Asahi Kasei Acquires Aicuris for €780 Million to Strengthen Antiviral Portfolio

Asahi Kasei, the Japanese pharmaceutical company, has entered into an agreement to acquire the German biotechnology firm Aicuris. This strategic move is aimed at enhancing Asahi Kasei’s capabilities in antiviral therapies, particularly those targeting infections associated with bone marrow transplants.

The acquisition, valued at €780 million (approximately $920 million), will enable Asahi Kasei to leverage Aicuris’s promising antiviral treatment, pritelivir. This oral medication is designed to combat the herpes simplex virus (HSV) and is currently awaiting FDA approval, anticipated later this year.

HSV poses a significant risk to patients undergoing haematopoietic stem cell transplants (HSCT), which are critical for treating conditions such as blood cancers, aplastic anaemia, and various inherited immune or metabolic disorders. The virus can remain dormant in many individuals but may reactivate in those with compromised immune systems, such as HSCT recipients. It is estimated that without prophylactic treatment, HSV infections occur in approximately 70% to 80% of seropositive patients.

Pritelivir has demonstrated promising results in a Phase 3 clinical trial, reported in October of last year, showing significantly enhanced lesion healing over a 28-day treatment period when compared to standard therapies, which have remained unchanged for decades. These standard treatments include antiviral agents like foscarnet, cidofovir, and imiquimod.

Aicuris has a proven track record in this domain, having developed another antiviral, Prevymis (letermovir), which is marketed by MSD and is utilised to prevent cytomegalovirus (CMV) infections in HSCT patients. Additionally, the company is progressing with another antiviral, AIC468, aimed at preventing and treating BK virus infections in kidney transplant recipients, which is currently in early clinical development.

Asahi Kasei’s history in the anti-infectives market is well-established, with products such as the antifungal Cresemba (isavuconazonium sulfate) and the aminoglycoside antibiotic Exacin (isepamicin). The acquisition of Aicuris aligns with Asahi Kasei’s objective to achieve pharmaceutical sales of JPY 300 billion (approximately $1.9 billion) by the fiscal year 2030.

The conglomerate, which has diversified interests spanning chemicals, electronics, real estate, and energy/infrastructure, anticipates that pritelivir will reach peak sales of around $400 million “after the mid-2030s,” with Prevymis contributing to total sales expected to rise to approximately $500 million.

This acquisition marks Asahi Kasei’s second significant investment in the pharmaceutical sector in recent years, following the acquisition of Sweden’s Calliditas Therapeutics for $1.1 billion in 2024. Furthermore, the company acquired Danish transplant drug developer Veloxis Pharma for $1.3 billion in 2020. The Aicuris acquisition is being facilitated by Veloxis, which has since relocated its headquarters to the United States.

Ken Shinomiya, head of Asahi Kasei’s healthcare unit, commented on the strategic importance of this acquisition: “This acquisition strategically enhances and further integrates the value chain across our priority focus areas of autoimmunity, renal-related diseases, transplantation, and severe infectious diseases. It supports the thoughtful, stepwise expansion of our pipeline while reinforcing our strong and sustainable growth trajectory toward becoming a leading global specialty pharma company.”