US Takeover of Australian Pharmaceutical Company Blocked by Treasurer

The proposal would be contrary to Australia’s national interest, Chalmers was advised.

Treasurer Jim Chalmers at a press conference at Parliament House in Canberra, Australia on July 30, 2025. AAP Image/Mick Tsikas

Treasurer Jim Chalmers has blocked the buyout of South Australian pharmaceutical company Mayne Pharma on national interest grounds.

Chalmers said he had accepted the recommendation from the Foreign Investment Review Board (FIRB) to block American-based Cosette from acquiring a 100 percent interest in Mayne Pharma.

“My decision is entirely consistent with the FIRB advice that the proposal would be contrary to Australia’s national interest,” he said.

Both companies are drug makers focused on women’s health, dermatology, and specialty medicines, producing both branded and generic treatments.

Chalmers said the decision was not taken lightly and made after months of deliberation.

“This robust process gave consideration to all available options, including whether any conditions could be applied to adequately mitigate national interest risks,” he said.

“As part of this, I took seriously the final ruling from the Takeovers Panel on Nov. 19, 2025. It is important to note that the Panel is independent and not governed by a national interest test.”

Chalmers received advice from Treasury and FIRB that no conditions could be put in place to mitigate national interest risks.

“Particularly unique risks to the supply of critical medicines,” he added.

The advice was based on opinions from the Health and Aged Care Department, Therapeutic Goods Administration, and the South Australian government.

Chalmers added that the federal government supports foreign investment.

“Australia welcomes foreign investment and operates a non‑discriminatory foreign investment framework to ensure foreign investment is in our national interest,” Chalmers added.

Mayne Pharma ‘Disappointed’

Cosette notified Mayne that the acquisition would not go through due to the treasurer’s opposition.

“Mayne Pharma was notified by Cosette shortly after market open this morning that it had received written notice from the Foreign Investment Review Board stating that the Treasurer has objected to the proposed Scheme,” the company said (pdf).

“As a result, Mayne Pharma is disappointed to inform shareholders that the FIRB condition precedent to the scheme will not be satisfied such that the scheme is unlikely to proceed.”

If the deal had gone ahead, Mayne would have been bought out through a scheme of arrangement, which is a court-approved takeover.

A court hearing in relation to the acquisition set for Nov. 23 was cancelled.

Mayne Pharma shares fell 23 percent to $4.45 on the back of this news.