Vitamin C misses primary endpoint in EVITA trial; exploratory analysis suggests survival benefit

Oral vitamin C did not affect the growth rate of precancerous or cancerous cells in the randomized, double-blind, placebo-controlled phase 2 EVITA trial, published in Cancer. The trial enrolled 109 participants in Denmark and the United States with precancerous blood disorders or low-risk blood cancers. Researchers assigned 55 participants to vitamin C 1,000 mg daily and 54 to placebo for 12 months. The rationale was that vitamin C can enhance TET enzyme activity, which is reduced in some blood cancers.

Although the groups were similar on the primary cell-growth endpoint, vitamin C recipients showed changes in inflammatory signaling described as favorable. They also had fewer cases of anemia, pneumonia, acute aseptic arthritis, and internal bleeding, but more gastrointestinal problems; the source did not provide event counts. At a median follow-up of 33.6 months in the intention-to-treat population, 35 participants had died: 11 assigned to vitamin C and 24 assigned to placebo.

The survival finding came from an exploratory analysis and does not establish a treatment benefit. The small phase 2 study and its unchanged primary endpoint limit clinical interpretation. This account is based on a Wiley-provided summary of the peer-reviewed report. Researchers said a larger phase 3 trial is needed and that the findings do not support new treatment recommendations.