BRAF + EGFR +/- MEK inhibitors after immune checkpoint inhibitors in BRAF V600E mutated and deficient mismatch repair or microsatellite instability high metastatic colorectal cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the guideline endorsed first choice for patients with deficient mismatch repair or microsatellite instability high (dMMR/MSI-H) mCRC, however a significant proportion experience primary or secondary resistance. BRAF V600E mutated (BRAFm) and dMMR/MSI-H mCRC can be treated with BRAF + EGFR inhibitors but specific data on the efficacy after progression to ICIs are missing. METHODS: We collected consecutive patients with BRAFm dMMR/MSI-H mCRC treated from 2017 to 2024 with a combination of BRAFi+EGFRi+/-MEKi, after disease progression on ICIs. A control cohort of BRAFm pMMR/MSS mCRC patients treated with encorafenib+cetuximab+/-binimetinib from 2nd line was used. RESULTS: dMMR/MSI-H (n = 50) BRAFm mCRC patients were more often > 70-year-old, with right-sided primary tumors, without liver but more lymphnode metastases than pMMR/MSS (n = 170). They were treated more frequently beyond 2nd line and 45 % were primary progressors to ICIs. Lower ORR (18 % versus 32 %, p = 0.09) and DCR (60 % versus 73 %, p = 0.11) was seen without reaching significance in dMMR/MSI-H as compared to pMMR/MSS patients. After a median follow-up of 14.04 months, no differences in PFS (median 5.13 versus 4.50 months, HR 0.83, 95 %CI: 0.57-1.20, p = 0.31) and OS (median 10.75 versus 9.11 months, HR 0.89, 95 %CI: 0.59-1.32, p = 0.55) were observed. CONCLUSIONS: Our results show that BRAFm dMMR/MSI-H mCRC patients benefit from BRAFi+EGFRi+/-MEKi after progression under ICIs. Despite lower ORR and DCR, the outcome is not different from that observed in pMMR/MSS BRAFm CRC and is in line with the results of the BEACON registration trial.

Laparoscopic Extended Segmentectomy VIII Guided by Three-Dimensional Reconstruction and Hepatic Veins with a Cranio-Caudal Approach.

INTRODUCTION: Minimally invasive resection of segment VIII is a technically challenging procedure, made even more challenging when the resection is extended to segment IV and/or segment VII. Parenchymal-sparing resections are frequently used in the management of liver metastases but expose to the risk of R1 resection, especially with a minimally invasive approach. Preoperative surgical planning with 3D reconstruction and intraoperative guidance with hepatic vein is helpful for laparoscopic oncological liver resection.1-3 PATIENT AND METHODS: We present the case of a 58-year-old female with three metachronous liver metastases from epidermoid anal cancer. The disease was stable 6 months after cessation of chemotherapy. Metastases were mainly located in segment VIII (with a large segment VIII dorsal) but also in the territory of glissonian pedicles from segments IV and VII. Prior to surgery, three-dimensional (3D) reconstruction showed that a segmentectomy VIII would not be sufficient to have a safety margin and showed the relation between metastases and hepatic veins. Transection of the liver was performed with an ultrasonic dissector. Exposure of the hepatic veins was performed by gently pulling of the hepatic tissue from the vein, using the nonactive blade of the ultrasonic device. Activation of ultrasonic energy was performed only for sealing and dividing small collateral veins. Three transection lines were necessary. The posterior transection line, in segment VII, was determined with intraoperative ultrasound (IOUS), at 1 cm below the metastasis. The liver was transected superficially only. The medial transection line, in segment IV, was determined with IOUS, at 1 cm on the left of the metastasis, parallel to the middle hepatic vein. Finally, the inferior transection line, between segment V and segment VIII, was approximately determined with IOUS, vertically aligned with the hepatic vein of segment V. The transection line was further corrected after clamping the glissonian pedicle of segment VIII, according to fluorescence. The surgical procedure began with the mobilization of the right liver, including division of the hepato-caval ligament, followed by the superficial transection of the posterior margin in segment VII. Then, transection of segment IV was performed near the termination of the middle hepatic vein, which was further exposed with a cranio-caudal approach to minimize the risk of vein injury. The hepatic vein of segment V was then used as a landmark for the identification of the Glissonian pedicle of segment VIII, which was transected.4 Termination of the right hepatic vein (RHV) was then identified, and the ventral branch of the RHV was transected. The dorsal branch of the RHV was exposed with a cranio-caudal approach. Finally, transection of segment VII was performed toward the transection line made initially. RESULTS: Operative time was 360 min with 450 mL blood loss. The Pringle maneuver was used during 148 min. The patient was discharged on the seventh postoperative day. Pathological examination confirmed R0 resection, with 20-60% necrosis of the three liver metastases. The resected liver weight was 225 g. Six months after liver resection, the patient had a recurrence in a celiac lymph node, which was treated by radiotherapy. Fifteen months after liver resection, the patient is free of disease without active treatment. CONCLUSION: Preoperative virtual hepatectomy facilitates surgical planning by increasing the understanding of the tumors-vessels relationship. Intraoperative hepatic vein guidance with a cranio-caudal approach enables to follow preoperative surgical planning and to perform safe complex laparoscopic liver resection.

