The Latest Option: Nivolumab and Relatlimab in Advanced Melanoma

PURPOSE OF REVIEW

Dual immune checkpoint inhibition with ipilimumab plus nivolumab is currently the most effective, but also by far the most toxic treatment for advanced melanoma. Therefore, other combination partners that also lead to high and long-lasting responses but cause fewer adverse events were explored.

RECENT FINDINGS

Relatlimab, a LAG-3 blocking antibody, was investigated in combination with nivolumab in a phase 2/3 randomized double-blind trial (RELATIVITY-047) and could demonstrate significantly improved progression-free survival in treatment-naive advanced melanoma patients compared with nivolumab monotherapy. While the safety profile is more favorable than that of ipilimumab plus nivolumab, no significant survival benefit has yet been demonstrated with the new combination over nivolumab monotherapy. The approval of relatlimab plus nivolumab by both the Food and Drug Administration and the European Medicines Agency expands the arsenal of treatment options for melanoma but raises new questions in clinical practice and a re-evaluation of currently established treatment standards and sequences.

Brain metastasis and survival outcomes after first-line therapy in metastatic melanoma: a multicenter DeCOG study on 1704 patients from the prospective skin cancer registry ADOREG

BACKGROUND

Despite the availability of effective systemic therapies, a significant number of advanced melanoma patients develops brain metastases. This study investigated differences in incidence and time to diagnosis of brain metastasis and survival outcomes dependent on the type of first-line therapy.

METHODS

Patients with metastatic, non-resectable melanoma (AJCCv8 stage IIIC-V) without brain metastasis at start of first-line therapy (1L-therapy) were identified from the prospective multicenter real-world skin cancer registry ADOREG. Study endpoints were incidence of brain metastasis, brain metastasis-free survival (BMFS), progression-free survival (PFS), and overall survival (OS).

RESULTS

Of 1704 patients, 916 were BRAF wild-type (BRAFwt) and 788 were BRAF V600 mutant (BRAFmut). Median follow-up time after start of 1L-therapy was 40.4 months. BRAFwt patients received 1L-therapy with immune checkpoint inhibitors (ICI) against CTLA-4+PD-1 (n=281) or PD-1 (n=544). In BRAFmut patients, 1L-therapy was ICI in 415 patients (CTLA-4+PD-1, n=108; PD-1, n=264), and BRAF+MEK targeted therapy (TT) in 373 patients. After 24 months, 1L-therapy with BRAF+MEK resulted in a higher incidence of brain metastasis compared with PD-1±CTLA-4 (BRAF+MEK, 30.3%; CTLA-4+PD-1, 22.2%; PD-1, 14.0%). In multivariate analysis, BRAFmut patients developed brain metastases earlier on 1L-therapy with BRAF+MEK than with PD-1±CTLA-4 (CTLA-4+PD-1: HR 0.560, 95% CI 0.332 to 0.945, p=0.030; PD-1: HR 0.575, 95% CI 0.372 to 0.888, p=0.013). Type of 1L-therapy, tumor stage, and age were independent prognostic factors for BMFS in BRAFmut patients. In BRAFwt patients, tumor stage was independently associated with longer BMFS; ECOG Performance status (ECOG-PS), lactate dehydrogenase (LDH), and tumor stage with OS. CTLA-4+PD-1 did not result in better BMFS, PFS, or OS than PD-1 in BRAFwt patients. For BRAFmut patients, multivariate Cox regression revealed ECOG-PS, type of 1L-therapy, tumor stage, and LDH as independent prognostic factors for PFS and OS. 1L-therapy with CTLA-4+PD-1 led to longer OS than PD-1 (HR 1.97, 95% CI 1.122 to 3.455, p=0.018) or BRAF+MEK (HR 2.41, 95% CI 1.432 to 4.054, p=0.001), without PD-1 being superior to BRAF+MEK.

CONCLUSIONS

In BRAFmut patients 1L-therapy with PD-1±CTLA-4 ICI resulted in a delayed and less frequent development of brain metastasis compared with BRAF+MEK TT. 1L-therapy with CTLA-4+PD-1 showed superior OS compared with PD-1 and BRAF+MEK. In BRAFwt patients, no differences in brain metastasis and survival outcomes were detected for CTLA-4+PD-1 compared with PD-1.

Characterisation and outcome of RAC1 mutated melanoma

BACKGROUND

Activating hot spot R29S mutations in RAC1, a small GTPase influencing several cellular processes including cell proliferation and cytoskeleton rearrangement, have been reported in up to 9% of sun-exposed melanomas. Clinical characteristics and treatment implications of RAC1 mutations in melanoma remain unclear.

METHODS

We investigated the largest set (n = 64) of RAC1 mutated melanoma patients reported to date, including a retrospective single institution cohort (n = 34) from the University Hospital Essen and a prospective multicentre cohort (n = 30) from the translational study Tissue Registry in Melanoma (TRIM; CA209-578), for patient and tumour characteristics as well as therapy outcomes.

RESULTS

From 3037 sequenced melanoma samples screened RAC1 mutations occurred in ^∼2% of samples (64/3037). The most common RAC1 mutation was P29S (95%, 61/64). The majority of tumours had co-occuring MAP kinase mutations (88%, 56/64); mostly activating NRAS (47%, 30/64) mutations, followed by activating BRAF (28%, 18/64) and NF1 (25%, 16/64) mutations. RAC1 mutated melanomas were almost exclusively of cutaneous origin (84%, 54/64) or of unknown primary (MUP, 14%, 9/64). C > T alterations were the most frequent mutation type identified demonstrating a UV-signature for RAC1 mutated melanoma. Most patients with unresectable disease (39) received immune checkpoint inhibitors (ICI) (77%, 30/39). Objective response rate of first-line treatment in patients with stage III/IV disease was 21%; median overall survival was 47.8 months.

CONCLUSIONS

RAC1 mutated melanomas are rare, mostly of cutaneous origin and frequently harbour concomitant MAP kinase mutations, particularly in NRAS. Patients with advanced disease benefit from systemic treatment with ICI.

Efficacy of ipilimumab 3mg/kg following progression on low dose ipilimumab in metastatic melanoma

BACKGROUND

Differing doses of ipilimumab (IPI) are used in combination with an anti-PD1 antibody in advanced melanoma. There is no data on the outcomes of patients who progress following low-dose IPI (< 3 mg/kg) and are subsequently treated with IPI 3 mg/kg (IPI3). We conducted a multicentre retrospective survey to assess the efficacy of this strategy.

