The first drug that treats the root cause of cystic fibrosis won approval Tuesday (01/31/12), offering a life-changing treatment for a handful of patients with the deadly illness and broader hope for thousands more patients with the inherited disease.

The FDA reviewed and approved Kalydeco in approximately three months under the agency’s priority review program that is designed to expedite the review of drugs. The priority review program uses a six-month review, instead of the standard 10 months, for drugs that may offer significant advances in treatment over available therapy.

Kalydeco is effective only in patients with CF who have the G551D mutation (about 4% of the CF population). It is not effective in CF patients with two copies of the F508 mutation in the CFTR gene, which is the most common mutation that results in CF. If a patient’s mutation status is not known, an FDA-cleared CF mutation test should be used to determine whether the G551D mutation is present.

Read the full FDA press release here.

Read an article on the Huffington Post here.