If you have been thinking about buying CSL Ltd (ASX: CSL) shares, then read on.

That's because Goldman Sachs has just named another reason to buy the biotechnology giant's shares.

Why are CSL shares a buy?

Goldman notes that both the Australian Therapeutic Goods Administration (TGA) and the UK's Medicines and Healthcare products Regulatory Agency (MHRA) have approved the registration of ANDEMBRY (garadacimab) for routine prevention of recurrent hereditary angiodema (HAE) attacks.

It highlights that the approvals in Australia and the UK are the first regions in the world for garadacimab but aren't likely to be the last.

That's because the therapy is also under review by regulatory agencies in the United States (US), European Union (EU) and Japan. Goldman appears confident that approvals are on the way. It said:

In our view, approvals by the TGA and MHRA reinforce garadacimab's strong clinical profile as reflected in the pivotal placebo-controlled Phase 3 VANGUARD trial and should support US and EU approvals. CSL has guided to FDA and EU approvals by 30 June 2025 and our FY26 forecasts reflect ~$250m of garadacimab sales.

Commercial opportunity

Approvals in the EU and US would be good news for CSL and its shares. That's because Goldman sees potential for garadacimab to deliver a big contribution to its sales in the near term and help claw back lost market share. It explains:

Over the last 5 years (CY19-CY24), we estimate CSL has lost ~700bps in HAE market share following the launches of TAKHZYRO and ORLADEYO. The introduction of garadacimab provides the opportunity to regain some share and grow the prophylactic HAE market, given its more convenient dosing schedule (once monthly). Our CSL HAE revenue growth forecast of 25% FY25-FY28 CAGR reflects ~27% market share by the end of this period which compares to CSL's target of 30%.

In response to the news, Goldman has reaffirmed its buy rating and $325.40 price target on CSL's shares. This implies potential upside of 19% for investors over the next 12 months. It adds:

Over the last 10 years, CSL's premium to the ASX 200 has ranged from 1.5x-3.0x. We adopt a premium of 1.8x as part of our valuation which is close to the 10-year average noting the current share price values the business cheaper relative to its 5 and 10-year averages. We believe ongoing momentum in CSL's IG revenue growth, Gross Margin recovery and execution on market share initiatives in Hemophilia and HAE are key drivers in driving re-rating.