Phase Ib/II Trial of Pharmacologic Ascorbate With Concurrent Preoperative Radiation in Patients With Locally Advanced Soft Tissue Sarcoma of the Trunk and Extremities JCO Oncology Advances Phase Ib/II Trial of Pharmacologic Ascorbate With Concurrent Preoperative Radiation in Patients With Locally Advanced Soft Tissue Sarcoma of the Trunk and Extremities Varun Monga, John Rieth, Benjamin Miller, Hisakazu Hoshi, Carlos Chan, Bryan Allen, Carryn Anderson, Kristen Plichta, Munir Tanas, Jonathan Davick, Steven Varga, Laura Stephens, Sarah L. Mott, John Smestad, Gustavo Fernandes Godoy Almeida, Mohammed Milhem JCO Oncology Advances 2025 :2
Date
12/11/2025Abstract
Purpose
To evaluate the safety and preliminary efficacy of pharmacologic ascorbate combined with neoadjuvant radiation in patients with localized high-risk soft tissue sarcoma (STS).
Methods
This phase Ib/II trial enrolled 25 patients with histologically confirmed STS of the extremities, chest wall, and retroperitoneum. Patients received intravenous ascorbate (75 g) three times a week during standard preoperative radiotherapy (50 Gy in 25 Fx). Primary objectives of phase Ib included safety assessment, with the primary objective of phase II being pathologic complete response (pCR) rate defined as tumor necrosis ≥95%. Secondary end points assessed event-free survival (EFS) and overall survival (OS). Exploratory end points included postinfusion ascorbate and immunophenotyping flow cytometry from peripheral blood and tumors.
Results
Treatment grade 3-4 adverse events included lymphopenia (20%), anemia (4%), and hypertension (8%). No therapy-related deaths occurred. The phase II trial primary end point was not met, with three (12%) of 25 patients achieving pCR. Partial responses were observed in two, with 22 demonstrating stable disease. EFS at 12 and 24 months was 68% and 60%, whereas OS was 96% at 12 months and 80% at 24 months. Flow cytometry analysis revealed increases in activated effector CD8+ T cells compared with control subjects who underwent neoadjuvant radiation without the addition of pharmacologic ascorbate. The study also revealed positive correlations between changes in tumor-infiltrating lymphocytes and peripheral blood T-cell populations.
Conclusion
Pharmacologic ascorbate plus neoadjuvant radiation demonstrated manageable safety but did not significantly improve primary end points. However, the observed correlations between peripheral blood and tumor T-cell changes provide valuable insights into potential immune mechanisms that could inform future combination strategies.
Author List
Varun Monga, John Rieth, Benjamin Miller, Hisakazu Hoshi, Carlos Chan, Bryan Allen, Carryn Anderson, Kristen Plichta, Munir Tanas, Jonathan Davick, Steven Varga, Laura Stephens, Sarah L. Mott, John Smestad, Gustavo Fernandes Godoy Almeida, Mohammed MilhemAuthor
John Smestad PhD, BS, MD Assistant Professor in the Medicine department at Medical College of WisconsinView Online
