Data from the first cohort of the Phase 2 KEYNOTE-158 trial, evaluating pembrolizumab for individuals with advanced thyroid carcinoma, showed positive safety and efficacy. According to Cancer Network, 103 participants aged 18+ enrolled in the first cohort. Participants received 200mg pembrolizumab, administered intravenously, every 3 weeks for 105 weeks or until their cancer progressed. 

In findings published in Cancer, the research team shares that: 

• Pembrolizumab treatment prompted an objective response rate of 6.8%, with 2 complete responses and 5 partial responses. 
• In people with PD-L1 positive tumors, the objective response rate was 8.7% compared to 5.7% in those with PD-L1 negative tumors. 
• Altogether, pembrolizumab contributed to a disease control rate of 67%. 
• Patients experienced a median duration of response of 18.4 months. 
• While pembrolizumab did confer benefits for some patients, a majority of patients also experienced side effects. These included itchiness, rashes, and fatigue. 9.7% of patients discontinued pembrolizumab use due to these side effects and two passed away from adverse reactions of arterial hemorrhage and malignant neoplasm progression. 
• At the point of data cutoff, 93.2% of participants had progression-free survival, with a median length of 4.2 months. Progression-free survival fell gradually by 6 and 12 months, with 6.8% of individuals still having progression-free survival by 24 months. 
• The overall survival rate fell from 81.6% at 12 months to 45.9% at 48 months. 

Ultimately, this treatment provided durable and sustained anti-tumor activity in some individuals with advanced or metastatic thyroid carcinoma. In the future, the study investigators recommend additional research exploring whether pembrolizumab in conjunction with other therapies could prompt stronger responses. 

What is Thyroid Carcinoma?

Just like you’d imagine from the name, thyroid cancer begins in the thyroid, a small gland at the base of the throat. There are multiple forms of thyroid carcinoma, including papillary, anaplastic, medullary, and follicular. Papillary is considered to be the most common form. Thyroid carcinoma is more common in females than males. A family history of thyroid cancer, radiation exposure (particularly around the head and neck), and genetic diseases like multiple endocrine neoplasia type 2A (MEN2A) also increase the risk of developing this cancer. 

In many cases, individuals may be asymptomatic until their cancer has progressed. Symptoms and severity are variable, but may include:

• A painless mass or lump in the neck
• Hoarseness or other vocal changes
• Neck pain that may progress to the ears
• Difficulty breathing
• A chronic cough that is not due to a cold
• Swollen lymph nodes
• Difficulty swallowing (dysphagia)
• Neck and throat inflammation

There are multiple treatment options for thyroid carcinoma: chemotherapy, radioactive iodine treatment, targeted therapy, surgery, radiation, and alcohol ablation. If you have thyroid cancer, please speak with your care team about your best treatment options.