Indonesia closes the door on second medical use patents

The decision

On 28 August 2026, Indonesia’s Constitutional Court (Case No. 255/PUU-XXIII/2025) restored Article 4(f) of the Patent Law, along with the explanatory notes that accompanied it under the 2016 law. The decision is final and took effect immediately.

Article 4(f)

Article 4 of the Patent Law defines what does not constitute an “invention” and Article 4(f) more particularly defines different categories of non-patentable “discoveries”:

• New uses of existing or known products.
• New forms of existing compounds that do not bring a meaningful increase in efficacy and have a related structural difference already known from the compound.

“Existing or known products” is defined broadly. It covers devices, goods, machines, compositions, formulas, methods, uses, compounds and systems, whether or not they are still under patent. The definition is not limited to medicines, so the first category may on its terms also reach new-use claims in other fields, such as agricultural, chemical or device inventions. However, how the Directorate General of Intellectual Property (DGIP) applies Article 4(f) outside the pharmaceutical field remains to be seen.

Article 4(f) was introduced by Law No. 13 of 2016 on Patents. However, Law No. 65 of 2024 resulted in its deletion with effect from 28 October 2024, in order to make second medical uses patentable.

Why the Court acted

A Petition to Indonesia’s Constitutional Court was filed by patient and public interest groups in December 2025 challenging the removal of Article 4(f). The Petition argued that deleting Article 4(f) lowered the bar for pharmaceutical patents, inviting low-quality secondary patents that prolong monopolies, delay generic competition and limit access to affordable medicines in Indonesia.

Whilst the legislature and government defended the decision to delete Article 4(f) as a legitimate policy choice which was consistent with the flexibilities in the TRIPS Agreement and argued that concerns around patent evergreening of pharmaceuticals were not yet backed by evidence, the Court ultimately sided with the petitioners. The Court held that the deletion of Article 4(f) was contrary to the 1945 Constitution, citing the rights to legal certainty and to health. It stressed that patent rights carry a social responsibility, particularly for health-related inventions. In its view, Article 4(f) was an upstream safeguard, operating when an application is assessed. Government use, compulsory licences, parallel imports and the Bolar exception come into play only once a patent exists, so they cannot stop evergreening before it begins. The Court also treated new uses of known products as discoveries rather than inventions, keeping patents for genuine innovation and leaving researchers freer to repurpose existing medicines.

The petition also challenged who may contest a patent after it has been granted. Under Article 70(1), an “interested party” may appeal the grant of a patent to the Patent Appeal Commission. That makes it the route for challenging a patent said to cover subject matter excluded by Article 4(f). The term is not defined in the Patent Law, and one of the petitioners had previously had an appeal against a tuberculosis medicine patent rejected for lack of standing. The petitioners asked the Court to confirm that patient and consumer groups qualify.

The Court left the term unchanged, finding that it can be applied case by case without further legislative clarification, but signalled that it should be read broadly. Patient groups, consumer bodies, health-focused organisations and independent researchers may have a real enough stake to appeal a patent grant.

What the decision means for applicants and patentees

The impact of this decision depends on the type of claims being pursued and on when the application was filed.

Claim types

• New-use claims, including second medical use. Expect to receive objections to second medical claims, including Swiss-type claims, on the basis that these claims are directed to excluded subject matter. Efficacy data is unlikely to rescue a claim whose substance resides in a new use.
• New forms of known compounds. The exclusion under Article 4(f) applies to new forms of known compounds that don’t confer a meaningful increase in efficacy and where any structural differences between the related compounds/forms were already known. Where an invention resides in a new form of a known compound, it may be prudent to present evidence of both the structural differences and improved efficacy.
• Dosage regimens and formulations. Claims directed to novel dosage regimens and formulation based on a known substance are likely to face closer scrutiny, particularly where the application fails to show a clear technical or therapeutic advance.

Timing and existing patents

• Applications filed between 28 October 2024 and 28 August 2026. The Directorate General of Intellectual Property (DGIP) has reportedly indicated that applications filed between 28 October 2024 and 28 August 2026 will be examined under the law that was in force at the filing date. However, it remains unclear whether this will hold, so applicants and patentees are advised to treat this guidance with caution until DGIP practice settles.
• Patents granted in that period. Unfortunately, the decision does not address how patents granted between 28 October 2024 and 28 August 2026 will be treated. It therefore cannot be assumed that patents granted in that period are automatically invalid or safe from challenge.
• Greater exposure to challenge. Owners of Indonesian pharmaceutical patents, particularly for high-profile medicines, should expect more appeals from patient and public interest groups.
• PCT national phase. Foreign applicants entering Indonesia from a PCT application should review their claims against Article 4(f) before national phase entry to avoid patentable subject matter objection. Where the specification allows, consider pursuing claims directed to compounds, formulations and/or processes that do not depend on a new use and that show a genuine technical advance.
• Rethink lifecycle strategy. Protection built around new indications is unlikely to be available in Indonesia. Weight your filings towards compounds and genuinely distinct formulation or process claims, bearing in mind that formulation and dosage-regimen claims built on a known substance may also attract closer scrutiny.
• Take stock of your portfolio. Flag Indonesian applications and patents that rely on new-use or new-form claims and note when each was filed.
• The importance of data. Where a patent application claims a new form of a known compound, make sure the specification and prosecution history document any meaningful differences in structure and efficacy relative to the known compound.

Key takeaways

The recent decision by Indonesia’s Constitutional Court reflects a wider debate regarding a tension and need for balance between rewarding incremental, yet impactful, innovations in the pharmaceutical sector on the one hand, whilst simultaneously ensuring access to affordable medicines via earlier generic competition on the other. Importantly, it does not shut out pharmaceutical protection altogether, with inventions that show a real technical advance and meet Indonesia’s usual patentability criteria remaining patentable. For applicants, the practical effect is that claim strategy for Indonesia must now be considered from the outset to avoid challenges during prosecution.

Get in touch with our team to discuss how this decision affects your portfolio and how we can assist you in developing an IP strategy across South East Asia.