Study design and rationale for the NeoTRACE trial: a multicenter phase II study of neoadjuvant sacituzumab govitecan plus zimberelimab followed by adjuvant zimberelimab with or without sacituzumab govitecan in patients with resectable non-small cell lung cancer.

TPS8120 Background: Phase III trials, including KEYNOTE-671, have established combined neoadjuvant chemoimmunotherapy followed by adjuvant immunotherapy (IO) as the standard of care for resectable NSCLC. However, a notable challenge in KEYNOTE-671 and similar studies was that ~17-22% of patients did not proceed to surgery following neoadjuvant chemoimmunotherapy, highlighting the need for more tolerable regimens. Recent data from studies such as NEOpredict (which demonstrated a 100% surgical completion rate with neoadjuvant nivolumab with/without relatlimab), NeoCOAST-2 (which reported a 34% pathological complete response [pCR] rate using a neoadjuvant combination of an anti-TROP2 antibody drug conjugate [ADC], IO, and single-agent platinum, thereby surpassing the ~20% pCR rates achieved with neoadjuvant chemoimmunotherapy), and EVOKE-02 (which showed promising objective response rates of 69% and 44% with the anti-TROP2 ADC sacituzumab govitecan plus pembrolizumab in first-line metastatic NSCLC patients with PD-L1 ≥50% and PD-L1 0-49%, respectively) demonstrate that chemotherapy-sparing approaches may reduce toxicity while maintaining or enhancing efficacy. These findings highlight the potential synergistic effect of ADC plus IO, suggesting this strategy may also be an effective treatment option in the perioperative setting with potentially lower toxicity compared to chemoimmunotherapy. Additionally, long-term adverse events associated with platinum-based chemotherapy, such as neuropathy, may be lower or avoided altogether. This study aims to improve the pCR rate, reduce toxicity, enhance surgical eligibility, and personalize adjuvant treatment. Methods: NeoTRACE is a phase II, multicenter, open-label, single-arm study evaluating the neoadjuvant combination of sacituzumab govitecan (SG) and the PD-1 inhibitor zimberelimab (ZIM) in patients with resectable stage II to IIIB (N2) NSCLC with no known EGFR or ALK alterations. Patients will receive neoadjuvant SG 10 mg/kg IV on days 1 and 8, and ZIM 360 mg IV on day 1, every 3 weeks for 4 cycles, followed by definitive surgery as per local standards. In the adjuvant phase, patients will either continue adjuvant SG plus ZIM for up to 4 cycles, followed by ZIM only for a total of up to 13 cycles, or receive adjuvant ZIM monotherapy (as per physicians’ choice). The primary endpoint is the rate of pCR in tumor and lymph nodes. Secondary endpoints include major pathological response, surgical resection rate, time to surgery, DFS, OS, safety, and quality of life. The study also explores circulating tumor DNA dynamics, TROP2 expression, and spatial transcriptomics and proteomics to identify potential biomarkers. As of June 2025, the NeoTRACE study is recruiting 50 patients across 15 sites in Germany. EudraCT: 2024-517561-16. Clinical trial information: 2024-517561-16 (EudraCT) .

Chemotherapy + PD-1/PD-L1 Blockade Should Be the Preferred Option in the Neoadjuvant Therapy of NSCLC

