Servier makes a rare big buy

Servier has spent the past year striking small deals, but now it’s gone for a much bigger proposition, acquiring Day One Biopharmaceuticals for $2.5bn.

The main draw is Day One’s Ojemda, a pan-RAF inhibitor that was FDA approved in 2024 for a common childhood brain cancer, relapsed/refractory, BRAF-altered low-grade glioma. Recently announced full-year sales of $155m outstripped analysts' expectations, but one question is whether revenues will ultimately justify Day One’s price tag.

On the first point, Jones Research described the valuation as “fair”. Indeed, the analysts had forecast in February that Day One could be a takeout target with a potential price tag of $2.4-2.6bn. At $21.50 per share, Servier’s offer represents a 68% premium over Day One’s closing price on 5 March.

Ojemda, which is licensed to Ipsen outside the US, has a chance to expand, with the phase 3 Firefly-2 trial in first-line low-grade glioma set to read out in mid-2027.

Another question is what the deal might mean for Black Diamond’s BDTX-4933, a rival RAF inhibitor that Servier licensed last year for a much less demanding $70m up front. That project, previously deprioritised by Black Diamond and now known as S241656, is currently in a phase 1/2 trial in RAS and RAF-mutated solid tumours that hasn’t yet yielded results.

Mersana bonus

As well as Ojemda, Servier will get projects originated by Mersana Therapeutics, which Day One acquired last November for the bargain price of $129m.

Mersana’s chief asset was its B7-H4-targeting ADC emiltatug ledadotin, which underwhelmed in triple-negative breast cancer. Day One reckoned it had seen promise for emilta-L in adenoid cystic carcinoma, a rare tumour type, and data are due here in mid-2026.

Mersana had also been developing calotatug ginistinag (XMT-2056), a Sting-agonist-based conjugate against HER2. However, this didn’t appear in Day One’s latest corporate presentation.

Day One’s pipeline is rounded out by DAY301, a PTK7-targeted ADC, which it licensed from MabCare for $55m up front. That asset is set to yield phase 1 data in the second half of this year. However, other projects with this mechanism haven’t fared well.

The Day One deal is the biggest in Servier’s history, just ahead of its acquisition of Shire’s oncology business for $2.4bn, back in 2018. The French group also paid $1.8bn in 2020 to get its hands on Agios’s cancer portfolio in 2020.

More recently, the company has been focused on smaller transactions. As well as the Black Diamond tie-up, Servier shelled out $210m to license Ideaya’s PKC inhibitor darovasertib outside the US, and also picked up BioNova's mid-stage menin inhibitor BN104 for an undisclosed fee.

Servier’s major oncology deals since 2020

Source: OncologyPipeline.