AstraZeneca's selumetinib receives Orphan Drug Designation

AstraZeneca was celebrating on Thursday, after the US Food and Drug Administration granted its investigational MEK ½ inhibitor, selumetinib, ‘Orphan Drug Designation’ for adjuvant treatment of patients with stage III or IV differentiated thyroid cancer.

The FTSE 100 company said differentiated thyroid cancer is diagnosed in around 60,000 people in the US each year, with radioactive iodine (RAI) recommended for those with known or suspected metastases at diagnosis and those at a high risk of recurrence.

A small proportion of patients do not benefit from the treatment, however, because they do not express sufficient sodium/iodine symporter (NIS) which is vital for RAI uptake - which selumetinib being tested to treat this issue.

"Uptake of RAI is crucial for patients with thyroid cancer where no other therapies have proven beneficial. Selumetinib could significantly enhance currently available treatment options for these patients,” said AstraZeneca chief medical officer Sean Bohen.

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

AstraZeneca said the programme provides orphan status to drugs and biologics which are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US.

Analysts were also keen on the prospects for the drug, with Shore Capital's Dr Tara Raveendran saying she forecast risk-adjusted sales of circa $550mn by 2023 for selumetinib.