Purpose: TROP2 is overexpressed in many tumor types and is being actively pursued as a target. Sacituzumab govitecan (SG), a humanized anti-TROP2 antibody conjugated with SN-38, was approved for treatment of metastatic triple negative breast cancer, with the greatest efficacy in patients with medium or high TROP2 levels. We sought to enhance efficacy of TROP2-targeted therapies by pharmacological regulation of TROP2 expression. Methods: TROP2 levels were assessed by immunohistochemistry (IHC) in two sets of breast tumors: a set of surgical samples and a tissue microarray. TROP2 mRNA expression was assessed in surgical samples and breast cancer patient-derived xenografts (PDXs) with RNAseq and assessed in the TCGA. In cell lines, expression of TROP2, E-cadherin (E-cad), and Schlafen family member 11 (SLFN11) were assessed by immunoblotting and qPCR following drug treatment or cell line manipulation. Epithelial-mesenchymal transition was evaluated by cell migration, cell invasion, and anchorage-independent growth assays. Antitumor efficacy of drug combination was assessed by cell survival, cell colony formation, and apoptosis assays. Results: By IHC, TROP2 was expressed in only 40% of metaplastic breast cancers (MpBC), but nearly all non-MpBC tumors. TCGA database evaluation further showed higher TROP2 levels in non-MpBC tumors than metaplastic tumors. In breast cancer surgical specimens, breast cancer PDXs, and the TCGA, there was a strong correlation between TROP2 and E-cad expression. In vitro, we demonstrated that downregulating transcriptional factor zinc finger E-box binding homeobox 1 (ZEB1) led to mesenchymal-epithelial transition with upregulation of both E-cad and TROP2 expression in breast cancer cells, leading to increased sensitivity to SG treatment. Screening of epigenetic modulators identified DNA methyltransferase inhibitor decitabine as an enhancer of TROP2 and E-cad expression in PDX cell lines of metaplastic cancer origin and mesenchymal subtype breast cancer cell lines. Decitabine increased TROP2 expression by decreasing TROP2 promoter methylation. Decitabine was significantly synergistic with SG, and enhanced apoptosis. Similarly, overexpression of TROP2 (by plasmid) in cell lines enhanced activity of SG. Furthermore, decitabine increased expression of SLFN11, a putative biomarker of SN38 sensitivity, and was synergistic with SG in TROP2 expressing, SLFN11 low breast cancer cell lines. Conclusion: TROP2 is expressed in most breast cancers, but is expressed less frequently in MpBC, an aggressive subtype unresponsive to traditional therapies. Epigenetic modulator decitabine upregulates TROP2 and SLFN11 expression and enhances antitumor efficacy of SG. Combinatorial treatment of TROP2 ADCs with epigenetic modulators of TROP2 represent a novel therapeutic strategy for tumors with low TROP2 or SLFN11 expression. Citation Format: Ming Zhao, Timothy P. DiPeri, Gabriela Raso, Yasmeen Q. Rizvi, Xiaofeng Zheng, Kurt Evans, Argun Akcakanat, Fei Yang, Debu Tripathy, Ecaterina Ileana Dumbrava, Senthil Damodaran, Funda Meric-Bernstam. Epigenetically upregulating TROP2 enhances therapeutic efficacy of TROP2 ADC sacitizumab govitecan [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 1791.

Background: Optimizing treatments for localized breast cancer is key to preventing metastatic recurrences and reducing mortality. Sacituzumab Govitecan (SG) is a novel antibody-drug conjugate in which the topoisomerase 1 inhibitor SN-38 (the active metabolite of irinotecan) is coupled to a humanized monoclonal antibody targeting the antigen Trop-2, which is highly expressed in triple negative breast cancer (TNBC). SG is FDA approved for patients with metastatic hormone receptor-positive (HR+) and TNBC. However, efficacy in localized BC is not known. The NeoSTAR clinical trial is evaluating SG in the neoadjuvant (NA) setting for participants with localized breast cancer. Cohort A1 evaluating NA SG monotherapy in localized TNBC is completed, and now cohorts A2 (SG + pembrolizumab (P) for TNBC), B1 (SG monotherapy for HR+ BC), and C (SG + P for HER2- inflammatory breast cancer (IBC)) are enrolling. Trial design: This is a single-arm phase II study of NA SG or SG + P with multiple cohorts across different breast cancer subtypes. In all cohorts, SG is administered via an IV infusion on days 1 and 8 of each 21-day cycle at a starting dose of 10 mg/kg for 4 cycles. For cohorts A2 and C, pembrolizumab is given on day 1 of each cycle. For A2 and B1, after 4 cycles, participants who have biopsy-proven residual disease will have the option to receive additional standard NA therapy at the discretion of the treating physician and subsequently proceed to surgery. Those with a complete response on imaging may proceed directly to surgery. If pathological complete response (pCR) is achieved after 4 cycles of SG + P, participants on A2 will remain on study and receive adjuvant weekly paclitaxel and carboplatin for 12 weeks along with continuation of P to complete a total of one year of the PD-1 inhibitor; participants on B1 will receive adjuvant therapy at the discretion of the treating physician, with the option to continue P to complete a total of one year. On cohort C, after 4 cycles of SG + P, dose-dense doxorubicin + cyclophosphamide + P for 4 cycles will be given before considering surgery. A baseline research biopsy is required for all cohorts, as well as tissue collection following treatment with SG (either at surgery or via biopsy prior to additional NA therapy). Eligibility criteria: Participants ≥ 18 years of age with previously untreated localized breast cancer as determined by the local institution will be enrolled. For A2, participants must either have a primary tumor >2 cm or be node positive. For B1, participants with anatomic clinical stage II-III breast cancer with primary tumor > 1.5 cm and high genomic risk are eligible. For the IBC cohort (C), participants with T4d and any N are eligible. An ECOG performance score of 0 or 1, and adequate bone marrow, hepatic, and renal function is required. Study Objectives: The primary objective is to assess the pCR rate in breast and lymph nodes (ypT0/isN0) with SG + P (A2), SG (B1), or SG + P followed by AC + P (C). Secondary objectives include assessment of overall response rate, evaluation of the safety and tolerability of SG or SG + P (CTCAE v5.0), event-free survival (EFS), and quality of life (EORTC QLQ-C30). Exploratory objectives include assessment of potential predictive biomarkers, including Trop-2 expression, DNA damage response markers and immunological markers, as well as changes in cell free DNA with SG. Statistical methods: The primary analysis is based on the estimated pCR rate with SG or SG + P and will be provided as a proportion (with two-sided 95% confidence interval). Each cohort will follow a Simon two-stage design. EFS will be analyzed using Kaplan-Meier methods and descriptive statistics. Target Accrual: 50 participants (A2), 56 participants (B1), 39 participants (C) Contact: Dr. Laura Spring (LSpring@mgh.harvard.edu) Clinicaltrials.gov #: NCT04230109 Citation Format: Laura Spring, Ana Garrido-Castro, Filipa Lynce, Nadine Tung, Rachel Abelman, Lianne Ryan, Megan Moran, Elizabeth Mittendorf, Leif Ellisen, Sara Tolaney, Aditya Bardia. Phase 2 study of response-guided neoadjuvant sacituzumab govitecan in patients with localized breast cancer (NeoSTAR) [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 PO2-19-03.