Trifluridine/tipiracil + oxaliplatin ± nivolumab vs FOLFOX ± nivolumab in HER2 negative advanced oesogastric adenocarcinoma: The PRODIGE73-UCGI40-LOGICAN trial.

BACKGROUND: Trifluridine/tipiracil (FTD/TPI) is approved in third-line treatment of patients with advanced/metastatic gastric and gastroesophageal junction adenocarcinomas (aGA/GEJA). The association of oxaliplatin with FTD/TPI is promising and the combination of FTD/TPI + oxaliplatin + nivolumab has shown a predictable and manageable safety profile. AIMS: The aim is to evaluate the efficacy and safety of FTD/TPI plus oxaliplatin with or without nivolumab in patients, with HER2 negative aGA/GEJA, unfit for triplet chemotherapy (TFOX/mFLOT regimen), in the first-line metastatic setting in comparison with the standard of care FOLFOX with or without nivolumab. METHODS: This study is a prospective randomised, open label, comparative, multicentre, phase II trial designed to include 118 patients. The primary objective is to evaluate the superiority of FTD/TPI plus oxaliplatin with or without nivolumab over FOLFOX regimen with or without nivolumab in terms of PFS in a population of patients non candidate for triplet chemotherapy. Nivolumab will be used for patients whose tumour express PD-L1 with a CPS score ≥5. DISCUSSION: PRODIGE73-UCGI40-LOGICAN study will provide efficacy and safety data on the association of FTD/TPI plus oxaliplatin with or without nivolumab versus FOLFOX regimen with or without nivolumab in first-line palliative setting, in patients with aGA/GEJA (NCT05476796).

Gemcitabine and Paclitaxel Versus Gemcitabine Alone After 5-Fluorouracil, Oxaliplatin, and Irinotecan in Metastatic Pancreatic Adenocarcinoma: A Randomized Phase III PRODIGE 65-UCGI 36-GEMPAX UNICANCER Study.

