The drug, which blocks a protective mechanism on the cancer cells allowing the immune system to destroy them, is used to treat advanced non-small cell lung cancer, which experts believe affects around 150 people a year in Scotland. The immunotherapy treatment can delay disease development, helping patients live a better quality of life during their last months.
Cancer Research UK's Gregor McNie is pleased with Scotland's decision to approve the drug's use, BBC Scotland reported.
"Scotland is the only part of the UK where lung cancer is the most common cancer. So it's great news that pembrolizumab will be made available for some patients in Scotland with this devastating disease," McNie said.
"We have spent many years trying to find better treatments for non-small cell lung cancer, and the chances of survival have been among the poorest of any type of cancer," he added.
In addition, a drug called Nivolumab was approved to treat patients with Hodgkin lymphoma [cancer of the white blood cells], who have exhausted all other treatment options.
The SMC also approved Ustekinumab, a human monoclonal antibody medication that can treat Crohn's Disease, a chronic inflammatory bowel disease that affects the digestive tract.
However, the SMC rejected a treatment for pulmonary arterial hypertension, called Selexipag, on the basis that the clinical and economic benefits of the drug are "not robust enough."
Several patients are unhappy with the SMC's disapproval of the high blood pressure medication.
Pauline Harrison, who was diagnosed with pulmonary arterial hypertension during pregnancy seven years ago, told BBC Scotland she hopes the SMC reconsiders its decision.
"They are just looking at the cost first," she said, alluding to Scotland's public health service.
"And I am sorry, but you cannot put a price on a life. That's the way I think.
"I think people should be given a chance to try the medication out. If the results are good, and it is beneficial for the patient, then I really don't think they should even look at the cost."
Nivolumab, Ustekinumab and Selexipag have also all been approved by the FDA.
