The US Food and Drug Administration has approved Ariad Pharmaceuticals' Iclusig to treat two rare types of leukaemia and given the thumbs-up to Novartis' Signifor for Cushing's disease.

First up, the agency has given the green light to Iclusig (ponatinib) to treat adults with chronic myeloid leukaemia (CML) and Philadelphia chromosome positive acute lymphoblastic leukaemia, two rare blood and bone marrow diseases. The approval comes well ahead of the product’s prescription user fee goal date of March 27, 2013.

Iclusig, which is taken once a day, targets CML cells that have a particular mutation, known as T315I, which makes these cells resistant to currently-approved tyrosine kinase inhibitors. In a trial of 449 patients with various phases of CML and Ph+ ALL, 54% of all patients and 70% of patients with the T315I mutation achieved major cytogenetic response.

Black box warning

However, despite the approval, Ariad shares slumped 21%, its largest decline in over four years, to close at $18.93, because the FDA has stuck a black box warning on the label, noting that Iclusig can cause blood clots and liver toxicity.

Nevertheless, Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research,  said the approval of Iclusig is important "because it provides a treatment option to patients with CML who are not responding to other drugs". He noted that the treatment is the third drug approved to treat CML and the second for ALL this year, "demonstrating the FDA’s commitment to approving safe and effective drugs for patients with rare diseases".

The agency approved Pfizer's Bosulif (bosutinib) in September and Teva Pharmaceutical Industries' Synribo (omacetaxine mepesuccinate) in October 2012 to treat various phases of CML. Talon Therapeutics' Marqibo (vincristine sulfate liposome injection) got the green light in August to treat Ph- ALL.

Meantime, the FDA has also approved Signifor (pasireotide)  for the treatment of Cushing’s disease, a rare condition caused by over-production of cortisol, a hormone made by the adrenal glands. The drug is a new treatment option for patients when "surgery hasn’t worked or isn’t an option,” said Mary Parks, director of the Division of Metabolism and Endocrinology Products at the FDA’s CDER.

The agency noted that Signifor,  which is administered subcutaneously twice-daily, caused increases in blood sugar levels, which could be detected as early as two weeks after starting treatment, and continued use caused or worsened diabetes in some patients.

It is therefore requiring three postmarketing studies - a clinical trial to assess high blood sugar management,  a long-term prospective observational cohort study of patients with Cushing’s treated with Signifor and focused safety monitoring for reports of serious hyperglycemia, acute liver injury and adrenal insufficiency.

The FDA gave the green light to Corcept Therapeutics' Korlym (mifepristone), a drug with the same active ingredient as abortion pill RU-486, to treat Cushing’s in February 2012.