Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease Codes in Patient Records.

PURPOSE: Current approaches to accurately identify immune-related adverse events (irAEs) in large retrospective studies are limited. Large language models (LLMs) offer a potential solution to this challenge, given their high performance in natural language comprehension tasks. Therefore, we investigated the use of an LLM to identify irAEs among hospitalized patients, comparing its performance with manual adjudication and International Classification of Disease (ICD) codes. METHODS: Hospital admissions of patients receiving immune checkpoint inhibitor (ICI) therapy at a single institution from February 5, 2011, to September 5, 2023, were individually reviewed and adjudicated for the presence of irAEs. ICD codes and an LLM with retrieval-augmented generation were applied to detect frequent irAEs (ICI-induced colitis, hepatitis, and pneumonitis) and the most fatal irAE (ICI-myocarditis) from electronic health records. The performance between ICD codes and LLM was compared via sensitivity and specificity with an α = .05, relative to the gold standard of manual adjudication. External validation was performed using a data set of hospital admissions from June 1, 2018, to May 31, 2019, from a second institution. RESULTS: Of the 7,555 admissions for patients on ICI therapy in the initial cohort, 2.0% were adjudicated to be due to ICI-colitis, 1.1% ICI-hepatitis, 0.7% ICI-pneumonitis, and 0.8% ICI-myocarditis. The LLM demonstrated higher sensitivity than ICD codes (94.7% v 68.7%), achieving significance for ICI-hepatitis (P < .001), myocarditis (P < .001), and pneumonitis (P = .003) while yielding similar specificities (93.7% v 92.4%). The LLM spent an average of 9.53 seconds/chart in comparison with an estimated 15 minutes for adjudication. In the validation cohort (N = 1,270), the mean LLM sensitivity and specificity were 98.1% and 95.7%, respectively. CONCLUSION: LLMs are a useful tool for the detection of irAEs, outperforming ICD codes in sensitivity and adjudication in efficiency.

Multi-organ immune-related adverse events from immune checkpoint inhibitors and their downstream implications: a retrospective multicohort study.

