Merck's Keytruda SC launch in Germany faces legal hurdle

Keytruda (pembrolizumab) is commonly used to treat certain types of the following types of cancers.

The FDA approved Keytruda for NSCLC based on several clinical trials. Keytruda was studied in people whose NSCLC had spread to other parts of the body (metastatic) and who had received no prior treatment for their cancer. People in this trial got either Keytruda plus chemotherapy or placebo plus chemotherapy. There were 616 people in this trial. Two-thirds of them were in the Keytruda group, the other third was in the placebo group. This study looked at overall survival (OS), which measured how long people survived after getting their treatment, and progression-free survival (PFS), which looked at how long people lived without their cancer growing. The median age was 64 with ages ranging from 34 to 84. There were more men in the Keytruda group (62%), and most of the people in each group were current or former smokers (88%). Most of the people in the study were White (94%) and 3% were Asian. At one year, the estimated OS was 69.2% for people in the Keytruda group versus 49.4% for the placebo group. This means people in the Keytruda group lived significantly longer. The median PFS in the Keytruda group was 8.8 months as compared to 4.9 months in the placebo group. This means that at least half of the people who received Keytruda had not had their cancer get worse after 8.8 months, compared to 4.9 months who received placebo. Keytruda was also studied in people who had NSCLC that was positive for PDL-1 and progressed after chemotherapy. People in this trial got either Keytruda 2 mg/kg, Keytruda 10 mg/kg, or chemotherapy. There were 1,475 people in this study, and they were evenly distributed between all three groups. The ages for each group ranged from 56 to 69 with 63 as the median age. There were more men in each group than women (about 62%). Most of the people in the study were white (72%) and 21% of people were Asian. This study looked at OS and PFS between all three groups. Median OS was 10.4 months for the Keytruda 2 mg/kg group, 12.7 months for the Keytruda 10 mg/kg group, and 8.5 months for the chemotherapy group. There was no difference in how long it took people's cancer to progress between the three groups. Another study looked at Keytruda in people who had planned surgery for their NSCLC. People in this study received either Keytruda and chemotherapy or placebo and chemotherapy before their surgery, and either Keytruda or placebo alone after their surgery. There were 797 people in this study, and they were split almost evenly between the two study groups. This study included people who had NSCLC and had not received any treatment for their cancer prior to the study. The median age of people in this trial was 64 with ages ranging from 26 to 83. Most of the people in this trial were men (about 70%). Most people were white (61%), 31% were Asian, 2% were Black, 9% were Hispanic or Latino, and for 4% the race was not reported. About 70% of people had stage III NSCLC with the rest being stage II. This study looked at event-free survival, which measures how long people lived without having an event including progression, recurrence (cancer coming back), or death. OS was also measured in this study. The estimated percentages of people alive without an event at 24 months was 62.4% in the Keytruda group and 40.6% in the placebo group. This means that at two years, 62.4% of people who received Keytruda had not had a cancer event, compared to 40.6% in the placebo group. There was no significant difference in OS rates at 24 months found between the Keytruda and placebo groups.

Keytruda stays in your system for up to 4 months after your last dose. Keytruda has a half-life of 22 days. This means it takes 22 days for your body to clear half a dose of Keytruda. Due to the long-acting effects of Keytruda, there are certain precautions to keep in mind after treatment ends. For example, if you can become pregnant, it’s recommended to use birth control for 4 months after your last dose. It’s also recommended to avoid breastfeeding for 4 months after your last dose. (For more information about this, see the “Things to consider when receiving Keytruda” section.) If you have questions about what to expect after stopping Keytruda, talk with your doctor or pharmacist. Keytruda is not known to interact with other medications, herbs, supplements, foods, or alcohol. The manufacturer did not list any interactions in Keytruda’s prescribing information. However, this doesn’t mean that interactions won’t be recognized in the future. For example, new drugs could be approved that interact with Keytruda. Before starting Keytruda treatment, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also, tell them about any vitamins, herbs, and supplements you take. Sharing this information can help you avoid potential interactions with Keytruda. If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist. If you can become pregnant, consider the following information about pregnancy, fertility, birth control, and breastfeeding.

Keytruda’s mechanism of action (how it works) is to promote the activity of your immune system in order to stop cancer cells from growing. The drug blocks a protein called programmed death receptor-1 (PD-1) from interacting with another protein called programmed death ligand-1 (PD-L1). This helps to activate your immune system so that it can detect cancer cells and stop them from growing and spreading. Your doctor will monitor your treatment progress with imaging tests. If these tests show that the cancer cells have stopped growing or that the tumor size has shrunk, this is a sign that Keytruda treatment is working. Your doctor will also order blood tests to see how active your immune system is. Side effects like inflammation can sometimes show that Keytruda is working. However, not having certain side effects doesn't necessarily mean the drug isn't working.