The European Commission has authorised a new, under-the-skin formulation of pembrolizumab, signalling a fundamental shift in how one of the world's most frequently used immunotherapies will be delivered. The green light authorises healthcare practitioners across the EU to administer the medicine as a rapid subcutaneous injection, which can take as little as one minute rather than the lengthy intravenous drip that was previously used. 

The medication, known as immune checkpoint inhibitors, aid the body's own defensive system in recognising and attacking cancer cells. Subcutaneous administration entails injecting the medicine beneath the skin rather than into a vein. This simpler technology can be implemented in a broader range of healthcare settings, potentially lowering patient wait times and relieving pressure on hospital infusion units.

"We are honoured to introduce Keytruda SC, the first and only subcutaneous immune checkpoint inhibitor in Europe that can be administered in one minute every three weeks or in two minutes every six weeks," said Dr. Marjorie Green, senior vice president and head of oncology and global clinical development at Merck Research Laboratories. "We are committed to discovering patient-focused innovations for people with cancer, such as Keytruda SC, which offers faster administration compared to Keytruda, provides two dosing options, and allows patients more choices of healthcare settings for receiving therapy." 

The approval is based on the findings of the landmark 3475A-D77 trial, which compared the new subcutaneous version to the old intravenous formulation in patients with untreated metastatic non-small cell lung cancer. All individuals got pembrolizumab in addition to chemotherapy. The study found that both delivery methods produced similar levels of the drug in the bloodstream and had comparable clinical outcomes. 

Simply put, the total response rate—the proportion of patients whose tumours shrank—was 45% in the subcutaneous arm and 42% in the intravenous arm. There were also no significant changes in progression-free survival (the amount of time patients lived before their cancer worsened) or overall survival. The most commonly reported side effects were nausea, exhaustion, and muscular or bone discomfort. 

With this decision, the subcutaneous formulation is now approved for all adult indications approved for pembrolizumab in the EU's 27 member states, including Iceland, Liechtenstein, and Norway. The actual availability will rely on the completion of country-specific reimbursement processes. 

Regulators and physicians have increasingly underlined the need for alternative delivery formats, particularly those that reduce time spent in clinics. Subcutaneous injections can be especially beneficial for patients with difficult-to-access veins, those who prefer treatment outside of large hospitals, and health systems looking to expand cancer services to community-based settings. The European clearance follows a similar approval in the United States earlier this year. 

As Europe's cancer care options expand, faster and simpler delivery systems are anticipated to play an increasingly important role in making lifesaving drugs more accessible— and adaptable to patients' lives.