Carfilzomib comes with unpredictable renal complications in RRMM

Renal complications associated with carfilzomib (CFZ) treatment among relapsed and refractory multiple myeloma (RRMM) patients are common and unpredictable, though they develop early after treatment initiation, a recent study has found.

The study included 114 consecutive RRMM patients (median age, 70 years; 60.5 percent male) undergoing CFZ treatment. All participants had undergone close monitoring and evaluation for renal complications, including renal biopsies. Events deemed to be linked to MM progression were not counted as treatment-related.

Over a median follow-up of 27 months from the start of CFZ initiation, 19 patients developed renal complications unrelated to disease progression. The resulting incidence rate was 17 percent. The median duration of CFZ treatment was 5.5 months, and at the time of analysis, 28 patients were still undergoing treatment.

The renal complications documented included thrombotic microangiopathy (5 percent), acute kidney injury grade ≥3 (5 percent), and albuminuria >1 g per day with very low serum free light chains or negative immunofixation (6 percent). Fifteen of the 19 patients who developed such complications eventually discontinued CFZ treatment.

The renal complications developed relatively early during treatment, with most manifesting within 2–3 months; albuminuria, however, developed later at a median of 6 months.

Notably, no significant predictor for treatment-related renal complications was found. Baseline factors such as proteinuria, myeloma subtype, patient age, previous treatments, CFZ dose and regimen, kidney function, and comorbidities were all unrelated to the risk of developing such complications.

“Further investigation of the underlying mechanisms of CFZ-induced nephrotoxicity is needed in order to predict and manage these complications and provide this active drug with safety,” the researchers said.