Imfinzi (durvalumab) is an immunotherapy medicine that helps the immune system detect and attack cancer cells. The FDA has approved a combination of Imfinzi and standard chemotherapy medicines – fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) – for treating adults with early-stage or locally advanced stomach (gastric) or gastroesophageal junction (GEJ) cancer that can be removed via surgery (resectable cancer). Patients receive Imfinzi together with FLOT before and after surgery and then continue with Imfinzi alone (monotherapy) to reduce the risk of the cancer coming back.
Gastric cancer is the fifth most common cancer worldwide, with nearly 1 million new cases and over 650,000 deaths reported in 2022. GEJ cancer is a type of gastric cancer that develops in the area where the food pipe (esophagus) joins the stomach. The number of new cases of gastric cancer is increasing in people younger than 50, with thousands of patients receiving treatment for early-stage or locally advanced stomach or GEJ cancer around the world. These cancers often come back, even after surgery and chemotherapy, with about 1 in 4 patients relapsing within a year. Long-term survival is poor, with less than half of the patients surviving beyond five years.
Imfinzi is a lab-made antibody that works by blocking a protein called PD-L1 (programmed death‑ligand 1), which is used by some cancer cells to evade your immune system. By stopping PD-L1 from binding with PD-1 (programmed cell death protein 1) and CD80 proteins on immune cells, Imfinzi helps your immune system recognize and fight tumor cells. This approval is important because Imfinzi is the first immunotherapy medicine approved for use in these types of cancer both before and after surgery, providing a new therapeutic option that may help improve long-term outcomes.
Imfinzi was first approved in 2017 and has been used to treat several cancers, including certain lung cancers and biliary tract, liver, endometrial (uterine), and bladder cancers, in adults.
Why Was It Approved?
The FDA has approved Imfinzi based on a clinical study, which showed that Imfinzi helped people with resectable, early-stage, or locally advanced (stage II to IVA) gastric or GEJ cancer live longer without their cancer getting worse or coming back.
In a study involving 948 patients, those receiving Imfinzi with FLOT had a 29% lower risk of the cancer progressing, returning, or causing death, compared with FLOT alone. They went longer than the study could measure without cancer-related events, compared with 32.8 months for the FLOT-only group. After one year, 78.2% of patients receiving the Imfinzi treatment were free of cancer-related events, versus 74% with FLOT alone. At two years, those numbers were 67% and 58%, respectively. Imfinzi also improved overall survival, reducing the risk of death by 22%. About 69% of patients were alive at three years with Imfinzi, compared with 62% with FLOT alone. More patients achieved a complete response before surgery with Imfinzi (19.2% vs. 7.2%), and benefits were seen regardless of PD-L1 status. The safety profile was consistent with known effects of each medicine in the combination.
Common side effects of Imfinzi when used with FLOT include diarrhea, nausea, nerve inflammation that can cause numbness or tingling in the arms and legs, fatigue, hair loss, decreased appetite, rash, belly pain, vomiting, muscle and joint pain, fever, and mouth pain or sores.
What Do I Need to Know?
Imfinzi is given through an intravenous (IV) infusion, which takes about 60 minutes, and the dose depends on your body weight. For gastric and GEJ cancers, the treatment plan involves giving Imfinzi with FLOT chemotherapy every four weeks, for up to two cycles before and two cycles after surgery, and then, giving Imfinzi alone every four weeks for up to 10 cycles. Treatment may be stopped sooner if your cancer comes back or if the side effects become too serious. If you miss an appointment, call your health care provider right away to reschedule it.
Before starting Imfinzi, tell your health care provider if you have immune system disorders like Crohn's disease, ulcerative colitis, or lupus, or nervous system conditions such as myasthenia gravis or Guillain-Barré syndrome; have had an organ or tissue transplant (including a corneal graft); or received donor stem cell transplants or chest radiation.
Let them know if you are pregnant, planning to become pregnant, or are breastfeeding. The medicine can harm a fetus, so a pregnancy test is required beforehand. Also, reliable birth control is required during treatment and for three months after, and do not breastfeed during this period. And tell your health care provider about all medicines, vitamins, and supplements you take to avoid possible interactions.
Your health care provider will watch you for side effects, especially those linked to your immune system. Imfinzi can sometimes cause your immune system to attack healthy parts of your body, such as your lungs, liver, intestines, skin, pancreas, or hormone glands, resulting in serious problems that may happen during or after treatment. Imfinzi may also cause reactions during the IV, such as chills or shaking, itching or rashes, dizziness, or a hard time breathing.
Call your health care provider right away if you notice new or worsening symptoms such as coughing; shortness of breath; diarrhea; black tarry or sticky stools; yellowing of your skin or eyes; unusual bleeding or bruising; feeling hungrier or thirstier than usual; eye pain, sensitivity to light, or other vision problems; unusual headaches; extreme tiredness; severe muscle pain or weakness; changes in mood or behavior such as crankiness, confusion, or forgetfulness; painful sores in the mouth, nose, throat, or private parts; or a rash or blistering or peeling of the skin.