Felza in AMR: A large Ph2 signal meets the Ph3 test in 2027

Research evidence excerpt

Felza in AMR: A large Ph2 signal meets the Ph3 test in 2027

IdeaMExhibit 7: Felza Ph2 safety, recurrence, and extension findings

Finding Observed result Takeaways

8/11 felzartamab; all mild or moderate; mainly Operationally manageable in the pilot, but IV

Infusion-related reactions

early dosing burden remains

1/11 SAEs with felzartamab vs 4/11 placebo; No adverse imbalance, but uncommon risk is

Serious adverse events / discontinuations

no felza discontinuations not resolved

3 of 9 initial biopsy responders had recurrent

Week-52 recurrence off therapy Supports ongoing or intermittent maintenance

AMR activity

11 participants; median MVI fell from 2 to 0; Supports re-suppression, not randomized

2026 open-label extension

7/11 reached MVI=0 efficacy confirmation

Median of two additional doses during six Suggests monitoring could reduce exposure

Biomarker-guided phase

months of guided treatment versus rigid continuous dosing

Source: Mayer et al., Bohmig et al. open-label extension, Morgan Stanley Research

AMR appears to require ongoing or intermittent suppression given that the recipient's

immune system continues to recognize the transplanted kidney as foreign. This dynamic

can increase lifetime exposure and revenue per patient; however, it also elevates the

clinical relevance of serious and opportunistic infections, hypogammaglobulinemia, viral

reactivation, attenuated vaccine responses, cytopenias, T-cell–mediated rejection, and

treatment convenience relative to what we would expect with a short, one-time

treatment course.

The open-label extension data support the feasibility of re-treatment. Median MVI

declined, molecular AMR and injury biomarkers improved, and kidney function remained

stable, while DSA was largely unchanged. We note that during the biomarker-guided