Randomization and masking
The allocation and randomization numbers were generated by SAS 9.4, through the interactive web response system. After participants signed informed consent, they were assigned a screening number for screening process. Every eligible participant who fully met the screening criteria was randomized on Day-1 after assigned a randomization number in ascending order of the screening number by gender respectively. All investigators, participants, study coordinators and related personnel, and the sponsor were masked to allocation. JMB2002 (WuXi Biologics) and placebo, both were colorless to light yellow and transparent to micro-opalescent liquid, were identical in the appearance, viscosity and color.