Drakaki, Alexandra

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.

LBA4500 Background: Cisplatin-based chemo is a standard 1L treatment (tx) for mUC and the only tx that prolongs OS; however, age or comorbidities render many pts ineligible, and 30-50% receive no tx. Atezo (MPDL3280A) is active and well tolerated in platinum-treated mUC, justifying testing atezo as 1L tx in cisplatin-ineligible pts. Methods: Pts were chemo naive in the metastatic setting and cisplatin ineligible (renal [GFR > 30 but < 60 mL/min]/hearing impairment, ≥ G2 peripheral neuropathy [PN] or ≥ ECOG PS2). Atezo 1200 mg was given IV q3w until PD (RECIST v1.1). Centrally assessed PD-L1 on tumor infiltrating immune cells (IC; SP142 IHC assay) was scored IC2/3, 1 or 0. The primary efficacy endpoint was confirmed ORR assessed per RECIST v1.1 (central independent review facility) using a data cutoff of Sep 14, 2015. Results: 119 efficacy/safety-evaluable pts of any PD-L1 IC had a median age of 73 y: 21% ≥ 80 y. 18% had prior systemic tx (21% [neo]adjuvant); 10% had radiotherapy. 66% had visceral mets. 71% had CrCl < 60 mL/min; 13% had hearing loss ≥ 25 dB; 6% had prior PN ≥ G2; 20% had ECOG PS2. ORR was 19% (95% CI 13-28; 5% CR), and responses occurred in all IC subgroups (Table; includes DCR/PFS/OS) and in pts with poor prognostic factors. 22/23 responses were ongoing with mDOR not reached. Median follow-up was 8.5 mo (range 0.2-14.3); median tx duration was 15 wk. Atezo was generally well tolerated. Tx-related all-G and G3-4 AEs were seen in 64% and 12% of pts, respectively. Related all-G AEs ≥ 10% included fatigue, pruritus, diarrhea. 1 G5 related AE occurred (sepsis). 3% had a G3-4 immune-mediated AE. Conclusions: Atezo has clinically meaningful activity in 1L cisplatin-ineligible mUC pts, and preliminary OS is encouraging. The durable nature of response and favorable AE profile makes this an attractive alternative to chemo. NCT02108652. Clinical trial information: NCT02108652. [Table: see text]