PURPOSE: GEMPAX was an open-label, randomized phase III clinical trial designed to assess the efficacy and tolerability of gemcitabine plus paclitaxel versus gemcitabine alone as second-line treatment for patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) who previously received 5-fluorouracil, oxaliplatin, and irinotecan. METHODS: Patients with histologically or cytologically confirmed mPDAC were randomly assigned (2:1) to receive GEMPAX (paclitaxel 80 mg/m2 + gemcitabine 1,000 mg/m2; IV; once at day (D) 1, D8, and D15/arm A) or gemcitabine (arm B) alone once at D1, D8, and D15 every 28 days until progression, toxicity, or patient's decision. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), quality of life, and safety. RESULTS: Overall, 211 patients (median age, 64 [30-86] years; 62% male) were included. After a median study follow-up for alive patients of 13.4 versus 13.8 months in arm A versus arm B, the median OS (95% CI) was 6.4 (5.2 to 7.4) versus 5.9 months (4.6 to 6.9; hazard ratio [HR], 0.87 [0.63 to 1.20]; P = 0.4095), the median PFS was 3.1 (2.2 to 4.3) versus 2.0 months (1.9 to 2.3; HR, 0.64 [0.47 to 0.89]; P = 0.0067), and the ORR was 17.1% (11.3 to 24.4) versus 4.2% (0.9 to 11.9; P = 0.008) in arm A versus arm B, respectively. Overall, 16.7% of patients in arm A and 2.9% in arm B discontinued their treatment because of adverse events (AEs). One grade 5 AE associated with both gemcitabine and paclitaxel was reported in arm A (acute respiratory distress), and 58.0% versus 27.1% of patients experienced grade ≥3 treatment-related AEs in arm A versus arm B, among which 15.2% versus 4.3% had anemia, 15.9% versus 15.7% had neutropenia, 19.6% versus 4.3% had thrombocytopenia, 10.1% versus 2.9% had asthenia and 12.3% versus 0.0% had neuropathy. CONCLUSION: While GEMPAX did not meet the primary end point of OS versus gemcitabine alone in patients with mPDAC in the second-line setting, both PFS and ORR were significantly improved.

Efficacy of immune checkpoint inhibitors in microsatellite unstable/mismatch repair-deficient advanced pancreatic adenocarcinoma: an AGEO European Cohort.

BACKGROUND: Immune checkpoint inhibitors (ICIs) improve oncological outcomes in patients with microsatellite instability-high (MSI) or mismatch repair-deficient (dMMR) advanced solid tumours. Nevertheless, based on limited published data, the outcome of patients with MSI/dMMR pancreatic ductal adenocarcinoma (PDAC) seems poorer when compared to other malignancies. This multi-institutional analysis sought to assess the efficacy and tolerability of ICIs in a large real-world cohort of patients with MSI/dMMR PDAC. METHODS: We retrospectively collected data from patients with MSI/dMMR advanced PDAC treated with ICIs in 16 centers. Progression-free survival and overall survival were calculated from the start of treatment, and we report objective response and disease control rates according to RECIST V1.1. RESULTS: Thirty-one MSI/dMMR advanced PDAC patients were identified. Twenty-five patients received single-agent anti-PD-1 antibodies, three patients received the combination of nivolumab and ipilimumab and three patients received immunotherapy in combination with chemotherapy. Among 31 evaluable patients, 15 (48.4%) had an objective response (three complete responses and 12 partial responses), and six (19.4%) had stable disease. With a median follow-up of 18 months, the median progression-free survival (PFS) was 26.7 months and the median overall survival (OS) was not reached. Disease control rates (DCRs) among patients with only one line of prior therapy (N = 17) was 76.5%. Grade 3-4 treatment-related adverse events were not observed. CONCLUSION: This retrospective analysis suggests that ICIs are effective and well tolerated in patients with MSI/dMMR advanced PDAC. Hence, our work supports the use of PD-1 inhibition in this group of patients with high unmet medical need.

Targeting HER2 in metastatic gastroesophageal adenocarcinomas: What is new?

