, the target cell dose was successfully manufactured in all cases, yielding up to 7.5 billion T-cells (67.5±11.8% transduced), without any batch failures. Treatment-related adverse events were all grade 2 or less, with no dose-limiting toxicities (Common Terminology Criteria for Adverse Events V.4.0). Frequent treatment-related adverse events were tumor swelling, pain, pyrexias, chills, and fatigue. There was no evidence of leakage of T4+ T-cells into the circulation following intratumoral delivery, and injection of radiolabeled cells demonstrated intratumoral persistence. Despite rapid progression at trial entry, stabilization of disease (Response Evaluation Criteria in Solid Tumors V.1.1) was observed in 9 of 15 subjects (60%) at 6 weeks post-CAR T-cell administration. Subsequent treatment with pembrolizumab and T-VEC oncolytic virus achieved a rapid complete clinical response in one subject, which was durable for over 3 years. Median overall survival was greater than for historical controls. Disease stabilization was associated with the administration of an immunophenotypically fitter, less exhausted, T4 CAR T-cell product. CONCLUSIONS: These data demonstrate the safe intratumoral administration of T4 immunotherapy in advanced HNSCC.

Germline genetic variation and predicting immune checkpoint inhibitor induced toxicity.

Immune checkpoint inhibitor (ICI) therapy has revolutionised the treatment of various cancer types. ICIs reinstate T-cell function to elicit an anti-cancer immune response. The resulting immune response can however have off-target effects which manifest as autoimmune type serious immune-related adverse events (irAE) in ~10-55% of patients treated. It is currently challenging to predict both who will experience irAEs and to what severity. Identification of patients at high risk of serious irAE would revolutionise patient care. While the pathogenesis driving irAE development is still unclear, host genetic factors are proposed to be key determinants of these events. This review presents current evidence supporting the role of the host genome in determining risk of irAE. We summarise the spectrum and timing of irAEs following treatment with ICIs and describe currently reported germline genetic variation associated with expression of immuno-modulatory factors within the cancer immunity cycle, development of autoimmune disease and irAE occurrence. We propose that germline genetic determinants of host immune function and autoimmune diseases could also explain risk of irAE development. We also endorse genome-wide association studies of patients being treated with ICIs to identify genetic variants that can be used in polygenic risk scores to predict risk of irAE.

Understanding the Lived Experiences of Patients With Melanoma: Real-World Evidence Generated Through a European Social Media Listening Analysis.

BACKGROUND: Cutaneous melanoma is an aggressive malignancy that is proposed to account for 90% of skin cancer-related mortality. Individuals with melanoma experience both physical and psychological impacts associated with their diagnosis and treatment. Health-related information is being increasingly accessed and shared by stakeholders on social media platforms. OBJECTIVE: This study aimed to assess how individuals living with melanoma across 14 European countries use social media to discuss their needs and provide their perceptions of the disease. METHODS: Social media sources including Twitter, forums, and blogs were searched using predefined search strings of keywords relating to melanoma. Manual and automated relevancy approaches filtered the extracted data for content that provided patient-centric insights. This contextualized data was then mined for insightful concepts around the symptoms, diagnosis, treatment, impacts, and lived experiences of melanoma. RESULTS: A total of 182,400 posts related to melanoma were identified between November 2018 and November 2020. Following exclusion of irrelevant posts and using random sampling methodology, 864 posts were identified as relevant to the study objectives. Of the social media channels included, Twitter was the most commonly used, followed by forums and blogs. Most posts originated from the United Kingdom (n=328, 38%) and Spain (n=138, 16%). Of the relevant posts, 62% (n=536) were categorized as originating from individuals with melanoma. The most frequently discussed melanoma-related topics were treatment (436/792, 55%), diagnosis and tests (261/792, 33%), and remission (190/792, 24%). The majority of treatment discussions were about surgery (292/436, 67%), followed by immunotherapy (52/436, 12%). In total, 255 posts discussed the impacts of melanoma, which included emotional burden (n=179, 70%), physical impacts (n=61, 24%), effects on social life (n=43, 17%), and financial impacts (n=10, 4%). CONCLUSIONS: Findings from this study highlight how melanoma stakeholders discuss key concepts associated with the condition on social media, adding to the conceptual model of the patient journey. This social media listening approach is a powerful tool for exploring melanoma stakeholder perspectives, providing insights that can be used to corroborate existing data and inform future studies.

