This study investigates patient preferences for adjuvant Osimertinib in EGFR-mutated NSCLC without complete OS data. This prospective survey assessed thresholds for DFS benefits and OS justifications. Findings reveal diverse patient preferences and highlight the importance of shared decision-making. Factors like employment, education, and willingness to pay significantly influenced decisions. Background: The ADAURA trial confirmed adjuvant Osimertinib's efficacy in EGFR-mutated Non-small-cell lung cancer (NSCLC), yet the limited mature overall survival (OS) data at approval poses a challenge. This study explores patient preferences in the absence of complete OS information, hypothesizing that disease-free survival (DFS) benefit alone may influence adjuvant Osimertinib pursuit. Methods: At Roswell Park Comprehensive Cancer Center (Jan-Dec 2021), patients assessed for adjuvant therapy received a survey probing OS and DFS preferences. Scenarios were (a) minimum OS justifying Osimertinib, (b) minimum DFS improvement justifying 3-years of adjuvant Osimertinib, (c) minimum 5-year DFS percent change, and (d) minimum OS justifying copay changes. Results were analyzed. Results: Of 524 NSCLC patients, 51 participated. Scenario 1 saw 56% requiring a 12-month OS benefit for Osimertinib justification. In scenario 2, 72% deemed a 12-month DFS benefit sufficient. Scenario 3 revealed 31% opting out despite a 10% OS increase. Scenario 4 showed varied willingness to pay, with 33% unwilling to any shoulder copayment even with a 10-year OS benefit. Conclusion: This study explores patient preferences without complete OS data, revealing diverse thresholds. Factors include employment, education, and willingness to pay. Findings underscore shared decision-making importance. Limitations include sample size, potential biases, and regional focus; larger cohorts are needed for validation.

Abstract Introduction KEYNOTE-355 investigated the addition of pembrolizumab to chemotherapy in advanced TNBC patients (pts) with PD-L1 positive tumors showing median overall survival (OS) of 23.0 months (mos) and median progression-free survival (PFS) of 16.1 mos. Given significant OS benefit with pembrolizumab, it is the current standard of care while the indication of atezolizumab has been withdrawn due to lack of OS benefit in IMPASSION-130. Clinical efficacy and adverse events in pts on this treatment regimen in clinical practice is unknown and understanding the real-world outcomes of this regimen is critical. Methods We conducted a retrospective, single-center observational study among TNBC pts treated with ICI (Pembrolizumab or Atezolizumab) at Roswell Park Comprehensive Cancer Center from January 2017 to May 2023. Demographics and clinicopathological variables were collected including comorbidities, laboratory data, sites of metastases (mets), treatment received, immune related adverse events (irAEs), and clinical outcomes. Adverse events were reported using the Common Terminology Criteria for Adverse Events v5.0. Serial CT scans were reviewed and response rate was determined using RECIST v1.1. Patient demographic, clinical and outcome characteristics were summarized by treatment and survival outcomes were obtained using standard Kaplan-Meier methods. Associations between survival outcomes and baseline or treatment characteristics were evaluated using Cox regression models using Firth’s method. All analyses were conducted in SAS v9.4 at a significance level of 0.05. Results A total of 44 pts with advanced TNBC treated with ICI were included (23 received pembrolizumab and 21 received Atezolizumab). The study population consisted of all female pts with stage IV disease, median age 53.7 years (IQR 30.4-85.2), 68.2 % (30/44) White, 25.0% (11/44) Black, 34.1% (15/44) obese (BMI≥30). 27.3% (12/44) pts developed any grade irAEs which included myocarditis (4.5%), rash (9.1%), hyperthyroidism (6.8%), hypothyroidism (4.5%), adrenal insufficiency (2.3%), diabetes mellitus (2.4%), colitis (2.3%), and transaminitis (2.3%). Distribution of reported irAE was 25% grade 1 (3/12), 66.7% grade 2 (8/12) and 8.3% grade 3 (1/12). 75% pts (33/44) received standard treatment (ICI+ chemotherapy) of which 72.7 % (24/33) received it in the first-line setting. Median OS in pts treated in first line was 16.2 mos (95% CI, 10.7-NR) and median PFS was 4.4 mos (95% CI, 2.7-8.4). Overall response rate (ORR) was 29.1% (7/24) of which 8.3% (2/24) had complete response and 20.8% (5/24) had partial response. ORR was 22.2 % (2/9) in pembrolizumab cohort and 33.3 % (5/15) in atezolizumab cohort. Among pts with first line treatment, obese pts were found to have improved PFS compared to non-obese (11.5 vs 3.8 mos, univariate hazard ratio (HR) 0.46, 95% CI 0.23-0.93, p= 0.031), and this difference was maintained in multivariable analysis even after adjusting for age (adjusted HR (aHR) 0.40, 95% CI 0.17-0.98, p= 0.044). Pts with brain mets had poor extracranial PFS compared to those without brain mets (2.8 vs. 5.2 mos, HR 2.25, 95% CI 1.08-4.68, p= 0.036), however this difference was not observed when further adjusted for age (aHR 2.27, 95% CI= 0.91-5.68, p= 0.08). Conclusion Clinical outcomes in our study were inferior to KEYNOTE-355 where median PFS was 16.1 mos and OS was 23.0 mos and ORR was 52.7% for PD-L1 positive population. This may reflect a more heterogeneous population of pts treated in routine clinical practice who are typically less fit than pts on clinical trials. Our study found improved outcomes among obese patients, similar to data reported in other disease settings. These data warrant multi-center validation with larger number of patients. Citation Format: Archit Patel, Arya Mariam Roy, Malak Alharbi, Kristopher Attwood, Chi-Chen Hong, Song Yao, Thaer Khoury, Amy Early, Tracey O'Connor, Ellis Levine, Shipra Gandhi. Real-world analysis of efficacy, adverse events and predictive biomarkers for advanced triple negative breast cancer (TNBC) treated with immune check point Inhibitors (ICI): A single center experience [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-06-08.

