Beike Biotechnology acquired China rights to ALT-803 from Altor BioScience on September 9, 2014. Under the agreement, Altor will receive $4 million upfront payment, $200 million milestones payment and double-digit royalties based on sales.
ALT-803 is a soluble complex of IL-15 mutant (IL-15N72D) and IL-15Rα/Fc fusion protein. This complex exhibits increased biological activity (approximately 25-fold) and long serum half-life (25 h vs. 40 min) compared to IL-15.
IL-15 is a T-cell growth factor similar to IL-2 which has been approved for the treatment of metastatic melanoma and renal cancer. In contrast to IL-2, IL-15 does not support maintenance of Treg cells or induce cell death of activated CD8+ T cells. Thus IL-15 could be more effective than IL-2.
ALT-803 is currently in four clinical trials for patients with metastatic melanoma, hematological malignancies, multiple myeloma, and bladder cancer. All of these trials are partially or fully supported by NCI/NIH.
Although a NCI review in 2008 listed IL-15 as the most promising immunotherapy candidate that could cure cancers, I am not very optimistic about these prospects.
The environment within the tumor is highly immunosuppressive, repressing the immune responses mediated by cytokines. ALT-803 exhibits anti-tumor activities in various pre-clinical models, however, no hard clinical date have been disclosed.
For metastatic melanoma, a head to head study of ALT-803 vs. IL-2 may be warranted. More importantly, would ALT-803 be superior to immune checkpoint blockade therapies? Is there a huge market in china? The price of $200 million is a pretty high.
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