Overall survival with sacituzumab govitecan in hormone receptor-positive and human epidermal growth factor receptor 2-negative metastatic breast cancer (TROPiCS-02): a randomised, open-label, multicentre, phase 3 trial

Response-guided neoadjuvant sacituzumab govitecan for localized triple-negative breast cancer: results from the NeoSTAR trial

Background: HR+/HER2– mBC, the most common subset of breast cancer, is treated with sequential endocrine therapy + targeted agents followed by sequential single-agent chemotherapy (CT), with increasingly shorter benefit duration with each subsequent treatment. High Trop-2 expression is observed in breast cancer regardless of subtype. SG is a Trop-2-directed antibody-drug conjugate approved for pre-treated metastatic triple-negative breast cancer. In the phase 3 TROPiCS-02 study, SG showed both significant progression-free survival (PFS) benefit (HR, 0.66; P<0.001; median 5.5 vs 4.0 mo; JCO 2022) at the primary analysis and overall survival (OS) benefit (median 14.4 vs 11.2 mo; HR, 0.79; P=0.02; ESMO 2022) at the 2nd planned interim OS analysis vs TPC in pretreated HR+/HER2- mBC. Here we compare efficacy outcomes for SG and TPC by Trop-2 expression. Methods: Eligible pts had HR+/HER2- locally recurrent inoperable or mBC; received ≥1 prior taxane, endocrine therapy, a CDK4/6 inhibitor; and received 2-4 prior CT regimens for mBC. Pts were randomized 1:1 to receive SG (10 mg/kg IV on d 1 and 8, every 21 d) or TPC (eribulin, gemcitabine, capecitabine, or vinorelbine) until disease progression or unacceptable toxicity. The primary endpoint was PFS by independent review per RECIST v1.1; OS and objective response rate (ORR) were key secondary endpoints. ORR was assessed by blinded independent central review per RECIST v1.1. Membrane Trop-2 expression on archival tumor tissue was assessed by immunohistochemistry and expressed as a histochemical score (H-score; range, 0-300); efficacy outcomes were assessed in H-score <100 and ≥100 groups. The H-score <100 group was further divided into H-score ≤10 and >10- <100 subgroups to assess the activity of SG in pts with very low Trop-2 expression. Results: Data cut-off was January 3, 2022 for PFS (median follow-up, 10.2 mo) and July 1, 2022 for OS (median follow-up, 12.5 mo). In total, 543 pts were randomized to receive SG (n=272) vs TPC (n=271). Pts had a median of 3 prior CT regimens for mBC; 95% had visceral metastases. There were 238 (88%) vs 224 (83%) Trop-2-evaluable pts in the SG vs TPC groups, respectively; of these, 95% had tumors with Trop-2 H-score >0. Of Trop-2-evaluable pts, 192 (42%) and 270 (58%) had H-scores <100 and ≥100, respectively. Demographics and baseline characteristics were generally consistent across H-score groups. PFS and OS benefit was observed for SG vs TPC across both Trop-2 groups (Table). Median PFS was 5.3 vs 4.0 mo (HR, 0.77; 95% CI, 0.54-1.09) and 6.4 vs 4.1 mo (HR, 0.60; 95% CI, 0.44-0.81) in the H-score <100 and ≥100 groups; median OS was 14.6 vs 11.3 mo (HR, 0.75; 95% CI, 0.54-1.04) and 14.4 vs 11.2 mo (HR, 0.83; 95% CI, 0.62-1.11), respectively. Disease response was observed in the 34 pts with H-score ≤10 who received SG. In pts who received SG, those with H-score ≤10, >10- <100, and ≥100 had ORRs of 24%, 18%, and 23%, respectively. The safety profile for SG by Trop-2 H-score was consistent with previous reports. Conclusions: In this TROPiCS-02 post-hoc analysis, improved efficacy with SG vs TPC was observed regardless of Trop-2 expression, and there was no clear level of Trop-2 expression at which a better treatment effect for SG was observed. These