From filings of Berkshire Hathaway for the September quarter (so, a bit dated, but its the most up-to-dat public info)

made new investments in large pharmaceutical companies Merck, Bristol Myers Squibb, AbbVie (between $1.8 billion and $1.9 billion in each) and a smaller investment in Pfizer ( $136m)

Via Wall Street Journal, more at the link (may be gated)