Following successive wins in Brighton, Nottingham and Dublin, Humphries had opened up a seven-point lead at the top of table
Jennifer Foster and Stephen Kirby will remain in charge until a successor is appointed.
England men's captain Jamie George has been helping prepare the national women's side for their Six Nations clash at home to Wales on Saturday after volunteering his services to Red Roses head coach John Mitchell.Mitchell got to know Saracens hooker George when working as an assistant when Australian Eddie Jones was England men's head coach.