EXECUTIVE SUMMARY

Fresh approaches to male contraception will receive a boost with funding to be administered by the Male Contraception Initiative. This nonprofit organization will deliver $500,000 for up to three years to at least one research project focused on the development of a new, reversible male contraceptive. The funding has been made available through an anonymous donor.

  • Projects that may be greenlighted include those that focus on late stages of sperm maturation, sperm function, or sperm transport. Proposals that look to potentially problematic routes, such as hormones, early-stage sperm development, or immunological approaches, will not be considered.
  • Approximately 30% of couples worldwide rely on male contraceptive methods, namely condoms and vasectomy. Shortcomings of these methods have led to efforts to develop new types of male contraceptives.

Approximately 30% of couples worldwide rely on male contraceptive methods, namely condoms and vasectomy.1 Shortcomings of these methods have led to efforts to develop new types of male contraceptives. However, when it comes to development of a male contraceptive, scientists have to grapple with the physiology of sperm production. Approaches include:

  • preventing sperm from reaching the egg by physical barriers (condoms, vasectomy, and experimental vas occlusion methods);
  • stopping sperm production (experimental hormonal and nonhormonal methods); or
  • killing or inhibiting the function of sperm or the sperm’s ability to bind the egg after ejaculation (spermicides, experimental antimotility agents).2

Novel approaches will get a boost with new funding to be administered by the Durham, NC-based Male Contraception Initiative. This nonprofit organization will deliver $500,000 for up to three years to at least one research project focused on the development of a new, reversible male contraceptive. The funding has been made available through an anonymous donor.

“What really sets this request for proposal apart is that this funding is exclusively for male contraceptive research,” said Executive Director Aaron Hamlin, MPH. “This is long overdue.”

Funding for the first year will be for up to $175,000, with monies beyond the first or second year to be dispersed contingent on satisfactory progress and availability of funds.

Projects that may be greenlighted include those that focus on late stages of sperm maturation, sperm function, or sperm transport. Proposals that look to potentially problematic routes, such as hormones, early-stage sperm development, or immunological approaches, will not be considered.

Grant recipients will be required to provide a plan ensuring public sector pricing. All publications stemming from funded research will be required to be in public-access journals or to pay a journal fee to ensure public access. All letters of interest were to be filed with the initiative by March 1, 2017.

Vasalgel Eyed in Early Research

In current research news, scientists are now looking at Vasalgel, a high molecular weight polymer consisting of styrene-alt-maleic acid, dissolved in dimethyl sulfoxide. The polymer forms a hydrogel after injection into the vas deferens, creating a blockage to the passage of sperm. Researchers believe that fluids are able to pass slowly through the gel, reducing back-pressure on the epididymis.

In a study just released online, use of Vasalgel was examined in 16 adult male rhesus monkeys. After a one-week recovery, each male was returned to outdoor group housing, which included three to nine intact, breeding females with a successful reproductive history. All males were monitored for at least one breeding season; seven of the 16 were almost continually housed with females for two years. There were no conceptions after Vasalgel injections, data indicate. Complications were minor and included one incident of incorrect placement of Vasalgel into the vas deferens and the development of a sperm granuloma in one animal. Unilateral vasectomy was performed in each subject without further complication.2

With proof of efficacy in monkeys and rabbits now published,3 preparations are underway for the first clinical trial in humans. If trials are successful, Parsemus Foundation, a nonprofit organization based in Berkeley, CA, plans for Vasalgel to be available worldwide, with a tiered international pricing structure to ensure affordability to all men. The first study will explore effectiveness; later studies will attempt reversal (flushing the gel to restore sperm flow), which has been demonstrated in rabbits, but not yet in larger animals, according to the foundation.

What About a Shot?

Scientists still look to a possible contraceptive injection for men. Data from a Phase II study, which focused on injections of 200 milligrams of a long-acting progestogen, norethisterone enanthate, and 1,000 milligrams of a long-acting androgen, testosterone undecanoate, indicate the combination was successful. However, frequency of side effects was relatively high, which included: acne, injection site pain, increased libido, and mood disorders. Because of these adverse events, the study was terminated before its completion.5 (Contraceptive Technology Update reported on the study; see the January 2017 article, “Data Indicate Male Birth Control Shot May Be Effective,” available at: http://bit.ly/2kxhPWk.)

Given the efficacy and acceptability of the method, there continues to be a strong rationale for continuing research, despite the side effects, researchers believe.

REFERENCES

  1. Page ST, Amory JK, Bremner WJ. Advances in male contraception. Endocr Rev 2008;29:465-493.
  2. Amory JK. Male contraception. Fertil Steril 2016;106:1303-1309.
  3. Colagross-Schouten A, Lemoy MJ, Keesler RI, et al. The contraceptive efficacy of intravas injection of Vasalgel™ for adult male rhesus monkeys. Basic Clin Androl 2017;27:4.
  4. Waller D, Bolick D, Lissner E, et al. Azoospermia in rabbits following an intravas injection of Vasalgel™. Basic Clin Androl 2016;26:6.
  5. Behre HM, Zitzmann M, Anderson RA, et al. Efficacy and safety of an injectable combination hormonal contraceptive for men. J Clin Endocrinol Metab 2016;101:4779-4788.