Teva has received US approval to market its Synribo injection for the treatment of the blood and bone cancer chronic myeloid leukaemia.
The Food and Drug Administration (FDA) said the drug should be available for use in patients whose cancer progressed after treatment with at least two tyrosine kinase inhibitors (TKIs), following an accelerated approval process.
This process allows the FDA to approve treatments for serious diseases based on early clinical data that demonstrates a drug is reasonably likely to offer a clinical benefit to patients and Teva said it expected full approval for Synribo (omacetaxine mepesuccinate) following the submission of further data from ongoing studies.
The FDA's decision come shortly after its approval for Pfizer's Bosulif (bosutinib) in a similar indication, although Pfizer's drug received a full rather than accelerated licensing decision.
Both drugs have been designated as orphan medicines due to the relatively small number of people who would eligible to receive them, with the US National Institutes of Health predicting 5,430 people will be diagnosed with CML in the US during 2012.
“While the CML treatment landscape has seen advancements with available TKI treatments, there are still cases where patients may not be able to continue using TKIs due to issues such as resistance, intolerance, suboptimal response, and disease progression,” said Dr Jorge Cortes, deputy chair and professor of medicine in the department of leukaemia at The University of Texas MD Anderson Cancer Center.
“With Synribo, physicians will now have access to another option, offering potential hope to patients who experience treatment failure.”
Early data to support Synribo's accelerated approval comes from two phase II trials evaluating the drug in patients with either chronic phase or accelerated phase CML whose cancer progressed after previous treatment with two or more TKIs.
For patients with chronic phase CML, 18 per cent of participants achieved a reduction in the percentage of cells expressing the Philadelphia chromosome genetic mutation patients within 3.5 months.
This mutation is found in most CML patients, and can lead to over-production in the bone marrow of tyrosine kinase, which can cause stem cells to develop in white blood cells.
In accelerated phase CML, the effectiveness of Synribo was predicted through the measurement of the number of patients who experienced a normalisation of white blood cell counts or had no evidence of leukaemia.
Of the 35 patients involved in the study, five were able to achieve this response in an average time of 2.3 months.