Vor Bio adds a longer-acting RemeGen drug, not yet tested in people, to its license outside Greater China

IN SOME ILLNESSES the immune system, which is meant to defend the body, "attacks the healthy cells of your organs and tissues by mistake," in the words of MedlinePlus, a service of the National Library of Medicine. These conditions are known as autoimmune diseases. In some of them, a class of immune cells known as B cells, and the plasma cells those B cells become, make antibodies that turn against the body.

Those cells depend on two chemical signals to survive, develop and keep making antibodies. One is known as B-cell activating factor, or BAFF. The other is known as a proliferation-inducing ligand, or APRIL. An open-access review in Frontiers in Medicine describes them as critical regulators of B-cell survival, differentiation and antibody production.

One way to cut off both signals is to build a protein from two parts joined together. Researchers attach the outer portion of a cell receptor called TACI, which can bind BAFF and APRIL, to the stem of a human antibody, known as its Fc fragment. The resulting molecule, a TACI-Fc fusion protein, intercepts both signals so that the cells receive less of them. The same review describes RemeGen's drug telitacicept as such a protein, "composed of the Fc fragment of human IgG1 fused to the extracellular domain of" TACI.

Telitacicept is RemeGen's first drug of this kind. On June 25, 2025, Vor Bio, based in Boston, received exclusive rights to develop and commercialize it outside Greater China, meaning the People's Republic of China, Hong Kong, Macau and Taiwan, and RemeGen kept the rights inside that region. Vor's latest release says telitacicept is approved in China for systemic lupus erythematosus, rheumatoid arthritis, generalized myasthenia gravis, IgA nephropathy and Sjögren's disease. "It has been approved in China for five indications, and its global multicenter clinical trials are progressing well," said Dr. Jianmin Fang, Chief Executive Officer of RemeGen. Vor's release also says three trials meant to support approval, known as registrational trials, are under way in myasthenia gravis and Sjögren's disease.

The companies have now added a later candidate in the same class, known as RC298. They describe it as a long-acting TACI-Fc fusion protein, designed to last longer in the body. It is still in the laboratory tests needed before a first trial in people. RemeGen expects to apply in China, in the first half of 2027, for permission to start that testing, and will lead the preclinical work and the first human trial, a Phase 1 study, in China. After that first trial, Vor is to take later development, regulatory work and sales outside Greater China. No results in people have been reported for RC298.

The agreement is dated November 11, 2026, and was announced on November 12. It amends and restates the 2025 license, adding RC298 and related compounds. Vor has exclusive rights to develop and commercialize the licensed products outside Greater China, and RemeGen has exclusive rights inside it. For the added products, Vor will pay $10 million in cash and, under a securities purchase agreement that closed the same day, will issue a right to buy 2.3 million Vor shares for a token price of $0.0001 each, a pre-funded warrant. Later payments are due only if contractual steps are met. For the new products, RemeGen could receive up to $300 million in development and commercial milestone payments, plus royalties on any sales. "Telitacicept remains our clinical foundation and near-term priority as we execute on our global Phase 3 programs in myasthenia gravis and Sjögren's disease," said Jean-Paul Kress, M.D., Chairman and Chief Executive Officer of Vor Bio.

Until RemeGen files its application in China and a first trial begins, RC298 remains a laboratory candidate, and Vor's own trials stay focused on telitacicept.