KEY TAKEAWAYS
- The phase I/II trials aimed to determine the optimal dose and assess the safety and efficacy of DB-1303 in patients previously treated and were HER2-expressing advanced/metastatic EC.
- DB-1303 proved safe and efficacious for treating advanced/metastatic EC.
DB-1303 is a targeted therapy candidate designed to fight cancers that express high levels of HER2, a protein known to promote tumor growth. The drug combined with a precisely targeted antibody potent enough to kill cancer cells.
In this study, the researchers’ primary goal was to pinpoint the most effective dosage and thoroughly evaluate the safety and effectiveness of DB-1303. This assessment specifically targeted patients who had previously undergone treatment and exhibited HER2 expression in advanced or metastatic endometrial cancer (EC).
About 32 patients were treated with 7 or 8 mg/kg of DB-1303. The predominant histological subtypes were uterine serous papillary carcinoma (USPC, 34.4%), adenocarcinoma (25.0%), and uterine carcinosarcoma (UCS, 18.8%). The median treatment duration was 2.6 months (range, 0.7-10.4), with 29 patients (90.6%) remaining on treatment. The median number of prior regimens for metastatic disease was 2 (range, 1-10), and 59.4% had prior immunotherapy.
The study evaluated 17 patients for response, with 58.8% showing objective partial tumor response per RECIST 1.1: 87.5% in USPC, 50.0% in UCS, 50.0% in mixed adenocarcinoma, and 33.3% in adenocarcinoma. The objective response rates(ORR) for patients at 7 and 8 mg/kg doses were 50.0% and 61.5%, respectively, and the overall disease control rate(DCR) was 94.1%.
Treatment-emergent adverse events (TEAEs) occurred in 93.8% of patients, with common events (≥20%) including nausea (50.0%), fatigue (31.2%), and vomiting (28.1%). Grade ≥3 TEAEs occurred in 31.2%, with hypokalemia (12.5%), anemia (6.2%), and syncope (6.2%) being the most common. No TEAEs led to drug discontinuation or death, and no interstitial lung disease occurred.
The results demonstrated that DB-1303 was safe and effective in treating advanced/metastatic EC, with most patients improving.
Source: https://www.emma.events/site/programme/?sessiondetail=4534534&trackid=0&a=esgo2023#!
Clinical Trial: https://clinicaltrials.gov/study/NCT05150691
Moore, K., Makker, V., Yeku, O., et al. (2023). “DB-1303, A HER2-Targeting ADC, For Patients With Advanced/Metastatic Endometrial Cancer: Preliminary Clinical Results From An Ongoing Phase 1/2a Trial (NCT05150691).” Presented at the ESGO Congress 2023. (Abstract 430).
