Grynberg, Shirly

Abstract Background There is limited data on immune checkpoint inhibitor (ICI) use in patients with non-small cell lung cancer (NSCLC) and known pericardial effusions. Methods This international multi-center observational retrospective study included patients with advanced NSCLC with or without pericardial effusions receiving ICIs. Immune-related adverse events (irAEs) were graded per CTCAE v5.0. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Cox proportional hazards multivariable models assessed the association between survival outcomes and clinicopathologic variables, and an inverse probability of treatment weighting (IPTW) model compared outcomes between the two groups. Results A total of 1248 patients with advanced NSCLC treated with ICIs across 13 institutions were included. Of these, 85 patients (6.8%) had pre-existing pericardial effusions. Compared to controls, patients with pericardial effusions were younger (median age 63 vs 67 years, P = .007), diagnosed more frequently with PD-L1 positive tumors (96% vs 76%, P < .001), and had a higher median number of baseline metastatic sites (3 vs 1, P < .001). IrAEs were similar between both groups (42% vs 38%), and no cardiac irAEs occurred in patients with pericardial effusions. PFS (median 5.6 vs 4.6 months, P = .3) and OS (median 10.2 vs 14.7 months, P = .50) were not statistically different between patients with pericardial effusions and the controls, respectively. In both multivariable and IPTW models, pericardial effusions were not associated with PFS or OS. Conclusions Among patients with NSCLC and pre-existing pericardial effusions, ICIs demonstrate meaningful clinical benefit similar to those without effusions, with no new cardiac or severe toxicities.

9567 Background: Resected stage IIB/C and microscopic stage IIIA/B/C/D melanoma presents a significant risk of recurrence risk of 37 to 62% at 5 years (yrs). While 1 year of adjuvant PD1 therapy reduces this risk by approximately half, the individual patient’s baseline risk without treatment and their specific benefit from adjuvant PD1 remain unknown. We aimed to generate two separate predictive models for recurrence – one for untreated and one for treated pts - to calculate the individualised benefit of adjuvant PD1. Methods: Pts with resected stage IIB/C or microscopic stage IIIA/B/C/D melanoma, either treated with adjuvant PD1 or untreated at 13 major melanoma centres, and with at least 2 years of follow-up from surgery were included. We analysed pts demographics, disease characteristics, blood parameters, pathological and imaging data at baseline, and clinical outcomes. Propensity scores were estimated using logistic regression with covariates associated with treatment in univariate screening (p<0.05). Separate penalised multivariable logistic regression models were built to predict recurrence for treated and untreated pts. A tool based on these models was created to calculate the individual patient benefit from adjuvant PD1. Results: A total of 3560 pts was included, divided into untreated (discovery n=2384 and validation n=597) and treated (discovery n=404 and validation n=175) cohorts. The model for untreated pts included age, gender, primary site, histological subtype, Breslow thickness, ulceration, mitosis, number and site of regional lymph nodes (LN), mutation status and LDH (AUC 0.70 in discovery, 0.69 in validation). The model for treated pts included age, gender, Breslow thickness, site of regional LN, and mutation status (AUC 0.69 in discovery, 0.61 in validation). ADAPT-M (ADjuvant Anti-PD-1 Tool for Melanoma) calculates the individualized benefit of adjuvant PD1. For example, patient A, a woman ≤45 years old with a primary head & neck melanoma (superficial spreading, thickness >1-2 mm, no ulceration, 1 mitosis/mm 2 ), 2 clinically occult LN metastases in the neck, NRAS mutant, and normal LDH, has a 12-month recurrence risk of 21.9% untreated vs 2.3% treated (benefit 19.6%), and a 24-month risk of 41.1% untreated vs 6.4% treated (benefit 34.7%). While, patient B, a man ≤45 years old with a primary melanoma in the lower limb (nodular, thickness >1-2 mm, no ulceration, 1 mitosis/mm 2 ), 2 clinically occult LN metastases in the groin, BRAF V600 mutant, and normal LDH, has a 12-month recurrence risk of 14.2% untreated vs 11.8% treated (benefit 2.5%), and a 24-month risk of 28.0% untreated vs 30.1% treated (no benefit). Conclusions: ADAPT-M, a clinical tool that estimate individualized recurrence risks with and without adjuvant anti-PD1 therapy, quantifies the absolute benefit of treatment for pts with high-risk resected melanoma, facilitating personalized adjuvant therapy decisions.

