Days after getting acquired by Biogen, Human Immunology Biosciences revealed Phase 2 data that helped seal the deal.
In the trial, which looked at the anti-CD38 antibody felzartamab’s potential to treat IgA nephropathy, patients saw an average reduction in protein urine levels of up to 50% after two years, HI-Bio said Friday. Patients received nine doses of the drug over the course of 24 weeks and saw eGFR levels stabilize, indicating normal kidney function.
The data come two days after Biogen announced it will buy out HI-Bio for $1.15 billion upfront and promising additional milestone payments for up to $650 million; and four months after HI-Bio closed a $95 million Series B.
“The promise of felzartamab is one that spans multiple indications,” HI-Bio CEO Travis Murdoch told Endpoints News. “And so the intention that we always had with the program was to find the optimal way to really pursue this across as many indications as possible.”
HI-Bio launched in 2021 from ARCH Venture Partners and Monograph Capital, getting a license from MorphoSys to run felzartamab trials. (Novartis has since announced its intention to acquire MorphoSys for $2.9 billion.)
In addition to the IgAN study, HI-Bio has completed Phase 2 trials for felzartamab in primary membranous nephropathy (PMN) and antibody-mediated rejection (AMR) in kidney transplant recipients. Both IgAN and PMN are orphan diseases, while AMR affects less than 10% of kidney transplant recipients.
Two serious side effects occurred in the latest trial, with one being an “infusion-related reaction” and another involving a tendon rupture, according to HI-Bio’s press release. Researchers also examined two-dose and five-dose regimens in the trial, and 54 patients were enrolled in total.
Murdoch emphasized that the continued low levels of urine protein shown in Friday’s results are the biggest takeaway for the nine-dose regimen.
“What we’re seeing with that dosing regimen, we’re actually seeing a durable treatment effect, the depleting plasma cells,” Murdoch said. “And we’re seeing a durable reduction in proteinuria, which is protein in the urine after 19 months off therapy.”
Editor’s note: This article has been updated to correct a transcription error and information about side effects from felzartamab’s Phase 2 trial. There was one infusion-related reaction and one tendon rupture.