Gastric and esophageal adenocarcinomas represent a biologically heterogeneous disease. The identification, in early eighties, of human epidermal growth factor receptor 2 (HER2) overexpression, being present in 12 to 20% of the cases, marked a major milestone in the efforts of unraveling the molecular complexity of this disease. This led to the development of anti-HER2-therapies, trastuzumab being the first to demonstrate, in combination with cisplatin and 5FU/capecitabine chemotherapy, an improvement in response rate and survival in the first-line setting of patients with metastatic, HER2-positive gastroesophageal adenocarcinomas. Afterwards, during a decade, several studies have tried new strategies either to block HER2 pathway differently or to combine different anti-HER2, without efficacy. Everything changed with studies demonstrating additive effect between anti-HER2 and immune checkpoint inhibitors and leading to phase III clinical trials combining anti-HER2 and anti-PD-L1/PD1 therapies. Pembrolizumab, a PD-1 inhibitor, was recently granted by FDA an accelerated approval, in patients with HER2-positive gastro-oesophageal adenocarcinomas, in combination with trastuzumab and platinum-based chemotherapy following meaningful improvement in overall response rate over standard treatment. Progression-free and overall-survival results are still awaited to change our first-line standard treatment. Furthermore, new HER2 inhibitors have been developed, blocking HER2-mediated pathway signaling via different mechanisms from pan-HER inhibition to anti-HER2 antibody drug conjugates with promising results in pretreated patients. Trastuzumab-deruxtecan has in particular showed interesting results in pretreated patients. We present here a review of the recent data and perspectives in HER2-positive metastatic gastroesophageal adenocarcinomas.

Chemotherapy in advanced pancreatic adenosquamous carcinoma: A retrospective multicenter AGEO study.

Pancreatic adenosquamous carcinoma (PASC) account for <5% of pancreatic malignancies. The efficacy of modern chemotherapy regimens in patients with advanced PASC is unknown. Patients with advanced PASC from 2008 to 2021 were consecutively included in this retrospective multicenter study. Overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier method. Ninety-four PASC from 16 French centers were included (median age, 67.3 years; males, 56.4%; metastatic disease, 85.1%). The first-line treatment was chemotherapy for 79 patients (84.0%) (37 FOLFIRINOX (FX), 7 Gemcitabine-nab paclitaxel (GN) and 35 for all other regimen) or best supportive care (BSC) alone for 15 patients (16.0%). No significant difference was observed between FX and GN in terms of PFS (P = .67) or OS (P = .5). Modern regimens pooled together (FX and GN) as compared to all others chemotherapy regimens showed an improvement of overall response rate (39.5% and 9.7%, P = .002), PFS (median, 7.8 vs 4.7 months, P = .02) and OS (median, 12.7 vs 9.2 months, P = .35). This large study evaluating first-line treatment regimens in advanced PASC suggests that modern regimens as FX or GN may be preferable to all other chemotherapy regimens. These results deserve confirmation in prospective studies.

Immunotherapy in MSI/dMMR tumors in the perioperative setting: The IMHOTEP trial.

BACKGROUND: Immune checkpoint inhibitors (ICI) targeting Programmed death-1 (PD-1) have shown their efficacy in advanced MSI/dMMR (microsatellite instability/deficient mismatch repair) tumors. The MSI/dMMR status predicts clinical response to ICI. The promising results evaluating ICI in localized MSI/dMMR tumors in neoadjuvant setting need to be confirmed in MSI/dMMR solid tumors. The aim of the IMHOTEP trial is to assess the efficacy of neoadjuvant anti-PD-1 treatment in MSI/dMMR tumors regarding the pathological complete response rate. METHODS: This study is a prospective, multicenter, phase II study including 120 patients with localized MSI/dMMR carcinomas suitable for curative surgery. A single dose of pembrolizumab will be administered before the surgery planned 6 weeks later. Primary objective is to evaluate the efficacy of neoadjuvant pembrolizumab according to pathological complete tumor response. Secondary objectives are to assess safety, recurrence-free survival and overall survival. Ancillary studies will assess molecular and immunological biomarkers predicting response/resistance to ICI. First patient was enrolled in December 2021. DISCUSSION: The IMHOTEP trial will be one of the first clinical trial investigating perioperative ICI in localized MSI/dMMR in a tumor agnostic setting. Assessing neoadjuvant anti-PD-1 is mandatory to improve MSI/dMMR patient's outcomes. The translational program will explore potential biomarker to improve our understanding of immune escape and response in this ICI neoadjuvant setting.