METHODS

Patients with resected stage III, unresectable stage III or IV melanoma who received low dose IPI (< 3 mg/kg) with an anti-PD1 antibody with recurrence (neo/adjuvant) or progressive disease (metastatic), who then received IPI3± anti-PD1 antibody were eligible. Best investigator-determined Response Evaluation Criteria in Solid Tumours response, progression-free survival (PFS) and overall survival (OS) were analysed.

RESULTS

Total 36 patients received low-dose IPI with an anti-PD1 antibody, 18 (50%) in the neo/adjuvant and 18 (50%) in the metastatic setting. Of which, 20 (56%) had primary resistance and 16 (44%) had acquired resistance. All patients received IPI3 for unresectable stage III or IV melanoma; median age 60 (29-78), 18 (50%) M1d disease, 32 (89%) Eastern Cooperative Oncology Group performance status 0-1. Around 35 (97%) received IPI3 with nivolumab and 1 received IPI3 alone. The response rate to IPI3 was 9/36 (25%). In patients with primary resistance, the response rate was 6/20 (30%). After a median follow-up of 22 months (95% CI: 15-27 months), the median PFS and OS were not reached in patients who responded; 1-year PFS and OS were 73% and 100%, respectively.

CONCLUSIONS

IPI3 following recurrence/progression on low dose IPI has clinical activity, including in primary resistance. IPI dosing is therefore critical in a subset of patients.

Efficacy and safety of immune checkpoint inhibitors in young adults with metastatic melanoma

BACKGROUND

The integration of immune checkpoint inhibitors (ICI) for the treatment of melanoma has resulted in remarkable and durable responses. Given the potential role of immunosenescence, age may contribute to differential ICI efficacy and toxicity. While older patients have been studied in detail, outcomes from ICI in young patients (≤40 years) are not well characterised.

METHODS

We performed a multi-institutional, retrospective study of patients with advanced melanoma treated with anti-PD-1 monotherapy or ICI combination (ipilimumab and anti-PD-1). Response rates, survival, and toxicities were examined based on age comparing those under 40 years of age with older patients (age 41-70 and ≥ 71 years).

RESULTS

A total of 676 patients were included: 190 patients (28%) aged ≤40 years, 313 (46%) between ages 41-70, and 173 patients (26%) aged ≥71. Patients ≤40 years had higher response rates (53% vs 38%, p = 0.035) and improved progression-free survival (median 13.7 vs 4.0 months, p = 0.032) with combination ICI compared to monotherapy. Progression-free survival was similar among groups while overall survival was inferior in patients >70 years, who had low response rates to combination therapy (28%). ICIs had a similar incidence of severe toxicities, though hepatotoxicity was particularly common in younger patients vs. patients >40 with monotherapy (9% vs. 2%, p = 0.007) or combination ICI (37% vs. 10%, p < 0.001).

CONCLUSIONS

ICIs had comparable efficacy between younger and older patients, although outcomes were superior with combination ICI compared to monotherapy in patients aged ≤40 years. Toxicity incidence was similar across age groups, though organs affected were substantially different.

Immune signatures predict development of autoimmune toxicity in patients with cancer treated with immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are among the most promising treatment options for melanoma and non-small cell lung cancer (NSCLC). While ICIs can induce effective anti-tumor responses, they may also drive serious immune-related adverse events (irAEs). Identifying biomarkers to predict which patients will suffer from irAEs would enable more accurate clinical risk-benefit analysis for ICI treatment and may also shed light on common or distinct mechanisms underpinning treatment success and irAEs.

METHODS

In this prospective multi-center study, we combined a multi-omics approach including unbiased single-cell profiling of over 300 peripheral blood mononuclear cell (PBMC) samples and high-throughput proteomics analysis of over 500 serum samples to characterize the systemic immune compartment of patients with melanoma or NSCLC before and during treatment with ICIs.

FINDINGS

When we combined the parameters obtained from the multi-omics profiling of patient blood and serum, we identified potential predictive biomarkers for ICI-induced irAEs. Specifically, an early increase in CXCL9/CXCL10/CXCL11 and interferon-γ (IFN-γ) 1 to 2 weeks after the start of therapy are likely indicators of heightened risk of developing irAEs. In addition, an early expansion of Ki-67⁺ regulatory T cells (Tregs) and Ki-67⁺ CD8⁺ T cells is also likely to be associated with increased risk of irAEs.

CONCLUSIONS

We suggest that the combination of these cellular and proteomic biomarkers may help to predict which patients are likely to benefit most from ICI therapy and those requiring intensive monitoring for irAEs.

FUNDING

This work was primarily funded by the European Research Council, the Swiss National Science Foundation, the Swiss Cancer League, and the Forschungsförderung of the Kantonsspital St. Gallen.

Ipilimumab plus nivolumab in avelumab-refractory Merkel cell carcinoma: a multicenter study of the prospective skin cancer registry ADOREG

Merkel cell carcinoma is a rare, highly aggressive skin cancer with neuroendocrine differentiation. Immune checkpoint inhibition has significantly improved treatment outcomes in metastatic disease with response rates to programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) inhibition of up to 62%. However, primary and secondary resistance to PD-1/PD-L1 inhibition remains a so far unsolved clinical challenge since effective and safe treatment options for these patients are lacking.Fourteen patients with advanced (non-resectable stage III or stage IV, Union international contre le cancer 2017) Merkel cell carcinoma with primary resistance to the PD-L1 inhibitor avelumab receiving subsequent therapy (second or later line) with ipilimumab plus nivolumab (IPI/NIVO) were identified in the prospective multicenter skin cancer registry ADOREG. Five of these 14 patients were reported previously and were included in this analysis with additional follow-up. Overall response rate, progression-free survival (PFS), overall survival (OS) and adverse events were analyzed.All 14 patients received avelumab as first-line treatment. Thereof, 12 patients had shown primary resistance with progressive disease in the first tumor assessment, while two patients had initially experienced a short-lived stabilization (stable disease). Six patients had at least one systemic treatment in between avelumab and IPI/NIVO. In total, 7 patients responded to IPI/NIVO (overall response rate 50%), and response was ongoing in 4 responders at last follow-up. After a median follow-up of 18.85 months, median PFS was 5.07 months (95% CI 2.43-not available (NA)), and median OS was not reached. PFS rates at 12 months and 24 months were 42.9% and 26.8 %, respectively. The OS rate at 36 months was 64.3%. Only 3 (21%) patients did not receive all 4 cycles of IPI/NIVO due to immune-related adverse events.In this multicenter evaluation, we observed high response rates, a durable benefit and promising OS rates after treatment with later-line combined IPI/NIVO. In conclusion, our patient cohort supports our prior findings with an encouraging activity of second-line or later-line IPI/NIVO in patients with anti-PD-L1-refractory Merkel cell carcinoma.

