The ‘878 and ‘997 patents are directed to methods to purify proteins expressed in a non-native soluble form in a non-mammalian expression system. Kashiv asserts that claims 7-8, 11-12, 13, 15-19, and 21 of the ‘878 patent, and claims 9-11, 13-15, 17-21, 23, and 26-30 of the ‘997 Patent are anticipated and/or obvious over the prior art. According to Kashiv, the challenged claims are directed to routine methods for purifying proteins expressed in non-mammalian expression systems, including (i) expressing a protein; (ii) lysing the cell; (iii) solubilizing the expressed protein; (iv) forming a refold solution; (v); directly applying that refold solution to a separation matrix; (vi) washing the matrix; and (vii) eluting the protein from the matrix.
Earlier this year, Kashiv Pharma, LLC acquired Adello Biologics and was renamed as Kashiv Biosciences. As we have reported, Adello submitted an aBLA for its filgrastim biosimilar candidate in 2017 and is currently engaged in patent litigation under the BPCIA relating to this product.