A Promising Biomarker and Therapeutic Target in Patients with Advanced PDAC: The Stromal Protein ßig-h3.

With an overall survival rate of 2-9% at 5 years, pancreatic ductal adenocarcinoma (PDAC) is currently the fourth leading cause of cancer-related deaths in the industrialized world and is predicted to become the second by 2030. Owing to often late diagnosis and rare actionable molecular alterations, PDAC has not yet benefited from the recent therapeutic advances that immune checkpoint inhibitors (ICI) have provided in other cancer types, except in specific subgroups of patients presenting with tumors with high mutational burden (TMB) or microsatellite instability (MSI). The tumor microenvironment (TME) plays a substantial role in therapeutic resistance by facilitating immune evasion. An extracellular stromal protein, ßig-h3/TGFßi, is involved in the pathogenesis of PDAC by hampering T cell activation and promoting stiffness of the TME. The study BIGHPANC included 41 patients with metastatic PDAC, and analyzed ßig-h3 levels in serum and tumor samples to assess the ßig-h3 prognostic value. ßig-h3 serum levels are significantly associated with overall survival (HR 2.05, 95%CI 1.07-3.93; p = 0.0301). Our results suggest that ßig-h3 serum levels may be considered a prognostic biomarker in patients with metastatic PDAC.

Sequential Treatment With Trifluridine/Tipiracil and Regorafenib in Refractory Metastatic Colorectal Cancer Patients: An AGEO Prospective "Real-World Study".

INTRODUCTION: Regorafenib (R) and trifluridine/tipiracil (FTD/TPI) are of proven efficacy in metastatic colorectal cancer (mCRC) patient's refractory to standard therapies. However, it remains unclear which drug should be administered first. PATIENTS AND METHODS: This French observational study was prospectively conducted in 11 centers between June 2017 and September 2019. All consecutive patients with chemorefractory mCRC and receiving FTD/TPI and/or R were eligible. The aim was to evaluate the efficacy and tolerability of FTD/TPI and/or R in real-world setting with adjusted analysis. RESULTS: A total of 237 mCRC patients (25% R and 75% FTD/TPI) were enrolled. As compared to R, FTD/TPI patients were significantly older and with more metastatic sites. Median OS and PFS were respectively 6.2 and 2.4 months in the FTD/TPI and 6.6 and 2.1 months in the R group. After matching 46 paired patients according to a propensity score, a trend to a longer OS (P = .58), and a significantly longer PFS (P = .048) were observed in the FTD/TPI group. In the 24% of patients receiving the R/T or T/R sequence, median OS from first treatment was similar. Tolerability profiles were similar to published data and dose reductions were more frequent in the R group. CONCLUSION: Efficacy and safety results in this real-world prospective study are in line with phase III trials. In a matched population, PFS was significantly longer in the FTD/TPI group. Despite a limited number of patients, clinical outcomes seemed similar in patients treated with the T/R or R/T sequence.

Precision medicine for patients with gastro-oesophageal cancer: A subset analysis of the ProfiLER program.

BACKGROUND: Chemotherapy, anti-HER2 and PD-1 antibodies are standard treatments but only a minority of patients derive long-term benefit from these agents. METHODS: In this report we describe the mutational landscape and outcome of patients with gastroesophageal cancers enroled in the ProfiLER program. RESULTS: Adenocarcinoma (n = 86, 59%), signet-cell (n = 37, 25%) and squamous-cell (n = 21, 14%) were the dominant histology amongst 147 patients. Genomic analyses could be performed for 114 (78%) patients. The most common genomic alterations involved ERBB2 (15%), KRAS (12%), CCND1 (7%), FGFR1-3 (8%), EGFR (5%) and MET (3%), TP53 (51%) and CDKN2A/B (10%). ERBB2, MET and FGFR alterations were found exclusively in the adenocarcinoma and signet-cell subtypes, while CCND1 amplification, TP53 mutations and CDKN2A/B loss were found in both adenocarcinoma and squamous-cell subtypes. Nine patients (8%) received therapy matched to their genomic alteration, with 5 of them achieving disease control. In an exploratory analysis, patients with stage IV disease at diagnosis who had an actionable alteration had longer overall survival compared to those without. CONCLUSION: Genomic profiling for patients with advanced gastroesophageal cancers allows the identification of actionable alterations in large proportion of patients. Increased accessibility to molecularly matched therapy may improve survival in this disease.

