AbstractPremature ovarian failure (POF) that could result from chemotherapy applied to young female cancer patients is a significant challenge in reproductive biology. It is widely believed that the hyperactivation of dormant primordial follicles following chemotherapy is a leading cause of POF, but it remains unclear how therapeutic cues are generated and transduced into follicular activation. Here, we provide evidence that supports that GV1001, an immunotherapeutic peptide targeting telomerase, plays a role in the deterrence of POF in mice. In vivo non-small cell lung carcinoma (NSCLC) tumor xenografts were produced by inoculating NSCLC cells into the flank of BALB/c female athymic mice and then subjected to cancer chemotherapy with GV1001 and bevacizumab, an anti-cancer antibody drug, humanized anti-VEGF monoclonal antibody. Bevacizumab when administered at the dosage of 5 mg/kg for three weeks was effective in inhibiting growth of NSCLC tumor xenografts, and its anti-cancer efficacy was not interfered by the presence of GV1001. As expected, bevacizumab induced follicular loss by accelerating primordial follicle growth into primary or secondary follicles concomitant with a decline of serum antimullerian hormone (AMH) level and deactivation of Foxo3 signaling as evidenced by immunohistochemical and immunofluorescent assessment. However, bevacizumab-induced follicle stimulating effects were mitigated by GV1001 co-administration as evidenced by the analysis of follicular count, serum AMH level, and Foxo3a expression. From this study, we propose that a combinatorial administration of GV1001 and bevacizumab could deter POF of young female cancer patients without hampering the anti-cancer effectiveness of bevacizumab.