Astellas takes $285m option on Audax's preclinical IL-12 drug in deal worth up to $1.34bn

Astellas Pharma and Audax Biosciences, a Melbourne biotech, agreed on 27 October 2026 an exclusive option and licence deal for DAX-044, Audax's lead cancer immunotherapy, with a total potential value of up to US$1.34 billion before royalties¹. Astellas commits up to $285 million in upfront and option fees for the chance to license a programme that has not yet been tested in people².

The terms

Audax receives an upfront payment and a possible future option exercise payment that together come to US$285 million¹. On top of that sit development and commercial milestones of up to US$1.05 billion and tiered double-digit royalties on worldwide net sales if the drug is approved¹. Exercising the option needs the usual conditions to be met, antitrust clearance among them¹.

The split of work is unusual for a deal this size. Audax, not Astellas, will pay to take DAX-044 into a Phase 1 study, which the companies expect to start in 2027¹. Only once Astellas exercises its option does it take sole charge of global development, manufacturing and commercialisation¹. Audax keeps a right to co-fund and co-promote the drug in Australia and New Zealand¹².

DAX-044 is an interleukin-12 (IL-12) antibody-cytokine fusion built on Audax's AVIKINE platform, intended to concentrate IL-12's immune activation inside tumours and limit the systemic toxicity that has held back the class¹. Fierce Biotech reports that Audax lowered the molecule's affinity for the IL-12 receptor to reduce activation of circulating immune cells, fused it to an antibody Fc region to extend its half-life, and added a binding domain aimed at immune cells in the tumour microenvironment². The asset is in IND/CTN-enabling development, and Audax says preclinical studies point to a potential best-in-class therapeutic index for an IL-12 agent¹.

Takahiko Iwaya, Astellas' chief strategy officer, described DAX-044 as "a promising investigational immuno-oncology program with a differentiated mechanism"¹. Jai Rautela, Audax's chief executive, said the partnership "will expedite the planned phase 1 clinical evaluation" of the drug¹.

What it means for the market

The structure tells buyers and investors how large pharma is pricing early, high-risk biology. Astellas pays for optionality rather than ownership, leaving the cost and risk of first-in-human work with the biotech while securing the asset if the data hold up¹. For Audax, the deal brings in up to $285 million before any milestone and keeps a domestic commercial role¹.

The bet runs against a poor record. Fierce Biotech notes that big pharma interest in IL-12 faded in 2022 and 2023 when AstraZeneca, Bristol Myers Squibb and Merck KGaA dropped programmes, and that development since then has largely moved to biotechs². It also recalls a 1990s phase 2 study of 17 patients that recorded 12 hospitalisations and two deaths². Competition is building: Gilead holds an option on a Xilio Therapeutics asset, with Xilio expecting phase 2 data next year, Imunon began a phase 3 trial of its candidate in ovarian cancer last year, and Iovance Biotherapeutics, PDS Biotechnology and Philogen have IL-12 programmes in the clinic².

For Astellas, the deal adds to immuno-oncology, which the company lists among the main focuses of its research strategy¹. BioPharma Dive reports that Astellas called the candidate a potential "best-in-class" prospect nearing human testing³.

Caveats

All the evidence so far is preclinical, and Audax has yet to show how DAX-044 behaves in humans². The headline value depends on Astellas exercising its option and on milestones that may never be reached, a risk Audax itself flags¹. The fee of $285 million combines upfront and future option money, and neither company has said how it divides¹. The next marker is the Phase 1 study, expected to begin in 2027¹³.