We sought to evaluate the safety and efficacy of TG4001 in patients with human papillomavirus (HPV) 16–related cervical intraepithelial neoplasia (CIN) 2/3 at 6 and 12 months.In all, 21 patients with HPV 16–related CIN 2/3 received 3 weekly subcutaneous injections of TG4001. Regression of the CIN 2/3 lesion and the clearance of HPV 16 infection were monitored by cytology, colposcopy, and HPV DNA/messenger RNA (mRNA) detection. A clinical response was defined by no CIN 2/3 found on conization, or no conization performed because not suspected at cytology or colposcopy.Ten patients (48%) were evaluated as clinical responders at month 6. Nine patients experienced an improvement of their HPV 16 infection, by mRNA ± DNA eradication. HPV 16 mRNA clearance was associated with CIN 2/3 cytologic and colposcopic regression in 7 of 10 patients. At month 12, 7 of 8 patients without conization reported neither suspicion of CIN 2/3 relapse nor HPV 16 infection. The remaining patient was lost to follow-up.These promising data warrant further development of TG4001 in CIN 2/3 treatment.