Temperature-sensitive baculovirus expression vector system for the production of baculovirus virion-free biopharmaceuticals

The invention relates to methods for the production of a biopharmaceutical product, comprising infecting an insect cell with a baculovirus, said baculovirus comprising an exogenous gene coding for a biopharmaceutical product, and wherein the genome of said baculovirus comprises a mutation in a gene that is essential for baculovirus particle formation and/or secretion, which mutation renders the baculovirus temperature-sensitive (ts). The invention further relates to the use of a baculovirus with a ts mutation in a gene that is essential for baculovirus particle formation and/or secretion, for production of a biopharmaceutical product.