{
  "patent_number": "US 6339142",
  "country": "US",
  "title": "How Genentech Purifies Therapeutic Antibodies for Cancer Treatment",
  "original_title": "Protein purification",
  "summary": "A method for refining mixtures of anti-HER2 antibodies to ensure that harmful acidic variants remain below 25 percent of the total composition.",
  "what_it_does": "This patent describes a process for purifying therapeutic proteins, specifically anti-HER2 antibodies, using ion exchange chromatography. The core mechanism involves adjusting the conductivity and pH levels of buffer solutions to separate the desired antibody from unwanted acidic variants. By carefully controlling these chemical conditions, the process ensures that the final mixture contains less than 25 percent of these acidic byproducts, which is critical for maintaining the safety and efficacy of the drug.",
  "what_it_does_not_cover": [
    "Does not cover general protein purification methods that do not specifically target anti-HER2 antibodies.",
    "Does not cover purification techniques that rely solely on size-exclusion chromatography rather than ion exchange.",
    "Does not cover compositions where the acidic variant concentration exceeds the 25 percent threshold."
  ],
  "filed": "2000-10-03",
  "granted": "2002-01-15",
  "expires": null,
  "status": "active",
  "holder": "Genentech Inc",
  "holder_url": "https://patentbrief.org/company/genentech-inc",
  "inventors": [
    {
      "name": "Carol D. Basey",
      "url": "https://patentbrief.org/inventor/carol-d-basey"
    },
    {
      "name": "Greg S. Blank",
      "url": "https://patentbrief.org/inventor/greg-s-blank"
    }
  ],
  "times_cited": 128,
  "tags": [
    "biotech",
    "pharmaceutical"
  ],
  "abstract": "A method for purifying a polypeptide by ion exchange chromatography is described which involves changing the conductivity and/or pH of buffers in order to resolve a polypeptide of interest from one or more contaminants.",
  "url": "https://patentbrief.org/patent/us/6339142/rituxan-rituximab",
  "markdown_url": "https://patentbrief.org/patent/us/6339142/rituxan-rituximab/md",
  "google_patents_url": "https://patents.google.com/patent/US6339142",
  "relatedPatents": []
}