Genentech cancer drug delayed
Published: 31 Aug 2010
The US Food and Drug Administration (FDA) has refused to consider for accelerated approval a HER2-targeted breast cancer medicine being developed by Roche's Genentech using ImmunoGen's tumour-activated prodrug technology.
Genentech is seeking approval for trastuzumab-DM1 (T-DM1) for use in patients with advanced HER2-positive breast cancer who have previously received multiple HER2-targeted medicines and chemotherapies. T-DM1 links ImmunoGen's tumour-activated prodrug DM1 to the HER2-targeted therapy trastuzumab, which Genentech markets under the brandname Herceptin. The two drugs are attached using a stable linker designed to keep T-DM1 in one piece until it reaches specific cancer cells and destroys them.
Genentech's Biologic Licensing Application (BLA), submitted in July, requested accelerated approval for T-DM1 based on the results of a single-arm phase II study showing that the therapy shrank tumours in one-third of women with advanced HER2-positive breast cancer who had received on average seven prior medicines.
Accelerated approval allows drugs to be cleared for marketing based on surrogate endpoints like tumour size rather than on clinical outcomes, provided that drug sponsors conduct postmarketing studies to confirm the clinical benefits. It is reserved for drugs that treat serious diseases and fill an unmet medical need.
In refusing to file the BLA, the FDA said the data did not meet the standard for accelerated approval because all currently marketed treatment choices for metastatic breast cancer, regardless of HER2 status, had not been exhausted in the subjects. Genentech said it expects to submit a new BLA in mid-2012, representing a significant delay for the drug.
In the meantime, Genentech will continue its ongoing phase III registrational trial comparing T-DM1 to lapatinib in combination with capecitabine in people with advanced, HER2-positive breast cancer whose disease has worsened after initial treatment.
ImmunoGen, which unlike Genentech does not have marketed products and relies heavily on milestone fees for income, said that it will have to revise its fiscal year 2011 financial guidance due to the setback and will provide updated estimates in the near future.
Genentech licensed exclusive worldwide rights to commercialise anti-HER2 targeting products using ImmunoGen's maytansinoid TAP technology in May 2000. The deal called for ImmunoGen to receive an upfront payment of $2m, potential milestones of up to $40m, and royalties on net sales.
Published: 31 Aug 2010
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