Intravenous (IV) vitamin C improves organ function and reduces inflammation in sepsis, an inflammatory state like the post-hematopoietic stem cell transplant (SCT) milieu. The safety and efficacy of parenteral vitamin C after allogeneic hematopoietic stem cell transplant (HSCT) were evaluated in a phase I/II trial and clinical outcomes compared with a propensity score - matched historical control. Methods: Patients with advanced hematologic malignancies were enrolled in a phase 2 clinical trial, receiving IV vitamin C, 50mg/kg/d, divided into 3 doses given on days 1- 14 after HSCT, followed by 500 mg bid oral from day 15 until 6 months post-SCT. Results 55 patients received IV vitamin C: these include 10/10 HLA-MRD and MUD (n=48) and 9/10 HLA MUD recipients (n=7). All patients enrolled were deficient in vitamin C at day 0, and had restoration to normal levels for the remainder of the course. Vitamin C recipients had lower non-relapse mortality (11% vs. 25%, p-value = 0.07) and improved survival compared to historical controls (82% vs 62% p=0.06), with no attributable grade 3 and 4 toxicities to vitamin C. Vitamin C recipients had similar relapse rate and acute graft versus host disease (GVHD) as historical controls (p=0.35), but lower severe chronic GVHD (11% vs 24%; p-value 0.35) compared to historical controls. Patients with myeloid malignancies had improved survival (83% vs. 54%, p=0.02) and non-relapse mortality (NRM) (10% vs. 37%, p=0.009), as well as chronic GVHD, with similar relapse rates compared to controls. Conclusions: In patients undergoing allogeneic HSCT the administration of IV vitamin C is safe and reduces non-relapse mortality and chronic GVHD improving overall survival. Randomized trials are necessary to confirm these findings.

The authors have declared no competing interest.

IND #138924, NCT03613727

This trial was supported by research funding from the NIH-NCI Cancer Center Support Grant (P30-CA016059; PI: Gordon Ginder, MD).

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Virginia Commonwealth University Institutional Review Board gave ethical approval for this work.

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