Genticel: two year trial of HPV16/18 immunotherapeutic candidate fails

Genticel, a clinical-stage biotechnology company and developer of innovative immunotherapies to prevent cancers caused by the human papillomavirus (HPV), has announced the final results (24-month time point) of the phase 2 trial of its HPV16/18 immunotherapeutic candidate, GTL001.

The final data at month 24 showed no statistical differences in viral clearance rates between the GTL001 and placebo groups. No consistent statistical differences between groups were demonstrated in any of the secondary endpoints (confirmed and sustained clearance) over the 2-year duration of the trial. The incidence of subjects progressing to high-grade lesions was identical in both groups. A significant increase in anti-CyaA antibodies following treatment was observed in the GTL001 group, but not in the placebo group. The significant increase in anti-CyaA titers in the treated group persisted during the entire course of the study.

The company said that the 12-month results announced in January 2016 showed no overall difference in viral clearance between the treatment and placebo groups, but a trend towards a significant difference in sub-group analyses was observed, most notably in the NILM[2] sub-group. The interim analysis at 18 months demonstrated that overall viral clearance, or by sub-group, did not statistically differ from the natural clearance observed in the placebo group.

Other than the first days following each vaccination, GTL001 and imiquimod were generally well tolerated with no unexpected safety signal identified at any point during the study.

This phase 2 trial was a randomized double-blind, placebo controlled study conducted at 33 investigational sites in 7 Western European countries. 233 patients positive for HPV 16/18 at baseline were evaluable for efficacy analysis, with a treated arm of 117 patients and a placebo arm of 116 patients. Enrolled patients were required to be HPV 16 and/or 18 positive with normal (NILM) or abnormal (ASCUS or LSIL[3]) cytology. All patients receiving at least one dose of vaccine or placebo were assessed for viral clearance. Compliance was excellent, with 218 subjects completing the study (112 in the treated group and 106 in the placebo group).

Sophie Olivier, MD, Chief Medical Officer of Genticel, commented: “The positive safety and tolerance data, as well as the strong and lasting induction of anti-CyaA antibodies, observed in this trial are positive indicators for our partnership with the Serum Institute of India[4]. I wish to thank all of the investigators and clinical teams, as well as all the women, who participated in this trial, which will hopefully contribute scientifically to identifying improved therapies for the millions of women infected with dangerous human papilloma virus types.”

Benedikt Timmerman, PhD, MBA, Chief Executive Officer of Genticel, added: “Genticel will now end its HPV therapeutics development program and the Company remains focused on seeking new drug candidates, as well as moving forward with our partnership with the Serum Institute, which recently resulted in a $1.2 million milestone payment to Genticel based on the successful completion of the last preclinical milestone.”