The FDA has approved the drug durvalumab for adults with limited-stage small-cell lung cancer (LS-SCLC) whose disease hasn’t gotten worse after getting platinum-based chemo and radiation at the same time.
LS-SCLC is an aggressive form of small-cell lung cancer that starts in the main airways of the lungs (bronchi) and is generally limited to one lung or one side of the chest. The LS-SCLC cells carry special proteins (PD-L1), which allow them to hide from the immune system, promoting their growth and spread. Often, despite early success with standard chemotherapy and radiotherapy, LS-SCLC often comes back with only about 15% to 30% of people surviving five years after diagnosis. This highlights the need for treatments that can target PD-L1 proteins to improve life expectancy.
Durvalumab, marketed under the brand name Imfinzi, is a human monoclonal antibody, a type of drug that uses your body’s immune system to fight cancer. It binds to the PD-L1 protein and prevents tumor cells from evading the immune system, helping it to find and attack cancer cells more effectively.
Imfinzi was first approved by the FDA in 2017 for use against various lung and liver cancers, either alone or along with other treatments. Imfinzi is now the first and only immunotherapy approved for treatment in patients with LS-SCLC, according to a news release from AstraZeneca, the drug’s maker.
The effectiveness of Imfinzi was studied in a clinical trial done at 164 centers across 19 countries in North and South America, Europe, and Asia. It included 730 patients with LS-SCLC whose cancer had not worsened after platinum-based chemotherapy and radiation therapy. Patients were randomly selected to receive either Imfinzi alone, Imfinzi along with Imjudo (tremelimumab), or a placebo.
The results showed that the patients on Imfinzi lived longer (nearly 56 months, on average) than those receiving a placebo (33.4 months). Imfinzi also delayed the cancer's progression. The average time before the disease worsened was 16.6 months for those on Imfinzi, compared to 9.2 months for the ones receiving a placebo. The most common side effects were inflamed lungs and tiredness. The treatment’s safety profile was the same as seen in previous trials, with no new safety concerns.