Male contraceptive pill breaks new ground in the birth control field
The novel androgen 11-beta-methyl-19-nortestosterone dodecylcarbonate (11β-MNTDC) – a modified testosterone with androgenic and progestational activity being developed as a male contraceptive – effectively suppressed endogenous gonadotropin and testosterone production in healthy men, consequently preventing pregnancies, according to data presented at ENDO 2019.
Researchers randomized 40 men aged 18–50 years to receive a daily dose of either 11β-MNTDC 200 or 400 mg (n=14 and 16, respectively) or placebo (n=10) for 28 consecutive days. Serial blood sampling was conducted over 24 hours on days 1 and 28 to evaluate the pharmacokinetic and pharmacodynamic effects of the drug, including 24-hour serum testosterone average concentration (Cavg24) and testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) suppression. [ENDO 2019, abstract SUN-LB042]
On day 28, recipients of 11β-MNTDC had a profound dose-related suppression of Cavg24 (median, 22.3 [200 mg dose] and 7.6 ng/dL [400 mg dose] vs 461.1 ng/dL [placebo]), LH (median, 1.9 and 0.3 IU/L vs 6.0 IU/L), and FSH (median, 1.2 and 0.2 IU/L vs 3.1 IU/L).
However, a higher adverse event* (AE) rate was observed in the 11β-MNTDC vs the placebo arm (n=22 vs 3). Nonetheless, the study drug was well-tolerated with no serious AEs or AE-related discontinuations.
Participants in the 11β-MNTDC arm also had significant dose-related increases in weight (median change, 1.3 [200 mg] and 1.9 kg [400 mg] vs 0.6 kg [placebo]), haematocrit (median change, 1.2 and 1.0 percent vs 0.0 percent), LDL-C (median change, 10.0 and 18.0 mg/dL vs 3.0 mg/dL), and HDL-C (median change, 9.0 and 11.5 mg/dL vs 3.0 mg/dL).
“Our results suggest that this pill, which combines two hormonal activities in one, will decrease sperm production while preserving libido,” said study investigator Dr Christina Wang from the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Centre in Torrance, California, US. “The drug effects were reversible after stopping treatment,” she added.
The idea of taking birth control pills has been gaining ground among men who want to try new reversible hormonal birth control methods. [Hum Reprod 2005;20:549-556] “Safe, reversible hormonal male contraception should be available in about 10 years,” said Wang.
She acknowledged that 28 days is insufficient to determine optimum sperm suppression, as the drug would take about 60–90 days to influence sperm production. Longer and larger studies involving sexually active couples are recommended to further establish the efficacy of the drug, she said.
These findings add to those of another study by the same research team on another male birth control drug, dimethandrolone undecanoate. [J Clin Endocrinol Metab 2019;104:423-432] Co-investigator Prof Stephanie Page from the University of Washington School of Medicine in Seattle, Washington, US said that the objective is to find a more effective drug with the least side effects. “We are developing two oral drugs in parallel in an attempt to move the [contraceptive medicine] field forward,” she said.