Leventakos, Konstantinos

12051 Background: The combination of ipilimumab and nivolumab (Ipi-Nivo) is a standard of care regimen in many malignancies. However, immune-related adverse events (irAE) are common and are of great concern, especially when treating the elderly population. This subgroup of patients may be at greater risk for serious irAEs and be less able to tolerate the potential treatment side effects. We sought to retrospectively evaluate our experience treating elderly patients ≥ 80 years with Ipi-Nivo to characterize adverse events. Methods: A retrospective chart review of the electronic medical records of all patients treated with Ipi-Nivo at the Mayo Clinic Health System was performed. Patients with any solid tumor who received their first dose of Ipi-Nivo at the age of ≥ 80 were included. Records were analyzed for baseline characteristics, cancer type, toxicity, and response to therapy. Differences between continuous and categorical variables were assessed using the students’ t-test and the chi-squared test, respectively. Overall survival (OS) was estimated using the Kaplan-Meier method. Cox proportional hazard models assessed the relative contribution of factors to survival after treatment. P values < 0.05 were considered statistically significant. All analyses were performed using SAS V.9.4. Results: Forty-six patients met inclusion criteria, 13 females and 33 males. Median age of first dose was 83 (Range: 80 - 94). Sixty-seven percent had an ECOG performance status (PS) 0-1 and 33% had an ECOG PS 2-3. Thirteen (28.3%) patients received 4 cycles of Ipi-Nivo. Cancers included: 18 (40%) melanomas, 10 (21%) mesothelioma, 9 (19.5%) lung cancers, and 9 (19.5%) other types. Thirty-one patients (67%) developed at least one irAE. Of the irAEs, 8 (17.4%) were grade 1, 20 (43.5%) were grade 2, 14 (30.4%) were grade 3, and 3 (6.5%) were grade 4. Systemic steroids were used in 29 (63%) patients. Twenty-six (56.5%) patients were hospitalized for any cause, and 12 (26.1%) were hospitalized due to an irAE. Of the 26 patients hospitalized during treatment, 19 (73%) died within 1 year of discharge; 11 (42%) died within < 1 month of discharge and 3 (12%) died within 1-3 months of discharge. Median OS from the date of first Ipi-Nivo dose was 14.6 months in the ECOG PS 0-1 and 6.5 months in the ECOG PS 2-3. ECOG PS of 0-1 was associated with a significantly decreased risk of mortality (HR [hazard ratio] 0.33, 95 % CI [confidence interval]: 0.15-0.70; p=0.0025) compared to ECOG PS of 2-3. Conclusions: This is the first analysis to evaluate the outcomes of Ipi-Nivo in patients ≥ 80 years. Approximately 60% of the patients required systemic steroids and a quarter were hospitalized with grade 3-4 irAEs. As expected, patients with ECOG PS 2-3 did significantly worse than ECOG PS 0-1. Ipi-Nivo should be used with caution in patients ≥ 80 years.

9093 Background: Pembrolizumab interrupts PD-1/-L1 interaction and is efficacious in many cancers. However, resistance invariably emerges in the majority of patients. Potential mechanisms include activation of compensatory pathways. The inhibition of sonic hedgehog signaling (sHH) was previously shown to induce intra-tumoral (IT) infiltration by CD4+, CD8+ and HLA-DR class II cells. Our preclinical data showed sHH inhibitor enhanced IT penetration by monoclonal antibodies and induced PD-L1 expression. We conducted a phase I study using a novel sequential pulse dosing of sonedegib followed by pembrolizumab in aST with an expansion cohort to determine the maximum tolerated dose (MTD), tolerability and preliminary efficacy. Methods: The dose escalation utilized a 3+3 design to determine the MTD and proceeded to expansion cohort upon