BACKGROUND: Understanding co-occurrence patterns and prognostic implications of immune-related adverse events is crucial for immunotherapy management. However, previous studies have been limited by sample size and generalisability. In this study, we leveraged a multi-institutional cohort and a population-level database to investigate co-occurrence patterns of and survival outcomes after multi-organ immune-related adverse events among recipients of immune checkpoint inhibitors. METHODS: In this retrospective study, we identified individuals who received immune checkpoint inhibitors between May 31, 2015, and June 29, 2022, from the Massachusetts General Hospital, Brigham and Women's Hospital, and Dana-Farber Cancer Institute (Boston, MA, USA; MGBD cohort), and between April 30, 2010, and Oct 11, 2021, from the independent US population-based TriNetX network. We identified recipients from all datasets using medication codes and names of seven common immune checkpoint inhibitors, and patients were excluded from our analysis if they had incomplete information (eg, diagnosis and medication records) or if they initiated immune checkpoint inhibitor therapy after Oct 11, 2021. Eligible patients from the MGBD cohort were then propensity score matched with recipients of immune checkpoint inhibitors from the TriNetX database (1:2) based on demographic, cancer, and immune checkpoint inhibitor characteristics to facilitate cohort comparability. We applied immune-related adverse event identification rules to identify patients who did and did not have immune-related adverse events in the matched cohorts. To reduce the likelihood of false positives, patients diagnosed with suspected immune-related adverse events within 3 months after chemotherapy were excluded. We performed pairwise correlation analyses, non-negative matrix factorisation, and hierarchical clustering to identify co-occurrence patterns in the MGBD cohort. We conducted landmark overall survival analyses for patient clusters based on predominant immune-related adverse event factors and calculated accompanying hazard ratios (HRs) and 95% CIs, focusing on the 6-month landmark time for primary analyses. We validated our findings using the TriNetX cohort. FINDINGS: We identified 15 246 recipients of immune checkpoint inhibitors from MGBD and 50 503 from TriNetX, of whom 13 086 from MGBD and 26 172 from TriNetX were included in our propensity score-matched cohort. Median follow-up durations were 317 days (IQR 113-712) in patients from MGBD and 249 days (91-616) in patients from TriNetX. After applying immune-related adverse event identification rules, 8704 recipients of immune checkpoint inhibitors were retained from MGBD, of whom 3284 (37·7%) had and 5420 (62·3%) did not have immune-related adverse events, and 18 162 recipients were retained from TriNetX, of whom 5538 (30·5%) had and 12 624 (69·5%) did not have immune-related adverse events. In both cohorts, positive pairwise correlations of immune-related adverse events were commonly observed. Co-occurring immune-related adverse events were decomposed into seven factors across organs, revealing seven distinct patient clusters (endocrine, cutaneous, respiratory, gastrointestinal, hepatic, musculoskeletal, and neurological). In the MGBD cohort, the patient clusters that predominantly had endocrine (HR 0·53 [95% CI 0·40-0·70], p<0·0001) and cutaneous (0·61 [0·46-0·81], p=0·0007) immune-related adverse events had favourable overall survival outcomes at the 6-month landmark timepoint, while the other clusters either had unfavourable (respiratory: 1·60 [1·25-2·03], p=0·0001) or neutral survival outcomes (gastrointestinal: 0·86 [0·67-1·10], p=0·23; musculoskeletal: 0·97 [0·78-1·21], p=0·78; hepatic: 1·20 [0·91-1·59], p=0·19; and neurological: 1·30 [0·97-1·74], p=0·074). Similar results were found in the TriNetX cohort (endocrine: HR 0·75 [95% CI 0·60-0·93], p=0·0078; cutaneous: 0·62 [0·48-0·82], p=0·0007; respiratory: 1·21 [1·00-1·46], p=0·044), except for the neurological cluster having unfavourable (rather than neutral) survival outcomes (1·30 [1·06-1·59], p=0·013). INTERPRETATION: Reliably identifying the immune-related adverse event cluster to which a patient belongs can provide valuable clinical information for prognosticating outcomes of immunotherapy. These insights can be leveraged to counsel patients on the clinical impact of their individual constellation of immune-related adverse events and ultimately develop more personalised surveillance and mitigation strategies. FUNDING: US National Institutes of Health.

Conversion of a Validated Melanoma Risk Stratification Tool Into a Tablet-Based Patient Questionnaire for Targeted Melanoma Screening in Primary Care Settings: A Pilot Study.

BACKGROUND: Risk stratification can identify individuals in primary care settings who are at increased risk of developing melanoma. OBJECTIVE: Converting and implementing a validated risk stratification tool as a patient self-administered tablet-based survey. METHODS: Mackie risk stratification tool was transformed into a patient questionnaire. The questionnaire was completed in academic dermatologist practices by patients and dermatologists and revised to optimize sensitivity and specificity using physician assessment as gold standard. The optimized survey was administered before routine primary care visits during 2019 to 2021. High-risk patients were referred to dermatology. The number needed to screen (NNS), sensitivity, specificity, positive predictive value, and negative predictive value to identify a melanoma were calculated. RESULTS: Of the 7,893 respondents, 5,842 (74%) and 2,051 (26%) patients were categorized as low-risk and high-risk population, respectively. The NNS to identify 1 melanoma was 64 in the high-risk population. CONCLUSION: Incorporating self-administered patient-risk stratification tools in primary care settings can identify high-risk individuals for targeted melanoma screening. Further studies are needed to optimize specificity and sensitivity in more targeted populations.

Organ involvement in adults with BPDCN is associated with sun exposure history, TET2 and RAS mutations, and survival.