Abstract Introduction: Socioeconomic and racial disparities can limit access to health care. Prior studies suggest that living in a disadvantaged neighborhood results in poorer outcomes in several malignancies. ADI is an index that categorizes areas based on socioeconomic variables. In this observational study, we aimed to investigate the ADI among patients (pts) with breast cancer (BC) seen at Roswell Park Comprehensive Cancer Center in Buffalo, New York, and study its association with clinical outcomes to identify the areas with the highest unmet need for possible intervention strategies. Methods: We reviewed data of 187 pts diagnosed with stages 1-3 and de-novo stage 4 BC between 2014 to 2018. We obtained information on ADI using pts’ home addresses via Neighborhood Atlas tool www.neighborhoodatlas.medicine.wisc.edu. ADI values were categorized into four quartiles Q1(80-100%), Q2(60-79%), Q3(40- 59%), and Q4(0-39%) from highest deprivation/poor social economic status areas to least disadvantaged areas, respectively. Demographic and clinicopathological characteristics including age, race, comorbidities, stage, type of insurance, duration on treatment were compared by ADI. Kruskal-Wallis and Chi-square was used for comparing continuous and categorical variables, respectively. Recurrence free survival (RFS), time to next treatment (TNT), and overall survival (OS) were estimated using Kaplan Meier method. Multivariate Cox regression model was used to analyze outcomes for pts with stage 4 in the most disadvantaged areas (ADI ≥60%) adjusting for relevant covariates. Analyses were performed using SAS v9.4 at a significance level of < 0.05. Results: 98% pts (183/187) were females, 85% (160/187) Whites, 9% (17/187) African Americans, and 3% (6/187) Asians. 62% (116/187) lived in the most disadvantaged areas: 37% (70/187) in Q1, and 24% (46/187) in Q2, while 27% (51/187) lived in Q3, and 11% (n=20/187) in Q4. 80% (150/187) pts were diagnosed with hormone receptor positive BC, 18% (34/187) HER2 positive, and 15% (28/187) triple negative BC. 45% of pts (83/187) had de novo stage 4, the rest were diagnosed with stages 1-3. There was no difference in the distribution of age, race, employment, insurance, comorbidities, substance use, smoking, access to contraception, screening mammogram, or adherence to anti-estrogen and radiation therapy by ADI. There was a significant difference in adherence to chemotherapy/anti HER2 therapy: 92% (36/39) in Q1,100% (24/24) in Q2 vs. 85% (24/28) in Q3 and 67% (6/9) in Q4, p=0.029. Among pts with stages 1-3, there was no difference in RFS (p= 0.700) or OS (p= 0.400) by ADI. Among stage 4 patients, there was an association between TNT and ADI, where patients living where there was a trend towards worse survival with increasingly disadvantaged neighborhoods, p=0.008 (Table 1). Moreover, there was a significant difference in OS by ADI, p=0.03 (Table 2). There was a significant association between ADI and both TNT and OS, even after adjusting to age, race, BC subtypes p= 0.004 and p= 0.034 respectively (Table 3). Conclusion: Our study in the Western New York region showed that BC pts living in disadvantaged areas had worse survival and shorter TNT despite being more adherent to chemotherapy/anti HER2 therapy. Our study validates prior studies showing that ADI is an important factor impacting BC outcomes. These data will help guide our future efforts to maximize resource allocation towards these disadvantaged areas to improve BC outcomes. Table 1 Table 2 Table 3 Citation Format: Malak Alharbi, Arya Mariam Roy, Archit Patel, Kayla Catalfamo, Kristopher Attwood, Angela Omilian, Elizabeth Bouchard, Ellis Levine, Tracey O'Connor, Amy Early, Shipra Gandhi. Area Deprivation Index (ADI) among Patients with Breast Cancer in Buffalo [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-06.

BACKGROUND showed that adding pembrolizumab (P) to chemotherapy improved overall survival (OS) and progression-free survival (PFS) in advanced PDL-1+ TNBC.Conversely, Atezolizumab (A) did not exhibit an OS benefit in IMPASSION-130.Gaining insights into real-world outcomes beyond the confines of clinical trials is crucial.