determination of the MTD. Patients enrolled to each dose level were observed for dose limiting toxicities (DLTs) during the 1st cycle. The expansion cohort consisted of NSCLC and head/neck squamous cell carcinoma (HNSCC) previously treated by anti-PD1/-L1. The recommended phase 2 dose (RP2D) was determined following the review of the toxicity profile of the combination from all cycles. The study treatment consisted of sonidegib oral daily from day 1 to 8 and pembrolizumab I.V. 200 mg on day 8 on an every 3-week cycle. The sonidegib dose levels explored were 400, 600 and 800 mg. Archival tumor and blood specimens were collected for correlative studies. Adverse events (AEs) were categorized and graded per CTCAE v5.0, and tumor response by RECIST v1.1. Results: The study enrolled a total of 33 patients and 29 received treatment (13 in escalation and 16 in expansion), including patients with NSCLC, HNSCC, skin cancer, gastric cancer and melanoma. The enrollment to the NSCLC cohort is complete and HNSCC continues. No DLT was encountered during dose escalation and the MTD was not reached. The highest planned dose level was selected to proceed to expansion (sonidegib 800mg days 1-8 in combination with pembrolizumab I.V. 200 mg on day 8 on an every 3-week cycle). The expansion cohort proceeded to enroll 15 patients evaluable for AEs (10 NSCLC and 5 HSNCC). Grade 3 and above treatment-related AEs across all patients were hyperglycemia, fatigue, dyspepsia, abdominal pain. The mature efficacy data will be reported at the meeting. Conclusions: The study successfully determined the RP2D of sonidegib when dosed sequentially with pembrolizumab in advanced solid tumors. The AE profile of the combination is similar to that for respective agents given individually. The efficacy data among anti-PD1/-PDL1-treated NSCLC will be reported at the meeting. Clinical trial information: NCT04007744 .

9029 Background: Molecular biomarkers such as EML4-ALK fusion variant 3 (V3) and TP53 mutation are associated with poor prognosis in patients (pts) with anaplastic lymphoma kinase fusion positive ( ALK+) non–small cell lung cancer (NSCLC). We evaluated the effect of EML4-ALK fusion variants and TP53 mutation status on time to treatment discontinuation (TTD) of first-line (1L) treatment with a next-generation ALK tyrosine kinase inhibitor (TKI) in pts with ALK+ NSCLC in the real-world setting. Methods: Pts with advanced/metastatic NSCLC who were ALK+ in circulating tumor DNA by Guardant360 (G360) liquid biopsy test from Jan 1, 2018, to Dec 31, 2021, and received 1L monotherapy with a next-generation ALK TKI (alectinib, brigatinib, ceritinib, lorlatinib) were identified in the Guardant INFORM clinical-genomics database. Median TTD of 1L ALK TKI treatment was determined by Kaplan-Meier (KM) methods. The impact of EML4-ALK fusion variant and TP53 mutation status on TTD was evaluated. Results: Database search identified 495 pts with advanced/metastatic NSCLC who had ALK fusion by G360; of these, 214 pts received 1L treatment with a next-generation ALK TKI; 164 had G360 testing before treatment (alectinib, n=147; brigatinib, n=7; ceritinib, n=2; lorlatinib, n=8). Among these 164 pts, median age was 58.6 y, 53% were female, and 29% had baseline brain metastases. Median follow-up from start of 1L treatment was 14.8 mo. Median TTD was 19.6 mo (95% CI: 13.6–not reached [NR]). TP53 mutations were detected in 66 pts (40%). Median (95% CI) TTD in pts with TP53 mutation vs WT was 17.1 (9.5–28.5) vs 21.9 mo (14.3–NR; log-rank P=0.1712). Of 130 pts with EML4-ALK fusion variant type detected, 63 (48%) had V1, 54 (42%) V3, 8 (6%) V2, 4 (3%) V5, and 1 (1%) V8. In pts with EML4-ALK fusion V1 vs V3, median (95% CI) TTD