ABSTRACT: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) can involve skin, bone marrow (BM), central nervous system (CNS), and non-CNS extramedullary sites. Preclinical models demonstrated clonal advantage of TET2-mutated plasmacytoid dendritic cells exposed to UV radiation. However, whether sun exposure, disease characteristics, and patient survival are clinically related is unclear. We classified organ involvement in 66 patients at diagnosis as skin only (n = 19), systemic plus skin (n = 33), or systemic only (n = 14). BM involvement was absent, microscopic (<5%), or overt (≥5%). UV exposure was based on clinical and demographic data. Patients with skin only BPDCN were more frequently aged ≥75 years (47% vs 19%; P = .032) and had lower rates of complex karyotype (0 vs 32%, P = .022) and mutated NRAS (0 vs 29%, P = .044). Conversely, those without skin involvement had lower UV exposure (23% vs 59%, P = .03) and fewer TET2 mutations (33% vs 72%, P = .051). The median overall survival (OS) was 23.5, 20.4, and 17.5 months for skin only, systemic plus skin, and systemic only, respectively. Patients with no BM involvement had better OS vs overt involvement (median OS, 27.3 vs 15.0 months; P = .033) and comparable with microscopic involvement (27.3 vs 23.5 months; P = .6). Overt BM involvement remained significant for OS when adjusted for baseline characteristics and treatment received. In summary, BPDCN clinical characteristics are associated with disease genetics and survival, which together may impact prognosis and indicate informative disease subtypes for future research.

Defining D-irAEs: consensus-based disease definitions for the diagnosis of dermatologic adverse events from immune checkpoint inhibitor therapy.

With an increasing number of patients eligible for immune checkpoint inhibitors, the incidence of immune-related adverse events (irAEs) is on the rise. Dermatologic immune-related adverse events (D-irAEs) are the most common and earliest to manifest, often with important downstream consequences for the patient. Current guidelines lack clarity in terms of diagnostic criteria for D-irAEs. The goal of this project is to better define D-irAE for the purposes of identification, diagnosis, and future study of this important group of diseases.The objectives of this project were to develop consensus guidance for an approach to D-irAEs including disease definitions and severity grading. Knowing that consensus among oncologists, dermatologists, and irAE subspecialists would be critical for usability, we formed a Dermatologic irAE Disease Definition Panel. The panel was composed of 34 experts, including oncologists, dermatologists, a rheumatologist, and an allergist/immunologist from 22 institutions across the USA and internationally. A modified Delphi consensus process was used, with two rounds of anonymous ratings by panelists and two virtual meetings to discuss areas of controversy. Panelists rated content for usability, appropriateness, and accuracy on 9-point scales in electronic surveys and provided free text comments. A working group aggregated survey responses and incorporated them into revised definitions. Consensus was based on numeric ratings using the RAND/UCLA Appropriateness Method with prespecified definitions.Following revisions based on panelist feedback, all items received consensus in the second round of ratings. Consensus definitions were achieved for 10 core D-irAE diagnoses: ICI-vitiligo, ICI-lichen planus, ICI-psoriasis, ICI-exanthem, ICI-bullous pemphigoid, ICI-Grover's, ICI-eczematous, ICI-eruptive atypical squamous proliferation, ICI-pruritus without rash, and ICI-erosive mucocutaneous. A standard evaluation for D-irAE was also found to reach consensus, with disease-specific exceptions detailed when necessary. Each disorder's description includes further details on disease subtypes, symptoms, supportive exam findings, and three levels of diagnostic certainty (definite, probable, and possible).These consensus-driven disease definitions standardize D-irAE classification in a useable framework for multiple disciplines and will be the foundation for future work. Given consensus on their accuracy and usability from a representative panel group, we anticipate that they can be used broadly across clinical and research settings.

Clinical outcomes and safety of immune checkpoint inhibitors in patients with solid tumors and paraneoplastic syndromes.