TPS1112 Background: Brain metastases develop in up to 50% patients (pts) with metastatic triple negative breast cancer (TNBC) and HER2 + BC, constituting an increasing source of morbidity and mortality. HER3, overexpressed in triple negative and HER2 + brain metastatic breast cancer (BMBC), is a resistance factor to HER2-targeted therapies and a driver of CNS metastasis. Disease progression is associated with loss of anti-HER2 and anti-HER3 immunity. Previously, we have demonstrated that glioma-specific peptide-loaded αDC1 which produce CXCL9, CXCL10, CXCL11, CCL5, the chemokines which attract CXCR3- and CCR5- expressing cytotoxic T-lymphocytes (CTLs) and T-helper 1 (Th1) cells, induce clinical responses and long-term disease stabilization in pts with aggressive recurrent primary brain tumors (Okada et al. JCO 2011. PMID: 21149657). We hypothesized that anti-HER2/3-loaded αDC1 in combination with PD1 blockade will result in strong Th1/CTL response against HER2/3 epitopes (Basu A et al. Cancer Immunol Res. 2022 PMID: 34785506), being effective against brain lesions and systemic disease. Methods: This is a phase II single-arm, non-randomized multicenter study (NCT04348747). Eligibility includes pts with triple negative and HER2 + BMBC ≥18 years, ECOG PS ≤1, normal marrow and organ function with asymptomatic untreated brain metastases ≥ 5 mm who will receive αDC1 q3 weeks x 3 along with pembrolizumab every 3 weeks. Thereafter, αDC1 booster doses (if available) would be administered every 3 months until disease progression, intolerable side effects or withdrawal from study, up to 24 months. Baseline and 9-week post-αDC1 peripheral biopsies (non-CNS) are required for six pts. 1 of the planned 21 pts have been enrolled and is undergoing treatment. Primary endpoint is CNS response rate (RR) by RANO-BM criteria. If no CNS response is observed after 12 pts, study will be terminated. If ≥ 1 response observed, then 9 more pts will be enrolled, for a total of 21 pts. If ≥ 3 CR are observed, the proposed therapy will be considered as promising for further evaluation. Secondary endpoints include non-CNS RR per RECIST v1.1, median CNS, non-CNS and overall progression-free survival, overall survival and safety. Exploratory endpoints include changes in intratumoral biomarkers (CTLs, PDL1, chemokines) in pre- and post-treatment peripheral tumor biopsies and immune changes in the blood. Clinical trial information: NCT04348747 .

9135 Background: CIMAvax-EGF (C-E) is a recombinant anti-human epidermal growth factor (EGF) depleting immunotherapy which has previously shown increased survival as maintenance after platinum-based chemotherapy in patients (pts) with advanced NSCLC. The primary objective of this single-arm phase II trial was to evaluate the 12-month overall survival (OS) in pts receiving C-E in combination with Nivolumab(N) as 2L therapy for advanced NSCLC. Methods: Pts with previously treated, immunotherapy-naive advanced NSCLC received 2.4 mg C-E IM every 2 weeks(w) for 4 doses (loading phase) in combination with N 240mg IV every 2 w, then continued monthly maintenance C-E combined with N 240mg IV every 2 w. Enrollment to this arm was terminated before estimated sample size was met due to poor accrual as immunotherapy became incorporated into 1 st line therapy. We present OS and progression-free survival (PFS) data [determined using a Kaplan-Meier test with 90% confidence intervals (CI)] of pts who were able to complete the loading phase per protocol (PP). Results: 21 out of 23 enrolled pts were included in the PP analysis. Among the 21 pts, 17 (81.0%) had non-squamous(nsq) histology, 12 (57.1%) were KRAS wildtype (9.5% unknown status), 13 (61.9%) had PD-L1 tumor proportion score 0%. 43% pts (n=3) with known KRAS mutation (n=7) had co-mutated STK11. Disease control rate was 47.6% (n=10) defined as pts who had stable disease or partial response as best response per RECIST v1.1. The 21 PP pts had a 29% 3-year(yr) OS rate (90% CI 14, 45; intention-to-treat [ITT] population in 23 pts with 26% 3-yr OS rate, 90% CI 13, 42). Median(m) OS for PP pts was 11.9 months, 90% CI 8.0 – 23.9 months (ITT mOS 10.4 months, 90% CI 6.8-13.6). Pts with squamous histology had a better 3-yr OS rate compared to those with nsq histology [50% (90% CI 10, 81) vs 24% (90% CI 9, 41), respectively]. Pts with PD-L1 expression ≥1% had higher 3-yr OS [38% (90% CI 12, 63)] and 3-year PFS [38% (90% CI 12, 63)] compared to pts with no PD-L1 expression (3-yr OS 23% [90% CI 8, 44] and 3-yr PFS 8% [90% CI 1, 25]). mOS, 1-yr and 3-yr OS for EGFR/ALK/KRAS wildtype pts was higher [31.7 months (90% CI 5.9, NR), 67% (90% CI 4, 84), 50% (90% CI 24,71), respectively) compared to KRAS mutated NSCLC [10.1 months (90% CI 6.5, 12.1), 29% (90% CI 6, 56), 0% (90% CI 1, 41), respectively]. Conclusions: NSCLC pts who were able to complete the PP combination of C-E plus N at the minimum had numerically better OS compared to historical study cohorts with N as 2L monotherapy. Among pts who completed PP treatment, pts with KRAS wildtype NSCLC had the longest mOS observed. C-E is currently being investigated in combination with pembrolizumab as maintenance therapy after completing 1L chemoimmunotherapy for NSCLC with PD-L1 < 50% and as 1L therapy in combination with pembrolizumab for EGFR/ALK wildtype NSCLC and PD-L1 ≥ 50%. Clinical trial information: NCT02955290 .