First-line chemotherapy with raltitrexed in metastatic colorectal cancer: an Association des Gastro-entérologues Oncologues (AGEO) multicentre study.

BACKGROUND: In case of contraindication or intolerance to fluoropyrimidines, raltitrexed is a validated alternative in metastatic colorectal cancer (mCRC), associated or not with oxaliplatin. Little is known about the outcomes of raltitrexed combined with irinotecan or targeted therapies. METHODS: This retrospective multicentre study enroled mCRC patients treated with first-line raltitrexed-based chemotherapy. Treatment-related toxicities were recorded. Progression-free survival (PFS) and overall survival (OS) were calculated from treatment start. RESULTS: 75 patients were treated with raltitrexed alone, TOMOX, or TOMIRI with or without bevacizumab. Grade 3-4 adverse events were seen in 31% of patients, without significant difference between the different treatment schedules. amongst the 36 patients with a history of fluoropyrimidine-induced cardiac toxicity, none developed cardiovascular events on raltitrexed. Median PFS and OS were 10.6 (95% CI 8.2 - 13.1) and 27.4 months (95% CI 24.1-38.1), respectively. Considering the chemotherapy regimen, TOMOX was significantly associated with better PFS and OS compared to TOMIRI and raltitrexed alone. CONCLUSIONS: In patients with mCRC not eligible for fluoropyrimidines, first-line raltitrexed-based chemotherapy had an acceptable safety profile. PFS and OS were consistent with usual survival data in mCRC, and significantly better in patients treated with TOMOX, independently of associated targeted therapies.

Hyperprogressive Disease After Combined Anti-PD-L1 and Anti-CTLA-4 Immunotherapy for MSI-H/dMMR Gastric Cancer: A Case Report.

Immune checkpoint inhibitors (ICI) have been developed in gastric adenocarcinomas and approved in first-line metastatic setting (in combination with chemotherapy) as well as in pretreated patients. Microsatellite instability-high (MSI-H) tumors are predicted to derive high benefit from ICI but data in gastric locations are limited. Here, we describe the case of a 68-year old patient with stage IV MSI-H gastric adenocarcinoma, referred to our center to receive immunotherapy after failure of standard of care (surgery with perioperative platin-based chemotherapy and paclitaxel plus ramucirumab at disease progression). The patient received one injection of durvalumab and tremelimumab and was hospitalized eighteen days after because of occlusive syndrome. The CT scan showed hyperprogression of the lymph nodes and hepatic lesions, compressing the gastric stump. He died few days later. Molecular analyses did not explain this outcome. To our knowledge, this is one of the first reported cases of hyperprogressive disease after combined ICI for a patient with MSI-H tumor. We review the potential causes and discuss the emerging literature regarding predictive factors of hyperprogression in the particular subset of MSI-H patients. If some data were available in retrospective studies, validation of strong predictive factors is needed to avoid such dramatic evolutions.

Immune checkpoint inhibitor sensitivity of DNA repair deficient tumors.

Faithful DNA replication is necessary to maintain genome stability and implicates a complex network with several pathways depending on DNA damage type: homologous repair, nonhomologous end joining, base excision repair, nucleotide excision repair and mismatch repair. Alteration in components of DNA repair machinery led to DNA damage accumulation and potentially carcinogenesis. Preclinical data suggest sensitivity to immune checkpoint inhibitors in tumors with DNA repair deficiency. Here, we review clinical studies that explored the use of immune checkpoint inhibitor in patient harboring tumor with DNA repair deficiency.

