Abstract 1408P
Background
PDT using the novel photosensitizer DVDMS has shown promising activity in treating esophageal stenosis and improving dysphagia in local recurrent or metastatic EC in phase II study previously, with an esophageal stenosis overall response rate (es-ORR) of 40% at day 28 under a 102 J/cm light dose at 24-hour intervals. This phase IIIb trial aims to further assess the efficacy and safety of DVDMS-mediated PDT.
Methods
This trial enrolled patients with previously treated advanced EC, with a Stooler dysphagia grade ≥ 2 (CTR20221271). Patients were randomized 2:1 to receive DVDMS-mediated PDT (DVDMS of 0.2 mg/kg, light dose of 102 J/cm, PDT delivered at 630±5 nm 24±2 hours intervals) or treatment of physician’s choice, including chemotherapy and best supportive care. The primary endpoint was es-ORR.
Results
As of December 31, 2023, 84 eligible pts had completed the day 28 follow-up or censored. At day 28, the DVDMS-PDT group (n=56) exhibited an es-ORR of 48.21% (95% CI: 34.66-61.97), significantly higher than the control group's 3.57% (95% CI: 0.09-18.35, P < 0.0001). Average esophageal diameter increases were 1.76 mm and -0.67 mm. Other endpoints are detailed in the table. Treatment-emergent adverse events occurred in 80.36% of the DVDMS-PDT group and 92.86% of controls. Phototoxicity was negative in 75% patients in DVDMS-PDT group on day 7, increasing to 94.64% by day 28. Two deaths related to adverse events in the DVDMS-PDT group (one possibly treatment-related) and four in the control group.
Conclusions
Preliminary results indicates that DVDMS-mediated PDT has significant higher es-ORR and improves dysphagia as well as quality of life with a favorable safety profile compared with treatment of physician’s choice, emphasizes this new option for advanced EC with dysphagia. The trial is ongoing. Table: 1408P
| Outcomes on day 28 | DVDMS PDT (n=56) | Treatment of physician’s choice (n=28) |
| Reduction at least 1 grade in Stooler's dysphagia grade, n (%) | 18 (32.14) | 0 |
| Mean change from baseline in Stooler's dysphagia score | -0.4 | 0.1 |
| Mean change from baseline in EORTC QLQ-C30 overall health score (Higher scores indicate better overall health) | 3.442 | -1.471 |
| Mean change from baseline in EORTC QLQ-OES18 dysphagia score (Higher scores indicate more severe symptoms) | -3.140 | 0.000 |
| Mean change from baseline in EORTC QLQ-OES18 eating score (Higher scores indicate more severe symptoms) | -10.145 | -3.431 |
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Shanghai Guangsheng Pharmaceutical Co., Ltd.
Funding
Shanghai Guangsheng Pharmaceutical Co., Ltd.
Disclosure
S. Zhang: Financial Interests, Personal and Institutional, Affiliate: Shanghai Guangsheng Pharmaceutical Co., Ltd. All other authors have declared no conflicts of interest.
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