9535 Background: MUM carries a poor prognosis with few effective treatments, especially for HLA-A*02:01-negative pts. While a subset of MUM pts responds to immune checkpoint inhibitors, the comparative efficacy of IPI+PD1 versus PD1 monotherapy is unclear. This study compares objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety between these regimens in MUM. Methods: MUM pts treated with PD1 or IPI+PD1 at 15 major melanoma centres (from Australia, Europe, United States and Israel) were included. Demographics, patient and disease characteristics, and clinical outcomes were examined. Univariate and multivariate (MVA) analyses were performed to identify clinical predictors of response and survival. Results: Of 412 MUM pts treated, 150 (36%) had PD1 and 262 (64%) received PD1+IPI. Compared to the PD1 group, PD1+IPI-treated pts were younger (64 vs. 70 years; p<0.001), had higher rate of elevated LDH (44% vs. 31%; p=0.037), and more frequently had prior treatment with tebentafusp (6.5% vs. 1.3%; p=0.031). Median follow-up from commencement of PD1+/-IPI was 4.9 years (95% CI 4.7 – 6.1). ORR was higher in IPI+PD1 group (18%) vs. PD1 (9%) (p=0.008), particularly in males (p=0.009), patients with liver metastases (p=0.018) and with lung metastases (p=0.011), with elevated LDH (p=0.047) and with no prior treatment with tebentafusp (p=0.007). PFS and OS at 1 and 2 years were numerically higher with IPI+PD1 (1- and 2-year PFS: 23% and 15%; 1- and 2-year OS: 63% and 39%) vs. PD1 (1- and 2-year PFS: 17% and 11%; 1- and 2-year OS: 54% and 36%), but these differences were not statistically significant (p>0.05). On MVA, adjusting for predefined variables (age, gender, ECOG PS, LDH, presence/absence of liver/lung metastases, prior treatment with tebentafusp), IPI+PD1 was associated with higher ORR (OR 2.71, 1.30 – 6.05; p=0.01) but not with PFS or OS compared to PD1. Presence of liver metastases (ORR [OR 0.28; 95% CI 0.13 - 0.64], PFS [HR 1.61; 95% CI 1.11 - 2.34], OS [HR 2.02; 95% CI 1.32 - 3.10]), ECOG PS≥2 (PFS [HR 1.82; 95% CI 1.07 - 3.10], OS [HR 2.24; 95% CI 1.25-4.01]), elevated LDH (PFS [HR 1.66; 95% CI 1.30 - 2.11], OS [HR 2.39; 95% CI 1.84-3.10]) and prior tebentafusp treatment (OS [HR 2.36; 95% CI 1.21-4.59]) were also independent predictors of response and/or survival. A higher percentage of pts experienced grade ≥3 immune-related adverse events (irAEs) in the IPI+PD1 group compared to the PD1 group (34% vs 13%, p<0.0001). Most pts ceased treatment due to progression (234, 57%), and more pts stopped due to toxicity in the IPI+PD1 vs. PD1 group (25% vs. 9%, p<0.0001). Conclusions: In pts with MUM, IPI+PD1 demonstrated a higher ORR but did not improve survival compared with PD1 alone. IPI+PD1 was more toxic, leading to early treatment discontinuation in one-quarter of pts. These findings may help guide treatment selection in MUM.

