Japan Generic Entry Calendar — subscriber edition (preview)

How a generic reaches the Japanese market

1. Re-examination period ends. A new active ingredient gets an 8-year re-examination period (orphan drugs up to 10, some extended for paediatric work). A generic cannot be filed until it ends.
2. Filing round. Generic applications run in two rounds: filed 1 March–31 August → approved the next August; filed 1 September–end of February → approved the following February (standard review 12 months).
3. NHI price listing. Generics are listed in June and December: February approvals in June, August approvals in December. Sales start after listing.
4. Patent linkage. MHLW does not approve a generic while a substance or use patent remains. The application can be filed during the patent term, so when a patent term extension (PTE) runs past the re-exam end, the earliest listing is the round right after the extended expiry (first 15 Feb / 15 Aug on or after expiry → June / December).
5. Carve-outs. Re-examination periods granted later for new indications do not block the generic, but those indications stay out of the generic label until they end.

Example: re-exam ends 18 Dec 2026 → file from 19 Dec (second round) → approval Feb 2028 → earliest listing June 2028. In 2016–2026 the first generic was listed at the earliest possible round for about a third of ingredients; the median was 4 rounds (about 2 years) later, which is the “typical listing” column.

Rules

• reexam_gate: A generic of the same active ingredient can be filed only after the originator's first (new active ingredient) re-examination period ends (reexam_end, from MHLW notices via data/reexam.json).
• application_windows: Generic applications run in two rounds: filed 1 Mar-31 Aug -> approved the next August -> NHI listing in December; filed 1 Sep-end Feb -> approved the following February -> listing in June (MHLW/PMDA 2024-07-03 schedule; standard review 12 months). Re-exam-bound earliest listing = generic_history.earliest_generic_listing().
• listing: Generics are listed on the NHI price list in June and December; approvals by 15 Feb go to June, by 15 Aug to December.
• patent_linkage: Japan's patent linkage (MHLW notice 医政経発第0605001号 / 薬食審査発第0605014号, 5 Jun 2009): a generic is not approved while a substance or use patent on the active ingredient remains. The application itself may be filed during the patent term. So for patent-bound rows the earliest approval is the first Feb/Aug approval round (taken as 15 Feb / 15 Aug) on or after the day after the latest extended expiry, and the earliest listing is that round's listing (Feb -> Jun, Aug -> Dec). This is a conservative reading; actual approval dates fall around the cut-off.
• combined: earliest_generic_listing = the later of the re-exam-based and the PTE-based earliest listing months.
• binding: binding_date = the later of reexam_end and pte_latest_extended_expiry; binding = 're-exam' or 'patent (PTE)'. Only registered PTEs are used. Base patent expiries without a PTE are not used as a gate.
• typical: typical_generic_listing: re-exam-bound = earliest + k x 6 months, k = median delay observed for first generics in 2016-2026 (data/generic_history.json typical_extra_cycles). Patent-bound = the later of the re-exam typical month and the PTE-based earliest month (generic makers waiting for a patent usually file in advance).
• carve_out: Re-examination periods granted later for new indications / dosages (later_periods) do not block the generic itself; those indications are carved out of generic labels until all_periods_end.
• pte_status: 'PTE found' = at least one registered extension found; 'no PTE found in search' = searched (pte.json checked=true) and no registered extension found; 'not checked' = not searched yet. pte_source = 'pte.json' (J-PlatPat facts) or 'manual' (hand-checked, data/pte_manual.json, with confidence).
• mf: MF registrants = distinct registrants of API / intermediate Drug Master Files (PMDA MF list) matched to the ingredient (salt, JP grade and maker suffix removed). thin_mf = 2 or fewer registrants. MF registration is optional in Japan, so few MF registrants does not prove few suppliers. Biologics: thin_mf = null (MF rarely used).
• focus: Rows with reexam_end in the future; within_5y = reexam_end within 5 years of 'today'.