Cancer and immunotherapy: a role for microbiota composition.

Human microbiota plays a key role in preserving homeostasis; therefore, alteration in its composition is associated with susceptibility to various diseases. Recent findings suggest that gut microbiota may influence response to cancer treatment, especially immune checkpoint blockers (ICBs). The development of ICBs has changed outcomes of patients with cancer and has allowed sustained recovery. Unfortunately, some patients do not respond to ICBs, and microbiota may be a promising new biomarker to identify patients who will have benefit from ICBs. This review presents relationship between microbiome composition or microbiota-derived metabolites and response to ICBs or immune-related adverse events. Furthermore, we will present different strategies to modulate microbiota composition in patients to enhance ICB efficacy or dampen their toxicities which could lead to the emergence of interesting complementary treatments.

Systemic short chain fatty acids limit antitumor effect of CTLA-4 blockade in hosts with cancer.

Gut microbiota composition influences the clinical benefit of immune checkpoints in patients with advanced cancer but mechanisms underlying this relationship remain unclear. Molecular mechanism whereby gut microbiota influences immune responses is mainly assigned to gut microbial metabolites. Short-chain fatty acids (SCFA) are produced in large amounts in the colon through bacterial fermentation of dietary fiber. We evaluate in mice and in patients treated with anti-CTLA-4 blocking mAbs whether SCFA levels is related to clinical outcome. High blood butyrate and propionate levels are associated with resistance to CTLA-4 blockade and higher proportion of Treg cells. In mice, butyrate restrains anti-CTLA-4-induced up-regulation of CD80/CD86 on dendritic cells and ICOS on T cells, accumulation of tumor-specific T cells and memory T cells. In patients, high blood butyrate levels moderate ipilimumab-induced accumulation of memory and ICOS + CD4 + T cells and IL-2 impregnation. Altogether, these results suggest that SCFA limits anti-CTLA-4 activity.

Evolution and recurrence of gastrointestinal immune-related adverse events induced by immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs), such as anti-CTLA-4 and anti-PD-1 antibodies, are effective against several malignancies. They are associated with gastrointestinal immune-related adverse events (GI-IrAEs), which may be severe and lead to ICI discontinuation. We assessed the risk of evolution of GI-IrAEs to chronic GI inflammation and the risk of recurrence after a second line of ICI. PATIENTS AND METHODS: This was a single-centre study. Included patients had a GI-IrAE due to ICIs between September 2010 and July 2017. We assessed the persistence of symptoms, endoscopic and/or histological inflammation, and the risk of recurrent GI-IrAEs after the second line of ICIs. RESULTS: Eighty patients were included. The median follow-up was 8.4 months (0.36-72.3). The median duration of GI symptoms was 1.5 months (5 days-10.3 months): 1.4 months (7 days-4.9 months) with anti-CTLA-4, 2.0 months (5 days-10.3 months) with anti-PD-1 and 1.0 month (8 days-3.4 months) with combination therapy (log-rank test: p = 0.02). Three and 6 months after the beginning of GI-IrAEs, 22% (95% confidence interval: 14%-33%) and 5.4% (2.0%-14.7%) of patients had persistent symptoms, respectively. After a median of 6 months, 20/27 patients had endoscopic and/or histological inflammation, of whom, seven were symptom free. After the first episode, 6/26 patients relapsed after receiving another course of ICIs. Among these 26, 89% (77%-100%) had no recurrence after 3 months, 71% or 95% if the second line was anti-CTLA-4 or anti-PD-1, respectively. CONCLUSION: GI-IrAEs seem to be acute or subacute, not chronic. Reintroduction of ICIs is possible in patients who had GI-IrAE.