Prognosis of Patients With Primary Melanoma Stage I and II According to American Joint Committee on Cancer Version 8 Validated in Two Independent Cohorts: Implications for Adjuvant Treatment

PURPOSE

The first randomized trial of adjuvant treatment with checkpoint inhibitor in stage II melanoma reported a significant reduction in risk of tumor recurrence. This study evaluates two independent data sets to further document survival probabilities for patients with primary stage I and II melanoma.

PATIENTS AND METHODS

The Central Malignant Melanoma Registry (CMMR) in Germany evaluated 17,544 patients with a primary diagnosis of stage I and II melanoma from 2000 to 2015. The exploratory cohort consisted of 6,725 patients from the Center for Dermato-Oncology at the University of Tübingen, and the confirmatory cohort consisted of 10,819 patients from 11 other German centers. Survival outcomes were compared with published American Joint Committee on Cancer version 8 (AJCCv8) stage I and II survival data.

RESULTS

For the two CMMR cohorts in stage IA compared with the AJCCv8 cohort, melanoma-specific survival rates at 10 years were 95.1%-95.6% versus 98%; 89.7%-90.9% versus 94% in stage IB; 80.7%-83.1% versus 88% in stage IIA; 72.0%-79.9% versus 82% in stage IIB; and 57.6%-64.7% versus 75% in stage IIC, respectively. Recurrence rates were approximately twice as high as melanoma-specific mortality rates in stages IA-IIA.

CONCLUSION

The melanoma-specific survival rates in the two CMMR cohorts across stages I and II are less favorable than published in AJCCv8. This has important implications for the consideration of adjuvant treatment in this population.

Circulating cell-free messenger RNA enables non-invasive pan-tumour monitoring of melanoma therapy independent of the mutational genotype

BACKGROUND

Plasma-derived tumour-specific cell-free nucleic acids are increasingly utilized as a minimally invasive, real-time biomarker approach in many solid tumours. Circulating tumour DNA of melanoma-specific mutations is currently the best studied liquid biopsy biomarker for melanoma. However, the combination of hotspot genetic alterations covers only around 80% of all melanoma patients. Therefore, alternative approaches are needed to enable the follow-up of all genotypes, including wild-type.

METHODS

We identified KPNA2, DTL, BACE2 and DTYMK messenger RNA (mRNA) upregulated in melanoma versus nevi tissues by unsupervised data mining (N = 175 melanoma, N = 20 normal skin, N = 6 benign nevi) and experimentally confirmed differential mRNA expression in vitro (N = 18 melanoma, N = 8 benign nevi). Circulating cell-free RNA (cfRNA) was analysed in 361 plasma samples (collected before and during therapy) from 100 melanoma patients and 18 healthy donors. Absolute cfRNA copies were quantified on droplet digital PCR.

RESULTS

KPNA2, DTL, BACE2 and DTYMK cfRNA demonstrated high diagnostic accuracy between melanoma patients' and healthy donors' plasma (AUC > 86%, p < .0001). cfRNA copies increased proportionally with increasing tumour burden independently of demographic variables and even remained elevated in individuals with radiological absence of disease. Re-analysis of single-cell transcriptomes revealed a pan-tumour origin of cfRNA, including endothelial, cancer-associated fibroblasts, macrophages and B cells beyond melanoma cells as cellular sources. Low baseline cfRNA levels were associated with significantly longer progression-free survival (PFS) (KPNA2 HR = .54, p = .0362; DTL HR = .60, p = .0349) and overall survival (KPNA2 HR = .52, p = .0237; BACE2 HR = .55, p = .0419; DTYMK HR = .43, p = .0393). Lastly, we found that cfRNA copies significantly increased during therapy in non-responders compared to responders regardless of therapy and mutational subtypes and that the increase of KPNA2 (HR = 1.73, p = .0441) and DTYMK (HR = 1.82, p = .018) cfRNA during therapy was predictive of shorter PFS.

CONCLUSIONS

In sum, we identified a new panel of cfRNAs for a pan-tumour liquid biopsy approach and demonstrated its utility as a prognostic, therapy-monitoring tool independent of the melanoma mutational genotype.

Genetic and methylation profiles distinguish benign, malignant and spitzoid melanocytic tumors

Accurate classification of melanocytic tumors is important for prognostic evaluation, treatment and follow-up protocols of patients. The majority of melanocytic proliferations can be classified solely based on clinical and pathological criteria, however in select cases a definitive diagnostic assessment remains challenging and additional diagnostic biomarkers would be advantageous. We analyzed melanomas, nevi, Spitz nevi and atypical spitzoid tumors using parallel sequencing (exons of 611 genes and 507 gene translocation analysis) and methylation arrays (850k Illumina EPIC). By combining detailed genetic and epigenetic analysis with reference-based and reference-free DNA methylome deconvolution we compared Spitz nevi to nevi and melanoma and assessed the potential for these methods in classifying challenging spitzoid tumors. Results were correlated with clinical and histologic features. Spitz nevi were found to cluster independently of nevi and melanoma and demonstrated a different mutation profile. Multiple copy number alterations and TERT promoter mutations were identified only in melanomas. Genome-wide methylation in Spitz nevi was comparable to benign nevi while the Leukocytes UnMethylation for Purity (LUMP) algorithm in Spitz nevi was comparable to melanoma. Histologically difficult to classify Spitz tumor cases were assessed which, based on methylation arrays, clustered between Spitz nevi and melanoma and in terms of genetic profile or copy number variations demonstrated worrisome features suggesting a malignant neoplasm. Comprehensive sequencing and methylation analysis verify Spitz nevi as an independent melanocytic entity distinct from both nevi and melanoma. Combined genetic and methylation assays can offer additional insights in diagnosing difficult to classify Spitzoid tumors.

Adjuvant nivolumab plus ipilimumab or nivolumab alone versus placebo in patients with resected stage IV melanoma with no evidence of disease (IMMUNED): final results of a randomised, double-blind, phase 2 trial

BACKGROUND

The IMMUNED trial previously showed significant improvements in recurrence-free survival for adjuvant nivolumab plus ipilimumab as well as for adjuvant nivolumab alone in patients with stage IV melanoma with no evidence of disease after resection or radiotherapy. Here, we report the final analysis, including overall survival data.

