Asahi Kasei buys antiviral firm Aicuris for €780m

Japanese drugmaker Asahi Kasei has agreed to buy German biotech Aicuris and its antiviral therapy to tackle an infection that can afflict people who undergo a bone marrow transplant.

Asahi Kasei has agreed a €780 million (around $920 million) price tag for Wuppertal-based Aicuris, which is hoping for FDA approval of pritelivir, an oral drug targeting herpes simplex virus (HSV), later this year.

HSV is a major threat to people getting haematopoietic stem cell transplants (HSCT) for blood cancers and other illnesses like aplastic anaemia and inherited immune or metabolic disorders. It is a common infection that lies latent in many people, but can reactivate as a result of the depleted immunity experienced by HSCT patients, which can last for months or even years. Without prophylaxis, HSV disease after HSCT occurs in approximately 70% to 80% of seropositive recipients.

Pritelivir was shown in a phase 3 trial, reported last October, to achieve significantly superior lesion healing up to 28 days of treatment compared with standard treatment, based on drugs like foscarnet, cidofovir, or imiquimod, which has remained unchanged for decades.

Aicuris has already developed one antiviral used for HSCT patients, MSD-marketed Prevymis (letermovir), which is used to prevent infection with cytomegalovirus (CMV), another type of herpes virus, and has another (AIC468) to prevent and treat BK virus infections in kidney transplant recipients in early clinical development.

Asahi Kasei has a long history in the anti-infectives arena, with products like antifungal Cresemba (isavuconazonium sulfate) and aminoglycoside antibiotic Exacin (isepamicin), and said that adding Aicuris will help it reach its goal of driving pharma sales to JPY 300 billion ($1.9 billion) by fiscal 2030.

The conglomerate – which also operates in the chemicals, electronics, real estate, and energy/infrastructure sectors - said it expects pritelivir to make peak sales of around $400 million "after the mid-2030s," with Prevymis taking the total to around $500 million.

The acquisition of Aicuris is its second in pharma in the last couple of years, coming after it bought Sweden's Calliditas Therapeutics for $1.1 billion in 2024. It also acquired Danish transplant drug developer Veloxis Pharma for $1.3 billion in 2020, and the Aicuris takeover is being carried out by Veloxis, which is now headquartered in the US.

"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," commented Ken Shinomiya, head of Asahi Kasei's healthcare unit.

"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."