Igyxos Biotherapeutics Announces Positive Results from Phase 1 Trial of IGX12, its First-in-Class Monoclonal Antibody for the Treatment of Male and Female Infertility

Tours, France – 10 December 2025 – Igyxos Biotherapeutics, a biotechnology company dedicated to developing innovative monoclonal antibodies for infertility treatment, today announced the successful completion of its Phase 1 clinical trial evaluation of IGX12.

The recent Multiple Ascending Dose (MAD) Phase 1 trial of IGX12 was a randomised, placebo-controlled study in 14 healthy male volunteers at two doses (20 & 40 μg/kg) given every other week as 4 subcutaneous injections over 6 weeks.

These results demonstrated an excellent safety profile at both doses, with no serious adverse events reported. The pharmacokinetic (PK) profile showed a gradual absorption phase and a slow elimination half-life which could be supportive of monthly dosing, important for fertility treatment. These results are supported by the preceding Single Ascending Dose (SAD) study in 32 healthy volunteers (16 men & 16 women), reported in March 2025. The company is now planning Phase 2 trials, due to start in leading fertility centres in Europe in 2026.

IGX12 is a first-in-class potentiating monoclonal antibody developed by Igyxos to enhance the potency and efficacy of follicle-stimulating hormone (FSH), a critical hormone involved in female and male gametogenesis. IGX12 has been designed to improve ovarian stimulation in women undergoing medically assisted reproductive technologies and enhance spermatogenesis in men with oligozoospermia, the medical term for a low sperm count.

Dr. Elke Bestel, Chief Medical Officer of Igyxos Biotherapeutics, said, “There has been little innovation in the field of infertility over the last 40 years. Unlike current IVF treatment regimens, our innovative monoclonal antibody-based approach addresses both female and male infertility. Male infertility accounts for nearly half of all infertility cases and currently has no approved treatment. We are excited by these promising results, this time in exclusively male cohorts. Our goal is to bring a new treatment option for infertility to everyone that needs it.” 

Florent Ferré, Chief Executive Officer of Igyxos Biotherapeutics, said, “Following the results of our Single Ascending Dose study in March, these MAD study results are another important new milestone in the clinical development of our innovative approach to treating infertility. We are extremely encouraged by these positive Phase 1 results in both male and female cohorts.”