METHODS

IMMUNED was an investigator-sponsored, double-blind, placebo-controlled, three-arm, phase 2 trial conducted in 20 academic medical centres in Germany. Eligible patients were aged 18-80 years with stage IV melanoma with no evidence of disease after surgery or radiotherapy. Patients were randomly assigned (1:1:1) to either nivolumab plus ipilimumab (nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for four doses followed by nivolumab 3 mg/kg every 2 weeks), nivolumab monotherapy (nivolumab 3 mg/kg every 2 weeks), or matching placebo, for up to 1 year. The primary endpoint was recurrence-free survival in the intention-to-treat population. Secondary endpoints were time-to-recurrence, overall survival, progression-free survival or recurrence-free survival 2 (in patients in the placebo group who crossed over to nivolumab monotherapy after experiencing disease recurrence), and safety endpoints. This trial is registered on ClinicalTrials.gov (NCT02523313), and is complete.

FINDINGS

Between Sept 2, 2015, and Nov 20, 2018, 175 patients were enrolled in the study, and 167 were randomly assigned to receive either nivolumab plus ipilimumab (n=56), nivolumab plus ipilimumab-matching placebo (n=59), or double placebo control (n=52). At a median follow-up of 49·2 months (IQR 34·9-58·1), 4-year recurrence-free survival was 64·2% (95% CI 49·2-75·9) in the nivolumab plus ipilimumab group, 31·4% (19·7-43·8) in the nivolumab alone group, and 15·0% (6·7-26·6) in the placebo group. The hazard ratio (HR) for recurrence for the nivolumab plus ipilimumab group versus placebo was 0·25 (97·5% CI 0·13-0·48; p<0·0001), and for the nivolumab group versus placebo was 0·60 (0·36-1·00; p=0·024). Median overall survival was not reached in any treatment group. The HR for overall survival was significantly in favour of the nivolumab plus ipilimumab group versus placebo (HR 0·41; 95% CI 0·17-0·99; p=0·040), but not for the nivolumab group versus placebo (HR 0·75; 0·36-1·56; p=0·44). 4-year overall survival was 83·8% (95% CI 68·8-91·9) in the nivolumab plus ipilimumab group, 72·6% (57·4-83·2) in the nivolumab alone group, and 63·1% (46·9-75·6) in the placebo group. The median progression-free survival or recurrence-free survival 2 of patients in the placebo group who crossed over to nivolumab monotherapy after experiencing disease recurrence was not reached (95% CI 21·2 months to not reached). Rates of grade 3-4 treatment-related adverse events remained largely unchanged compared with our previous report, occurring in 71% (95% CI 57-82) of the nivolumab plus ipilimumab group, and 29% (95% CI 17-42) of patients receiving nivolumab alone. There were no treatment-related deaths.

INTERPRETATION

Both active regimens continued to show significantly improved recurrence-free survival compared with placebo in patients with stage IV melanoma with no evidence of disease who were at high risk of recurrence. Overall survival was significantly improved for patients receiving nivolumab plus ipilimumab compared with placebo. Use of subsequent anti-PD-1-based therapy was high in patients in the placebo group after recurrence and most likely impacted the overall survival comparison of nivolumab alone versus placebo. The recurrence-free and overall survival benefit of nivolumab plus ipilimumab over placebo reinforces the change of practice already initiated for the treatment of patients with stage IV melanoma with no evidence of disease.

FUNDING

Bristol-Myers Squibb.

Characteristics of immune checkpoint inhibitor-induced encephalitis and comparison with HSV-1 and anti-LGI1 encephalitis: A retrospective multicentre cohort study

AIM

Immune checkpoint inhibitor-induced encephalitis (ICI-iE) is a rare but life-threatening toxicity of immune checkpoint inhibitor treatment. We aim to identify the characteristics of ICI-iE and describe factors that discriminate it from herpes simplex virus (HSV)-1 encephalitis and anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis, as two alternative entities of encephalitis.

METHODS

In this retrospective multicentre cohort study, we collected patients with ICI-iE reported to the Side Effect Registry Immuno-Oncology from January 2015 to September 2021 and compared their clinical features and outcome with 46 consecutive patients with HSV-1 or anti-LGI1 encephalitis who were treated at a German neurological referral centre.

RESULTS

Thirty cases of ICI-iE, 25 cases of HSV-1 encephalitis and 21 cases of anti-LGI1 encephalitis were included. Clinical presentation of ICI-iE was highly variable and resembled that of HSV-1 encephalitis, while impairment of consciousness (66% vs. 5%, p = .007), confusion (83% vs. 43%; p = .02), disorientation (83% vs. 29%; p = .007) and aphasia (43% vs. 0%; p = .007) were more common in ICI-iE than in anti-LGI1 encephalitis. Antineuronal antibodies (17/18, 94%) and MRI (18/30, 60%) were mostly negative in ICI-iE, but cerebrospinal fluid (CSF) showed pleocytosis and/or elevated protein levels in almost all patients (28/29, 97%). Three patients (10%) died of ICI-iE. Early immunosuppressive treatment was associated with better outcome (r = 0.43).

CONCLUSIONS

ICI-iE is a heterogeneous entity without specific clinical features. CSF analysis has the highest diagnostic value, as it reveals inflammatory changes in most patients and enables the exclusion of infection. Early treatment of ICI-iE is essential to prevent sequelae and death.

COVID-19 vaccination in advanced skin cancer patients receiving systemic anticancer treatment: A prospective singlecenter study investigating seroconversion rates

Background

COVID-19 vaccination reduces risk of SARS-CoV-2 infection, COVID-19 severity and death. However, the rate of seroconversion after COVID-19 vaccination in cancer patients requiring systemic anticancer treatment is poorly investigated. The aim of the present study was to determine the rate of seroconversion after COVID-19 vaccination in advanced skin cancer patients under active systemic anticancer treatment.

Methods

This prospective single-center study of a consecutive sample of advanced skin cancer patients was performed from May 2020 until October 2021. Inclusion criteria were systemic treatment for advanced skin cancer, known COVID-19 vaccination status, repetitive anti-SARS-CoV-2-S IgG serum quantification and first and second COVID-19 vaccination. Primary outcome was the rate of anti-SARS-CoV-2-S IgG seroconversion after complete COVID-19 vaccination.

