Teva Pharmaceutical Industries Ltd. (TEVA) said on Wednesday that a sub-analysis of data from its phase III clinical trial of Milprosa vaginal ring for luteal phase support in women going through in vitro fertilization, of IVF, showed Milprosa to offer comparable safety and efficacy to daily 8 percent progesterone vaginal gel. Milprosa is a once per week therapy that is designed to deliver a steady dose of micronized progesterone.

The Israel-based drug maker presented the results at the 61st Annual Meeting of the Pacific Coast Reproductive Society.

In many cases, the luteal phase – the second half of the menstrual cycle, or period from ovulation to menstruation – is compromised in women undergoing in vitro fertilization, making progesterone supplementation necessary. Progesterone has several functions, including building the uterine wall for egg implantation and stopping the menstrual cycle.

The phase III trial was a single-blinded, randomized study of 1,297 women aged between 18 and 42 conducted across 22 clinical sites. The reported numbers were extremely similar with the Milprosa-treated group delivering slightly better results. At eight weeks gestation, multiple pregnancy rates (twins or triplets) were 41.3% in the Milprosa group, versus 39.7% in the gel-treated group. At 12 weeks, the figures were 39.3% for the Milprosa group and 37.8% for the gel group. Overall multiple birth rates were 38.7% for Milprosa and 36.2 for the gel. The mean number of transferred embryos was identical at 2.13 for both groups.

Neither group had multiple gestations beyond triplets.

Earlier data from the trial disclosed by Teva showed comparable or better efficacy and safety as well in evaluating Milprosa versus the daily gel. Amongst that information, 97.4 percent of patients pregnant at week 12 (when the treatments were ended) in the Milprosa group went on to have a live birth, compared to 96.5 percent in the gel-treated arm of the study.

Frequency and severity of adverse events were similar in both groups and, if serious, were not related to treatment.

If approved, Milprosa would provide women undergoing in vitro fertilization another option to current therapies that provide luteal phase support, perhaps even a more convenient approach.

Earlier this month, the FDA gave Teva approval for Quartette, the company’s new pregnancy prevention drug that it called “the next generation of extended regimen oral contraceptives.”

Shares of TEVA have not responded favorably to the FDA approval of the latest information on Milprosa, sliding about 3 percent in April to add to a 12 percent drop in the last 52 weeks.

In early trading on Wednesday, shares are basically flat at $38.65.