results support SG as an effective novel treatment option for patients with pretreated, endocrine-resistant HR+/HER2- mBC, and reinforce that Trop-2 testing is not required for SG treatment. Table Citation Format: Hope Rugo, Aditya Bardia, Frederik Marmé, Javier Cortés, Peter Schmid, Delphine Loirat, Olivier Trédan, Eva Ciruelos, Florence Dalenc, Patricia Gómez Pardo, Komal Jhaveri, Monica Motwani, Oh Kyu Yoon, Hao Wang, Wendy Verret, Sara Tolaney. Sacituzumab Govitecan (SG) vs Treatment of Physician’s Choice (TPC): Efficacy by Trop-2 Expression in the TROPiCS-02 Study of Patients (Pts) With HR+/HER2– Metastatic Breast Cancer (mBC) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS1-11.

Adjuvant chemotherapy for surgically resected non–small cell lung cancer

512 Background: Sacituzumab govitecan (SG), a novel antibody-drug conjugate in which the topoisomerase 1 inhibitor SN-38 (active metabolite of irinotecan) is linked to a humanized monoclonal antibody targeting the tumor antigen Trop2, is currently approved for treatment of patients (pts) with pre-treated metastatic triple negative breast cancer (TNBC). We conducted a phase 2 study evaluating neoadjuvant (NA) SG as upfront therapy for pts with localized TNBC (NCT04230109). The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) with SG. Secondary objectives included assessment of radiological response rate, evaluation of the safety and tolerability (CTCAE v5.0) and event-free survival (EFS). Methods: Patients with localized TNBC (tumor size ≥1cm, or any size if node positive) with no prior treatment were eligible. SG was administered IV on Days 1, 8 of each 21-day cycle at a starting dose of 10 mg/kg for 4 cycles. After 4 cycles, patients with biopsy-proven residual disease, considered as no pCR for primary endpoint, had the option to receive additional NA therapy at the discretion of the treating physician. Radiologic response (US or MRI) was defined by RECIST version 1.1 using a composite response of CR & PR. Standard descriptive statistics were utilized, including 95% binomial confidence intervals for all rates estimated. Results: From 7/14/20 – 8/31/21, 50 pts were enrolled (median age = 48.5; 11 stage I disease, 24 stage II, 11 stage III, 4 unknown; 62% node negative). The majority (98%; n = 49) of pts completed 4 cycles of SG. Overall, the radiological response rate with SG alone was 62% (n = 31, 95% CI 48%, 77%). 26 pts proceeded directly to surgery after SG. Overall, the pCR rate with SG alone was 30% (n = 15/50, 95% CI 18%, 45%). The other 11 pts had RCB-1 (n = 3), RCB-2 (n = 5), and RCB-3 (n = 3) disease, respectively. Of the 24 pts who received additional NA therapy, 6 had a pCR (3 received anthracycline-based regimen, 2 carboplatin/taxane, and 1 docetaxel/cyclophosphamide). Among pts with a germline BRCA mutation (n = 8), 7 proceeded directly to surgery after SG and 6 had a pCR (86%, 95% CI 42%, 99%). The most common AEs with SG were nausea (82%, n = 41), fatigue (78%, n = 39), alopecia (76%, n = 38), neutropenia (58%, n = 29), anemia (36%, n = 18), and rash (48%, n = 24). 6% of pts required dose-reduction. No pts discontinued SG therapy due to disease progression or AEs; 1 discontinued due to minimal response per investigator preference. At the time of data cut-off (1/18/22), no pts experienced disease recurrence. Updated biomarker and EFS results will be presented at the meeting. Conclusions: In the first neoadjuvant trial in TNBC with an ADC, SG demonstrated single agent efficacy in localized TNBC. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed. Clinical trial information: NCT04230109.