Background Presence of cytotoxic T lymphocytes (CTL) in the tumor microenvironment (TME) predicts the effectiveness of cancer immunotherapies. The ability of toll-like receptor 3 (TLR3) ligands, interferons (IFNs) and COX2 inhibitors to synergistically induce CTL-attracting chemokines (but not regulatory T cell (Treg)-attractants) in the TME, but not in healthy tissues, observed in our preclinical studies, suggested that their systemic application can reprogram local TMEs.Methods Six evaluable patients (33–69 years) with metastatic triple-negative breast cancer received six doses of systemic chemokine-modulating (CKM) regimen composed of TLR3 ligand (rintatolimod; 200 mg; intravenous), IFN-α2b (20 MU/m2; intravenous) and COX2 inhibitor (celecoxib; 2×200 mg; oral) over 2 weeks. The predetermined primary endpoint was the intratumoral change in the expression of CTL marker, CD8α, in the post-CKM versus pre-CKM tumor biopsies. Patients received follow-up pembrolizumab (200 mg, intravenously, every 3 weeks), starting 3–8 days after completion of CKM.Results Post-CKM biopsies showed selectively increased CTL markers CD8α (average 10.2-fold, median 5.5-fold, p=0.034) and granzyme B (GZMB; 6.1-fold, median 5.8-fold, p=0.02), but not FOXP3 (Treg marker) relative to HPRT1 expression, resulting in the increases in average CD8α/FOXP3 ratio and GZMB/FOXP3 ratio. CKM increased intratumoral CTL-attractants CCL5 and CXCL10, but not Treg-attractants CCL22 or CXCL12. In contrast, CD8+ T cells and their CXCR3+ subset showed transient decreases in blood. One clinical response (breast tumor autoamputation) and three stable diseases were observed. The patient with clinical response remains disease free, with a follow-up of 46 months as of data cut-off.Conclusions Short-term systemic CKM selectively increases CTL numbers and CTL/Treg ratios in the TME, while transiently decreasing CTL numbers in the blood. Transient effects of CKM suggest that its simultaneous application with checkpoint blockade and other forms of immunotherapy may be needed for optimal outcomes.

8520 Background: There are clinical controversies surrounding the US FDA approval of Osimertinib in December 2020 as adjuvant therapy, based on disease-free survival (DFS) improvement in patients (pts) with surgically resected stage IB-IIIA EGFRm NSCLC. We initiated a survey study to investigate our hypothesis that DFS benefit alone even without significant OS maybe deemed a valuable endpoint to pts after considering trade-offs. Methods: Participants were recruited from pts seen at the RP Thoracic Clinic from 01/21 to 12/21. Eligible pts who were being evaluated for adjuvant systemic therapy following surgical resection were given a self-administered survey based on the validated questionnaire by Blinman et al, which was modified to provide explanation of the differences between OS and DFS and the ADAURA trial results. Survey responses were collected in an online repository. Associations between survey responses and demographics were assessed using Fisher’s exact test. Changes in preference responses were assessed using McNemar’s test. Results: A total of 524 pts with NSCLC were screened, of which 101 pts were eligible to receive the survey. 51 pts (50%) responded to the survey. Median age of respondents was 69yrs (37-83), majority were female (69%, n = 35,), married (61%, n = 31), retired ( 63%, n = 32), had at least some college or higher education level(54%, n = 28), with history of smoking (84%, n = 43) and with stage IIIA (43%, n = 22) adenocarcinoma (80%, n = 41). To evaluate toxicity-related tradeoffs (Q1), a ≥12 mo. improvement in OS benefit was needed for 66% of pts to consider adjuvant Osi. However, an increase of ≥ 6 mo. of DFS was enough for 66% of pts to justify taking a daily medication (Q2). One mo. increase in DFS or OS was not enough for 60% and 78% of pts respectively to justify taking the medication. A threshold 1% increase in 5-year OS was sufficient to persuade patients to take Osi for three years, even with respect to toxicity side effects (p = 0.023). (Q3). Finally, in the hypothetical cost-based scenario (Q4), there was no indication that pts were willing to pay more for each incremental increase in OS. There appears to be some association between employment status (p =.033) or educational degree (p =.049) for tolerance of side effects if there is at least 1 additional year of DFS or OS. Conclusions: We observed that the value patients ascribe to adjuvant Osimertinib is influenced by factors besides efficacy. Knowing pts' preferences for cancer treatments can better inform regulatory bodies in formulating cost-sharing structure for cancer therapies. Our study highlights the importance of shared decision making based on individual pts' preferences.