CDK Inhibition Primes for Anti-PD-L1 Treatment in Triple-Negative Breast Cancer Models.

Triple-negative breast cancers (TNBC) expressing PD-L1 qualify for checkpoint inhibitor immunotherapy. Cyclin E/CDK2 is a potential target axis in TNBC; however, small-molecule drugs at efficacious doses may be associated with toxicity, and treatment alongside immunotherapy requires investigation. We evaluated CDK inhibition at suboptimal levels and its anti-tumor and immunomodulatory effects. Transcriptomic analyses of primary breast cancers confirmed higher cyclin E/CDK2 expression in TNBC compared with non-TNBC. Out of the three CDK2-targeting inhibitors tested, the CDK 2, 7 and 9 inhibitor SNS-032 was the most potent in reducing TNBC cell viability and exerted cytotoxicity against all eight TNBC cell lines evaluated in vitro. Suboptimal SNS-032 dosing elevated cell surface PD-L1 expression in surviving TNBC cells. In mice engrafted with human immune cells and challenged with human MDA-MB-231 TNBC xenografts in mammary fat pads, suboptimal SNS-032 dosing partially restricted tumor growth, enhanced the tumor infiltration of human CD45+ immune cells and elevated cell surface PD-L1 expression in surviving cancer cells. In tumor-bearing mice engrafted with human immune cells, the anti-PD-L1 antibody avelumab, given sequentially following suboptimal SNS-032 dosing, reduced tumor growth compared with SNS-032 alone or with avelumab without prior SNS-032 priming. CDK inhibition at suboptimal doses promotes immune cell recruitment to tumors, PD-L1 expression by surviving TNBC cells and may complement immunotherapy.

Oral beclomethasone dipropionate is an effective treatment for immune checkpoint inhibitor induced colitis.

INTRODUCTION: Systemic corticosteroids are the mainstay of treatment for immune checkpoint inhibitor induced (CPI) colitis but are associated with complications including life-threatening infection. The topically acting oral corticosteroid beclomethasone dipropionate (BD) is an effective treatment for mild to moderate flares of ulcerative colitis, and has fewer side effects than systemic corticosteroids. We hypothesized that BD would be an effective treatment for CPI-induced colitis. METHODS: We performed a retrospective analysis of all patients who started BD for CPI-induced colitis at three UK cancer centers between November 2017 and October 2020. All patients underwent endoscopic assessment and biopsy. The initial regimen of BD was 5 mg once daily for 28 days. Data were collected from electronic patient records. Clinical outcomes were assessed at 28 days after initiation of treatment. RESULTS: Twenty-two patients (14 male) with a median age of 64 (range 45-84) with CPI-induced colitis were treated with BD. At baseline, the median number of loose stools in a 24-hour period was six (common terminology criteria for adverse events, CTCAE grade diarrhea=2). Thirteen patients (59%) were dependent on systemic corticosteroids prior to starting BD. Baseline sigmoidoscopy showed moderate inflammation (Mayo Endoscopic Score (MES) = 2) in two patients (9%), mild inflammation (MES=1) in nine patients (41%) and normal findings (MES=0) in eleven patients (50%). Twenty patients (91%) had histopathological features of inflammation. All 22 patients (100%) had a clinical response to BD and 21 (95%) achieved clinical remission with a return to baseline stool frequency (CTCAE diarrhea=0). Ten patients (45%) had symptomatic relapse on cessation of BD, half within 7 days of stopping. All patients recaptured response on restarting BD. No adverse events were reported in patients treated with BD. CONCLUSIONS: Topical BD represents an appealing alternative option to systemic immunosuppressive treatments to treat colonic inflammation. In this study, BD was effective and safe at inducing remission in CPI-induced colitis, which was refractory to systemic corticosteroids. Further randomized studies are needed to confirm these findings and determine the optimum dosing regimen.