e20074 Background: This study aimed to evaluate the safety and efficacy of neoadjuvant camrelizumab combined with chemotherapy in patients with resectable non-small cell lung cancer (NSCLC). Methods: In this single-arm phase II clinical trial, patients aged 18-75 with pathologically confirmed resectable stage IIIA-IIIB (T3-4N2) NSCLC without EGFR, ALK, and ROS1 gene mutations were enrolled since December 2022. Patients were assigned to receive 3 cycles of camrelizumab (200 mg) plus chemotherapy (nab-paclitaxel, 130 mg/m2 or pemetrexed (for adenocarcinoma), 500mg/m2 plus platinum [cisplatin, 75 mg/m2; carboplatin, area under the curve, 5]). Radical surgery was performed within 4-6 weeks after neoadjuvant therapy. Patients undergo 18F-fluorodeoxyglucose (FDG) PET/CT scans within 1 week before treatment and surgery, respectively. The primary endpoints for follow-up are pathologic complete response (pCR) rate and major pathological response (MPR) rate, while secondary endpoints include safety and disease-free survival (DFS). Exploratory endpoints include molecular imaging research and biomarker analysis. Results: Up to December 2023, 30 patients (median age: 64 years) have been enrolled, including 22 cases of squamous carcinoma and 8 cases of adenocarcinoma. All patients received 3 cycles of neoadjuvant camrelizumab plus chemotherapy, and 27 patients underwent radical sugery. Three patients did not receive surgical treatment, 2 of whom refused surgery and 1 was unable to undergo surgery due to disease progression. Among patients received surgery, 27 (100%) achieved R0 resection, 10 (37.0%) achieved pCR, and 15 (55.6%) achieved MPR. For patients with squamous cell carcinoma, the MPR and pCR rates were 70% (14/20) and 45% (9/20), respectively, while for adenocarcinoma patients, the MPR and pCR rates were 14.3% (1/7) and 14.3% (1/7), respectively. There was no significant difference in pathological response rates between the PD-L1 tumor proportion score (TPS) ≥ 1% group and the PD-L1 TPS < 1% group. Most of treatment-related adverse events (TRAEs) were grade 1-2, and the most common TRAEs was leukopenia (63.0%). Five patients (18.5%) developed grade ≥ 3 TRAEs, including 3 leukopenia, 1 neutropenia, and 1 pneumonia. Biomarker analysis showed that among patients with pCR, the proportion of increased circulating M1 macrophages and decreased mononuclear myeloid-derived suppressor cells (M-MDSCs) and M2 macrophages after treatment was higher than those in non-pCR patients. Circulating ctDNA analysis showed that the ctDNA concentration of patients with non-pCR after treatment was higher than that of patients with pCR. Patients with ctDNA remaining positive after treatment were all in the non-pCR group. Conclusions: Neoadjuvant camrelizumab combined with chemotherapy for NSCLC patients show promising pathological response rates and tolerable safety. Clinical trial information: NCT06241807 .