BackgroundIt is critically important to study the real-world data of FDA-approved medications to understand the response rates and toxicities observed in the real-world population not represented in the clinical trials. MethodsWe reviewed charts of patients diagnosed with metastatic, hormone receptor-positive, human epidermal growth factor receptor 2 negative, PIK3CA-mutated breast cancer treated with alpelisib from May 2019 to January 2022. Clinical characteristics and treatment outcomes were collected. The association of clinical characteristics with responses and adverse events (AEs) was evaluated using the logistic regression model. Results27 patients were included. Median age at alpelisib initiation 67 years (range: 44, 77 years). Majority of patients had excellent performance status at time of alpelisib initiation. Most patients had chronic comorbidities, notably; 2 patients had controlled type 2 diabetes mellitus at time of alpelisib initiation. Majority had a median of three lines of therapy (range: 1, 7) before alpelisib. Clinical responses were determined using RECIST v1.1. 3/27 (11.11%) patients discontinued therapy before response assessment due to grade 3 AEs. Overall response rate was 12.5% (3/24), with all partial responses (PR). The median duration of response was 5.77 months (range: 5.54, 8.98). 14/27 (51.9%) of patients required dose interruption/reduction. Overall, 23/27 (85.19%) patients discontinued alpelisib of which 11 (47.83%) discontinued alpelisib due to AEs. Median duration of treatment was 2 months in patients who had grade 3 AEs (range: <1.00, 8.30) and 6.28 (1.15, 10.43) in those who did not. Any grade AEs were reported in 24/27 (88.9%) patients, namely, hyperglycemia 16/27 (59.3%), nausea 11/27 (40.7%), diarrhea 10/27 (37.0%), fatigue 7/27 (25.9%) and rash 6/27 (22.2%). Grade 3 AEs were reported in 13/27 patients (50%), namely, hyperglycemia in 7/27 (53.8%) patients followed by skin rash 4/27 (30.8%), GI side effects 3/27 (23.1%). Those with progressive disease as best response to alpelisib, had more non-metabolic comorbidities, higher number of liver metastases, PIK3CA E545K mutations, and shorter duration on therapy compared to those with PR and stable disease. ConclusionPatients should be counseled about the toxicity and modest benefit observed with alpelisib in real-world clinical practice when used in later lines of therapy.

Abstract Background: Effective immune therapies depend on the presence of cytotoxic T-lymphocytes (CTLs) in the tumor microenvironment (TME). Our preclinical data showed synergy between TLR3 ligands and interferon-α (IFN-α) in reprogramming the TME, but not healthy tissues, to selectively enhance CTL attraction, providing rationale for their systemic application to enhance local CTL densities in “cold” tumors. The pilot study NCT03599453 evaluated the safety of systemic chemokine modulating regimen (CKM) composed of i.v. rintatolimod (Ampligen; selective TLR3 ligand) and IFN-α, and its ability to promote local CTL influx to mTNBC lesions. Methods: Six evaluable patients (33-75 years) with mTNBC received 6 doses of rintatolimod (200 mg i.v.), IFN-α (INTRON-A; 20MU/m2 i.v.) and COX-2 inhibitor (celecoxib; 2 x 200 mg, p.o.) over 2 weeks, with tumor biopsies obtained before (within 6 days) and after (within 5 days) CKM. All patients received follow-up pembrolizumab (200 mg, i.v, Q3 weeks). The primary endpoint was the change in the CTL marker CD8α in the TME with a planned interim analysis after 3 patients (α=0.03) and final analysis after 6 patients (α=0.084). Correlative studies analyzed additional markers of CTLs, regulatory T-cells (Tregs), and CTL- and Treg-attracting chemokines in the TME and blood. Results: Treatment was well tolerated with mostly grade 1/2 adverse events and one grade 3 clinically significant pneumonitis and immune thrombocytopenic purpura observed during follow up pembrolizumab treatment. We observed uniform increases of intratumoral type-1 immune markers upon treatment: CD8α mRNA (6.1-fold; p=0.034), GZMB (3.5-fold; p=0.058), ratios of CD8α/FOXP3 and GZMB/FOXP3 (5.7-fold; p=0.036, and 7.6-fold; p=0.024 respectively), and CTL attractants CXCL10 (2.6-fold; p=0.104) and CCL5 (3.3-fold; p=0.019), successfully meeting the primary endpoint. In contrast, neither Treg marker Foxp3 nor Treg attractants CCL22 or CXCL12 were enhanced. These TME changes were accompanied by transient decreases in circulating CD3+CD8+ CTLs and CD3-CD56+ NK cells (but not Tregs), selectively affecting the cells expressing CXCR3 (receptor for CXCL10), but not CCR4 or CXCR4 (receptors for CCL22 and CXCL12). Three patients had stable disease lasting 2.4, 2.5 and 3.8 months, as of September 1, 2021 cut-off. An additional patient had a partial response (breast auto-amputation) with massive tumor necrosis observed in the post-CKM biopsy. Conclusion: This proof-of-concept study shows that short-term systemic CKM followed by pembrolizumab is safe and selectively enhances local CTL infiltration in the TME, providing rationale for concurrent CKM and PD1 blockade in prospective phase II studies. Citation Format: Shipra Gandhi, Mateusz Opyrchal, Melissa Grimm, Ronald Slomba, Kathleen Kokolus, Sebastiano Battaglia, Kristopher Attwood, Adrienne Groman, Lauren Williams, Mary Lynne Tarquini, Paul Wallace, Kah Teong Soh, Tracey O'Connor, Amy Early, Ellis Levine, Igor Puzanov, Marc Ernstoff, Pawel Kalinski. Systemic rintatolimod and interferon-α2b selectively reprogram local tumor microenvironment in patients with metastatic triple negative breast cancer for enhanced influx of cytotoxic T-lymphocytes but not regulatory T-cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT145.

