Patent No. EP3351261 (titled "Combination Medicament Comprising Il-12 And An Agent For Blockade Of T-Cell Inhibitory Molecules For Tumour Therapy") was filed by Universitt Zrich on Oct 10, 2012. The application was issued on Jun 2, 2021.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.