859MO - Sacituzumab govitecan (SG) in patients (pts) with relapsed/refractory (R/R) advanced head and neck squamous cell carcinoma (HNSCC): Results from the phase II TROPiCS-03 basket trial

Background

Although programmed death (ligand) 1 (PD-[L]1) inhibitors have improved outcomes in pts with advanced HNSCC, most pts experience disease progression and need subsequent treatment. SG is a Trop-2-directed antibody-drug conjugate. TROPiCS-03 (NCT03964727) is an open-label, multicohort, phase 2 study evaluating SG in pts with metastatic or locally advanced solid tumors. Here, we report initial data from the HNSCC cohort.

Methods

Adult pts with R/R metastatic or locally advanced HNSCC that progressed after prior platinum-based chemo and anti-PD-(L)1 therapy (in combination or sequentially in either order) received SG 10 mg/kg on Days 1 and 8 of a 21-day cycle. The primary endpoint was objective response rate (ORR) by investigator assessment (INV) per RECIST v1.1. Key secondary endpoints included clinical benefit rate (CBR), duration of response (DOR), progression-free survival (PFS), overall survival, and safety. Pts who received ≥1 dose of SG were included in the safety and efficacy analyses.

Results

As of 18 April 2023, 43 pts received ≥1 dose of SG. Median age was 62 years (range, 46-75) and 79% of pts had an ECOG performance status of 1. Median number of prior therapies was 3 (range, 2-9). With median follow-up of 7.5 months (range, 0.6-19.7), ORR was 16%, CBR was 26%, and median DOR was 4.2 months (Table). Median PFS was 4.1 months (Table). Treatment was ongoing for 5 (12%) pts. Any-grade treatment-related adverse events (TRAEs) occurred in 100% (grade ≥3, 44%) of pts. No TRAEs leading to discontinuation of study treatment were reported to date. Three (7%) deaths due to AEs were reported, and only 1 (2%) was considered related to study treatment. Table: 859MO

^aBy INV. ^bPts with CR + PR + SD for ≥ 6 mo. BOR, best overall response; CI, confidence interval; CR, complete response; mo, months; NR, not reached; PD, progressive disease; PR, partial response; SD, stable disease.

Conclusions

SG demonstrated single agent activity and manageable safety, with no TRAEs leading to discontinuation to date, in heavily pretreated pts with advanced HNSCC.

Clinical trial identification

NCT03964727.

Editorial acknowledgement

Editorial support was provided by Dominic Singson, MD, of Parexel and funded by Gilead Sciences, Inc.

Legal entity responsible for the study

Gilead Sciences, Inc.

Funding

Gilead Sciences, Inc.

Disclosure

A. Jimeno: Financial Interests, Personal, Advisory Board: Bluedotbio; Financial Interests, Personal, Stocks/Shares: Suvica, Champions Oncology; Financial Interests, Institutional, Local PI: Genentech, Khar, Merck, Sanofi, Debbie, Cantargia, Lovance; Financial Interests, Institutional, Coordinating PI: SQZ. T. Beck: Financial Interests, Institutional, Local PI: Lilly, AZ, Novartis, DSI, AbbVie, Pfizer, johnson and Johnson, BMS, Merck, EMD serono, Tesaro, Mersano, ascentage pharma, Gritstone, Gilead. J.W.Y. Chiu: Financial Interests, Personal, Invited Speaker: MSD, Eli Lilly, Daichi Sankyo. J. Hilton: Financial Interests, Personal, Advisory Board: Merck, Novartis, Astra Zen, Pfizer, Eli Lilly; Financial Interests, Personal, Invited Speaker: Merck, Novartis ; Financial Interests, Personal, Other, DSMC: BMS; Financial Interests, Personal, Research Grant: GSK. A. hollebecque: Financial Interests, Personal, Invited Speaker: Servier, Incyte, EISAI; Financial Interests, Personal, Advisory Board: Basilea, Tahio, Relay Theraeutics, QED Therapeutics, Debiopharm, MSD, Boehringer Ingelheim; Financial Interests, Institutional, Funding: Incyte; Financial Interests, Institutional, Research Grant: AstraZeneca; Non-Financial Interests, Principal Investigator, M19-345: AbbVie; Non-Financial Interests, Principal Investigator, CO42216; WP42627; CO40939: Roche; Non-Financial Interests, Principal Investigator, MCLA-158: Merus; Non-Financial Interests, Principal Investigator, SGNB6A: Seatle Genetics; Non-Financial Interests, Principal Investigator, TAS-120-202: Tahio; Non-Financial Interests, Principal Investigator, Krystal-10: Mirati; Non-Financial Interests, Principal Investigator, ADP-0033: Adaptimmune; Non-Financial Interests, Principal Investigator, ACT16902: Sanofi; Non-Financial Interests, Principal Investigator, C4201002: Pfizer; Non-Financial Interests, Principal Investigator, RLY-4008: Relay Therapeutics; Non-Financial Interests, Principal Investigator, CC-90011: Celgene/BMS; Non-Financial Interests, Principal Investigator, Loxo-IDH: Loxo/Lilly; Non-Financial Interests, Principal Investigator: AstraZeneca; Non-Financial Interests, Principal Investigator, SN-201 study: Sotio; Non-Financial Interests, Principal Investigator, Tropics-03: Gilead; Non-Financial Interests, Principal Investigator, BI1403: Boehringer Ingelheim. J. Patel: Financial Interests, Personal, Stocks/Shares: Gilead Sciences, Inc.. S. Mekan: Financial Interests, Institutional, Full or part-time Employment: Gilead Sciences. T. Wu: Financial Interests, Personal, Stocks/Shares: Gilead Sciences; Financial Interests, Personal, Full or part-time Employment: Gilead Sciences. E.E. Dumbrava: Financial Interests, Institutional, Other, Research/grant funding: Bayer HealthCare Pharmaceuticals, Immunocore Ltd, Amgen, Aileron Therapeutics, Compugen Ltd, Gilead, BOLT Therapeutics, Aprea Therapeutics, Bellicum, PMV Pharma, Triumvira, Seagen Inc, Mereo BioPharma 5 Inc, Sanofi, Rain Oncology, Astex Therapeutics, Sotio, Mersana Therapeutics, Poseida, Boehringer Ingelheim; Financial Interests, Personal, Invited Speaker: PMV Pharma; Financial Interests, Personal, Advisory Board: BOLT Therapeutics, Mersana Therapeutics, Orum Therapeutics, Summit Therapeutics. All other authors have declared no conflicts of interest.