Human Immunology Biosciences (HI-Bio) has reported positive results from two Phase ll trials of felzartamab, M-PLACE and NewPLACE, for the treatment of primary membranous nephropathy (PMN).

M-PLACE, a Phase lb/lla proof-of-concept, open-label, multinational trial, was designed to evaluate the safety and efficacy of nine doses of felzartamab in adults with aPLA2R-positive PMN over five months.

It included 31 patients who were recently diagnosed and relapsed or refractory to immunotherapies.

The NewPLACE Phase ll, two-arm, multi-centre, open-label, parallel-group trial enrolled 24 patients.

It evaluated the efficacy, safety, pharmacokinetics and pharmacodynamics of alternative two and five doses of felzartamab over two weeks and two months, respectively.

It also assessed the retreatment of felzartamab in patients with aPLA2R-positive PMN showed for immunosuppressive therapy.

The studied dose level across both trials and all arms was in line with the target dose for felzartamab at 16mg/kg.

The nine-dose arm as evaluated in M-PLACE was found to have the most durable reductions in aPLA2R levels against the two and five dose arms monitored in NewPLACE.

In the final examination of M-PLACE, early and significant reductions in aPLA2R titers were found in most of the patients in one week and deep responses in maximum patients at six months after completing the treatment.

In M-PLACE, improvements in proteinuria and serum albumin levels were observed in patients when given felzartamab. It showed the potential of the therapy in renal recovery.

Felzartamab was reported to be generally well tolerated in both trials.

Common treatment emergent adverse events (TEAEs) observed in the trials were mild to moderate and in accordance with felzartamab’s known mechanism of action in PMN patients.

HI-Bio CEO Travis Murdoch said: “These results, the tolerability profile observed, and the fact that PMN is a high burden disease with no approved therapies all support our intention to advance felzartamab into late-stage development and discuss the path forward with regulators.

“We are focused on developing felzartamab in PMN and other autoantibody driven IMDs where patients have serious unmet needs.”