SY13-03: Neoadjuvant immunotherapy for operable non-small cell lung cancer: Lessons learned and current challenges

PurposeThe role of neoadjuvant epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) targeted therapy for patients with EGFR-mutant non-small cell lung cancer (NSCLC) has not been clarified. A pooled analysis of prospective clinical trials was conducted to evaluate the efficacy and safety of neoadjuvant EGFR-TKI therapy.MethodsThe PubMed, Embase, Web of Science, and Cochrane Library databases, as well as meeting abstracts were searched for prospective clinical trials evaluating the efficacy and safety of neoadjuvant EGFR-TKI for treatment of EGFR-mutant NSCLC. The main outcomes included the objective response rate (ORR), downstaging rate, surgical resection rate (SRR), pathologic complete response (pCR) rate, progression-free survival (PFS), and adverse events.ResultsA total of five, phase II, prospective, clinical trials involving 124 patients with resectable or potentially resectable EGFR-mutant NSCLC treated with neoadjuvant erlotinib or gefitinib treatment were included in this pooled analysis. The median neoadjuvant medication time was 42 (range, 21–56) days and the median time of response evaluation was 45 (range, 42–56) days. The pooled ORR was 58.5% [95% confidence interval (CI), 45.5%–71.8%] and the surgical resection and complete resection (R0) rates were 79.9% (95% CI, 65.3%–94.5%) and 64.3% (95% CI, 43.8%–84.8%), respectively. In the stage IIIA subgroup (n = 68), the pooled ORR, SRR, and R0 rate were 51.4%, 72.9%, and 57.0%, respectively, while the downstaging and pCR rates were 14.0% and 0.0%, respectively. The pooled median PFS and overall survival were 13.2 and 41.9 months, respectively. Of the most common grade 3/4 adverse events in the overall group, the incidences of hepatotoxicity and skin rash were 5.3% and 14.7%, respectively. The most commonly reported postoperative complications were lung infection, arrhythmia, and pneumothorax.ConclusionNeoadjuvant EGFR-TKI therapy provides a feasible treatment modality for patients with resectable or potentially resectable EGFR-mutant NSCLC, with satisfactory surgical outcomes and low toxicity. Although further phase III clinical trials are needed to confirm these findings, it is necessary to explore the feasibility of a more effective EGFR-TKI combination neoadjuvant therapy given the modest downgrade and pCR rates for EGFR-TKI alone.

Background: Optimizing treatments for triple negative breast cancer (TNBC) in the localized breast cancer setting is key to preventing metastatic recurrences and reducing mortality from this devastating disease. Sacituzumab Govitecan (SG), a novel antibody-drug conjugate in which the topoisomerase 1 inhibitor SN-38 (the active metabolite of irinotecan) is coupled to a humanized monoclonal antibody targeting the tumor antigen Trop-2, was granted FDA accelerated approval in April 2020 for treatment of patients with metastatic TNBC. The NeoSTAR clinical trial is evaluating SG in the neoadjuvant setting for patients with localized TNBC. Trial design: This is a single arm phase II study of neoadjuvant SG in patients with localized TNBC. SG will be administered via an IV infusion on Days 1, 8 of each 21-day cycle at a starting dose of 10 mg/kg for 4 cycles. After 4 cycles, patients who have biopsy-proven residual disease will have the option to receive additional standard neoadjuvant therapy at the discretion of the treating physician and subsequently proceed to surgery. Those with a complete response on imaging may proceed directly to surgery. A baseline research biopsy prior to initiation of study therapy is required as well as tissue collection following treatment with SG (either at surgery or via biopsy prior to additional neoadjuvant therapy). Eligibility criteria: Patients ≥ 18 years of age with previously untreated primary TNBC as determined by the local institution according to ASCO/CAP criteria will be enrolled. Patients must either have a primary tumor >1 cm measured by imaging (cT1c-T4), or be node positive. An ECOG performance score of 0 or 1, and adequate bone marrow, hepatic, and renal function is required. Specific aims: The primary objective is to assess the pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) with SG. Secondary objectives include assessment of radiological response rate, evaluation of the safety and tolerability of SG (CTCAE v5.0), disease-free survival (DFS), and quality of life (EORTC QLQ-C30). Exploratory objectives include assessment of potential predictive biomarkers, including Trop-2 expression, DNA damage response markers and immunological markers, as well as changes in cell free DNA with SG. Statistical methods: The primary analysis is based on the estimated pCR rate with SG and will be provided as a proportion (with two-sided 95% confidence interval). Accounting for up to a 14% drop out rate, a sample size of 43 patients will provide 80% power to exclude a lower limit of pCR of 20% (alpha 0.05, two-sided test). DFS will be analyzed using Kaplan-Meier methods and descriptive statistics. Target Accrual: 50 patients. Contact: Dr. Laura Spring (LSpring@mgh.harvard.edu) Clinicaltrials.gov #: NCT04230109 Citation Format: Laura M. Spring, Sara M. Tolaney, Neelam Desai, Amy Comander, Therese Mulvey, Ian E. Krop, Eric P. Winer, Elizabeth A. Mittendorf, Leif W. Ellisen, Aditya Bardia. Phase 2 study of response-guided neoadjuvant sacituzumab govitecan (IMMU-132) in patients with localized triple-negative breast cancer (NeoSTAR) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-03-06.