Results

Of 60 patients with advanced skin cancers, 52 patients (86.7%) received immune checkpoint inhibition (ICI), seven (11.7%) targeted agents (TT), one (1.7%) chemotherapy. Median follow-up time was 12.7 months. During study progress ten patients had died from skin cancer prior to vaccination completion, six patients were lost to follow-up and three patients had refused vaccination. 41 patients completed COVID-19 vaccination with two doses and known serological status. Of those, serum testing revealed n=3 patients (7.3%) as anti-SARS-CoV-2-S IgG positive prior to vaccination, n=32 patients (78.0%) showed a seroconversion, n=6 patients (14.6%) did not achieve a seroconversion. Patients failing serological response were immunocompromised due to concomitant hematological malignancy, previous chemotherapy or autoimmune disease requiring immunosuppressive comedications. Immunosuppressive comedication due to severe adverse events of ICI therapy did not impair seroconversion following COVID-19 vaccination. Of 41 completely vaccinated patients, 35 (85.4%) were under treatment with ICI, five (12.2%) with TT, and one (2.4%) with chemotherapy. 27 patients (65.9%) were treated non adjuvantly. Of these patients, 13 patients had achieved objective response (complete/partial response) as best tumor response (48.2%).

Conclusion and relevance

Rate of anti-SARS-CoV-2-S IgG seroconversion in advanced skin cancer patients under systemic anticancer treatment after complete COVID-19 vaccination is comparable to other cancer entities. An impaired serological response was observed in patients who were immunocompromised due to concomitant diseases or previous chemotherapies. Immunosuppressive comedication due to severe adverse events of ICI did not impair the serological response to COVID-19 vaccination.

Clinical and pathological characteristics of familial melanoma with germline TERT promoter variants

Around 10% of melanoma occur in patients with a suspected familial predisposition. TERT promoter mutations are the most common somatic hotspot mutations in human cancers. However, only two families with germline mutations have been identified to date. We present detailed histological, clinical and molecular pathologic analyses of affected patients and details of newly identified individuals in one of these previously reported families. TERT (NM_198253.3) Chr.5:1,295,161T>C (c.-57 T>C) promoter variants were detected in all melanoma-affected (n=18) and one non-diseased family member. Median age at diagnosis was 30 years (n=18, range 16-46 years, 2 unknown). While most primary melanoma arose on the upper extremities (n=7, 21%) and were superficial spreading melanoma (SSM, n=8, 24%), many primary melanoma also originated from non UV-exposed mucosal (n=2, 6%) and acral (n=4, 12%) locations. One SSM sample harboured a Chr.5:1,295,228C>T TERT promoter region in addition to the germline Chr.5:1,295,161T>C variant, arguing additional pathway activation can support tumor pathogenesis. Patients treated with BRAF inhibitor and/or immune checkpoint inhibition (ICI) showed responses, although of limited duration. One mucosal melanoma harboured both a KIT copy number gain and an activating c.1727 p.Leu576Pro mutation. Following modest response to ICI, subsequent KIT inhibitor (imatinib) therapy demonstrated an ongoing complete pathological response (currently 7 months).

Right ventricular and atrial strain in patients with advanced melanoma undergoing immune checkpoint inhibitor therapy

AIMS

While immune checkpoint inhibitor (ICI) therapy significantly improves survival rates in advanced melanoma, ICI can evoke severe immune-related cardiovascular adverse events. Right ventricular (RV) dysfunction negatively impacts the outcomes in cardiovascular diseases and may be an early sign for overall cardiotoxicity. We aimed to assess RV function in melanoma patients undergoing ICI therapy using conventional echocardiographic and strain imaging techniques.

METHODS AND RESULTS

We retrospectively examined 30 patients (40% women, age 59 ± 13 years) with advanced melanoma (stage III/IV) before and 4 weeks after the start of ICI therapy (follow-up at 39 ± 15 days); n = 15 of the patients received nivolumab, and n = 15 received the combination therapy nivolumab/ipilimumab. Two-dimensional echocardiography with assessment of RV longitudinal strain of the free wall (RV-LSFW) and assessment of right atrial (RA) strain from speckle tracking was performed at baseline and after the start of ICI therapy. Short-term ICI therapy caused a reduction of RV-LSFW (-25.5 ± 6.4% vs. -22.4 ± 4.3%, P = 0.002) and of RA strain during contraction phase (-10.6 ± 3.5% vs. -7.7 ± 3.1%, P = 0.001). Conventional parameters including tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and pulmonary artery systolic pressure were not different between the two time points (TAPSE 26 ± 5 vs. 25 ± 5 mm, P = 0.125; FAC 38 ± 13% vs. 38 ± 14%, P = 0.750; and pulmonary artery systolic pressure 27 ± 10 vs. 25 ± 8 mmHg, P = 0.268).

CONCLUSIONS

Analysis of RV and RA strain shows alterations even in a short-term follow-up, while changes in RV function are not visible by conventional RV parameters. Alterations in RV and RA strain could be early signs of cardiotoxicity and therefore should be assessed in patients undergoing ICI therapy.

Phase Ib/II Trial of Ribociclib in Combination with Binimetinib in Patients with NRAS-mutant Melanoma

PURPOSE

Enhanced MAPK pathway signaling and cell-cycle checkpoint dysregulation are frequent in NRAS-mutant melanoma and, as such, the regimen of the MEK inhibitor binimetinib and the selective CDK4/6 inhibitor ribociclib is a rational combination.

PATIENTS AND METHODS

This is a phase Ib/II, open-label study of ribociclib + binimetinib in patients with NRAS-mutant melanoma (NCT01781572). Primary objectives were to estimate the MTD/recommended phase II dose (RP2D) of the combination (phase Ib) and to characterize combination antitumor activity at the RP2D (phase II). Tumor genomic characterization and pharmacokinetics/pharmacodynamics were also evaluated.

RESULTS

Ten patients (16.4%) experienced dose-limiting toxicities in cycle 1 of phase Ib. Overall response rate in the phase II cohort (n = 41) for the selected RP2D (binimetinib 45 mg twice daily + ribociclib 200 mg once daily, 21 days on/7 days off) was 19.5% [8/41; 95% confidence interval (CI), 8.8-34.9]. The response rate was 32.5% (13/40; 95% CI, 20.1-48.0) in patients with NRAS mutation with concurrent alterations of CDKN2A, CDK4, or CCND1. Median progression-free survival was 3.7 months (95% CI, 3.5-5.6) and median overall survival was 11.3 months (95% CI, 9.3-14.2) for all patients. Common treatment-related toxicities included creatine phosphokinase elevation, rash, edema, anemia, nausea, diarrhea, and fatigue. Pharmacokinetics and safety were consistent with single-agent data, supporting a lack of drug-drug interaction.