Background Data on the safety profiles and clinical outcomes of patients with solid tumors and cardiac metastasis treated with immune checkpoint inhibitors (ICIs) are limited. Methods This is an international multicenter retrospective study of patients with cancer and cardiac metastasis at baseline. Patients who had received ≥1 dose of ICI were included. Treatment-related adverse events (trAEs) were graded per Common Terminology Criteria for Adverse Event V.5.0. Objective response rates (ORR) were evaluated by Response Evaluation Criteria in Solid Tumors V.1.1 when available. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Results Among 110 pts, median age at ICI initiation was 65 (IQR: 59–75). Median follow-up time since ICI initiation was 36 (95% CI: 26 to 51) months. Melanoma (38%, n=42) and non-small cell lung cancer (24%, n=26) were the most common. 68 (62%) patients received ICIs as first-line, and 29 (26%) patients were treated with combination anti-programmed death-1 and anti-cytotoxic T-lymphocyte antigen 4. The most common location of cardiac metastasis was in the atria (37%, n=41) and ventricles (35%, n=39). 15 patients (13.6%) had bilateral cardiac/pericardial metastasis, 44 (40%) had left-sided, and 43 (39.8%) had right-sided. At ICI initiation, 21% (n=23) had a cardiac thrombus. Cardiology referrals and cardiac MRIs at the time of cancer diagnosis were completed on 58 (53%) and 52 (47%) patients, respectively. Cardiac events occurred in 40 (36%) patients, including arrhythmias (n=14, 13%), arterial/venous emboli (n=4, 3.6%), and cardiac tamponade (n=3, 2.7%). 53 (47%) patients developed trAEs; most common were colitis/diarrhea (n=16, 15%), dermatitis (n=13, 12%), and hepatitis (n=9, 8.2%). ICI-related major cardiac trAEs occurred in 2 (1.8%) patients. 22 patients (20%) developed grade ≥3 trAE. Patients with multiple cardiac metastases had significantly lower responses to ICI-based regimens compared with patients with single cardiac metastasis (11% vs 63%, p=0.02). For melanoma, ORR, median PFS, and median OS were 38%, 9.0 months, and 28.9 months, respectively. 83% of patients with melanoma had concordant responses in overall disease burden and cardiac disease. 91 patients discontinued ICIs, and the main reason was progression or death in 55 (49%) patients. Conclusions Among patients with pre-existing cardiac metastasis, ICIs demonstrated meaningful clinical efficacy with no increase in safety signals. Most patients had concordant responses in the overall disease burden and cardiac mass. Multidisciplinary teams are crucial for the appropriate management of patients with cardiac metastasis.

2653 Background: Given underlying differences in the tumor microenvironment across metastatic sites, ICIs demonstrate variable efficacy depending on sites of met involvement. Data on the safety and outcomes of pts on ICIs with cardiac mets are limited. Methods: In an international multi-center retrospective study, pts with solid tumors and baseline mets to the heart who had received ≥1 cycle of ICIs were included. Immune-related adverse events (irAEs) were graded per CTCAE v5.0. Objective response rates (ORR) were evaluated by RECIST1.1 when available. Median overall survival (mOS) and median progression-free survival (mPFS) were calculated from time of ICI initiation using the Kaplan-Meier method. Results: 110 pts across 20 institutions were identified with a median follow-up of 36 (95% CI 26-51) months. Melanoma (38%, n=42) and non-small cell lung cancer (NSCLC, 24%, n=26) were the most common cancers. Median age at ICI initiation was 65 (IQR: 59-75) years and 29% (n=26) received combination ICI therapy with anti-PD1 and anti-CTLA4. Overall, 62% (n=68) received ICIs as 1st line. The mets were mostly located in the atria (37%, n=41) and ventricles (35%, n=39). At ICI initiation, 21% (n=23) had a cardiac thrombus. Of 78 pts with available echocardiographic data at time of ICI initiation, the mean ejection fraction was 61+/- 7.1%. Cardiology referrals and cardiac MRIs since time of cancer diagnosis were completed on 53% (n=58) and 47% (n=52) of pts, respectively. Overall, 36.4% (n=40) of pts had cardiac complications from the mets, including arrhythmias (13%, n=14), arterial/venous emboli (3.6%, n=4), and cardiac tamponade (2.7%, n=3). For NSCLC, ORR, mPFS (95% CI), and mOS (95% CI) were 23%, 4.4 months (3.0-7.5), and 9.9 months (5.9-14.7), respectively. For melanoma, ORR, mPFS, and mOS were 35.7%, 9.1 months (5.2-20), and 29 months (14-58), respectively. Cardiac met ORRs for NSCLC and melanoma were 27% and 43%, respectively. 74% (N=71/96) of pts with evaluable response data had concordant response in the burden of overall disease and cardiac disease. IrAEs are shown. Conclusions: Although cardiac mets are frequently associated with cardiac complications, ICIs demonstrate meaningful efficacy with no overtly concerning safety signals. Close to three-quarter of pts have concordant response in the overall disease and cardiac disease burden. Multi-disciplinary approach involving cardiologists and oncologists need to be implemented to appropriately manage pts with cardiac mets. [Table: see text]