was 19.0 (13.6–NR) vs 21.8 mo (8.7–NR; HR: 0.73; log-rank P=0.3039), with the KM plot showing numerically longer TTD in pts with V1 vs V3 during the first 18 mo and lines crossing at the tail end. Of 117 pts with both an EML4-ALK fusion variant (V1/V3) and TP53 data, 21 (18%) had both V3 and a TP53 mutation. Pts with co-occurring EML4-ALK V3 and TP53 mutation had the shortest TTD (median TTD 8.7 [3.9–NR; HR: 2.59; P=0.0219]; Table). Conclusions: Among pts with NSCLC and ALK fusion, co-occurrence of EML4-ALK V3 and TP53 mutation is common and associated with poor prognosis and high risk of early discontinuation of 1L treatment with a next-generation ALK TKI, most likely due to disease progression. Additional novel or combination therapies are warranted for this subpopulation. [Table: see text]

9004 Background: Despite advances in first-line (1L) immunotherapy ± CT, most patients (pts) with aNSCLC experience disease progression, necessitating novel strategies. Dato-DXd is an antibody drug conjugate (ADC) composed of a humanized anti-TROP2 IgG1 monoclonal antibody covalently linked to a topoisomerase I inhibitor payload via a plasma-stable tetrapeptide-based cleavable linker. Dato-DXd had encouraging efficacy and manageable safety in heavily pretreated aNSCLC. Dato-DXd + immunotherapy yielded greater preclinical activity than either agent alone. Methods: TROPION-Lung02 (NCT04526691) is a phase 1b, global, dose-escalation and -expansion study evaluating Dato-DXd (4 or 6 mg/kg) + pembro 200 mg ± Pt-CT (cisplatin 75 mg/m2 or carboplatin AUC 5) every 21 days across 6 cohorts. Pts in escalation may have received ≤2 prior lines of therapy for aNSCLC. Pts in expansion were primarily treatment (tx) naive (pts receiving Dato-DXd + pembro may have ≤1 prior Pt-based tx). The primary objective is to assess safety and tolerability, including dose-limiting toxicities (DLTs). Secondary objectives include evaluation of efficacy, pharmacokinetics, and immunogenicity. Results: As of the Oct 31, 2022, data cutoff (DCO), 120 pts were treated. All cohorts met DLT criteria to move to escalation. Median age was 65 years. PD-L1 expression was <1%, 1%-49%, and ≥50% in 40%, 33%, and 26% of pts, respectively. Median tx duration was 4.6 mo, with 55% receiving tx at DCO. The most frequent any-grade (gr) tx-emergent adverse events (TEAEs) were nausea (45%) and stomatitis (45%). Gr ≥3 TEAEs occurred in 61% of pts; most frequent were neutrophil count decreased (8%) and amylase increased (8%). TEAEs that were serious, associated with discontinuation, or associated with death occurred in 31%, 24% (16% associated with Dato-DXd), and 6% of pts, respectively. Dose reductions due to TEAEs associated with Dato-DXd occurred in 17%. Drug-related interstitial lung disease occurred in 12 pts (10%; 9 gr 1/2; 3 gr 3). The objective response rate (ORR) with 1L Dato-DXd + pembro doublet and Dato-DXd + pembro + Pt-CT triplet tx was 60% (95% CI, 36%-81%; 12 [2 unconfirmed]/20) and 55% (95% CI, 39%-70%; 23 [5 unconfirmed]/42), respectively. The ORR for any line of therapy was 38% (95% CI, 25%-54%; 18 [2 unconfirmed]/47) with doublet and 47% (95% CI, 34%-60%; 28 [5 unconfirmed]/60) with triplet tx. In both subsets, the disease control rate was 85% and median duration of response was not reached. Responses were observed in all 3 PD-L1 expression level subgroups. Although immature, median progression-free survival (95% CI) was 10.8 (8.3-15.2) and 7.8 mo (5.5-NE) with doublet and triplet tx, respectively. Conclusions: Dato-DXd + pembro ± Pt-CT demonstrated tolerable safety with notable 1L activity in this first and largest dataset with an ADC + immunotherapy ± Pt-CT in aNSCLC pts. Clinical trial information: NCT04526691 .