BACKGROUND: Patients with paraneoplastic syndromes (PNS) are excluded from clinical trials involving immune checkpoint inhibitors (ICIs) due to safety concerns. Moreover, real-world data on efficacy and safety is scarce. METHODS: In this retrospective study, data were collected on patients with PNS and solid tumors receiving ICI between 2015 and 2022 at nine institutions. Patients were classified into: Cohort 1 (pre-existing PNS before ICI initiation), cohort 2 (PNS during ICI treatment), and cohort 3 (PNS after ICI discontinuation). Patients with metastatic non-small cell lung cancer (NSCLC) (mNSCLC) from cohort 1 were matched to patients who were PNS-free at each institution up to a 1:3 ratio for age, sex, type of ICI, use of concurrent chemotherapy, and number of lines of systemic therapy prior to ICI initiation. Kaplan-Meier method was used to assess overall survival (OS) and time-to-next treatment (TTNT). RESULTS: Among 109 patients with PNS treated with ICIs, median age at ICI initiation was 67 years (IQR: 58-74). The most represented cancer type was NSCLC (n=39, 36%). In cohort 1 (n=55), PNS exacerbations occurred in 16 (29%) patients with median time to exacerbation after ICI of 1.1 months (IQR: 0.7-3.3). Exacerbation or de novo PNS prompted temporary/permanent interruption of ICIs in 14 (13%) patients. For cohort 2 (n=16), median time between ICI initiation and de novo PNS was 1.2 months (IQR: 0.4-3.5). Treatment-related adverse events (trAEs) occurred in 43 (39%) patients. Grade ≥3 trAEs occurred in 18 (17%) patients. PNS-directed immunosuppressive therapy was required in 55 (50%) patients. We matched 18 patients with mNSCLC and PNS (cohort 1) to 40 without PNS, treated with ICIs. There was no significant difference in OS or TTNT between patients with mNSCLC with and without PNS, although a trend was seen towards worse outcomes in patients with PNS. TrAEs occurred in 6/18 (33%) and 14/40 (35%), respectively. Grade ≥3 trAEs occurred in 4 (22%) patients with PNS and 7 (18%) patients without PNS. CONCLUSIONS: Exacerbations of pre-existing PNS occurred in 29% of patients treated with ICIs and both exacerbations and de novo PNS occur early in the ICI course. TrAE from ICIs were similar between patients with and without PNS. Our data suggest that pre-existing PNS should not preclude consideration of ICI therapy although patients may not derive the same clinical benefit compared with patients without PNS.

Cancer type and histology influence cutaneous immunotherapy toxicities: a multi-institutional cohort study.

BACKGROUND: Cutaneous immune-related adverse events (cirAEs) are the most common toxicities to occur in the setting of immune checkpoint inhibitor (ICI) therapy. Identifying patients who are at increased risk of developing cirAEs may improve quality of life and outcomes. OBJECTIVES: To investigate the influence of cancer type and histology on the development of cirAEs in the setting of ICI therapy and survival outcomes. METHODS: This retrospective cohort study included patients recruited between 1 December 2011 and 30 October 2020. They received ICI from 2011 to 2020 with follow-up of outcomes through October 2021. We identified 3668 recipients of ICI therapy who were seen at Massachusetts General Brigham and Dana-Farber. Of these, 669 developed cirAEs. Records that were incomplete or categories of insufficient sample size were excluded from the study cohort. Multivariate Cox proportional hazards models were used to investigate the impact of cancer organ system and histology on cirAE development, after adjusting for demographics, Charlson Comorbidity Index, ICI type, cancer stage at ICI initiation, and year of ICI initiation. Time-varying Cox proportional hazards modelling was used to examine the impact of cirAE development on mortality. RESULTS: Compared with other nonepithelial cancers (neuroendocrine, leukaemia, lymphoma, myeloma, sarcoma and central nervous system malignancies), cutaneous squamous cell carcinoma [cSCC; hazard ratio (HR) 3.57, P < 0.001], melanoma (HR 2.09, P < 0.001), head and neck adenocarcinoma (HR 2.13, P = 0.009), genitourinary transitional cell carcinoma (HR 2.15, P < 0.001) and genitourinary adenocarcinoma (HR 1.53, P = 0.037) were at significantly higher risk of cirAEs in multivariate analyses. The increased risk of cirAEs translated into an adjusted survival benefit for melanoma (HR 0.37, P < 0.001) and cSCC (HR 0.51, P = 0.011). CONCLUSIONS: The highest rate of cirAEs and subsequent survival benefits were observed in cutaneous malignancies treated with ICI therapies. This study improves our understanding of patients who are at highest risk of developing cirAEs and would, therefore, benefit from appropriate counselling and closer monitoring by their oncologists and dermatologists throughout their ICI therapy. Limitations include its retrospective nature and cohort from one geography.