Background In patients (pts) with non-metastatic NSCLC, surgery has curative potential but 30-80% who undergo resection experience recurrence. Neoadjuvant or adjuvant chemo is recommended for pts with high recurrence risk; however, benefits are modest and pathological complete response (pCR) with neoadjuvant chemo is low. Although immunotherapy targeting the PD-1 pathway has shown survival benefits in metastatic NSCLC, phase 3 trial results in resectable disease are yet to be reported. Recently, neoadjuvant NIVO, alone or in combination with chemo, has shown encouraging pCR rates in single-arm phase 2 studies. Here, we report the final analysis of one of the primary endpoints, pCR, of CheckMate 816 (NCT02998528)-a randomized, phase 3, open-label study evaluating NIVO + chemo vs chemo as neoadjuvant tx for resectable NSCLC. Methods Adults with clinical stage IB (≥ 4 cm)-IIIA (per AJCC 7th ed), resectable NSCLC, ECOG PS 0-1, and no known EGFR/ALK alterations were randomized to either NIVO 360 mg + platinum-doublet chemo Q3W or chemo Q3W for 3 cycles, followed by surgery. Stratification was by disease stage (IB/II vs IIIA), PD-L1 (≥ 1% or < 1%), and sex. pCR by blinded independent pathological review (BIPR) and event-free survival by blinded independent central review (BICR) are the primary endpoints. pCR was defined as 0% viable tumor cells in resected lung and lymph nodes; pts who did not undergo surgery were counted as non-responders. Overall survival, major pathological response (MPR; ≤ 10% viable tumor in both lung and lymph nodes) per BIPR, and time to death or distant metastases are secondary endpoints. Key exploratory endpoints are objective response rate (ORR) per BICR and potential predictive biomarkers including PD-L1 and tumor mutational burden (TMB). Results Baseline characteristics were balanced between arms (n = 179 each). Neoadjuvant NIVO + chemo significantly increased pCR rates vs chemo in the intent-to-treat population (ITT) (24.0% vs 2.2%; odds ratio 13.94 [99% CI 3.49-55.75]; P < 0.0001). Improvement in pCR with NIVO + chemo vs chemo was consistent across key subgroups including disease stage (IB/II [26.2% vs 4.8%]; ≥ IIIA [23.0% vs 0.9%]), PD-L1 (< 1% [16.7% vs 2.6%]; ≥ 1% [32.6% vs 2.2%]), and TMB (low [22.4% vs 1.9%]; high [30.8% vs 2.7%]). NIVO + chemo also improved MPR rates vs chemo in the ITT (36.9% vs 8.9%), as well as ORR (53.6% vs 37.4%) and radiographic down-staging rates (30.7% vs 23.5%). Definitive surgery occurred for 83.2% of pts treated with NIVO + chemo and 75.4% with chemo; surgery was cancelled rarely due to AEs (2 pts/arm) and due to disease progression in 12 and 17 pts, respectively. Grade 3-4 tx-related AEs and grade 3-4 surgery-related AEs were reported in 33.5% vs 36.9% and 11.4% vs 14.8% of pts in the NIVO + chemo vs chemo arms, respectively. Conclusions CheckMate 816 met its first primary endpoint with a statistically significant improvement in pCR with neoadjuvant NIVO + chemo vs chemo alone per independent review. The safety profile of NIVO + chemo was consistent with the known profile of this combination regimen, and the addition of NIVO did not decrease the ability to perform surgery. CheckMate 816 is the first positive phase 3 trial demonstrating a significant improvement in pathologic response with neoadjuvant immunotherapy plus chemo in resectable NSCLC. Citation Format: Patrick M. Forde, Jonathan Spicer, Shun Lu, Mariano Provencio, Tetsuya Mitsudomi, Mark M. Awad, Enriqueta Felip, Stephen Broderick, Julie Brahmer, Scott J. Swanson, Keith Kerr, Changli Wang, Gene B. Saylors, Fumihiro Tanaka, Hiroyuki Ito, Ke-Neng Chen, Cecile Dorange, Junliang Cai, Joseph Fiore, Nicholas Girard. Nivolumab (NIVO) + platinum-doublet chemotherapy (chemo) vs chemo as neoadjuvant treatment (tx) for resectable (IB-IIIA) non-small cell lung cancer (NSCLC) in the phase 3 CheckMate 816 trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT003.

