Abstract 161P
Background
This prospective multi-central randomized phase II trial is to evaluate the efficacy and safety of oral vitamin B12 500μg/day replacement to that of oral vitamin B12 1500μg/day in patients with vitamin B12 deficiency after total gastrectomy for gastric cancer.
Methods
Patients were randomly assigned to receive oral Vitamin B12 500μg/day or Vitamin B12 1500μg/day in a 1:1 ratio with a minimization method. The primary endpoint was incidence of the normal serum vitamin B12 level at 3 months after treatment. The secondary endpoints were improvement of neurologic symptom and safety.
Results
From January 2018 to December 2021, 3 institutions collaborated with the present study, and 74 patients were registered from 3 institutions. The study was prematurely closed due to poor accrual after reaching almost 50% of its goal. Among 74 patients, 36 were allocated to the Vitamin B12 500μg/day arm and 38 to Vitamin B12 1500μg/day arm. The incidences of the patients who were Vitamin B12 normal level at 3 months (serum Vitamin B12 level is more than 200pg/ml) were 91.7% (3/36) in Vitamin B12 500μg/day arm and 100% (38/38) Vitamin B12 1500μg/day arm (p=0.3587). The improvement of clinical symptoms were not significantly differences between the vitamin B12 500μg/day arm and vitamin B12 1500μg/day arm. The types of clinical symptoms with vitamin B12 deficiency that improved with vitamin B12 treatment and the degree of improvement were also similar. In vitamin B12 500μg/day arm, median number of clinical symptoms grade 2 or more was 3.0 before treatment, while median number of clinical symptoms grade 2 or more was 1.4 after treatment. In vitamin B12 1500μg/day arm, median number of clinical symptoms grade 2 or more was 3.2 before treatment, while median number of clinical symptoms grade 2 or more was 1.5 after treatment.
Conclusions
Although the primary endpoint of the present study was unmet and the power for the formal statistical analysis was limited, the major findings of this study were that oral vitamin B12 500μg/day replacement is equally effective and safe treatment to oral vitamin B12 1500μg/day replacement for the vitamin B12 deficiency.
Clinical trial identification
This clinical trial was registered at the University Hospital Medical Information Network Clinical Trials Registry (UMIN000030727).
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.