September 3, 2024 9:00 pm EDT

Organon K.K., a global healthcare company with a focus on women’s health (Headquarters: Minato-ku, Tokyo; President:
Ryota Sakurai) announced that the primary endpoint was achieved in a domestic Phase III clinical trial (referred here
as “the trial”) evaluating the efficacy and safety of OG-8276A (referred here as “the drug”), which is being developed
as a treatment for dysmenorrhea. Based on the results obtained from the trial, Organon K.K. will prepare an
application for marketing approval and launch in Japan.

OG-8276A is a combination of desogestrel and ethinylestradiol. It has been marketed under the brand name ‘Mercilon’
as an oral contraceptive and is currently sold by Organon in 51 countries worldwide, excluding Japan. Organon
initiated development of the drug in Japan to address the unmet needs of Japanese patients with dysmenorrhea. Further
analysis of the trial details will be conducted, and the findings may be published later.

Dysmenorrhea is characterized by pelvic and/or low abdominal pain as a main symptom with others including bloating,
nausea, vomiting, headache, and dizziness during the menstrual period that can have negative effects on quality of
life (QoL) and productivity^1,2. Menstrual problems may affect work productivity and dysmenorrhea is one of
the most common reasons¹. A survey by the National Center for Child Health and Development reported that
approximately 70% of the 10,000 women surveyed experienced premenstrual physical discomfort, with about one in four
experiencing difficulty with everyday life, such as work or household chores³.

Ryota Sakurai, Representative Director and President of Organon K.K., commented, “The development of OG-8276A began
in response to the voice of Japanese women suffering from dysmenorrhea. We will continue to make swift preparations to
deliver this new treatment option to address these patients’ unmet needs.”

Organon K.K. will continue to support patients and healthcare professionals in Japan by delivering medicines that
improve women’s health with our vision of “a better and healthier every day for every woman”.

About the Phase 3 Study

This Phase 3, placebo-controlled, double-blind, randomized, and parallel-group study assessed the efficacy and safety
of desogestrel/ethinylestradiol (DSG/EE) 150/20 µg in Japanese patients with dysmenorrhea during treatment for the
equivalent of 3 conventional 28-day cycles, with an extension to the equivalent of 10 cycles of treatment to evaluate
1-year safety and maintenance of efficacy in treating dysmenorrhea.

The study randomized 211 Japanese female patients, ages between 17 and 50, with a diagnosis of moderate to severe
dysmenorrhea, and with a history of regular menstrual cycles of 28 ± 7 days when not using hormonal products. The
primary efficacy was measured by the total dysmenorrhea score (TDS) at Days 29, 57 and 85.

This primary analysis results were based on data from the 211 randomized patients in the 3-month double-blind
treatment period and will be the support for a regulatory submission in Japan. The study is ongoing in the open-label
treatment period.

About Organon (Organon & Co.) and Organon K. K.

Organon is an independent global healthcare company with a strategy to help improve the health of women throughout
their lives. Organon’s diverse portfolio offers more than 60 medicines and products in women’s health, biosimilars,
and a large franchise of established medicines across a range of therapeutic areas. In addition to Organon’s current
products, the company invests in innovative solutions and research to drive future growth opportunities in women’s
health and biosimilars. In addition, Organon is pursuing opportunities to collaborate with biopharmaceutical partners
and innovators looking to commercialize their products by leveraging its scale and presence in fast growing
international markets.

Organon has a global footprint with significant scale and geographic reach, world-class commercial capabilities, and
approximately 10,000 employees with headquarters located in Jersey City, New Jersey.

For more information, visit http://www.organon.com and connect with us
on LinkedIn, Instagram, X
(formerly known as Twitter) and Facebook.

For information about Organon K. K., a Japan subsidiary of Organon & Co., visit https://www.organon.com/japan/ and connect with us on LinkedIn and Instagram.

Cautionary Note Regarding Forward-Looking Statements

Some statements and disclosures in this press release are “forward-looking statements” within the meaning of the safe
harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, including, but not limited to,
statements about expectations regarding the drug as a treatment for dysmenorrhea, as well trials and regulatory
approvals for the drug. Forward-looking statements may be identified by words such as “foresees” “expects,” “intends,”
“anticipates,” “plans,” “believes,” “seeks,” “estimates,” “will” or words of similar meaning. These statements are
based upon the current beliefs and expectations of management and are subject to significant risks and uncertainties.
If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially
from those set forth in the forward-looking statements. Risks and uncertainties that may affect Organon’s future
results and events include, but are not limited to, an inability of Organon to fully execute on its commercialization
plan for the drug and/or an inability to obtain required licenses to commercialize that asset; efficacy, safety, or
other quality concerns with respect to the drug or other marketed products, including market actions such as recalls,
withdrawals, or declining sales; an inability to adapt to the industry-wide trend toward highly discounted channels;
changes in tax laws or other tax guidance that could adversely affect our cash tax liability, effective tax rates, and
results of operations and lead to greater audit scrutiny; an inability to execute on our business development strategy
or realize the benefits of our planned acquisitions; political and social pressures, or regulatory developments, that
adversely impact demand for, availability of, or patient access to contraception or fertility products; general
economic factors, including recessionary pressures, interest rate and currency exchange rate fluctuations; general
industry conditions and competition; the impact of pharmaceutical industry regulation and health care legislation in
the United States and internationally; global trends toward health care cost containment; technological advances; new
products and patents attained by competitors; the impact of higher selling and promotional costs; any failure by
Organon to obtain an additional period of market exclusivity in the United States for Nexplanon subsequent to the
expiration of certain key patents in 2027; challenges inherent in new product development, including obtaining
regulatory approval; Organon’s ability to accurately predict its future financial results and performance;
manufacturing difficulties or delays; financial instability of international economies and sovereign risk;
difficulties developing and sustaining relationships with commercial counterparties; dependence on the effectiveness
of Organon’s patents and other protections for innovative products; and the exposure to litigation, including patent
litigation, and/or regulatory actions. Organon undertakes no obligation to publicly update any forward-looking
statement, whether as a result of new information, future events or otherwise. Additional factors that could cause
results to differ materially from those described in the forward-looking statements can be found in Organon’s filings
with the Securities and Exchange Commission (“SEC”), including Organon’s most recent Annual Report on Form 10-K and
subsequent SEC filings, available at the SEC’s Internet site ( www.sec.gov ).

# # #

Media contact: 

Yoko Ueki
Strategy & Corporate Affairs, Organon K.K.
mobile: 080-3213-4624
email: yoko.ueki1@organon.com

¹ Iwata M, et al. Efficacy of Low-Dose Estrogen-Progestins and Progestins in Japanese Women with
Dysmenorrhea: A Systematic Review and Network Meta-analysis. Adv Ther. 2022 Nov;39(11):4892-4909.

² Itani R, Soubra L, Karout S, Rahme D, Karout L, Khojah HMJ. Primary Dysmenorrhea: Pathophysiology,
Diagnosis, and Treatment Updates. Korean J Fam Med. 2022 Mar;43(2):101-108.

³ National Center for Child Health and Development, Press Release, November 26, 2020. “Approximately 70% of
10,000 People Surveyed Experience Physical Problems Before Menstruation – One in Four Experience Premenstrual Symptoms
That Interfere with Work or Household Chores”https://www.ncchd.go.jp/press/2020/20201126.html (Last
accessed August 15, 2024).