Keytruda With Paclitaxel: FDA Approves New Combination Therapy for Certain Cancers Affecting the Ovaries, Fallopian Tubes, or Peritoneum

The FDA has approved a new combination therapy for adults with epithelial cancers that start in the ovaries, fallopian tubes, or lining of the abdomen (peritoneum). This treatment is meant for patients whose cancers express a protein called PD-L1 and that has not responded to platinum-based chemotherapy. This approval allows Keytruda (pembrolizumab) or its under-the-skin injectable version Keytruda Qlex (pembrolizumab and berahyaluronidase alfa-pmph) to be used in combination with the chemotherapy medicine paclitaxel, with or without targeted therapy with bevacizumab (Avastin).

The FDA has also approved a diagnostic test to identify patients with these epithelial cancers whose tumors produce sufficient levels of the PD-L1 protein to make them eligible for the new combination therapy.

Ovarian cancer usually starts in the ovaries or fallopian tubes and is a common and serious cancer in women. Most patients receive platinum-based chemotherapy as their first treatment, but about 70%-80% see their cancer return, and roughly 25% develop platinum-resistant ovarian cancer within six months. This type of cancer is harder to treat and has a poor prognosis, and there are limited treatment options. In the U.S., primary peritoneal cancer is rare, with outcomes similar to those of advanced ovarian cancer.

This therapy combines three medicines that target and destroy cancer cells in three different ways. Keytruda is an immunotherapy medicine that helps your immune system recognize and attack cancer cells by blocking the PD-L1 protein, which normally helps tumor cells hide from your immune system. Paclitaxel kills fast-growing cancer cells, and bevacizumab blocks the blood supply tumors need to survive.

Initially approved in 2014, Keytruda is already used to treat many types of cancer, including lung, skin, kidney, cervical, liver, bladder, breast, endometrial, and head and neck cancers. Keytruda Qlex was first approved in 2025

This approval is important because this new combination therapy may help delay disease progression and improve outcomes for people who haven’t had new options in many years.

Why Was It Approved?

The FDA’s approval was based on clinical studies that showed that adding Keytruda to chemotherapy delayed the worsening of the disease and helped people with PD-L1-positive ovarian, fallopian tube, or primary peritoneal tumors live longer.

The effectiveness of Keytruda was studied in a large trial with 643 patients who had platinum-resistant ovarian, fallopian tube, or primary peritoneal cancer who had received one or two prior systemic treatments for ovarian cancer. All patients with ovarian cancer had previously received at least one platinum-based chemotherapy regimen and showed evidence of disease progression within six months. People in the study were randomly assigned to receive either Keytruda plus paclitaxel, with or without bevacizumab, or a placebo plus paclitaxel, with or without bevacizumab.

Among 466 patients whose tumors expressed PD-L1, those treated with the Keytruda-based regimen, versus those treated with the placebo-containing regimen, had a median progression-free survival of 8.3 months, versus 7.2 months, and a median overall survival of 18.2 months, versus 14 months. This shows that compared with a placebo, the Keytruda-based combination therapy delayed worsening of the disease and extended the overall survival of the patients.

The overall safety of pembrolizumab combined with paclitaxel, with or without bevacizumab, was consistent with that seen in other cancer trials.

Common side effects across these studies included tiredness, nausea, diarrhea, tingling and numbness, hair loss, anemia, fatigue, and immune-related problems such as inflammation in the lungs, liver, kidneys, thyroid, or other hormone-producing organs, or intestines.

What Do I Need to Know?

Keytruda is usually given through an intravenous line every three or six weeks based on the dose decided by your health care provider. The newer version, Keytruda Qlex, is given as a shot under the skin (in the thigh or belly area). You may continue treatment until your cancer gets worse or side effects become too serious, or for up to two years. Your health care provider will decide which version and schedule are best for you.

Before starting treatment, your provider may test your tumor for the PD-L1 protein to help predict how well the medicine might work for you. Your health care provider may also check your liver, kidneys, and thyroid function before and during treatment and will monitor any side effects.

Be sure to let your health care provider know if you have any kidney or liver conditions, lung or heart or thyroid problems, hormone issues, skin or allergic conditions, autoimmune conditions, or have had or are planning to have stem cell transplants. Also, tell them about all medicines, including any over-the-counter products, immune-suppressing medicines, vitamins, and herbal supplements, you take, as some may increase the risk of side effects. You should not take Keytruda or Keytruda Qlex if you’ve had a serious allergic reaction to any of their ingredients.

Keytruda or Keytruda Qlex may harm a fetus. Let your health care provider know if you are pregnant or planning to get pregnant or are breastfeeding. Use birth control during treatment and for four months after your last dose if you can become pregnant. Avoid breastfeeding during the treatment and for four months after your final dose.

Your provider will also monitor you closely and may adjust or pause treatment or give medicines such as corticosteroids or hormone replacements to manage side effects.

While on the medicine, contact your health care provider right away if you notice any new or worsening symptoms, such as shortness of breath, coughing, chest pain, severe diarrhea or belly pain, dark urine, yellowing of the skin or eyes, easy bruising or bleeding, unusual tiredness, changes in mood, rashes, fever, or pain.