Background: Pegylated interferon alpha (P-IFN) + ribavirin (RBV) combination (P-R) is effective in eradicating HCV in some HIV⁺ patients (pts). However, P-R use is complicated by serious dose-limiting neutropenia and hemolytic anemia. Dose reduction and/or interruption of therapy are major obstacles to treating HIV/HCV co-infected pts. This study evaluated the cost of adjunctive growth factor (GF) therapy to maintain P-IFN and RBV doses in an attempt to enhance the response rate.

Methods: Pts with HIV/HCV co-infection and CD4⁺ T-cell ≥ 100 cells/mm³ were treated in an open-label prospective trial of P-IFN a-2b sc 1.5mg/kg/wk + RBV 600 mg po bid for 48 wks. G-CSF was initiated for ANC < 750 cells/mm³ and darbopoetin (DARB) for Hct < 30%. The costs of HCV, HAART, and GF were extrapolated to 48 wks based on 2002 Average Wholesale Prices (AWP).

Results: Nineteen (19) subjects (mean age 46 yrs; mean CD4⁺ T-cell 628; median HIV-RNA < 50 copies/mL; 16 genotype 1 or 4) received P-R for a median of 22 wks (1–46 wks), 16/19 (84.2%) pts were on HAART. 8/19 (42%) pts required initiation of G-CSF (median dose = 300 mcg/wk) at a median of 5 days (3–28 days) and 7/19 (36.8%) pts required DARB (median dose 40 mcg/wk) at a median of 4 wk (1.4–25 wks). Twelve (12; 63.2%) pts required either G-CSF or DARB, 3 required both. With adjunctive G-CSF, no pt required P-IFN dose reduction for neutropenia; with addition of DARB, 1 pt dose-reduced and 1 pt discontinued RBV due to refractory anemia. One-third (33.3%) pts without ARV needed GF vs 11/16 (68.8%) HAART-treated pts. The AWP price for a 48-wk course of P-R is US$38,649. Total mean cost for P-R, HAART, and GF extrapolated to 48 wks is $54,473/pt for the entire cohort. The mean drug costs for pts who did and did not require GF are $58,559 ($46,629–$77,508) and $47,740 ($35,051–$59,330), respectively. For pts who completed >12 wks of P-R, 12/17 (70%) had a ≥ 2-log decline in HCV viral load within the first 12 wks.

Conclusions: GF are useful adjuncts to support the bone marrow suppressive effects of P-R. GF therapy resulted in an added cost of over US$10,000/pt for the 63% of pts who required this treatment. Maintaining therapeutic doses of P-R may increase the chance of HCV eradication. Considering the poor response to anti-HCV therapy in HIV co-infected pts, cost of GF therapy is justifiable, provided the early virologic response is sustainable.