Lilly reunites with ImmunoGen to expand into ADCs, paying $13M upfront and $1.7B on the back end

Eli Lilly has jumped back into bed with ImmunoGen. Several years after terminating an earlier deal, Lilly has struck a new agreement, paying $13 million upfront and committing up to $1.7 billion in total to pick up rights to another antibody-drug conjugate (ADC) technology. 

The new deal covers ADCs based on ImmunoGen’s camptothecin technology. Interest in using antibodies to guide the delivery of camptothecins, a class of drugs that includes the chemotherapies irinotecan and topotecan, dates back years. ImmunoGen has sought to advance the field, listing novel camptothecin toxins among its early-stage intellectual property, and been rewarded with a new Lilly partnership.

Lilly is securing rights to use the camptothecin technology against certain targets in return for $13 million upfront. The deal gives Lilly the option to add additional targets in return for $32.5 million. Once all the exercise fees and milestones are factored in, ImmunoGen could receive up to $1.7 billion from Lilly.

The agreement gives Lilly the chance to find out whether ImmunoGen’s efforts to widen the therapeutic window and improve safety and efficacy have paid off. ImmunoGen has developed its own camptothecin linker-payloads that are designed to optimize the existing technology and retained the right to use it against targets outside of the Lilly deal.

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Lilly previously teamed up with ImmunoGen in 2011, when it received three exclusive licenses as part of a deal that saw it pay $20 million upfront and $4 million in exercise fees. The ADC market has changed immeasurably since then, with clinical data and approvals validating the technology and setting the stage for a series of big-ticket deals.

Having ducked out of the ImmunoGen deal in 2018, Lilly has spent the ADC gold rush on the periphery, inking a deal to access antibody-oligonucleotide conjugate technology in 2019 but watching on as others have bet big and brought drugs to market. The new ImmunoGen deal offers Lilly a path back into ADCs, although the early-stage nature of the deal means it will be years before the bet pays off.