Abstract 462P
Background
Combining biomarker-directed therapies with chemotherapy improves survival in patients with advanced G/GEJ cancer. Thus, timely testing for actionable biomarkers is needed to match patients with appropriate treatments, but data on real-world testing rates and treatment patterns are limited. This cohort study describes biomarker testing results and treatment patterns in patients with advanced G/GEJ cancer.
Methods
Deidentified health record data from the Tempus database in the US were used to identify adults with diagnosis codes for advanced G/GEJ cancer between 1 January 2020–11 July 2023. The primary outcomes were testing results for actionable biomarkers (human epidermal growth factor receptor 2 [HER2], programmed cell death ligand 1 [PD-L1], and microsatellite instability/mismatch repair [MSI/MMR]) and associated treatment patterns.
Results
The study included 829 patients with advanced G/GEJ cancer. Biomarker testing results and treatment patterns are reported in the table. Testing for all 3 biomarkers (HER2, PD-L1, and MSI/MMR) occurred in 363/829 (43.8%) patients in the Tempus database. Use of matched treatment based on actionable biomarkers occurred in only 107/826 (13%) patients. Table: 462P
| HER2 | PD-L1 | MSI/MMR | |
| Tested for biomarker, n/N (%) | 528/829 (63.7) | 513/829 (61.9) | 826/829 (99.6) |
| Tested between advanced diagnosis and 1st line of therapy, n/N (%) | 311/829 (37.5) | 294/829 (35.5) | 443/829 (53.4) |
| Positive, n/n (%) | 82/528 (15.5) | PD-L1 combined positive score >1: 219/513 (42.7)PD-L1 combined positive score ≥5: 144/513 (28.1) | MSI-high/MMR-deficient: 29/826 (3.5) |
| Positive and received matched therapy, n/n (%) | 52/82 (63.4) | 50/144 (34.7) | 4/29 (13.8) |
| Tested and received unmatched therapy, n/n (%) | 327/528 (61.9) | 330/513 (64.3) | 500/826 (60.5) |
Conclusions
Contrary to current treatment guidelines, not all patients with advanced G/GEJ cancer had documentation of testing for actionable biomarkers, and of those who did, not all were treated with appropriate matched therapies. Increased biomarker testing and use of matched therapies would likely improve survival in these patients. Further research is needed to understand nonadherence to treatment guidelines.
Editorial acknowledgement
Medical writing support was provided by Ann Ferguson, PhD, of Oxford PharmaGenesis Inc., and was funded by Astellas Pharma Inc.
Legal entity responsible for the study
Astellas Pharma Inc.
Funding
Astellas Pharma Inc.
Disclosure
S.J. Klempner: Financial Interests, Personal, Other, Payment to Me - All support for the present abstract (e.g., funding, provision of study materials, medical writing, article processing charges, etc.): Astellas; Financial Interests, Personal, Other, Consulting fees - Payment to me: Astellas; Financial Interests, Personal, Other, Consulting fees - Payment to me, ended 1/2024: Novartis; Financial Interests, Personal, Other, Consulting fees - Payment to me, ended 7/2023: Merck; Financial Interests, Personal, Advisory Board, Payment to me, gastric cancer advisory board: Astellas, Amgen, Pfizer, Sanofi-Aventis, Merck, BMS, I-Mab, Mersana, Natera, AstraZeneca, Daiichi Sankyo, Servier, Coherus; Financial Interests, Personal, Stocks/Shares, Me, ended in 6/2022: Turning Point Therapeutics; Financial Interests, Personal, Stocks/Shares, Me, ended 11/2022: Nuvalent; Non-Financial Interests, Personal, Other, Unpaid relationship, member of guidelines committee: NCCN Guidelines. R. Fuldeore: Financial Interests, Personal and Institutional, Full or part-time Employment, Employee of Astellas. A. Brackey, C. Sangli, S. Nishtala: Financial Interests, Personal, Full or part-time Employment: Tempus AI, Inc. D. Nimke, S. Braun: Financial Interests, Personal and Institutional, Full or part-time Employment: Astellas Pharma Global Development, Inc. R. Mehta: Financial Interests, Personal, Advisory Board, Paid to self: Merck, BMS, Eli Lilly, Novartis, Astellas, Seagen, Guardant Health, BostoGene, Eisai, AstraZeneca, Arcus Biosciences, GSK, Natera.