CONCLUSIONS

Ribociclib + binimetinib can be safely administered and is clinically active in patients with NRAS-mutant melanoma. Co-mutations of cell-cycle genes may define a population with greater likelihood of treatment benefit. See related commentary by Moschos, p. 2977.

Efficacy of anti-PD-1 and ipilimumab alone or in combination in acral melanoma

BACKGROUND

Acral melanoma is a rare melanoma subtype with poor prognosis. Importantly, these patients were not identified as a specific subgroup in the landmark melanoma trials involving ipilimumab and the anti-programmed cell death protein-1 (PD-1) agents nivolumab and pembrolizumab. There is therefore an absence of prospective clinical trial evidence regarding the efficacy of checkpoint inhibitors (CPIs) in this population. Acral melanoma has lower tumor mutation burden (TMB) than other cutaneous sites, and primary site is associated with differences in TMB. However the impact of this on the effectiveness of immune CPIs is unknown. We examined the efficacy of CPIs in acral melanoma, including by primary site.

METHODS

Patients with unresectable stage III/IV acral melanoma treated with CPI (anti-PD-1 and/or ipilimumab) were studied. Multivariable logistic and Cox regression analyses were conducted. Primary outcome was objective response rate (ORR); secondary outcomes were progression-free survival (PFS) and overall survival (OS).

RESULTS

In total, 325 patients were included: 234 (72%) plantar, 69 (21%) subungual and 22 (7%) palmar primary sites. First CPI included: 184 (57%) anti-PD-1, 59 (18%) anti-PD-1/ipilimumab combination and 82 (25%) ipilimumab. ORR was significantly higher with initial anti-PD-1/ipilimumab compared with anti-PD-1 (43% vs 26%, HR 2.14, p=0.0004) and significantly lower with ipilimumab (15% vs 26%, HR 0.49, p=0.0016). Landmark PFS at 1 year was highest for anti-PD-1/ipilimumab at 34% (95% CI 24% to 49%), compared with 26% (95% CI 20% to 33%) with anti-PD-1 and 10% (95% CI 5% to 19%) with ipilimumab. Despite a trend for increased PFS, anti-PD-1/ipilimumab combination did not significantly improve PFS (HR 0.85, p=0.35) or OS over anti-PD-1 (HR 1.30, p=0.16), potentially due to subsequent therapies and high rates of acquired resistance. No outcome differences were found between primary sites.

CONCLUSION

While the ORR to anti-PD-1/ipilimumab was significantly higher than anti-PD-1 and PFS numerically higher, in this retrospective cohort this benefit did not translate to improved OS. Future trials should specifically include patients with acral melanoma, to help determine the optimal management of this important melanoma subtype.

Efficacy and safety of anti-PD1 monotherapy or in combination with ipilimumab after BRAF/MEK inhibitors in patients with BRAF mutant metastatic melanoma

BACKGROUND

Patients with V600BRAF mutant metastatic melanoma have higher rates of progression-free survival (PFS) and overall survival (OS) with first-line anti-PD1 (PD1]+anti-CTLA-4 (IPI) versus PD1. Whether this is also true after BRAF/MEKi therapy is unknown. We aimed to determine the efficacy and safety of PD1 versus IPI +PD1 after BRAF/MEK inhibitors (BRAF/MEKi).

METHODS

Patients with V600BRAF mutant metastatic melanoma treated with BRAF/MEKi who had subsequent PD1 versus IPI+PD1 at eight centers were included. The endpoints were objective response rate (ORR), PFS, OS and safety in each group.

RESULTS

Of 200 patients with V600E (75%) or non-V600E (25%) mutant metastatic melanoma treated with BRAF/MEKi (median time of treatment 7.6 months; treatment cessation due to progressive disease in 77%), 115 (57.5%) had subsequent PD1 and 85 (42.5%) had IPI+PD1. Differences in patient characteristics between PD1 and IPI+PD1 groups included, age (med. 63 vs 54 years), time between BRAF/MEKi and PD1±IPI (16 vs 4 days), Eastern Cooperative Oncology Group Performance Status (ECOG PS) of ≥1 (62% vs 44%), AJCC M1C/M1D stage (72% vs 94%) and progressing brain metastases at the start of PD1±IPI (34% vs 57%). Median follow-up from PD1±IPI start was 37.8 months (95% CI, 33.9 to 52.9). ORR was 36%; 34% with PD1 vs 39% with IPI+PD1 (p=0.5713). Median PFS was 3.4 months; 3.4 with PD1 vs 3.6 months with IPI+PD1 (p=0.6951). Median OS was 15.4 months; 14.4 for PD1 vs 20.5 months with IPI+PD1 (p=0.2603). The rate of grade 3 or 4 toxicities was higher with IPI+PD1 (31%) vs PD1 (7%). ORR, PFS and OS were numerically higher with IPI+PD1 vs PD1 across most subgroups except for females, those with <10 days between BRAF/MEKi and PD1±IPI, and those with stage III/M1A/M1B melanoma. The combination of ECOG PS=0 and absence of liver metastases identified patients with >3 years OS (area under the curve, AUC=0.74), while ECOG PS ≥1, progressing brain metastases and presence of bone metastases predicted primary progression (AUC=0.67).

CONCLUSIONS

IPI+PD1 and PD1 after BRAF/MEKi have similar outcomes despite worse baseline prognostic features in the IPI+PD1 group, however, IPI+PD1 is more toxic. A combination of clinical factors can identify long-term survivors, but less accurately those with primary resistance to immunotherapy after targeted therapy.

Single-agent anti-PD-1 or combined with ipilimumab in patients with mucosal melanoma: an international, retrospective, cohort study

BACKGROUND

Mucosal melanoma (MM) is a rare melanoma subtype with distinct biology and poor prognosis. Data on the efficacy of immune checkpoint inhibitors (ICIs) is limited. We determined the efficacy of ICIs in MM, analysed by primary site and ethnicity/race.

PATIENTS AND METHODS

Retrospective cohort study from 25 cancer centres in Australia, Europe, USA and Asia. Patients with histologically confirmed MM were treated with anti-PD1+/-ipilimumab. Primary endpoints were response rate (RR), progression-free survival (PFS), overall survival (OS) by primary site (naso-oral, urogenital, anorectal, other), ethnicity/race (Caucasian, Asian, Other) and treatment. Univariate and multivariate Cox proportional hazard model analyses were conducted.