PURPOSE: The immunohistochemistry companion diagnostic test for pembrolizumab (IHC 22C3 pharmDx) lacks sensitivity, challenging immunotherapy selection for NSCLC patients with lower levels of expression. Unlike IHC 22C3, which restricts assessment of PD-L1 expression to viable tumor cells as a tumor proportion score (% TPS), mRNA next generation sequencing (RNA-seq) measures PD-L1 expression in the tumor microenvironment for both tumor and inflammatory background cells. RNA-seq previously demonstrated concordance with IHC and may be a robust alternative testing method for multiple tumor types. Here, we sought to optimize PD-L1 RNA-seq cutoff values in NSCLC to improve clinical sensitivity. PROCEDURE: NSCLC patients included in the study (n=3,465) were tested for PD-L1 expression by IHC 22C3 and clinically validated RNA-seq, measured as % rank (0-100) relative to a reference population based on normalized reads per million (nRPM). Patients were divided into an RNA-seq cut-off discovery cohort (n=3,168), and a test cohort pembrolizumab treated patients. Principal components analysis (PCA) was used to classify patients based on test results and explore cut-off values in the discovery cohort. Kaplan Meier curves and a Cox proportional hazards regression models assessed overall survival (OS) hazard ratios (HR) for RNA-seq versus standard of care IHC cut-offs in the test cohort. RESULTS: Unsupervised PCA clustering identified three distinct PD-L1 groups separated by combinations of significant over- and under-representation of RNA-seq and IHC result measures from prior testing. The groups were labeled as “low” (rank ≤40), “moderate” (rank 41-73), and “high” (rank ≥74), based on the median RNA-seq rank for each group (+/- 1SD for low and high). Both the low and moderate groups were overrepresented by patients in the PD-L1 IHC low and negative groups. The moderate group was overrepresented by patients with moderately high PD-L1 RNA-seq ranks (median=70), while the low group was overrepresented by patients that were not PD-L1 high by RNA-seq. The high group was overrepresented by patients high for PD-L1 by both IHC and RNA-seq. OS HRs were better for RNA-seq high versus moderate (HR=0.05, CI 0.00-0.63, p=.02), and RNA-seq high versus low (HR=0.16, CI 0.03-0.86, p=.03) groups compared to standard of care IHC 22C3 high versus low groups, (HR=0.21, CI 0.04-1.07, p=.06). Findings were non-significant for the RNA-seq moderate versus low groups, likely due to the limited and disproportionately high number of patients with poor performance status in these groups. CONCLUSIONS: PD-L1 expression by RNA-seq demonstrated improved clinical sensitivity in predicting OS versus standard of care PD-LI IHC in a pembrolizumab treated NSCLC patient cohort. Additional studies are needed to further define cut-offs in the context of performance status, and better understand immune escape mechanisms in the moderate group. Citation Format: Mary K. Nesline, Sarabjot Pabla, Yong Hee Lee, Paul DePietro, Amy Early, Roger Klein, Shengle Zhang, Jeffrey Conroy. PD-L1 expression by RNA-sequencing and survival from pembrolizumab in non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1259.

e21167 Background: CGIP analyzes FFPE tumor tissue by DNA/RNA sequencing for SNVs, indels, copy gain/loss, fusions, splice variants, MSI and TMB, along with PD-L1 IHC. A purported advantage of CGIP in NSCLC is the ability to identify targeted and immunotherapy biomarkers to inform clinical management. However, the extent to which CGIP supports treatment decisions and benefits NSCLC patients in various treatment settings is limited. Methods: A retrospective analysis of OmniSeq CGIP results (June 2017-March 2019) and real-world clinical data (through March 2020) for NSCLC patients (n = 300) was performed to evaluate treatment strategies at Roswell Park Comprehensive Cancer Center. Patient targeted and immunotherapies following CGIP were classified as “matched” to biomarker results (established or potentially clinically significant) at the indication level (single or multi-marker results, histology, treatment line) based on AMP/ASCO/CAP guidance for strength of biomarker clinical evidence. We estimated overall survival (OS) from CGIP report date for patients who first received either matched therapy or chemotherapy (and no subsequent matched therapy), and assessed the predictive value of matched therapy for OS in the first or subsequent line setting, adjusting for clinicopathologic covariates. Results: Most CGIP tested patients were female (55%), stage IIIB/IV (89%), ECOG < 2 (83%), non-squamous (86%), treatment naïve (62%), ever smokers (88%). 74% (228) of patients were treated post-CGIP, with 71% receiving at least one matched therapy. Matched therapies received in the frontline setting were supported by the highest (Tier 1A) category of evidence more often than subsequent line therapies (97% vs. 68%). 90% of patients with oncogenic driver mutations received targeted agents (17% of total) and 57% received matched immunotherapy. In the frontline setting, compared to chemotherapy, OS was highest for patients who first received matched targeted therapy (median = 23.4 mo; HR 0.26; p = .004; 95% CI 0.13-0.68) vs matched immunotherapy (median = 17.9 mo; HR 0.38; p = .001; 95% CI 0.21-0.69). Subsequent line, OS was also highest for patients who first received matched targeted therapy (median not est., mean = 27.5 mo; HR 0.20; p = .063; 95% CI 0.04-1.09) vs matched immunotherapy (median = 17.4 mo; HR 0.20; 95% CI 0.04-1.09), however, these differences were non-significant. Conclusions: CGIP supports evidence-based clinical decision making for NSCLC in the first and subsequent line settings and leads to improved survival for patients who receive matched targeted or immunotherapy compared to chemotherapy. Better predictive markers are needed to identify NSCLC patients who are more likely to respond to immunotherapies. Heterogeneity of patient biomarker profiles and treatment strategies over time in real world practice are a challenge to assessing CGIP efficacy.