3109 Background: WSD0922-Fu is an oral, central nervous system (CNS)-penetrant, small molecule, ATP non-competitive, reversible EGFR inhibitor which potently inhibits EGFR aberrations specific to non-small cell lung cancer (NSCLC) and high-grade astrocytoma (HGA). We report initial results of a first-in-human phase 1 dose-escalation trial (NCT04197934) in patients with EGFR aberrant recurrent HGA and NSCLC. Methods: Adult patients with either recurrent EGFR mutant NSCLC with CNS metastases or recurrent EGFR mutant and/or EGFR amplified HGA were enrolled. WSD0922-Fu was orally administered, and dose escalated in cohorts based on a standard 3+3 design to determine the maximum tolerated dose (MTD). Toxicities were graded per CTCAE v5.0 and preliminary efficacy was based on modified RANO criteria or RECIST 1.1 as appropriate. Results: 25 patients (17 HGA, 8 NSCLC) were enrolled and treated in six cohorts (40 mg once daily to 320 mg twice daily, 28-day cycles). The median age was 57 years (range 39-75 years). 24% were female and 36% were ECOG 0. For patients with HGA, all patients were previously treated with radiation and temozolomide; the median number of prior lines of systemic therapy was 1 (range 1-4). For patients with NSCLC, all patients were previously treated with an EGFR inhibitor (prior osimertinib 88%); the median number of prior lines of systemic therapy was 1.5 (range 1-6). The median duration of exposure to WSD0922-Fu among all patients was 54 days (range 2-258 days). The most common (≥25%) treatment-related adverse events included fatigue (68%), acneiform rash (68%), diarrhea (52%), nausea (48%) and pruritis (28%). The frequency of severe AEs was dose dependent. The most common Grade 3+ AEs (≥10%) included lymphopenia (16%), acneiform rash (12%), headache (12%) and diarrhea (12%). The MTD was defined as 160 mg twice daily. At Cycle 1 Day 15 for patients treated at this dose level, the mean terminal elimination half-life (%CV) in the plasma was 31.6 h (102%) (median 14.5 h; range 6.2-78.7 h). The mean Cmax, Tmax, oral clearance at steady state, and AUC (0-12 h) (%CV) were 4513 ng/mL (50%), 2.0 hr (69%), 6.9 L/hr/m2 (42%), and 28084 h*ng/mL (52%), respectively. Oral clearance at steady state was inversely related with dose, suggesting either inhibition or saturation of clearance processes. Among patients treated at MTD or higher dose levels and with available response data, 100% (5/5) of patients with NSCLC demonstrated clinical benefit (SD + PR) while 60% of patients had partial responses (intracranial and extracranial). Furthermore, prolonged stable disease (9 cycles) was observed in a patient with EGFRvIII mutant GBM. Conclusions: The MTD for WSD0922-Fu monotherapy is 160 mg BID. Preliminary efficacy was observed in patients with osimertinib-resistant NSCLC and EGFRvIII mutant HGA. Enrollment to expansion cohorts is ongoing. Clinical trial information: NCT04197934 .

e13552 Background: Real-world data from Electronic Health Records (EHR) have been widely used for patient identification to build study cohorts for clinical research. Traditionally, diagnosis codes in the EHR, such International Classification of Diseases (ICD), are used to identify the target patients. However, the accuracy of this approach is dependent on the accuracy of ICD coding, with potential errors especially for tumor types that are frequent locations for metastases (which may contribute to mis-coding). In this study, we attempted to develop a Machine Learning (ML) based approach on EHR data to improve the accuracy of identification of patients with lung cancer. Methods: We used survey respondents in the Enhanced, EHR-facilitated Cancer Symptom Control (E2C2, NCT03892967) cluster-randomized trial at Mayo Clinic as our initial pan-cancer cohort. E2C2 includes adults receiving Medical Hematology/Oncology care for a solid or liquid tumor at Mayo Clinic. We collected cancer diagnoses from the individually abstracted Mayo Clinic Cancer Registry to annotate the cancer type for the patients. Lung cancer related ICD-9 (162.X) and ICD-10 (C34.X) codes were used to build a search query on the Mayo’s EHR to find target patients from the E2C2 cohort, and to investigate the ICD-based lung cancer patient identification performance. Diagnosis, radiation oncology treatment (CPT 77261 - 77799), and antineoplastic drug administration data were collected from EHR as variables. Logistic Regression (LR), Support vector machine (SVM), Random Forest (RF), and eXtreme Gradient Boosting (XGB) were selected to build models for lung cancer patient identification. 