The collaboration agreement between the two companies will see IGM Biosciences use its proprietary immunoglobulin M (IgM) antibody platform to discover and develop six agonists.
As part of the financials of the agreement, IGM will receive $150m (€134m) in upfront payment and could be eligible for over $6bn in development, regulatory and commercial milestones.
At the heart of the deal are IGM’s engineered IgM antibody agonists, which the companies state offer ‘superior features’ over conventional IgC antibodies for stimulating cell surface receptors. IgM antibodies are the first class of antibodies that are generated in response to an antigenic challenge.
A spokesperson for Sanofi explained to BioPharma-Reporter the advantages offered by IgM antibodies: “While the IgMs offer low affinity compared to conventional IgG antibodies, they are powered by stronger avidity due to 10 binding sites contributing to their multivalency.”
By comparison, IgC antibodies only have two target binding sites, as a result, “the ability to fine tune the spatial arrangement and the avidity parameters is the key differentiator,” the spokesperson concluded.
When asked for further details, IGM’s CEO, Fred Schwarzer, explained: “IgM antibodies have unique structural characteristics that make them particularly well suited to targets that require multimeric binding. We have seen encouraging signals both pre-clinically and clinically in that IgM antibodies provide greater stimulation of these targets than corresponding IgG antibodies.”
Financial incentives
The potential to add a first-in-class antibody therapy to its portfolio meant that Sanofi was prepared to offer approximately $1bn in milestone payments per drug candidate developed.
In terms of the development process, the oncology targets will be progressed by IGM up until first marketing approval of any of the three candidates, at which point Sanofi would lead all subsequent development and commercialization activities. The companies would split profits 50:50 in ‘certain major markets’ and IGM would receive tiered royalties on net sales in the rest of the world.
For the immunology/inflammation targets, IGM will lead R&D activities up to the completion of Phase I clinical trials, after which Sanofi would then be responsible for both development and commercialization activities. IGM would receive high single-digit to low-teen royalties on global net sales of any approved products.
According to Schwarzer, the work to be done with Sanofi on these targets will be ‘additive’ to its current R&D efforts, with IGM currently progressing four preclinical and clinical oncology assets through its own pipeline.
Another strategic partnership
Continuing a trend across the industry, Sanofi has preferred to agree a collaboration rather than pursue an acquisition to gain access to IGM’s antibody platform.
Sanofi previously opted for such a structure before striking a deal to acquire Translate Bio in 2021, after having begun its relationship with the mRNA specialist through a collaboration agreement. Similarly to its deal with Translate Bio, where Sanofi made an investment directly into purchasing shares of the company, the company is looking to pursue a similar approach with IGM.
As part of the announcement on the collaboration deal, a statement was included reading: “Sanofi has also expressed an interest in purchasing up to $100M of IGM non-voting common stock in a public financing.”
On the same day as the Sanofi deal announcement, IGM published a notice that it would be looking to offer $200m in shares of its common stock.