Briquilimab

KIT-targeting antibody biotech Jasper Therapeutics is being renewed via a merger with Nasdaq-listed Kira Pharmaceuticals—but not all of Kira's pipeline is coming along for the ride. The merger ends a rough patch for Jasper, which halved its workforce and lost its chief medical officer in 2025 after a dud batch of its anti-KIT antibody briquilimab derailed a phase 1/2 study in patients with spontaneous urticaria, despite preliminary data that showed a “rapid onset of deep and durable clinical responses” across multiple dosing cohorts in the trial. The batch was also used in an asthma trial, and Jasper said at the time that it was halting its asthma program as well. What followed was an evaluation of strategic alternatives that led to Kira, according to Jasper CEO Jeet Mahal, who will lead the combined company. “Kira has built a truly differentiated complement portfolio that includes dual [mechanism of action] beyond single-pathway agents and long-acting complement inhibitors, reflecting the quality of their science and the deep expertise of their team,” Mahal said in a July 16 post-market release. “We are excited by the robust pipeline that this transaction creates, and are looking forward to advancing these important medicines for patients.” This pipeline is headed up by KP-104, also known as vensobafusp alfa, a dual complement inhibitor for patients with nephrology indications and the blood disorder paroxysmal nocturnal hemoglobinuria (PNH). Data from a phase 2 study of the drug in rare renal indications is expected in the fourth quarter, with Jasper hoping to schedule a meeting with the FDA to confirm a pathway into phase 3. The company also hasn't given up on briquilimab, which it is aiming to discuss with the agency after viewing “positive, long-term data” in severe combined immunodeficiency (SCID). “The combined company also continues to assess the mast-cell mediated disease landscape and will provide an update on its anticipated clinical development in the second half of this year,” Jasper said in the release. Another piece of the pipeline is a preclinical B-cell receptor-targeted therapy dubbed KP-701. Jasper hopes to read out first-in-human data for the dual-acting anti-CD79BxCD32B antibody in the third quarter of next year. The company will fund these clinical plans through a $132 million private placement, which Jasper also disclosed yesterday. As a result of the transaction, Jasper's equity holders will own almost 7% of the new company’s stock, while Kira's shareholders will own almost 50% and the new investors in the private financing will own slightly over 43%. William Blair analysts said the combined pipeline was promising as an alternative to Novartis' PNH drug Fabhalta. “We are intrigued by the phase 2 data with KP-104 in PNH as being competitive with Fabhalta, and see additional potential in IgA nephropathy and C3 glomerulopathy given the known role of complement in these renal diseases,” the analysts wrote in a July 7 note. But not all of Kira's drugs are transferring over. Precision medicine biotech Mirador Therapeutics revealed yesterday that it has bagged two drugs from Kira for $12 million upfront—namely the long-acting anti-C5a monoclonal antibody KP-301 and small molecule C5a receptor agonist KP-402. That deal also includes potential milestone payments. Explaining the deal, Mirador noted that while “C5aR inhibition has demonstrated meaningful clinical benefit and commercial adoption in AAV”—notably Amgen's Tavneos—there “remains a need for effective next-generation therapies with a favorable safety and tolerability profile.” “Mirador believes KP-301’s antibody modality is well-positioned to help address that need,” the company added.