RESULTS

In total, 545 patients were included: 331 (63%) Caucasian, 176 (33%) Asian and 20 (4%) Other. Primary sites included 113 (21%) anorectal, 178 (32%) urogenital, 206 (38%) naso-oral and 45 (8%) other. 348 (64%) received anti-PD1 and 197 (36%) anti-PD1/ipilimumab. RR, PFS and OS did not differ by primary site, ethnicity/race or treatment. RR for naso-oral was numerically higher for anti-PD1/ipilimumab (40%, 95% CI 29-54%) compared with anti-PD1 (29%, 95% CI 21-37%). 35% of patients that initially responded progressed. Median duration of response (mDOR) was 26 months (95% CI 18-NR [Not Reached]). Factors associated with short PFS were ECOG PS ≥3 (p<0.01), LDH >ULN (p=0.01), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01). Factors associated with short OS were ECOG PS ≥1 (p<0.01), LDH >ULN (p=0.03), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01).

CONCLUSIONS

MM has poor prognosis. Treatment efficacy of anti-PD1+/-ipilimumab was similar and did not differ by ethnicity/race. Naso-oral primaries had numerically higher response to anti-PD1/ipilimumab, without difference in survival. The addition of ipilimumab did not show greater benefit over anti-PD1 for other primary sites. In responders, mDOR was short and acquired resistance was common. Other factors, including site and number of metastases were associated with survival.

Multicenter real-world data of adjuvant treatment and disease outcome of patients with melanoma with high-risk of recurrence

9570

Background: Clinical trials demonstrated a significantly improved recurrence-free survival (RFS) of melanoma patients treated adjuvantly with immune checkpoint inhibition (ICI) and targeted therapy (TT). As data from controlled trials are based on selected populations, we investigated melanoma patients with high risk of recurrence who opted for ICI, TT, or no adjuvant treatment (NoTx) under real-world conditions. Methods: In a prior analysis of this multicenter, retrospective cohort study, patients with resected melanoma stage III-IV between 06/2018 and 09/2019 were analyzed for adjuvant therapy choice (Lodde et al., Cancers 2021). In this follow-up study, the treatment course of ICI- and TT-treated patients as well as recurrence characteristics, subsequent management and outcomes also including NoTx patients were examined. Results: 814 patients were included (72 stage IIIA, 266 IIIB, 383 IIIC, 24 IIID, 69 IV; 309 BRAF mut); 533 patients received ICI (66%), 114 TT (14%, 36.9% of all BRAF mutated patients), 167 patients had opted for NoTx (21%). Median treatment duration was 10.2 and 11.7 months for ICI and TT, respectively. ICI was discontinued prematurely in 51% (273/533) and TT in 44% (50/114) of patients. The main reason for discontinuation was progressive disease (PD) in ICI patients (58%, 158/273) and adverse events in TT patients (60%, 33/50). At a median follow-up (FU) of 24.6 months for ICI, 25.3 months for TT, and 21.8 months for NoTx, 48% of ICI (255/533), 35% of TT (40/114), and 45% of NoTx (75/167) patients had developed a recurrence mostly at distant sites (ICI 62%, TT 63%, NoTx 64%). In patients with recurrence, median time from start of adjuvant treatment to 1st recurrence was 6.1 months in ICI and 17.6 months in TT. Median RFS was 32.0 months for ICI (95% CI 25.7-38.3), not reached for TT, and 22.3 months for NoTx (95% CI 15.2-29.4). Among BRAF mut patients with stage III, risk of recurrence was higher for ICI than TT (hazard ratio adjusted for age, sex and tumor stage, 2.31; 95% CI 1.56-3.43). Subsequent systemic treatment for the 1st recurrence was given in 76% (192/253) of ICI, 83% (33/40) of TT, and 53% (40/75) of NoTx patients. Among patients who received the 1st subsequent systemic treatment for metastatic disease, PD was the best response in 67% (82/123) for ICI, 55% (11/20) for TT, and 50% (16/32) for NoTX. Conclusions: After 2 years of FU, recurrences were mostly at distant sites in all groups. ICI had higher discontinuation rates and more and earlier recurrences than TT. BRAF mut melanoma patients treated with ICI had a significantly higher risk of relapse than TT-treated patients. Response to subsequent systemic treatment was low for both ICI and TT.

Efficacy and safety of sequencing with vemurafenib (V) plus cobimetinib (C) followed by atezolizumab (Atezo) in patients (pts) with advanced BRAFV600-positive melanoma: Interim analysis of the ImmunoCobiVem study

9548

Background: Immunotherapies (ICI) and targeted therapies (TT) have improved PFS and OS in BRAFV600-mutated advanced melanoma pts, but evidence regarding their optimal sequence is limited. The randomized phase 2 ImmunoCobiVem study evaluated efficacy and safety of an early switch to Atezo after initial treatment with V + C. Interim results are reported. Methods: Pts with previously untreated BRAFV600-mutated advanced melanoma received a 3-mo run-in with V (960 mg twice daily) + C (60 mg once daily for 21/28 days). Pts without PD/treatment interruption due to AEs during run-in were then randomized 1:1 to continue V + C (Arm A) or switch to Atezo (1200 mg every 3 wks; Arm B) until first documented PD (PD1), followed by crossover to the alternate treatment until second documented PD (PD2). End points were PFS1 (time from start of run-in until PD1 or death from any cause), PFS2 (time from start of run-in until PD2 or death from any cause), PFS3 (time from PD1 until PD2 or death from any cause), DCR, ORR, OS, and safety. Results: 185 pts were enrolled between Nov 2016 and Dec 2019 (63% male; median age 58 y); 135 pts completed run-in and were randomized to Arm A (n=69) or Arm B (n=66). At data cutoff, median follow-up for all pts was 19.0 mo. In Arm A, 36/69 pts (52%) discontinued V + C due to PD and 21/36 (58%) crossed over to Atezo; in Arm B, 49/66 pts (74%) discontinued Atezo due to PD and 35/49 (71%) crossed over to V + C. Median PFS1 was significantly longer in Arm A vs Arm B (HR 0.55; 95% CI 0.37–0.84; P=0.001), while median PFS3 was significantly shorter in Arm A vs Arm B (HR 2.24; 95% CI 1.17–4.30; P=0.013); median PFS2 was not significantly different between arms (HR 1.57; 95% CI 0.83–2.96; P=0.163) (Table). During the randomized phase, ORR and DCR were higher in Arm A before crossover and in Arm B after crossover (Table). OS was similar between arms (HR 1.22; 95% CI 0.69–2.16; P=0.389). Median (range) treatment duration across treatment phases was 11.2 mo (2.3–56.1) for Arm A and 10.7 mo (2.8–56.7) for Arm B. Grade 3/4 AEs occurred in 55% of pts in Arm A and 64% in Arm B; AEs led to discontinuation in 10% and 12%, respectively. Conclusions: Early switch from V + C to Atezo is feasible and safe, but tumor control achieved in run-in is maintained in only a subset of pts on subsequent ICI monotherapy. Crossover to ICI monotherapy at PD results in low response, while response to TT re-exposure is frequent. Clinical trial information: NCT02902029. [Table: see text]

