Treatment of Diuretic Refractory Pleural Effusions with Bevacizumab in Four Patients with Primary Systemic Amyloidosis (AL).

Introduction

Refractory pleural effusions present a challenging management problem and are associated with a poor prognosis in patients with primary systemic amyloidosis (AL). Vascular endothelial growth factor (VEGF) has been implicated to play a role in both malignant and non-malignant pleural effusions through its ability to regulate vascular permeability. VEGF can induce morphologic changes in vascular endothelial cells, regulate gene expression, stimulate cell proliferation and migration, and inhibit apoptosis. We report a series of four patients with AL who presented with bilateral pleural effusions that were refractory to diuretic therapy. After treatment with bevacizumab, an anti-VEGF antibody, three of the four patients had improvement in their pleural effusions, peripheral edema, and functional status.

Methods

A retrospective chart review was conducted four patients with AL and refractory pleural effusions who received bevacizumab. Three of the patients had documented renal amyloid by biopsy and two had suspected cardiac involvement. Serum creatinine ranged from 1.3–3.8 mg/dL (mean=2.15 mg/dL), 24 hour urine protein ranged from 190 mg – 12.5 grams per 24 hours (mean=6.1 grams). Bevacizumab 5 mg/kg was administered for 1–4 cycles (mean=2).

Results

Three of the four patients had demonstrable improvement in their pleural effusions, peripheral edema and functional status after a single dose of bevacizumab. One patient had no objective response to treatment. The three responders experienced a 2–7 kg (mean= 4.6 kg) decrease in weight within two weeks after receiving bevacizumab. This effect was observed in patients who were re-treated. All three patients received concurrent diuretic therapy, however, they had not previously responded to diuretic therapy. Two weeks after the first dose of bevacizumab, the 24 hour urine protein of the patient who received four cycles of bevacizumab increased to 18.2 grams per 24 hours, however it returned to baseline (12.5 grams per 24 hours) one week later, and increased slightly to 13.3 grams per 24 hours after the fourth dose. A second patient also experienced an increase in 24 hour protein excretion (6.9 grams per 24 hours to 9.2 grams per 24 hours) after the first dose of bevacizumab. One patient experienced a deep vein thrombosis after the third cycle of bevacizumab. No hemorrhagic complications were observed.

Conclusion

Bevacizumab may represent a novel non-invasive management strategy for patients with systemic amyloidosis and diuretic-refractory pleural effusions, however, additional studies are needed to further define the role of bevacizumab in the management of this group of patients.