Jemperli: A New Treatment for Endometrial Cancer

Written by Courtney Krueger, PharmD, BCPS
Medically Reviewed by Dena Westphalen, PharmD on February 08, 2025
6 min read

Endometrial cancer is a type of cancer in the lining of the uterus (also known as the endometrium). It is the most common type of gynecologic cancer in women. There are many treatments for endometrial cancer, and the choice of treatment will depend on the extent (stage) of your disease along with other things. 

Jemperli is a treatment for endometrial cancer. It is used for people with advanced endometrial cancer or those whose cancer has come back (also called recurrent cancer). 

Jemperli is a type of immunotherapy known as an immune checkpoint inhibitor. Jemperli works by attaching itself to a protein on specific immune system cells, called T cells. This helps the T cells work better to find cancer cells and kill them, which slows or stops the tumor from growing.

Jemperli is an intravenous (IV) infusion given by your health care provider. Your infusion of Jemperli is given into a vein over 30 minutes. 

If you are receiving Jemperli along with chemotherapy, you will receive your Jemperli infusion followed by your chemotherapy on that same day. You will continue this treatment every three weeks for about six treatments. After six treatments, you will receive only Jemperli without any chemotherapy, and Jemperli will be given about every six weeks. 

Your health care provider may also decide to give you Jemperli without any chemotherapy. With this treatment, you will receive Jemperli every three weeks for four treatments, then every six weeks after the first four treatments.

Your health care provider may consider treatment with Jemperli if you have advanced endometrial cancer. This includes stage III or stage IV cancer. You may also receive Jemperli if you have endometrial cancer that has come back.

Your health care provider may test you for a biomarker known as mismatch repair deficiency (also known as dMMR) to help decide which treatment for endometrial cancer is right for you. People who have dMMR are more likely to respond to therapies like Jemperli. People who do not have dMMR may also benefit from Jemperli.

There are two studies known as RUBY and GARNET that looked at how well Jemperli works for people with endometrial cancer.

The RUBY study included people with stage III, stage IV, or recurrent endometrial cancer. A total of 494 people were treated with either chemotherapy alone or chemotherapy plus Jemperli. Neither the people in the study nor the doctors knew who received which medicines. People in the study were 28 to 85 years old, and 77% were White, 12% were Black, 3% were Asian, and 3% were Hispanic or Latino. The study included both people with and without mismatch repair deficiency (dMMR). Chemotherapy was given with Jemperli for the first six treatments, then the Jemperli was continued for up to three years.

People in the GARNET study had advanced or recurrent solid tumors including endometrial cancer and had cancer progression during or after chemotherapy. The median age of people in the study was 65 years, and 77% were White, 3% were Black, 4% were Asian, and 4% were Hispanic or Latino. All people in GARNET had dMMR and were treated with Jemperli. The first four doses were given every three weeks, then the doses were given every six weeks until there was progression of the disease, discontinuation of the therapy, or withdrawal from the study. A total of 327 people were included in the overall study, including 141 people with endometrial cancer. 

The researchers measured how well Jemperli treated endometrial cancer by looking at:

  • The RUBY study looked at survival. Both overall survival (the length of time people stayed alive) and progression-free survival (length of time people stayed alive and their cancer did not progress) were evaluated.
  • The GARNET study looked at the overall response rate, which is the percentage of people who had cancer that shrank (a partial response) or could no longer be detected (a complete response). The study also looked at how long the response lasted. This is the period of time from the start of the study until death or progression of the cancer.

The RUBY study

Progression-free survival: The median progression-free survival for people treated with Jemperli and chemotherapy was 11.8 months, compared with 7.9 months for people who received chemotherapy alone.

Overall survival: The median overall survival for people treated with Jemperli and chemotherapy was 44.6 months, compared with 28.2 months for people who received chemotherapy alone.

Impact of dMMR: People who were mismatch repair deficient or had high microsatellite instability (a biomarker for DNA stability in a tumor) had a nearly two-year improvement (22.6 months) in progression-free survival with Jemperli and chemotherapy, compared with chemotherapy alone.

The GARNET study

Overall response rate: A total of 64 people responded to treatment with Jemperli for an overall response rate of 45.4%.

Duration of response: Most people who responded maintained response through at least one year (85.9%) and many for at least  two years (54.7%).

Your results may differ from what was seen in clinical studies.

Based on the results of the RUBY clinical trial, Jemperli along with chemotherapy is one of the first-line preferred therapy options for certain types of advanced or recurrent endometrial cancer, according to the National Comprehensive Cancer Network.

Because Jemperli makes your immune system work harder, it can sometimes cause your immune system to attack normal organs or tissues in your body. This can lead to inflammation, which can become severe or life-threatening and can happen anytime during or after your treatment with Jemperli. You should contact your health care provider right away if you have any of the following:

  • Coughing, shortness of breath, or chest pain, which may be signs of lung problems
  • Diarrhea, dark-colored or bloody stools, or stomach pain, which may be signs of intestinal problems
  • Yellowing of your skin or the whites of your eyes, severe nausea or vomiting, stomach pain, dark urine, or bleeding or bruising more easily than usual, which may be signs of liver problems
  • Headaches, a fast or irregular heartbeat, sweating, tiredness, weight gain or loss, hair loss, changes in mood, peeing more than usual, or feeling cold, which may be signs of hormone gland problems
  • Changes in the amount or color of your pee, swelling in your ankles, or loss of appetite, which may be signs of kidney problems
  • A rash; itching; skin blistering or peeling; swollen lymph nodes; painful sores in your mouth, nose, throat, or genital area; or a fever or flu-like symptoms, which may be signs of skin problems

The most common side effects of Jemperli include:

  • Tiredness
  • Weakness
  • Low red blood cell count (anemia)
  • Diarrhea
  • Nausea
  • Constipation
  • Vomiting

Not all side effects can be prevented, but there are things you can do to help.

  • To help prevent tiredness, consider rest breaks, short naps, exercise, and adequate sleep at night (seven to eight hours). Avoid caffeine or exercising in the evening, as these may affect sleep patterns.
  • If you have nausea, avoid skipping meals. Snacking on bland foods such as dry toast or crackers may be helpful. Avoid fatty, fried, spicy, or very sweet foods. In some cases, a medicine for nausea may be needed.
  • If you have diarrhea, avoid fried and high-fiber foods, and reduce your use of alcohol or tobacco. In some cases, a medicine for diarrhea may be needed.
  • Slowly sip liquids if you are vomiting until you feel well enough to drink more. Talk with your health care provider about ways to stay hydrated.

These are not all of the possible side effects of Jemperli. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088).

There may be cost assistance to help you afford Jemperli. You may have options even if you do not have health insurance. With the Jemperli copay assistance program, you may pay as little as a $0 copay. Your health care provider will help you get started. You can call 844-447-5662 or visit this website for more information.