Efficacy of ipilimumab 3mg/kg following progression on low dose ipilimumab in metastatic melanoma

e21533

Background: Anti-cytotoxic T lymphocyte-associated antigen 4 inhibitors, such as ipilimumab (IPI), are commonly used in melanoma management. Whilst a clear dose-toxicity relationship exists, and a dose-response relationship is seen with monotherapy in people with anti PD-1 antibody-naïve melanoma, there is no data on the outcomes of patients who progress following low dose IPI and are subsequently treated with standard dose IPI. We conducted a multicentre, retrospective review to assess the efficacy of this strategy. Methods: Patients with resected stage III, unresectable stage III or IV melanoma who received low dose IPI (< 3mg/kg) with an anti-PD1 antibody in the neoadjuvant, adjuvant or metastatic setting with recurrence (neo/adjuvant) or progressive disease (metastatic) as best response, who then received standard dose IPI (3mg/kg, IPI3) alone or in combination with an anti-PD1 antibody were eligible. IPI dose, frequency and best investigator-assessed RECIST response were collected. Progression free survival (PFS) and overall survival (OS) were analysed using the Kaplan Meier method. Results: 36 patients from 8 centres; 27 (75%) male, BRAF V600 mutant (18, 50%). All patients received low dose IPI with an anti-PD1 antibody, 18 (50%) in the neo/adjuvant and 18 (50%) in the metastatic setting; 15 (42%) received IPI 1mg/kg every 6 weeks, 13 (36%) IPI 1mg/kg every 3 weeks, 3 (8%) IPI 50mg every 6 weeks or 100mg every 12 weeks respectively, and 2 (6%) IPI 1mg/kg every 8 weeks. 23 (64%) received >1 intervening line of systemic therapy prior to IPI3. The most common intervening therapy was BRAF/MEK inhibitors; 14/23 (61%) as 2nd line treatment, 4/8 (50%) as 3rd line treatment, and all progressed. All patients received standard dose IPI3 for unresectable stage III or stage IV melanoma; median age 60 (29-78), 18 (50%) had M1d disease, 32 (89%) ECOG 0-1, 18 (50%) normal lactate dehydrogenase. 35 (97%) received IPI3 with nivolumab and 1 received single agent IPI3. 15 (42%) received 4 cycles of IPI3. The most common reason for IPI3 cessation was progressive disease (16, 44%). The response rate to IPI3 following progression on low dose IPI was 9/36 (25%); the disease control rate was 12/36 (33%). After a median follow up of 22 months (95% CI: 15-27 months), the median PFS and OS were not reached in patients who responded;1-year PFS and OS were 73% and 100% respectively. 13/36 (36%) had grade 3-4 immune-related adverse events (irAE). In 3/36 (8%), the same irAE was observed at low dose IPI and IPI3, and 1 patient had the same irAE (rash) at a higher grade with IPI3 compared to low dose IPI. Conclusions: Standard dose IPI3 following progression on low dose IPI has clinical activity.This is a reasonable treatment strategy for patients who progress on low dose IPI and provides further evidence of a dose-response relationship for IPI. Further research is needed to manage resistance to IPI with anti-PD1.

Management of infliximab-refractory immune checkpoint inhibitor gastrointestinal toxicity: A multicenter case series

2665

Background: Immune checkpoint inhibitor (ICI) GI tox (gastritis, enteritis, colitis) is a major cause of morbidity and treatment-related death. Guidelines agree steroid-refractory cases warrant infliximab (IFx); however not all pts respond and best management of IFx-Refractory ICI GI toxicity (IRIGItox) is not clear. Methods: We conducted an international multi-centre retrospective case series. IRIGItox was defined as failure of symptom resolution ≤ Gr 1 (CTCAE v5.0) following ≥ 2 IFx doses or failure of symptom resolution ≤ Gr 2 after 1 dose. Data were extracted regarding demographics, steroid use, response and survival. Tox was graded at symptom onset and time of IFx failure. Efficacy of IFx refractory therapy was assessed by symptom resolution, time to resolution and steroid wean. Results: 78 pts were identified; med age 60 yrs (95% CI 56-65), 56% male. 70 (90%) had melanoma, 55 (71%) had advanced-stage, 60 (77%) received anti-CTLA-4 (with anti-PD1 50, single agent 10). Most had colitis (N=75, 96%) and ≥ Gr 3 tox (N=74, 95%) at symptom onset. Pre-IFx investigation varied: imaging 37%; faecal calprotectin 29%; endoscopy 59%. All pts received Med time to steroid initiation was 3 days (95% CI 2-4). 46 (59%) had primary steroid refractory disease,. Med time from symptom onset to IFx was 18 days (95% CI 12-23), a med 2 (range 1-6) doses of IFx were given, 69 (88%) pts received > 1 IFx dose. Across 78 pts, 105 post IFx treatments were given: calcineurin inhibitors (ciclosporin, tacrolimus, 32); antimetabolites (mycophenolate, azathioprine, 26); non-TNF-α MABs (vedolizumab, ustekinumab, 20); non-targeted anti-inflammatory (mesalazine, 16); non-pharmacological (colectomy 5, faecal transplant 1, photophoresis 1). 4 pts did not receive therapy for IRIGItox. Of these, 2 died of melanoma prior to resolution of tox; 1 had resolution after 4 doses IFx, 1 had recurrent melanoma and flare of tox on PD1 re-challenge. IRIGItox outcomes by post IFx treatment are shown in Table. Conclusions: This retrospective case series confirms heterogeneous management of IRIGItox. Non-pharmacological interventions and calcineurin inhibitors appear most likely to result in tox resolution. Calcineurin inhibitors have the shortest time to resolution in responders. Further details on post-IFx management and oncological outcomes will be examined. [Table: see text]