BeOne Medicines is cashing in on its interest in Amgen’s Imdelltra, a first-in-class therapy for lung cancer, in a deal worth as much as $950 million.
Details of the Royalty Agreement
Royalty Pharma has agreed to pay $885 million upfront in exchange for specific royalties linked to Imdelltra’s sales outside of China. BeOne also holds an option, exercisable within the next year, to sell further royalty rights for up to $65 million. According to BeOne’s Aug. 25 securities filing, the royalties cover a major part of tiered payments on the firm’s global revenue exceeding $1.5 billion. In its own announcement, Royalty Pharma specified the royalty rate is approximately 7%.
Background of the Partnership
BeOne, previously operating under the name BeiGene, secured rights to Imdelltra through a wide-ranging strategic alliance with Amgen in 2019. The agreement covered commercialization of Amgen’s cancer medicines in China along with joint global clinical development efforts.
Imdelltra’s Regulatory Journey and Clinical Data
Imdelltra marked a milestone in May 2024 when it became the first DLL3-targeted therapy given the green light by the FDA. The accelerated approval applied to patients with extensive-stage small cell lung cancer (SCLC) who had previously undergone platinum-based chemotherapy. Now, a full approval appears attainable. Results from the phase 3 DeLLphi-304 trial recently demonstrated that the bispecific antibody reduced the risk of mortality by 40% in SCLC patients who had already received one round of platinum chemo. Amgen is also advancing Imdelltra into earlier treatment settings, with the phase 3 DeLLphi-305 and DeLLphi-306 trials designed to evaluate the drug as a first-line therapy. Meanwhile, BeOne is conducting the DeLLphi-307 study in China, aiming for regulatory clearance in third-line SCLC.
Commercial Performance and Market Potential
As the inaugural DLL3-directed therapy on the market, Imdelltra has quickly demonstrated strong commercial potential. The drug generated over $200 million in sales in the first six months 2025. Notably, second-quarter revenue reached $134 million, surpassing analyst projections by over 40%. Small cell lung cancer impacts roughly 360,000 people globally each year, giving Imdelltra a sizable patient pool. Analysts following the program project that sales could climb to $2.8 billion by 2035, Royalty noted.
Competitive Landscape
Still, the therapy is not without limitations. Its side-effect profile highlights opportunities for future improvement, and the commercial success of DLL3 targeting has prompted interest from other major drugmakers. In early 2025, Roche entered a deal worth up to $1 billion with Innovent Biologics to secure rights to IBI3009, a DLL3-focused antibody-drug conjugate. Similarly, in 2024, Merck & Co. acquired Harpoon Therapeutics, which had been advancing its own DLL3 T-cell engager candidate as a competitor to Imdelltra.
Strategic Rationale
BeOne’s CEO, John V. Oyler, stated that converting a large part of the company’s royalty stake in Imdelltra into capital allowed them to reinforce the balance sheet and add considerable value. He further noted that the agreement offered the company greater room to maneuver both in day-to-day operations and in longer-term strategy. For Royalty, the agreement aligns with its core strategy, which centers on purchasing royalties in therapies that demonstrate strong commercial potential and long-term growth.