10-fold cross-validation was implemented to assess the models. Precision, Recall, F1 Score, and area under the curve (AUC) were selected to measure the performance. Results: We collected 13,893 patients with a specific cancer diagnosis, and 1,394 were identified as having lung cancer. The identification performance across different methods is shown. The ICD-based method only had 0.65 precision. It means we collected a lot of false positive cases (other cancer but no lung cancer patient), as we mentioned in the background. SVM gets the best precision results, but its recall and F1 score are not good enough. XGB shows the best F1 Score and AUC, which also means this method achieved the best and most balanced performance. Conclusions: In this study, we found that XGB-based methods achieved the best identification performance for lung cancer. In the future, we will investigate if this is also true for the identification of other cancer types. [Table: see text]

1552 Background: Immune checkpoint inhibitor therapy-related (ICI) pneumonitis poses a significant challenge in patients with cancer. There is a need for predictive modeling to identify those at high risk of developing serious adverse events of ICI pneumonitis. Methods: A newly created database of cancer patients diagnosed with ICI pneumonitis seen at Mayo Clinic from 2014-2022 was utilized for exploratory data analysis. Modeling was used to determine if three clinical outcomes could be predicted, namely risk of death from: pneumonitis prior to starting immunotherapy, pneumonitis at time of diagnosis of ICI pneumonitis, and any cause at time of ICI pneumonitis diagnosis. The data consisted of 170 patients with annotation for 71 clinical features. Data was divided into features available at time of cancer diagnosis and at time of ICI pneumonitis diagnosis. Exploratory modeling was performed using the gradient boosting technique Xgboost (Chen, 2015) and conducted using k-fold balanced cross validation best practices as well as a train/test/validate schema with 70%/20%/10% data proportions, respectively. Model reverse engineering was done with Shapley statistics (Lundberg, 2017) to determine which features had the largest contribution per model. Once identified, only those highly weighted features were used for logistic regression analysis providing more reproducible predictions by decreasing model variance. Results: Risk of death from pneumonitis prior to starting immunotherapy was modeled with an area under the curve of the receiver operator characteristic (AUC-ROC) of 0.79 with the most contributory features including lymphocyte count, oxygen dependence, PFT values, and PD-L1 expression. Logistic regression produced an AUC-ROC of 0.87 (95% CI 0.72-1.0, p < 0.0013). Risk of death from pneumonitis at the time of ICI pneumonitis diagnosis was modeled with an AUC-ROC of 0.85 and the most contributory features were similar to the list described in the previous endpoint. Logistic regression produced an AUC-ROC of 0.89 (95% CI 0.81-0.96, p < 0.0001). Risk of death from any cause at the time of ICI pneumonitis diagnosis until follow up concluded by 12/2022 produced a model with an AUC-ROC of 0.75 with the most contributory features including supplemental oxygen, PFT values, basic laboratory values, and PD-L1 expression, among others. Logistic regression produced an AUC-ROC of 0.85 (95% CI 0.76-0.93, p < 0.0001). Conclusions: We demonstrate that commonly available clinical data can be used to identify patients at high risk of death from ICI pneumonitis. This study identified clinical features that were predictive in each scenario from which further concerted effort could produce a new clinical model to provide clinician decision support when considering immunotherapy. Further studies should be done to further elucidate feature interdependence and generalizability.

Abstract Poorly differentiated extrapulmonary neuroendocrine carcinomas (EP NECs) are aggressive cancers characterized by a high Ki‐67 index, rapid tumor growth and poor survival, and are subdivided into small and large cell carcinoma. For small cell carcinoma of the lung, a pulmonary NEC, the combination of cytotoxic chemotherapy (CTX) and a checkpoint inhibitor (CPI) is considered standard therapy and superior to CTX alone. EP NECs are typically treated with platinum‐based regimens, some clinicians have adopted the addition of a CPI to CTX based on data from trials in patients with small cell carcinoma of the lung. In this retrospective study of EP NECs, we report 38 patients treated with standard first‐line CTX and 19 patients treated with CTX plus CPI. We did not observe any additional benefit of adding CPI to CTX in this cohort.