To examine the association between race and clinical outcomes (pathological complete response [pCR]; recurrence-free survival [RFS], and overall survival [OS]) in patients diagnosed with triple-negative (TNBC) or HER2-positive breast cancer treated with neoadjuvant chemotherapy (NAC). Patients who self-identified as non-Hispanic white (NHW) or non-Hispanic Black (NHB) and were diagnosed with Stage I–III TNBC (n = 171 including 124 NHW and 47 NHB) and HER2-positive (n = 161 including 136 NHW and 25 NHB) breast cancer who received NAC from 2000 to 2018 at Roswell Park Comprehensive Cancer Center were included. Associations of race with pCR and survival outcomes were evaluated using logistic and Cox regression models, respectively. There was no statistically significant difference in pCR between NHB and NHW patients with TNBC (31.9 vs 29.8%; OR: 1.11, 95% CI 0.54–2.29) or HER2-positive breast cancer (36.0 vs 39.7%; OR: 0.87, 95% CI 0.36–3.11). After controlling for potential confounders, including age, stage, treatment regimens, insurance status, and comorbidities, no statistically significant difference in OS or RFS was observed between NHB and NHW patients within either subtype. TNBC or HER2-positive breast cancer patients treated at a single academic center in Buffalo, NY, showed similar outcomes independent of patients’ race. Given the known genetic diversity of African American ancestry in the US, further studies investigating the interplay between race, geography, and clinical outcomes are warranted.

Background: The use of immune PD-1/-L1 checkpoint inhibitors (ICI) has dramatically altered the treatment of advanced non-small cell lung cancer (NSCLC). However, a large proportion of patients with NSCLC do not derive clinical benefit from ICI treatment. Recent studies have identified certain genomic subsets of NSCLC as drivers of primary resistance to ICI treatment. Methods: We evaluated NSCLC patients treated at Roswell Park Comprehensive Cancer Center from 2017-2020 with successful genomic and immune profiling using a CLIA-certified laboratory developed test that included targeted next-generation genomic sequencing, PD-L1 assessment by immunohistochemistry (IHC), and targeted RNA-seq of 394 immune transcripts. Results: A total of 379 treatment-naive non-squamous NSCLC subjects were identified with 113 subjects treated with an FDA approved ICI regimen and evaluable for response. Using a gene expression signature based on differential gene expression analysis in the 113 subjects with and without disease control with ICI treatment, we performed unsupervised clustering of the larger 379 subject cohort and identified a responder (R) cluster and non-responder (NR) cluster. The R cluster was associated with high PD-L1 expression, T-cell infiltration, and KRAS mutations. The NR cluster was associated with negative PD-L1 expression, lack of T-cell infiltration, and mutations in STK11, APC/CTNNB1, and NFE2L2. Of the mutation subsets, STK11 was most associated with NR with a trend towards lower PD-L1 expression by clinical IHC, but much more significantly associated by gene expression signatures with low PD-L1 and T-cell inflammation. In our gene panel, we identified elevated TRIM29 expression in STK11 mutant NSCLC tumors and confirmed TRIM29 expression by IHC on a separate 64 subject cohort with known STK11 mutation status and archival formalin fixed paraffin embedded (FFPE) tissue. A subset of STK11 mutant NSCLC cell lines also demonstrated elevated TRIM29 expression and we generated knockouts of TRIM29 with CRISPR-Cas9 in these cell lines which resulted in decreased tumor growth in xenograft models. Using Nanostring nCounter multiplex inflammation gene expression panel on both the 64 patient FFPE cohort and TRIM29 knockout cell lines, we identified the innate immune complement pathway as a target of therapeutic interest and specifically the high expression of complement component C3 by TRIM29 high tumor cells. We then generated a syngeneic mouse model where loss of Stk11 resulted in elevated expression of Trim29 and C3 for preclinical studies to evaluate the therapeutic modulation of the complement pathway on response to ICI. Conclusion: Using a large clinical cohort of non-squamous NSCLC patients we characterized the immune environment of mutational subsets of NSCLC and identified the complement pathway as a potential therapeutic target in STK11 mutant NSCLC. Citation Format: Edwin H. Yau, Bojidar Kandar, Lei Deng, Te-An Chen, Wiam Bshara, Sean Glenn, Sarabjot Pabla, Antonios Papanicolau-Sengos, Mary Nesline, Hongbin Chen, Amy Early, Carl Morrison, Grace Dy. Immunogenomic analysis identifies the complement pathway as a therapeutic target in STK11 mutant non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1320.