Cutaneous immune-related adverse events (cirAEs) are the most common complications to occur for oncology patients treated with immune checkpoint inhibitors (ICIs). cirAEs can lead to increased use of healthcare resources and significant morbidity. Identifying patients who are at increased risk of developing cirAEs may improve quality of life and outcomes. In this study, we aimed to investigate the influence of cancer organ system and histology on the development of cirAEs and survival outcomes. To do this, we included a cohort of patients retrospectively between 1 December 2011 and 30 October 2020. We identified 3668 ICI recipients who were seen at Massachusetts General Brigham and Dana-Farber in Boston, Massachusetts. Of these, 669 people developed cirAEs. Multivariate Cox proportional hazards models were used to investigate the impact of cancer organ system and histology on cirAE development, after adjusting for demographics, Charlson Comorbidity Index, ICI type, cancer stage at ICI start, and year of ICI initiation. Time-varying Cox proportional hazards modelling was used to examine the impact of cirAE development on mortality. We found that, compared with other nonepithelial cancers, patients with cutaneous squamous cell carcinoma (cSCC) and melanoma were at significantly higher risk of cirAEs. The increased risk of cirAEs translated into an adjusted survival benefit for melanoma and cSCC. This study improves our understanding of patients who are at highest risk of developing cirAEs ­ those with melanoma and cSCC. Therefore, many patients could benefit from appropriate counselling and close monitoring by their oncologists and dermatologists throughout ICI therapy.

Multi-center retrospective review of vitiligo-like lesions in breast cancer patients treated with cyclin-dependent kinase 4 and 6 inhibitors.

PURPOSE: Cutaneous adverse effects from cyclin-dependent 4 and 6 kinase inhibitors (CDK4/6i) used in metastatic breast cancer are prevalent and well described. Vitiligo-like lesions have been reported and are rare. They can negatively impact patients' quality of life and may be associated with survival benefits. We describe the clinical characteristics of vitiligo-like lesions in an international cohort of patients treated with CDK4/6i to help improve recognition and management. METHODS: Retrospective review of patients diagnosed with vitiligo-like lesions from CDK4/6i from five academic institutions in the USA and Europe was performed. Ten patients were included in the study. RESULTS: Median age of our patients was 55 (range 37-86). Median progression-free survival was 24 months in 5 patients. The median time to rash was 10 months. Sun-exposed areas such as the arms and face were the most affected areas. Multiple skin-directed therapies such as topicals, laser, and phototherapy were trialed with minor success. Mild repigmentation was seen in one patient treated with ruxolitinib cream. CDK4/6 treatment was discontinued due to the vitiligo-like lesions in one patient. CONCLUSION: Clinical characteristics are similar to previously reported findings in case reports and series. We add topical ruxolitinib as a potential treatment option for these patients and include data regarding progression-free survival that should continue to be collected. No definitive conclusions can be made regarding survival benefits from our cohort. Clinicians should refer these patients to dermatologists to aid with management.

Phototherapy Restores Deficient Type I IFN Production and Enhances Antitumor Responses in Mycosis Fungoides.