Background: The Phase 3 TROPiCS-02 study found that the efficacy of sacituzumab govitecan (SG), an antibody-drug conjugate (ADC) directed to tumor-associated calcium signal transducer 2 (Trop2), in breast cancer (BC) does not depend on Trop2 expression levels. SG is the only FDA-approved ADC for advanced HR+/HER2− BC and triple-negative BC; it targets Trop2 by delivering SN-38, a topoisomerase I inhibitor. AT-rich interactive domain–containing protein 1A (ARID1A) is the most prevalent mutation in the SWItch/Sucrose Non-Fermentable (SWI/SNF) complexes in metastatic BC. ARID1A interacts with transcription factors involved in gene transcription and DNA repair, acting as a tumor suppressor. It is essential for maintaining luminal characteristics and influences treatment response. Patients with tumors harboring ARID1A alterations experience significantly shorter progression-free survival on selective estrogen receptor degraders than those with tumors with wild-type ARID1A. We hypothesize that loss or suppression of ARID1A expression results in a high level of Trop2 expression in HR+/HER2− BC. Identifying the mechanism linking ARID1A and Trop2, as well as determining the presence or absence of ARID1A mutations, could help identify patient groups that may benefit from combination therapy with SG and other inhibitors, enhancing treatment efficacy even in those with ARID1A mutations. Methods: We used transposase-accessible chromatin sequencing (ATAC-seq) and an RNA-seq database (GSE124228) from ARID1A-knockout MCF7 cells to determine whether ARID1A regulates Trop2 gene transcription. To elucidate how SG regulates the ARID1A-Trop2 axis in HR+/HER2− BC, we used specific small-molecule inhibitors, siRNA, and an expression plasmid targeting ARID1A. Target proteins in the ARID1A-Trop2 axis were detected with immunofluorescence staining, immunohistochemistry, flow cytometry, Western blotting, quantitative real-time PCR, and the TCGA database. Results: ARID1A protein expression negatively correlated with Trop2 expression in HR+/HER2− BC cell lines. Through Ataxia-Telangiectasia Mutated (ATM), the protein kinase critical for the cellular response to DNA damage activation, SG or SN-38 reduces ARID1A protein expression in HR+/HER2− BC cells. Further, ARID1A expression is diminished in tissue samples from SG-treated MCF7 xenografts resistant to both tamoxifen and abemaciclib. Mechanistic studies showed that overexpression of ARID1A reduces Trop2 mRNA and protein expression, whereas ARID1A knockdown elevates Trop2 levels in HR+/HER2− BC cells. Immunofluorescence staining data indicated an inverse correlation between ARID1A expression and Trop2 expression. ATAC-seq data revealed increased chromatin accessibility at the Trop2 promoter in ARID1A-knockout MCF7 cells. T47D cells, which exemplify low ARID1A and high Trop2 expression, are approximately ten times more sensitive to SG than MCF7 and HCC1428 cells, which have high ARID1A and low Trop2 expression. Thus, low ARID1A expression leads to elevated Trop2 levels, resulting in increased therapeutic activity of SG. Conclusion: We discovered that SG induces Trop2 expression through SN-38–mediated reduction of ARID1A protein expression in HR+/HER2− BC cell lines. Moreover, lower ARID1A in HR+/HER2− BC cells was associated with increased sensitivity to SG. These results suggest a novel mechanism for Trop2 ADC efficacy in HR+/HER2− BC with low Trop2 expression. Our findings highlight the importance of knowing a patient’s ARID1A status to predict the efficacy of Trop2-ADCs. Further mechanistic studies will be presented at SABCS. Citation Format: Nanae Ogata, Nakyung Oh, Dileep R. Reddy, Lan Vo, Naoto T. Ueno, Jangsoon Lee. ARID1A as a Novel Regulator of Trop2-ADC Efficacy in Trop2-Low Hormone Receptor–Positive Breast Cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr PS13-08.