TPS657 Background: Poorly differentiated neuroendocrine carcinoma (NEC) is an aggressive malignancy comprising both pulmonary and extrapulmonary primary sites. NEC includes both small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), as well as other neuroendocrine carcinomas arising from any primary organ. A substantial portion (~40%) of NEC arises from gastrointestinal primary sites. The optimal systemic therapy beyond first line platinum and etoposide is not established. There is a critical need to improve upon the median survival in the second line, as most patients do not survive more than 6 months. The efficacy of single agent immune checkpoint inhibitors (ICIs) in NEC has been disappointing. One possible explanation for this is that the tumor microenvironment in NEC is non-inflamed. VSV-IFNβ-NIS is a vesicular stomatitis virus (VSV)-based oncolytic virus being tested in multiple early phase clinical trials. Preliminary studies of immune responses in patients receiving VSV-IFNβ-NIS therapy suggest some patients develop T cell responses to viral antigens and known tumor antigens. We hypothesize that VSV-IFNβ-NIS therapy may convert a non-inflamed or immune-excluded phenotype in NEC to a highly inflamed phenotype that sensitizes the tumor to ICIs. Methods: This is a phase 1-2 safety run-in study designed to determine the safety of VSV-IFNβ-NIS in combination with a single agent ICI, pembrolizumab, followed by dose expansion in patients with refractory non-small cell lung cancer (NSCLC) or NEC. The safety run-in portion of this study has been completed, and we are presently testing the recommended phase 2 dose (RP2D) of VSV-IFNβ-NIS in an expansion cohort of patients with SCLC or NEC of any primary site. Patients must have previously progressed on at least one line of systemic therapy. Prior treatment with checkpoint inhibitors is permitted. Patients are treated one time with the RP2D of 1.0x10^11 TCID50 VSV-IFNβ-NIS on day 1, followed by pembrolizumab on day 8 and then pembrolizumab every 21 days until progression, up to 2 years. The primary objective is to estimate the response rate by RECIST 1.1. Secondary objectives include estimation of disease-control rate, duration or response, progression-free survival, overall survival, and safety signals. The NEC expansion cohort will seek to enroll 10 patients. If at least one objective response is observed, and safety is confirmed, the regimen will be considered for future study. Clinical trial information: NCT03647163 .

125 Background: The advent of immunotherapy (IO) has led to significant improvement in outcomes for patients (pts) with advanced non-small cell lung cancer (adv NSCLC). The rate of crossovers and receipt of post-protocol IO in pivotal trials leading to FDA approvals of IO in NSCLC has not been systematically evaluated. Here, we evaluate crossover rates and post protocol therapies for pts with adv NSCLC across multiple first-line (1L) IO monotherapy and chemotherapy/IO (chemo/IO) combination trials. Methods: We utilized the publicly available data from pivotal clinical trials leading to approvals of IO or chemo/IO regimens in 1L treatment of adv NSCLC. We extracted data on outcomes, rate of crossover from control arm to IO, proportion of pts in control arm receiving IO and the start dates of these clinical trials. The primary outcomes were the rates of crossover and the proportion of patients in control arms who received post-control IO. Results: The study included 4 trials with IO monotherapy and 12 trials with chemo/IO combinations in 1L adv NSCLC. The primary endpoints for these trials were PFS (25%), OS (19%), and both PFS and OS (56%). The crossover rate from control arm to experimental arm (with IO) ranged from 0-74% in IO monotherapy trials and 0-49% in chemo/IO trials. Two IO monotherapy trials and five chemo/IO trials did not allow crossover; among them, 3 trials had a PFS/OS co-primary endpoint, while others had OS as primary endpoint. Ten of 16 trials provided explicit information on use of subsequent post-protocol therapies in their publications. Among the two IO monotherapy trials which did not allow crossover, post-protocol IO was administered in only 20-30% of patients. Among the six chemo/IO trials with information on post-protocol therapies, 30%-59% patients on the control arm subsequently received some form of IO on progression. Nine of 12 trials started accrual after 10/2015, when nivolumab was approved in the United States as second-line (2L) therapy for adv NSCLC regardless of tumor PD-L1 expression. Conclusions: Despite the highly significant OS benefit from 2L IO, which was the standard of care (SOC) in the United States, the rates of crossover and post-protocol IO administration was distressingly low in 1L IO monotherapy and chemo/IO trials for 1L adv NSCLC. This low rate of 2L treatment with IO may have been due to limited global availability prior to widespread regulatory approval during the conduct of these trials. There is an increased need for consistency in reporting of crossover treatment and post-protocol treatments to allow adequate assessment of the true 1L benefit with IO. Control arms in pivotal trials require scrutiny to ensure confirmation with SOC to provide access to optimal treatments for patients and prevent magnification of observed benefits in experimental arms. The difficulty lies in the global conduct of large randomized clinical trials with differing regulatory approvals.