Rapt Therapeutics, Inc.

A phase 2 study of ozurepubart Rapt Therapeutics initiated is due to read out in 2027, according to GSK.\n GSK is paying $2.2 billion to buy Rapt Therapeutics and its anti-immunoglobulin E (IgE) antibody to protect against food allergy reactions.Rapt only licensed the therapy, called ozureprubart, from China’s Jemincare Pharmaceutical a year ago. While Jemincare had been evaluating the drug in phase 2 trials for asthma and chronic spontaneous urticaria in China, Rapt took ozureprubart into a phase 2b study in the U.S., Canada and Australia as a prophylactic for patients with food allergies in October 2025.Ozureprubart targets the same epitope as Novartis and Roche’s injectable IgE antibody inhibitor Xolair, which, in 2024, became the first medicine approved by the FDA to reduce allergic reactions that can occur from accidental exposure to certain foods.While Xolair is injected every two or four weeks, Rapt had been banking that ozureprubart’s extended half-life means it could match Xolair’s efficacy and safety while only needing to be administered every 12 weeks.Tuesday morning, it appeared that GSK has bought into this vision. The British Big Pharma announced it is paying $58 per share of Rapt—39% above the Bay Area biotech’s closing price of $35.10 on Friday, Jan. 16.That price equates to an aggregate equity value of $2.2 billion, according to GSK, which added that the upfront investment net of cash acquired comes to $1.9 billion. Taking over Rapt will give GSK the rights to ozureprubart outside of China, where the drug is still owned by Jemincare’s subsidiary.“The addition of ozureprubart brings another promising new, potential best-in-class treatment to GSK’s pipeline,” GSK Chief Scientific Officer Tony Wood, Ph.D., said in the Jan. 20 release.“Food allergies cause severe health impacts to patients with existing treatment requiring injections as frequently as every two weeks,” Wood added. “Ozureprubart offers the opportunity to bring sustained protection to patients with dosing every 12 weeks, and is consistent with our approach to acquire assets that address validated targets and where there is clear unmet medical need.”The phase 2 study of ozurepubart Rapt initiated is due to read out in 2027, according to GSK, which also referred to plans to launch a phase 3 program. Rapt CEO Brian Wong, M.D., Ph.D., said the acquisition by GSK “offers an attractive path forward for our programs, particularly the opportunity we envision for ozureprubart in food allergy.”“This transaction has the potential to provide access to the global development and commercialisation capabilities, resources and infrastructure that GSK has to offer and ultimately bring added value to our pipeline, patients and stockholders,” Wong added.Not everything has gone smoothly for Rapt in recent years, including two rounds of layoffs and dropping its lead asset zelnecirnon. The FDA placed phase 2 atopic dermatitis and asthma trials of the small-molecule CCR4 inhibitor on hold in February 2024 after a patient in the atopic dermatitis trial experienced liver failure after taking the small-molecule CCR4 inhibitor.That setback led the company to drop zelnecirnon and pivot to ozureprubart.In addition to ozureprubart, Rapt also has two CCR4 antagonists still in development, according to the biotech’s website. One is in the preclinical stage for an undisclosed inflammation indication, and the other is a Hanmi-partnered small molecule, tivumecirnon, which completed a phase 2 trial for gastric cancer in combination with Merck & Co.’s Keytruda in 2024.