Transcriptional profiling demonstrated markedly reduced type I IFN gene expression in untreated mycosis fungoides (MF) skin lesions compared with that in healthy skin. Type I IFN expression in MF correlated with antigen-presenting cell-associated IRF5 before psoralen plus UVA therapy and epithelial ULBP2 after therapy, suggesting an enhancement of epithelial type I IFN. Immunostains confirmed reduced baseline type I IFN production in MF and increased levels after psoralen plus UVA treatment in responding patients. Effective tumor clearance was associated with increased type I IFN expression, enhanced recruitment of CD8+ T cells into skin lesions, and expression of genes associated with antigen-specific T-cell activation. IFNk, a keratinocyte-derived inducer of type I IFNs, was increased by psoralen plus UVA therapy and expression correlated with upregulation of other type I IFNs. In vitro, deletion of keratinocyte IFNk decreased baseline and UVA-induced expression of type I IFN and IFN response genes. In summary, we find a baseline deficit in type I IFN production in MF that is restored by psoralen plus UVA therapy and correlates with enhanced antitumor responses. This may explain why MF generally develops in sun-protected skin and suggests that drugs that increase epithelial type I IFNs, including topical MEK and EGFR inhibitors, may be effective therapies for MF.

Immunomodulator use, risk factors and management of flares, and mortality for patients with pre-existing rheumatoid arthritis after immune checkpoint inhibitors for cancer.

OBJECTIVE: To investigate immunomodulator use, risk factors and management for rheumatoid arthritis (RA) flares, and mortality for patients with pre-existing RA initiating immune checkpoint inhibitors (ICI) for cancer. METHODS: We performed a retrospective cohort study of all patients with RA meeting 2010 ACR/EULAR criteria that initiated ICI for cancer at Mass General Brigham or Dana-Farber Cancer Institute in Boston, MA (2011-2022). We described immunomodulator use and changes at baseline of ICI initiation. We identified RA flares after baseline, categorized the severity, and described the management. Baseline factors were examined for RA flare risk using Fine and Gray competing risk models. We performed a landmark analysis to limit the potential for immortal time bias, where the analysis started 3 months after ICI initiation. Among those who survived at least 3 months, we examined whether RA flare within 3 months after ICI initiation was associated with mortality using Cox regression. RESULTS: Among 11,901 patients who initiated ICI for cancer treatment, we analyzed 100 pre-existing RA patients (mean age 70.3 years, 63 % female, 89 % on PD-1 monotherapy, 50 % lung cancer). At ICI initiation, 71 % were seropositive, 82 % had remission/low RA disease activity, 24 % were on glucocorticoids, 35 % were on conventional synthetic disease-modifying antirheumatic drugs (DMARDs), and 10 % were on biologic or targeted synthetic DMARDs. None discontinued glucocorticoids and 3/35 (9 %) discontinued DMARDs in anticipation of starting ICI. RA flares occurred in 46 % (incidence rate 1.84 per 1000 person-months, 95 % CI 1.30, 2.37); 31/100 flared within 3 months of baseline. RA flares were grade 1 in 16/46 (35 %), grade 2 in 25/46 (54 %), and grade 3 in 5/46 (11 %); 2/46 (4 %) required hospitalization for RA flare. Concomitant immune-related adverse events occurred in 15/46 (33 %) that flared. A total of 72/100 died during follow-up; 21 died within 3 months of baseline. Seropositivity had an age-adjusted sdHR of 1.95 (95 % CI 1.02, 3.71) for RA flare compared to seronegativity, accounting for competing risk of death. Otherwise, no baseline factors were associated with RA flare, including cancer type, disease activity, RA duration, and deformities. 9/46 (20 %) patients had their ICI discontinued/paused due to RA flares. In the landmark analysis among 79 patients who survived at least 3 months, RA flare in the first 3 months was not associated with lower mortality (adjusted HR 1.24, 95 % CI 0.71, 2.16) compared to no RA flare. CONCLUSION: Among patients with pre-existing RA, few changed immunomodulator medications in anticipation of starting ICI, but RA flares occurred in nearly half. RA flares were mostly mild and treated with typical therapies. Seropositivity was associated with RA flare risk. A minority had severe RA flares requiring disruption of ICI, and RA flares were not associated with mortality.

