Can pharma M&A survive Australia’s new national interest doctrine?

Australia’s Treasurer Jim Chalmers delivered a decisive blow to what would have been one of the most significant cross-border healthcare acquisitions of 2025. On advice from the Foreign Investment Review Board, the Treasurer blocked the proposed AUD 660 million acquisition of Mayne Pharma Group Limited (ASX: MYX) by Cosette Pharmaceuticals, a U.S.-based player with ambitions to dominate women’s health and dermatology. The rationale was grounded in national interest concerns that could not be mitigated through regulatory conditions.

At the center of the decision was Mayne Pharma’s manufacturing facility in Salisbury, South Australia, a U.S. Food and Drug Administration-approved plant that plays a crucial role in domestic drug production. The Australian government concluded that foreign ownership of such a strategically valuable asset could jeopardize the nation’s access to critical medicines, particularly in the face of future global supply disruptions.

This ruling is more than a regulatory rejection. It reflects a deeper recalibration of how Australia defines sovereignty in the life sciences sector and could serve as a precedent for how future pharmaceutical mergers and acquisitions will be evaluated.

How did Australia’s pharma policy evolve from open investment to strategic gatekeeping?

Australia has long promoted an open and welcoming stance on foreign investment, including in the healthcare and life sciences sectors. In previous years, deals involving pharmaceutical firms or manufacturing assets often passed Foreign Investment Review Board scrutiny with relatively minimal conditions. However, the COVID-19 pandemic revealed weaknesses in global supply chains that have reshaped national policy thinking across multiple sectors.

During the height of the pandemic, Australia faced challenges in securing consistent access to essential medicines, diagnostic kits, and vaccines. These vulnerabilities, alongside growing geopolitical tensions, led to an increased emphasis on health security and domestic production capabilities. As a result, national interest reviews have become more stringent, particularly when transactions involve assets tied to pharmaceutical manufacturing, cold-chain logistics, or sovereign drug reserves.

The Cosette Pharmaceuticals–Mayne Pharma decision marks one of the clearest examples of this policy shift in action. The Treasurer’s office, backed by assessments from Treasury, the Therapeutic Goods Administration, the Department of Health and Aged Care, and the South Australian Government, determined that no combination of undertakings or conditions could sufficiently neutralize the strategic risks associated with the proposed takeover.

Which parts of the pharma value chain are now considered sensitive under FIRB doctrine?

Although the Australian government has not published a definitive list of sensitive pharmaceutical infrastructure, the Cosette–Mayne Pharma decision offers insight into how regulators are likely drawing these lines. Assets that provide domestic manufacturing capacity for critical, high-demand, or low-substitute medicines appear to fall under heightened scrutiny. Mayne Pharma’s Salisbury facility, given its regulatory status and export capabilities, was a central factor in the FIRB’s recommendation to block the deal.

Other areas of concern may include biologics manufacturing, vaccine fill-finish sites, contract development and manufacturing organizations with strategic clients, and digital platforms that house clinical or patient data. The trend toward treating pharmaceutical manufacturing and distribution as elements of sovereign infrastructure mirrors similar patterns seen in energy, telecom, and defense sectors.

Industry advisors now believe that any foreign bid involving these categories will likely face enhanced scrutiny, especially if the buyer does not have an established, trusted presence in Australia or fails to offer clear domestic benefit guarantees.

What does this mean for future pharma M&A in Australia—and who is still welcome?

Going forward, foreign buyers looking to acquire Australian pharmaceutical companies or infrastructure assets will need to prepare for more intensive regulatory engagement. Full acquisitions may no longer be viable if they involve sovereign-sensitive operations. Instead, deal structures may need to evolve to include minority stakes, licensing arrangements, or joint ventures that retain Australian operational control.

Companies from allied countries with existing footprints in Australia, such as Pfizer, Johnson & Johnson, or Merck, may still be viewed more favorably. Even then, transactions involving domestic drug production or government supply contracts will likely need to include local manufacturing guarantees, job retention plans, and potential commitments to invest in new sovereign capabilities.

The Cosette–Mayne Pharma decision sends a message to global pharmaceutical firms: market access in Australia increasingly depends on strategic alignment with the country’s health security goals.

How did the FIRB decision affect Mayne Pharma’s share price, investor sentiment, and market positioning on the ASX?

The proposed AUD 7.40 per share acquisition price from Cosette Pharmaceuticals had buoyed Mayne Pharma’s share price and investor confidence in the months following the announcement in February 2025. Shareholders had anticipated a straightforward close in the second quarter of the year, with many institutional holders positioning around the takeover premium.

That optimism was abruptly extinguished on November 21, when Mayne Pharma confirmed that the FIRB condition under the Scheme Implementation Deed would not be met. The Second Court Hearing, scheduled for November 23, was cancelled, and Cosette issued a formal request to initiate good faith consultations regarding alternatives. The announcement triggered immediate market reaction, as traders and institutions reassessed the company’s valuation without the support of a premium-backed transaction.

While the stock retreated from its deal-implied highs, analysts tracking ASX-listed life sciences firms are now incorporating FIRB risk into their future valuations, particularly for companies with manufacturing infrastructure or U.S. commercial exposure. For Mayne Pharma, the blocked deal raises questions about whether a domestic bidder or alternative structure might now be considered more viable.

Can local players or sovereign capital step in to fill the investment gap left by blocked deals?

With foreign ownership now facing more stringent barriers in certain healthcare verticals, attention is shifting toward domestic institutional capital. Australia’s Future Fund, superannuation vehicles, or private equity firms with local governance could play a larger role in consolidating and expanding the country’s pharmaceutical production footprint.

There is growing sentiment among health policy observers that a sovereign pharmaceutical strategy is needed, one that mirrors Australia’s investments in defense, cybersecurity, and energy resilience. This may include federal support for CDMO scale-up, accelerated approvals for domestic drug repurposing, and targeted tax credits for production of strategic medicines. If implemented, such a strategy could help mitigate the effects of blocked cross-border capital flows while building a more self-reliant ecosystem.

Mayne Pharma’s situation also opens the door for locally anchored partnerships with clinical-stage biotech firms, hospitals, or public research agencies seeking manufacturing capability without triggering FIRB red flags.

Is this the end of large-scale cross-border M&A in Australian life sciences—or a new phase of strategic negotiation?

The rejection of Cosette Pharmaceuticals’ proposal is not necessarily a sign that all foreign investment in Australian life sciences is off the table. Rather, it marks a turning point in how such transactions will be assessed and structured. National interest considerations are now inseparable from commercial due diligence, especially when a transaction touches sovereign capabilities in drug manufacturing or supply continuity.

Foreign firms will need to adapt by demonstrating clear benefits to the Australian health system, committing to onshore production, and building long-term regulatory relationships before pursuing large-scale transactions. Strategic patience and stakeholder alignment will be required to succeed in the new environment.

For some, this may reduce the appeal of Australian targets. For others, it could offer a roadmap for sustainable market entry and influence, without triggering FIRB objections. What is certain is that the regulatory environment has changed, and the Cosette–Mayne Pharma decision will become a case study in how national interest is redefined in the global pharmaceutical M&A landscape.