169 - A Novel Regimen of Liposomal Irinotecan Plus Capecitabine as Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer (LipCap): A Phase II Trial

11:25am - 11:35am ET

Room 162

Presenter(s)

Lin-Lin Xiao, MS, RT - The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei

F. P. Wu^1,2, and L. L. Xiao^3,4; ¹Department of Radiotherapy, Fourth Hospital of Hebei Medical University, Shijiazhuang, China, ²The fourth hospital of hebei medical university, Shijiazhuang, Hebei, China, ³Department of Radiation Oncology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China, ⁴Department of Radiation Oncology, Fourth Hopital of Hebei Medical University, Shijiazhuang, China

Purpose/Objective(s):

This prospective phase II trial aims to evaluate the efficacy and safety of liposomal irinotecan in this treatment field, with the goal of establishing a novel neoadjuvant therapeutic option for locally advanced rectal cancer (LARC).

Materials/Methods:

Patients diagnosed with LARC (cT3-4NanyM0) were enrolled. Treatment commenced with long-course concurrent chemoradiotherapy (LCRT, 50.4Gy/28f). The concurrent chemotherapy regimen consisted of capecitabine and liposomal irinotecan. After completing LCRT, consolidation chemotherapy comprising 4-6 cycles of liposomal irinotecan plus capecitabine was administered. The primary endpoint was the rate of pathological complete response (pCR). Secondary endpoints encompassed the rates of major pathological response (MPR) and clinical complete response (cCR), the incidence of adverse events (AEs), 3-year progression-free survival and overall survival.

Results:

Between February 2024 and March 2025, 60 patients were enrolled and initiated LCRT. Of these, 57 proceeded to consolidation chemotherapy upon completion of the initial phase. Ultimately, 47 patients underwent surgical resection, all of whom achieved R0 resection. Pathological evaluation confirmed a pCR in 10 (21.3%) surgical patients and a MPR (defined as TRG 0–1) in 23 (48.9%). Among the 10 patients without surgery, 3 achieved a cCR, resulting in an overall complete response rate (pCR + cCR) of 21.7% (13/60) for the entire cohort. The incidence of grade 3–4 AEs was 16.7%, with the most common being diarrhea (10.0%) and leukopenia (5.0%).

Conclusion:

Combining a promising pathological response with a more manageable toxicity profile, this regimen offers a well-tolerated and effective alternative for total neoadjuvant therapy in LARC.