Indonesia's Constitutional Court has struck down a two-year-old amendment that removed a prohibition on "patent evergreening," restoring a legal barrier against a tactic drugmakers use to file secondary patents on minor tweaks to existing medicines and delay competition.

The decision directly affects portfolio strategy for any pharmaceutical company selling into Southeast Asia's largest market, because the reinstated restriction narrows the pathway for extending exclusivity on established products through incremental patent filings.

Patient advocates say the ruling sends a critical message to other countries: evergreening prohibitions can survive constitutional challenge, and governments that remove them can be forced to reverse course.

What did the court actually decide?

The Constitutional Court ruled that the amendment — contained in Indonesian Law No. 65 of 2024, which amended Law No. 13 of 2016 on Patents — was unconstitutional. The amendment had removed the original law's prohibition on evergreening. The court concluded that the original restriction is needed to balance the rights of patent holders with the broader public interest, particularly public health.

Several patients and advocacy groups brought the case. The court sided with them, holding that public health considerations justify limiting the ability to stack incremental patents on existing medicines.

The core mechanics matter for R&D and IP planners:

• Evergreening involves filing additional patents containing minor modifications to existing medicines.
• The practical effect is to forestall competition, typically from generics, beyond the life of the original patent.
• Indonesia's original patent law banned this practice; the 2024 amendment lifted the ban; the Constitutional Court has now voided that change.

Why does this matter beyond Indonesia?

The case is the latest battle over access to medicines, and advocates frame it as precedent-setting. Their argument is that the decision demonstrates a workable legal route — constitutional litigation brought by patients and civil society groups — for challenging industry-friendly patent reforms in other jurisdictions.

For pharma R&D managers, the risk is not confined to one market. Lifecycle-management strategies that rely on secondary patents — formulation changes, dosing regimens, polymorphs and similar incremental claims — face a demonstrated constitutional counterargument grounded in public health. Where courts accept that reasoning, the effective exclusivity window for a product can shorten regardless of how many patents the portfolio carries.

The ruling also illustrates how quickly patent regimes can move in both directions. The prohibition stood in the 2016 law, was removed by the 2024 amendment, and was reinstated by judicial decision within roughly two years. Portfolio decisions priced against the amended regime now need to be repriced against the original one.

What remains uncertain?

The ruling restores the pre-amendment legal position in Indonesia, but the source material does not detail how regulators will implement the reinstated prohibition, which pending or future patent filings it will affect, or whether the industry will mount a further legal or legislative response. What is clear is the court's reasoning: patent-holder rights must be weighed against public health, and in that weighing, the evergreening ban passed constitutional muster.

Patient advocates will now push the ruling's logic into other markets where evergreening remains lawful, making constitutional and public-health challenges to secondary patenting a live risk for lifecycle planning well beyond Indonesia.