OSE Immunotherapeutics turns to IRIS for €19.3m bridge financing

The planned financing, structured through IRIS’s SmartATM mechanism, would allow IRIS to subscribe for up to 4 million new OSE shares, corresponding to around 17% of the company’s current share capital. The shares would be issued through warrants at an exercise price equal to 95% of the lowest daily volume-weighted average price observed over the three trading days before each exercise.

OSE said the mechanism is the first step in a broader financing strategy designed to support its new three-year strategic plan. The company is looking to extend its runway while it continues discussions with institutional investors in the US and Europe, and while it explores other options such as new strategic partnerships, an institutional equity offering, debt restructuring, and potential milestone payments from existing collaborations.

The immediate financial context is tight. OSE reported €17.0m in cash and cash equivalents at the end of March 2026 and stated that it does not currently have sufficient net working capital to meet its obligations over the next 12 months. If fully used, the IRIS facility would extend its cash runway only to the end of December 2026, based on current plans and excluding any potential future milestone payments.

Priority reset

The financing comes after a change in governance last October and a reset of OSE’s development priorities. Chief Executive Officer Marc Le Bozec said the company had designed a “more pragmatic” three-year plan, with chronic pouchitis selected as a new rare-disease indication for lusvertikimab, OSE’s anti-IL-7 receptor monoclonal antibody that is being developed as a treatment for inflammatory bowel diseases. OSE is also developing a subcutaneous formulation of the antibody to support further clinical development in ulcerative colitis.

In oncology, OSE continues to recruit patients into ARTEMIA, the Phase III trial of Tedopi, its cancer vaccine-based immunotherapy candidate designed to stimulate the immune system to target tumour cells, in non-small cell lung cancer. Tedopi also recently cleared a Phase II in ovarian cancer in combination with Keytruda.  The company has described the IRIS financing as a bridge toward a larger funding package rather than a standalone long-term solution.

The structure gives OSE some flexibility. IRIS would make an upfront payment of €2m when the financing is signed. After that payment has been offset against warrant exercises, or otherwise reimbursed, OSE can limit the number of warrants exercised over a given period, change the floor price, pause the facility, or terminate it at no cost. The company will also publish the number of shares issued through the mechanism on its website.

White knight

IRIS has become a recurring name in this type of financing among financially constrained French biotechs. Earlier this year, Poxel implemented a €5m equity line with IRIS as part of its court-approved recovery plan. In that case, the mechanism was also presented as a way to provide liquidity in stages while the company pursued partnerships and managed its obligations under a constrained financing horizon.

The OSE transaction is different in that the company is not under judicial reorganisation, but the underlying logic is similar. The facility gives management time and optionality while negotiations continue with longer-term investors or partners. It does not remove the need for a broader financing solution, and OSE’s own wording makes clear that the company is still trying to secure the capital needed to fund its full three-year plan.

OSE explicitly warned that IRIS does not intend to remain a shareholder. Shares issued to IRIS are expected to be sold on the market at short notice, which can weigh on the share price and increase volatility.