Mortality and immune-related adverse events after immune checkpoint inhibitor initiation for cancer among patients with pre-existing rheumatoid arthritis: a retrospective, comparative, cohort study.

Background: Patients with pre-existing rheumatoid arthritis initiating immune checkpoint inhibitors for cancer might be at risk of increased mortality, rheumatoid arthritis flares, and other immune-related adverse events (AEs). We aimed to determine whether pre-existing rheumatoid arthritis was associated with higher mortality and immune-related AE risk in patients treated with immune checkpoint inhibitors. Methods: This retrospective, comparative cohort study was conducted at the Mass General Brigham Integrated Health Care System and the Dana-Farber Cancer Institute in Boston (MA, USA). We searched data repositories to identify all individuals who initiated immune checkpoint inhibitors from April 1, 2011, to April 21, 2021. Patients with pre-existing rheumatoid arthritis had to meet the 2010 American College of Rheumatology-European Alliance of Associations for Rheumatology (ACR-EULAR) criteria. For each pre-existing rheumatoid arthritis case, we matched up to three non-rheumatoid arthritis comparators at the index date of immune checkpoint inhibitor initiation by sex (recorded as male or female), calendar year, immune checkpoint inhibitor target, and cancer type and stage. The coprimary outcomes were time from index date to death and time to the first immune-related AE, measured using an adjusted Cox proportional hazards model. Deaths were identified by medical record and obituary review. Rheumatoid arthritis flares and immune-related AE presence, type, and severity were determined by medical record review. Findings: We identified 11 901 patients who initiated immune checkpoint inhibitors for cancer treatment between April 1, 2011, and April 21, 2021; of those, 101 met the 2010 ACR-EULAR criteria for rheumatoid arthritis. We successfully matched 87 patients with pre-existing rheumatoid arthritis to 203 non-rheumatoid arthritis comparators. The median age was 71·2 years (IQR 63·2-77·1). 178 (61%) of 290 participants were female, 112 (39%) were male and 268 (92%) participants were White. PD-1 was the most common immune checkpoint inhibitor target (80 [92%] of 87 patients with rheumatoid arthritis vs 188 [93%] of 203 comparators). Lung cancer was the most common cancer type (43 [49%] vs 114 [56%]), followed by melanoma (21 [24%] vs 50 [25%]). 60 (69%) patients with rheumatoid arthritis versus 127 (63%) comparators died (adjusted hazard ratio [HR] of 1·16 [95% CI 0·86-1·57]; p=0·34). 53 (61%) patients with rheumatoid arthritis versus 99 (49%) comparators had any all-grade immune-related AE (adjusted HR 1·72 [95% CI 1·20-2·47]; p=0·0032). There were two (1%) grade 5 immune-related AEs (deaths) due to myocarditis, both in the comparator group. Rheumatoid arthritis flares occurred in 42 (48%) patients with rheumatoid arthritis, and inflammatory arthritis occurred in 14 (7%) comparators (p<0·0001). Those with rheumatoid arthritis were less likely to have rash or dermatitis (five [6%] vs 28 [14%]; p=0·048), endocrinopathy (two [2%] vs 22 [11%]; p=0·0078), colitis or enteritis (six [7%] vs 28 [14%] comparators; p=0·094), and hepatitis (three [3%] vs 19 [9%]; p=0·043). Interpretation: Patients with pre-existing rheumatoid arthritis initiating immune checkpoint inhibitors had similar risk of mortality and severe immune-related AEs as matched comparators. Although patients with pre-existing rheumatoid arthritis were more likely to have immune-related AEs, this finding was mostly due to mild rheumatoid arthritis flares. These results suggest that this patient population can safely receive immune checkpoint inhibitors for cancer treatment. Funding: None.

Diffuse Cutaneous Aphthosis After Combined Targeted Cancer Therapies and Responsive to Pentoxifylline.

This case series describes 3 patients who developed cutaneous aphthosis while taking an epidermal growth factor receptor inhibitor in combination with an MEK inhibitor.