What is the recommended management of acute renal failure in a patient receiving pembrolizumab (Keytruda)?

Management of Acute Renal Failure in Patients Receiving Pembrolizumab (Keytruda)

For grade 2 acute kidney injury (AKI), immediately hold pembrolizumab, consult nephrology, rule out alternative causes, and start prednisone 0.5-1 mg/kg/day if no other etiology is found; for grade 3-4 AKI, permanently discontinue pembrolizumab, consult nephrology, and start prednisone 1-2 mg/kg/day. 1

Grade-Based Management Algorithm

Grade 1 (Creatinine 1.5x baseline or <1.5x ULN)

• May hold pembrolizumab temporarily while evaluating for alternative causes
• Consider recent IV contrast, nephrotoxic medications, dehydration, or urinary obstruction
• Note: Even changes below 1.5x ULN can be clinically meaningful 1
• If improved to baseline, resume routine creatinine monitoring 1

Grade 2 (Creatinine 1.5-3x baseline)

• Must hold pembrolizumab immediately 1
• Consult nephrology urgently
• Exclude other causes: IV contrast exposure, NSAIDs, antibiotics, dehydration, bladder/renal ultrasound if indicated
• Start prednisone 0.5-1 mg/kg/day if other etiologies ruled out 1
• If worsening or no improvement: escalate to prednisone 1-2 mg/kg/day and permanently discontinue pembrolizumab 1
• If improved to grade 1 or less: taper corticosteroids over at least 3-4 weeks before considering resumption 1
• If elevations persist >7 days or worsen with no other cause: treat as grade 3 1

Grade 3-4 (Creatinine >3x baseline or requiring dialysis)

• Permanently discontinue pembrolizumab 1
• Immediate nephrology consultation 1
• Rule out alternative causes comprehensively
• Start prednisone 1-2 mg/kg/day immediately 1
• For grade 3: If elevations persist >3-5 days or worsen, add additional immunosuppression (mycophenolate) 1
• For grade 4: If elevations persist >2-3 days or worsen, add additional immunosuppression (mycophenolate) 1
• If improved to grade 1: taper corticosteroids over at least 4 weeks 1

Critical Diagnostic Considerations

Monitor serum creatinine before every pembrolizumab dose 1. Routine urinalysis is not necessary unless evaluating for infection or other specific causes 1.

The typical presentation of pembrolizumab-induced AKI:

• Usually asymptomatic with isolated creatinine elevation 2
• Onset typically 3-10 months after starting treatment 2
• Occasionally presents with oliguria, hematuria, peripheral edema, or anorexia 2

Kidney biopsy findings when performed show:

• Acute tubulointerstitial nephritis (most common - 92% in one series) 1
• Acute tubular injury 3
• Minimal change disease 3
• Rarely: thrombotic microangiopathy or granulomatous nephritis 1, 2

Biopsy should be considered to confirm etiology and guide management, particularly if diagnosis is uncertain or patient fails to respond to initial corticosteroid therapy 2. However, if no alternative cause is identified, proceed directly with immunosuppressive therapy rather than delaying for biopsy 1.

Key Pitfalls and Caveats

Do not assume prior tolerance means safety: Patients who previously tolerated pembrolizumab can develop severe nephrotoxicity upon rechallenge, sometimes with higher grade toxicity than initial presentation 4. One case demonstrated grade 3 AKI with PR3-ANCA positivity after reintroduction 4.

Incidence may be underreported: While package labeling suggests 1-2% incidence with single-agent pembrolizumab 1, emerging real-world data indicates 9.9-29% of patients develop some degree of AKI, though most is stage I with electrolyte disturbances rather than significant creatinine elevation 1. In the ARON-1 real-world study, nephritis led to treatment discontinuation in 3% of patients 5.

Combination therapy increases risk: When pembrolizumab is combined with TKIs (axitinib, lenvatinib), the risk of severe multiorgan toxicity including renal failure increases 6. Combination with chemotherapy can mask immune-related nephrotoxicity, as chemotherapy agents themselves cause kidney injury 7.

Corticosteroid response predicts outcome: In a case series of 13 patients with biopsy-proven checkpoint inhibitor nephritis, 9 of 11 patients treated with corticosteroids improved, while 2 patients who received no immunosuppression did not recover renal function 1. However, recovery may be partial rather than complete 3, 8.

Resumption Considerations

For grade 2 toxicity that improves: If no recurrence of renal insufficiency occurs after corticosteroid taper, discuss resumption with the patient after weighing risks versus benefits 1. This decision should account for cancer prognosis, alternative treatment options, and severity of initial nephrotoxicity.

Never rechallenge after grade 3-4 toxicity: Permanent discontinuation is mandatory 1.

Special population - renal transplant recipients: Patients with renal allografts face near-universal rejection risk with PD-1 inhibitors like pembrolizumab and should generally not receive this therapy 1.