Background Maintenance therapy with pemetrexed has shown survival benefit in patients with advanced stage non-small cell lung cancer (NSCLC). The recommended dose schedule is 500 mg/m 2 in 21-day cycles. Prolonged treatment with maintenance pemetrexed can result in cumulative toxicities. We sought to compare treatment outcomes in patients receiving an alternate maintenance schedule in realworld practice. Methods This single-center, retrospective study investigated patients with advanced stage (IIIB and IV) NSCLC receiving at least two doses of maintenance pemetrexed from May 1, 2011 to June 30, 2016. The objective was to compare time on treatment with maintenance pemetrexed therapy initiated at a standard schedule (q3 weeks) versus an alternate schedule (q4 weeks or longer). Also evaluated were progressionfree survival (PFS) and overall survival (OS) differences between the two groups. Results 129 patients were included, of whom 40 started the alternate schedule no later than cycle 3 of treatment (29 of 40 patients initiated maintenance treatment on the alternate schedule). Average time on maintenance treatment for patients appeared to be longer in the patients who received the alternate schedule regimen (195 vs 263 days, p =0.008). OS trended towards better survival among patients receiving the alternate schedule regimen (11.9 vs 18.1 months, p =0.3). Limiting the analysis to ALK wildtype, the patients showed a similar trend, with median PFS (7.6 vs 11.5 months, p =0.46) and OS (11.9 vs 17.6 months, p =0.38), still favoring the alternate schedule. Conclusions The alternate dosing schedule of maintenance pemetrexed (q4 weeks or longer) is feasible and not detrimental to OS. Future investigations evaluating the optimal administration schedule of maintenance pemetrexed is warranted.

BACKGROUND:The medical literature defining breast cancer recurrence and secondary cancers after autologous tissue reconstruction for breast cancer is sparse. We sought to identify and analyze occurrences at our institution.PATIENTS AND METHODS:A 20-year retrospective review of cancer recurrences and atypical breast neoplasms after autologous tissue breast reconstruction at Roswell Park Comprehensive Cancer Center was conducted after being granted a waiver from the institutional review board.RESULTS:Eighteen locoregional recurrences among 337 cases were identified and analyzed. Overall recurrence rate was 5.3%. Four secondary cancers (1.2%) were radiation-induced angiosarcoma, undifferentiated pleomorphic sarcoma, and metaplastic carcinoma. One case of flat epithelial atypia was identified.CONCLUSION:Our retrospective review found incidence and survival after treatment of breast cancer concordant with reports in the literature. We also identified and analyzed secondary neoplasms, including a unique case of undifferentiated pleomorphic sarcoma and metachronous recurrence of breast carcinoma. A case of recurrence as metaplastic carcinoma was identified.

Background The CBR3 V244M single nucleotide polymorphism has been linked to the risk of anthracycline-related cardiomyopathy in survivors of childhood cancer. There have been limited prospective studies examining the impact of CBR3 V244M on the risk for anthracycline-related cardiotoxicity in adult cohorts. Objectives This study evaluated the presence of associations between CBR3 V244M genotype status and changes in echocardiographic parameters in breast cancer patients undergoing doxorubicin treatment. Methods We recruited 155 patients with breast cancer receiving treatment with doxorubicin (DOX) at Roswell Park Comprehensive Care Center (Buffalo, NY) to a prospective single arm observational pharmacogenetic study. Patients were genotyped for the CBR3 V244M variant. 92 patients received an echocardiogram at baseline (t 0 month ) and at 6 months (t 6 months ) of follow up after DOX treatment. Apical two-chamber and four-chamber echocardiographic images were used to calculate volumes and left ventricular ejection fraction (LVEF) using Simpson’s biplane rule by investigators blinded to all patient data. Volumetric indices were evaluated by normalizing the cardiac volumes to the body surface area (BSA). Results Breast cancer patients with CBR3 GG and AG genotypes both experienced a statistically significant reduction in LVEF at 6 months following initiation of DOX treatment for breast cancer compared with their pre-DOX baseline study. Patients homozygous for the CBR3 V244M G allele (CBR3 V244) exhibited a further statistically significant decrease in LVEF at 6 months following DOX therapy in comparison with patients with heterozygous AG genotype. We found no differences in age, pre-existing cardiac diseases associated with myocardial injury, cumulative DOX dose, or concurrent use of cardioprotective medication between CBR3 genotype groups. Conclusions CBR3 V244M genotype status is associated with changes in echocardiographic parameters suggestive of early anthracycline-related cardiomyopathy in subjects undergoing chemotherapy for breast cancer.

Background: Despite the approval of mTOR inhibitor everolimus and CDK4/6 inhibitors in the management of hormone-receptor-positive HER2 non-amplified metastatic breast cancer (HR+ HER2-MBC), the optimal sequence of therapy is unclear. There are no clinical data on efficacy of everolimus in HR+ HER2-MBC after cancer progresses on CDK4/6 inhibitors. Objective: The objective of this study is to find the efficacy of everolimus in HR+ HER2-MBC after they progress on a CDK4/6 inhibitor palbociclib. Methods: This is a retrospective, 2-institute review of HR+ HER2-MBC from Jan 2015 to March 2018 treated with everolimus after progression on palbociclib. Primary end point was median progression-free survival (PFS), secondary end points objective response rate (ORR), clinical benefit ratio (CBR), and overall survival (OS). Results: Out of 41 women with median age 61 years (33, 87) enrolled, 66% had received adjuvant systemic therapy, 61% had visceral disease, and 95% had prior nonsteroidal aromatase inhibitors. About 83% women had 3 or more chemotherapy or hormonal therapies prior to everolimus. Kaplan-Meier estimates showed a median PFS of 4.2 months (95% confidence interval [CI]: 3.2-6.2). The median OS was 18.7 months (95% CI 9.5 to not reached). Objective response rate and CBR were both 17.1%. Conclusion: Everolimus was associated with modest PFS and ORR in HR+ HER2-MBCs postprogression on palbociclib.