Corifollitropin alfa injection, the first and only sustained follicle stimulant, is approved in Europe for controlled ovarian stimulation (COS) in combination with a GnRH antagonist for the development of multiple follicles in women participating in an assisted reproductive technology (ART) program. Due to its ability to initiate and sustain multiple follicular growth for an entire week, a single subcutaneous injection of the recommended dose may replace the first seven injections of any conventional daily rFSH preparation in a COS treatment cycle.

"This data is important for women who choose assisted reproductive technologies such as in vitro fertilization (IVF), but are concerned about the number of daily injections required during a treatment cycle," said Robert Boostanfar, M.D., study author, reproductive endocrinologist at HRC Fertility and clinical assistant professor at the Keck School of Medicine, Department of Obstetrics and Gynecology, University of Southern California. "A single-dose injection for controlled ovarian stimulation for IVF– one with comparable pregnancy and live birth rates, and no observed difference in neonatal safety - is a significant and welcome option in fertility treatment."

Cumulative pregnancy rates and live birth rates were comparable
In Engage, the largest double-blind, randomized Phase III trial ever performed in in vitro fertilization that involved 1,506 patients (mean age 31.5 years; body weight 68.6 kg), patients were treated with either a single dose of 150 μg corifollitropin alfa injection or daily 200 IU rFSH injections for the first seven days of ovarian stimulation in a GnRH antagonist protocol. In the follow-up study, 541 patients who became pregnant following fresh embryo transfer were followed to delivery, and live-birth deliveries were recorded. In addition, data on 344 of the patients in the Engage trial with cryopreserved embryos in the intervention cycle were evaluated to assess the cumulative ongoing pregnancy rates.

In line with the ongoing pregnancy rates after fresh embryo transfer (38.9% and 38.1%) for the corifollitropin alfa and rFSH groups respectively, live birth rates of 35.6 percent and 34.4 percent were observed in the corifollitropin alfa and rFSH treatment arms of patients. Cumulative pregnancy rates of those with cryopreserved plus fresh embryos were 47.2 in the corifollitropin alfa treatment arm and 44.9 percent in the rFSH treatment arm.

No differences observed in neonatal outcome or congenital malformation rates
Pregnancy and infant follow-up data were also collected from the Engage study and Ensure study, another double-blind, controlled, randomized phase III clinical trial. Ensure involved 396 patients in Europe and Asia, aged 18-36 years, weighing 60 kg or less. The follow-up included patients with ongoing pregnancies who were previously treated during the first week of stimulation with either a single dose of corifollitropin alfa injection or with daily rFSH injections. Information on pregnancy and delivery complications, mode of delivery, and neonatal characteristics was prospectively collected through routine assessments. Safety was assessed from medical examinations at birth and within three months thereafter. Any abnormalities were recorded as adverse events and reviewed externally by an independent medical expert as either major or minor congenital malformations (a major malformation was defined as any that causes functional impairment or requires surgical correction).

Follow-up data on 440 fetuses from 342 women who became pregnant after corifollitropin alfa treatment and 381 fetuses from 312 women who became pregnant after rFSH treatment were assessed. There were no relevant differences between the groups in type and incidence of pregnancy complications. The health of 424 live-born infants conceived after treatment with corifollitropin alfa injection indicates that there are no differences in neonatal characteristics or in major or minor malformation rates when compared with the 370 live-born infants conceived after treatment with daily rFSH injections.

"The live birth rate and safety for mother and child are always critical considerations for MSD when developing new fertility treatments," said Mirjam Mol-Arts, senior vice president, Merck Research Laboratories. “MSD’s pioneering fertility research continues to grow with the unveiling of today's positive data, yet another chapter in our proud history of providing innovative fertility treatment options - and ultimately the joy of a new life - to patients and fertility specialists."

About COS for ART
COS for ART involves multiple steps. As part of in vitro fertilization (IVF) treatment, stimulating the follicles (eggs) in the ovaries during each monthly cycle is the first step. Traditionally, daily rFSH injections are required to start the process. Human chorionic gonadotropin (hCG) then triggers ovulation, which increases the chance of successful conception as part of an IVF pregnancy. As a single-dose option to replace daily rFSH injections, corifollitropin alfa injection is an important advance in fertility treatment.

Infertility: a condition affecting 50 - 80 million people worldwide
A couple is often diagnosed as infertile if they have not conceived after one year of regular, unprotected, well-timed intercourse. Women over the age of 35 are encouraged to seek diagnosis and treatment for infertility following six months of regular, unprotected intercourse.

With infertile couples, the source of infertility lies with the male in 40 percent of cases and 40 percent with the female. The remaining 20 percent is either a joint problem or unknown. There are a variety of treatments available for infertility; these include surgery, hormone treatments, insemination, IVF and natural treatments, among others.

About MSD
Today's MSD is a global healthcare leader working to help the world be well. MSD is known as Merck in the United States and Canada. Through our prescription medicines, vaccines, biologic therapies, and consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. MSD. For more information, visit www.msd.com.