Startup

Aculys Pharma logoAP

Aculys Pharma

アキュリスファーマ株式会社

Biotech

#35 (tie) in the Japan Top 100 Startups

Founded / HQ2021 · Tokyo
Cumulative raised¥14B
“シリーズC完了時の累計資金調達額は140億円”
Company-stated cumulative · as of 24 Mar 2025 · Aculys Pharma
STARTUP DB lists ¥17.55B after a further 2025 close.
Last round24 Mar 2025 · Series C · ¥4.4B
総額44億円
Latest public valuationNot publicly disclosed (we do not estimate)
UnicornNo
Websiteaculys.com

From Japanese sources

Findings from Japanese-language filings, government records, trade press, interviews and job posts, with our English analysis. Items tagged Japanese-only had no English coverage when we checked quickly. Most insightful first.

2025-10-15Regulatory filingViatris acquires Aculys Pharma outright, including Japan rights to pitolisant
Viatrisによる…アキュリスファーマ完全子会社化のお知らせ

Aculys is no longer an independent startup. Viatris bought 100% for the Japanese pitolisant rights and APAC rights to Spydia (diazepam nasal spray). This is a trade-sale exit for a 2021-founded in-licensing biotech, the model of buying Western drugs for Japan and selling before launch. We treat it as an exit.

Source: Viatris Japan
2026-09-16GovernmentJapan approves pitolisant (Wakix), the asset Aculys in-licensed
「ウエキクス®錠 5mg/20mg」(ピトリサント塩酸塩錠)製造販売承認を取得

Japan's first H3-receptor antagonist is approved for narcolepsy and for excessive daytime sleepiness in sleep apnoea patients on CPAP. This is the regulatory milestone Viatris paid for, less than a year after the exit.

Source: Viatris Japan (MHLW approval)

Overview

Aculys Pharma is a Tokyo drug developer focused on neurological and psychiatric conditions, licensing in drug candidates for development in Japan. Founded in 2021, it raised a ¥2.8B Series B in 2022 and a ¥4.4B Series C in March 2025, after which it put cumulative funding at ¥14B.

Built from: Series C release

Company timeline

Founded

Date2021-01· Mix Online
FoundersKazunari Tsunaba, Takeshi Takahashi

Funding

DateRoundAmountLead / key investorsSource
2022-03-27Series B¥2.8B
28億円
Company release
2025-03-24Series C¥4.4B; cumulative ¥14B
累計資金調達額は140億円
Company release

Key hires & board

2023-11LeadershipCo-founder Kazunari Tsunaba steps down as CEO; co-founder Takeshi Takahashi becomes president· Mix Online

Milestones

2024-06-28CorporateChange of corporate form and head-office relocation· Aculys Pharma
2024-07-16RegulatorySelf-inspection report on generic-drug approval and manufacturing consistency (as of 4 Jul 2024)· Aculys Pharma
2024-08-14RegulatorySelf-inspection report on generic-drug approval and manufacturing consistency (as of 6 Aug 2024)· Aculys Pharma
2024-09-11RegulatorySelf-inspection report on generic-drug approval and manufacturing consistency (as of 5 Sep 2024)· Aculys Pharma
2024-10-10RegulatorySelf-inspection report on generic-drug approval and manufacturing consistency (as of 4 Oct 2024)· Aculys Pharma
2024-11-13RegulatorySelf-inspection report on generic-drug approval and manufacturing consistency (as of 31 Oct 2024)· Aculys Pharma

News

2025-11-20Joint project with Medii on early diagnosis of cystinosis
シスチン症の早期診断に関するMediiとの共同プロジェクトの· Aculys Pharma
2025-03-24Series C: ¥4.4B; cumulative ¥14B· Company release
2024-11-13Self-inspection report on generic-drug approval and manufacturing consistency (as of 31 Oct 2024)
後発医薬品の製造販売承認書と製造方法及び試験方法の実態の整合性に係る自主点検に関する情報(2024年10月31日時点)· Aculys Pharma
2024-10-10Self-inspection report on generic-drug approval and manufacturing consistency (as of 4 Oct 2024)
後発医薬品の製造販売承認書と製造方法及び試験方法の実態の整合性に係る自主点検に関する情報(2024年10月4日時点)· Aculys Pharma
2024-09-11Self-inspection report on generic-drug approval and manufacturing consistency (as of 5 Sep 2024)
後発医薬品の製造販売承認書と製造方法及び試験方法の実態の整合性に係る自主点検に関する情報(2024年9月5日時点)· Aculys Pharma
2024-08-14Self-inspection report on generic-drug approval and manufacturing consistency (as of 6 Aug 2024)
後発医薬品の製造販売承認書と製造方法及び試験方法の実態の整合性に係る自主点検に関する情報(2024年8月6日時点)· Aculys Pharma
2024-07-16Self-inspection report on generic-drug approval and manufacturing consistency (as of 4 Jul 2024)
後発医薬品の製造販売承認書と製造方法及び試験方法の実態の整合性に係る自主点検に関する情報(2024年7月4日時点)· Aculys Pharma
2024-07-09Support for victims of the 2024 Noto Peninsula earthquake
令和6年能登半島地震による被害への支援· Aculys Pharma
2024-06-28Change of corporate form and head-office relocation
会社形態の変更および本社移転の· Aculys Pharma
2022-03-27Series B: ¥2.8B· Company release

See all news on the company site →

Funding rounds in 2026

No 2026 rounds in our database yet. Earlier funding is summarised above from the cited source.