Keytruda (pembrolizumab), MSD's anti-PD-1cancer immunotherapy, has received approval for two additional indications in Korea.

MSD Korea said Keytruda received the permit from the Ministry of Food and Drug Safety (MFDS) as a first-line treatment in adult patients with HER2-positive advanced gastric cancer or gastroesophageal junction (GEJ) adenocarcinoma.

Keytruda has received approval for its use as a first-line treatment in patients with PD-L1-expressing (CPS ≥1), inoperable, locally advanced, or metastatic HER2-positive adenocarcinoma of the stomach or GEJ. This approval is for Keytruda's combination with trastuzumab, fluoropyrimidine, and platinum-based chemotherapy.

Between 10 and 30 percent of gastric cancer patients exhibit HER2-positive status. The subset of HER2-positive gastric cancer represents a notable area of unmet medical need, especially considering that no new treatment options have been approved since the approval of the trastuzumab and chemotherapy combination in 2010.

With this expanded approval, Keytruda became the first cancer immunotherapy in Korea to demonstrate clinical utility in the first-line treatment of unresectable locally advanced HER2-positive gastric or GEJ adenocarcinoma in 13 years, compared to the existing standard of care.

This expanded indication was based on KEYNOTE-811, a phase 3 clinical trial assessing the combination of Keytruda with trastuzumab and chemotherapy, in comparison to the control arm receiving trastuzumab and chemotherapy alone.

Also, MSD Korea said Keytruda in combination with platinum-based chemotherapy won the regulatory nod as preoperative neoadjuvant therapy and postoperative adjuvant therapy to treat resectable non-small cell lung cancer (NSCLC) (tumor size >4 cm or positive lymph nodes).

Keytruda has become the first immuno-oncology drug approved for both pre-and post-operative adjuvant therapy in early-stage lung cancer. This approval signifies a notable expansion from its initial four indications for metastatic lung cancer to now include early-stage lung cancer.

The expanded indication was established through KEYNOTE-671, a phase 3 study that assessed the efficacy of Keytruda as pre- and post-operative adjuvant therapy in stage 2, 3A, or 3B NSCLC.