ICMR’s male contraceptive 99% effective: Report
The study found that RISUG had a lower failure rate than male condoms and showed no serious adverse effects.
A male contraceptive developed by the Indian Council of Medical Research has shown 99% efficacy in preventing pregnancy, scientists found in clinical trials conducted among 303 participants.
“The overall efficacy of RISUG in terms of achieving azoospermia (absence of viable sperm in the semen) was 97.6%. And, overall efficacy based on the occurrence of pregnancies due to drug failure was 99.02%,” said the study published in Andrology, an open access journal, last month.
RISUG is short for reversible inhibition of sperm under guidance. It is designed as a replacement for surgical vasectomy, which is the only male sterilisation method available in the world.
“The efficacy of a product like this determined based on two criteria -- protection against pregnancy and viability of sperms, and the drug has shown excellent results in meeting both the criteria,” said RS Sharma, one of the lead researchers. “This product has the potential to emerge as a popular modern male contraceptive for population control.”
India was inching closer to developing world’s first male contraceptive injection, HT reported in November 2019, quoting preliminary findings of the study.
Several projects were disrupted because of the pandemic and RISUG was one of them, Sharma said. “We had planned further studies on it,” he added. “Now the results have been formally published.”
At 21 days after the injection, 77.2% of the test subjects achieved azoospermia (absence of viable sperm in the semen) and 13.5% showed oligozoospermia (low sperm count), the published paper reported. The percentage of subjects achieving azoospermia increased to 97.2% six months after the injection and reached the highest level of 97.3% a year after the injection.
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The study was conducted amongst those visiting family planning clinics or departments of urology or surgery for vasectomy at hospitals in five cities, including New Delhi, Udhampur, Ludhiana Jaipur, and Kharagpur. Permission to conduct phase III clinical trial was granted by the Drugs Controller General India and approved by the institutional ethical committees of the respective centres.
“Failure rate of RISUG is also lower than the rate of male condom breakage that can be as high as 12.9% and 18.6% (two different studies),” the study found. “Thus, RISUG is a one-time male contraceptive with high efficacy and low failure rate.”
Clinical examinations showed no serious adverse effects in terms of pyrexia (abnormal increase in body temperature), local inflammation at the injection site and reproductive system, and infection in urinary tracks.
“Even no sign of urethritis (inflammation of urethra), vesiculitis (inflammatory disease of seminal vesicles), cystitis (inflammation of the bladder), prostatitis (inflammation of the prostate), epididimytis (inflammation of the coiled tube at the back of the testicle), orchitis (testes inflammation), and dysuria (painful urination) was reported post RISUG injection,” the researchers said. “But 41.9% subjects low to moderate grade scrotal pain was reported on 3rd day post RISUG injection, which reduced significantly during subsequent follow up visits and disappeared after 2.5 month.”
Sexual partners of the test subjects did not show any adverse effects either during the course of the study.
“A detailed clinical examination of all female subjects was done. Similar to their husbands, the female subjects had normal baseline characteristics at the pre-injection stage,” the study said. “Female subjects also did not show any serious adverse side effects during the scheduled follow-up visits up to 7 years post RISUG injection to their husbands.”
The results show that a standard dose of 120 micro litre of RISUG injected into each vas deferens (ducts that transport sperm from the epididymis to the ejaculatory ducts during ejaculation) covered for variabilities in the lumen diameters and overall size of the vas deferens. It means the dosage do not have to be tailored, making RISUG an ideal candidate for a mass contraceptive delivery programme.
“A few more studies need to be done, such as clinical reversibility study and post marketing surveillance, for which we need to acquire a license to manufacture the drug at a GMP (good manufacturing practice) facility,” Sharma said. “An application has been moved to the office of the Drugs Controller General of India to seek permission.”