cancer

The US Food and Drug Administration (FDA) has granted Orphan Drug Designation to AstraZeneca’s investigational MEK 1/2 inhibitor, selumetinib (AZD6244, ARRY-142886), to treat patients with stage III or IV of differentiated thyroid cancer (DTC).

Radioactive iodine (RAI) is suggested for the patients with known or suspected metastases at DTC diagnosis, as well as those who are at high risk of recurrence.

However, a small proportion of patients do not benefit from the available treatment with RAI because they do not exhibit necessary sodium / iodine symporter (NIS), which is essential for RAI uptake into thyroid cells.

Selumetinib is being examined for its ability to increase expression of NIS with the ability to add a treatment option for patients who do not respond significantly to RAI.

AstraZeneca global medicines development executive vice-president and chief medical officer Dr Sean Bohen said: "Uptake of RAI is crucial for patients with thyroid cancer where no other therapies have proven beneficial.

"The Orphan Drug Designation is an important achievement as we advance our development plans for this potential treatment in differentiated thyroid cancer."

"Selumetinib could significantly enhance currently available treatment options for these patients. The Orphan Drug Designation is an important achievement as we advance our development plans for this potential treatment in differentiated thyroid cancer."

In a bid to prevent growth of tumour, Selumetinib inhibits the MEK pathway in cancer cells.

Selumetinib is being tested in the Phase III ASTRA trial in patients suffering from DTC and are at a high risk of recurrence.

In a Phase II study of selumetinib in patients with advanced thyroid cancer, clinically significant increases in iodine uptake and retention were visible in patients afflicted with thyroid cancer that was refractory to RAI.


Image: Histopatholgical image of papillary carcinoma of the thyroid gland obtained by a total thyroidectomy. Photo: courtesy of KGH.