The biopharma industry was hungry for an M&A deal during last week’s JP Morgan Healthcare Conference. It’s finally getting one. GSK is scooping up RAPT Therapeutics for $2.2 billion, with a $1.9 billion upfront investment, the companies said Tuesday. The move came five days after much of the industry left the annual gathering in San Francisco, where RAPT is based. It’s also the first acquisition under new CEO Luke Miels , though the deal was likely hammered out during Emma Walmsley ’s transition out of the top post. GSK made deals at the past two JPM gatherings. It bought cancer startup IDRx last year for up to $1.15 billion and snapped up Aiolos Bio for up to $1.4 billion at the beginning of 2024. Eli Lilly bought Ventyx and Amgen acquired Dark Blue Therapeutics in the other two main biotech buyouts of the year. RAPT’s anti-IgE antibody, called RPT904 or ozureprubart, is in Phase 2b for food allergies. Data are expected in the first half of 2027. The company recently said it had enough cash to get to that readout. A GSK spokesperson said Phase 3 trials in food allergy are slated to begin in the second half of 2027 with the possibility to launch the drug in 2031. The company is positioning it as a potential billion-dollar-plus medicine. GSK will aim to go up against Novartis and Roche’s IgE blocker Xolair. The blockbuster drug got FDA approval for food allergies in February 2024. It was first greenlit in 2003 for allergic asthma. Xolair is dosed every two or four weeks. GSK chief scientific officer Tony Wood said in a statement that “ozureprubart offers the opportunity to bring sustained protection to patients with dosing every 12 weeks.” The food allergy space has had a few hurdles in recent years, with the shuttering of Alladapt Immunotherapeutics and the underwhelming market launch of a peanut allergy pill. It’s a relatively quick turnaround for RAPT. The Bay Area biotech acquired the ex-China rights to ozureprubart from Shanghai Jeyou Pharmaceutical for $35 million upfront in December 2024. That move salvaged RAPT after the biotech’s CCR4 antagonist, called zelnecirnon, ran into safety hurdles in atopic dermatitis, leading to a clinical hold , layoffs and program culling in 2024. Now, GSK said the UK pharma giant is on the hook for paying the milestones to Jeyou. At the time of the 2024 deal, RAPT said that amounts to up to $672.5 million. It follows a similar narrative to GSK’s Aiolos deal, in which the small biotech nabbed the rights to an asthma drug from China’s Hengrui Pharma and then sold it to GSK. RAPT’s ozureprubart is also in mid-stage testing for chronic spontaneous urticaria. Jeyou released data from a China-based Phase 2 in October and planned to move into late-stage testing there. At its JPM presentation last Wednesday, RAPT said it expected to start a Phase 3 in CSU in the second half of this year. GSK and RAPT did not mention CSU in their press release on Tuesday. In a statement, RAPT CEO Brian Wong said the deal “offers an attractive path forward for our programs, particularly the opportunity we envision for ozureprubart in food allergy.” Editor’s note: This story was updated to include additional details on Phase 3 and timing of a potential market launch.

Aiming to broaden its allergy portfolio, GSK announced Tuesday it entered a definitive agreement to acquire US-based RAPT Therapeutics for $58.00 per share or approximately $2.2 billion in equity value. Accounting for cash acquired, the UK drugmaker's estimated upfront investment totals $1.9 billion.The acquisition primarily centres on the ozureprubart (RPT904), a long-acting anti-IgE monoclonal antibody in mid-stage development for food allergy prophylaxis, ex-China rights of which RAPT gained from Jemincare Pharmaceutical in 2024, paying up to $700 million.GSK noted, as opposed to current injectable anti-IgE therapies that need to be administered every two to four weeks, ozureprubart could potentially provide a quarterly dosing regimen, thereby improving adherence — particularly in pediatric patients — and potentially broadening access to a larger population of patients currently ineligible for approved therapies."Ozureprubart offers the opportunity to bring sustained protection to patients with dosing every 12 weeks, and is consistent with our approach to acquire assets that address validated targets and where there is clear unmet medical need," said GSK's Chief Scientific Officer Tony Wood.Top-line data from the ongoing Phase IIb prestIgE trial investigating ozureprubart as monotherapy are expected next year, with pivotal studies planned for both adult and paediatric at-risk populations.As part of the transaction, expected to conclude in the first quarter of the year, GSK will secure global rights to ozureprubart excluding mainland China, Macau, Taiwan and Hong Kong. Jemincare continues to hold Greater China rights to the drug, exploring it in asthma and chronic spontaneous urticaria.If approved, ozureprubart would be positioned to compete with Roche and Novartis' anti-IgE monoclonal antibody Xolair (omalizumab), the first therapy approved in the US to reduce allergic reactions in adults and children aged 1 year and older with at least one food allergy.