Comparison of gastrointestinal tolerability and patient preference for treatment with the 625 mg and 250 mg nelfinavir tablet formulations

OBJECTIVES

To compare gastrointestinal (GI) tolerability and patient preference for the new 625 mg formulation of nelfinavir (NFV) and the marketed 250 mg tablets (Viracept) in HIV-1-infected patients.

METHODS

Virologically controlled patients (n=126) treated with a nelfinavir (NFV) 250 mg-containing regimen for > or =8 weeks completed a stool diary for 14 days to assess baseline bowel function. After switching to the NFV 625 mg formulation [1250 mg twice a day (bid)] for 28 days, patients continued their stool diaries and at study completion answered a questionnaire regarding formulation preferences.

RESULTS

The incidence and mean weekly duration of GI upset over a 2-week period were lower with NFV 625 mg than with NFV 250 mg (79.8% vs. 84.9% of patients and 2.1 vs. 3.0 days, respectively). Fewer patients experienced moderate or severe diarrhoea with NFV 625 mg (6.5% vs. 11.1%), and the incidence of investigator-assessed diarrhoea also decreased with NFV 625 mg. Importantly, there was a significant improvement overall in the incidence of diarrhoea (any grade) when patients switched to NFV 625 mg [38 of 124 (31%) improving, 69 of 124 (56%) stable and 17 of 124 (14%) worsening on NFV 625 mg; P<0.01]. At study completion, most patients expressed a preference to continue treatment with NFV 625 mg [112 of 122 (91.8%); P<0.0001], with only one patient (0.8%) preferring to resume treatment with NFV 250 mg. The new formulation was well tolerated with no new safety concerns.

CONCLUSIONS

The new NFV 625 mg formulation is better tolerated and preferred by patients switching from NFV 250 mg tablets. By reducing the daily pill count and improving GI tolerability, the NFV 625 mg formulation may enhance patient adherence to NFV-containing antiretroviral regimens and thus potentially improve virological outcomes.

Avanti 3: A Randomized, Double-Blind Trial to Compare the Efficacy and Safety of Lamivudine plus Zidovudine versus Lamivudine plus Zidovudine plus Nelfinavir in HIV-1-Infected Antiretroviral-Naive Patients

The objective of our randomized, multicentre, double-blind, placebo-controlled study was to investigate the safety, tolerability, and antiretroviral and immunological effect of double and triple combination therapy regimens. A total of 105 antiretroviral therapy-naive patients were randomized to receive either zidovudine (300 mg twice per day) plus lamivudine (150 mg twice per day) plus nelfinavir placebo (three times per day) ( n=52), or zidovudine/lamivudine (dose as before) plus nelfinavir (750 mg three times per day) ( n=53) for 28 weeks. After this time, patients were allowed to switch to open-label zidovudine/lamivudine/nelfinavir. The overall log10 reduction from baseline in plasma HIV-1 RNA was significantly greater in the zidovudine/lamivudine/nelfinavir group than the zidovudine/lamivudine group ( P=0.001; median treatment difference, –1.01 log10 copies/ml; 95% confidence interval –1.23 to –0.79), as measured by the average area under the curve minus baseline over 28weeks. Increases from baseline in CD4 cell counts were statistically significantly greater in the zidovudine/lamivudine/nelfinavir group (101.5 cells/ml) than the zidovudine/lamivudine group (47.0 cells/ml; P=0.027) at week 28.

Of note, the addition of nelfinavir from weeks 28–52 led to an increase in the proportion of subjects with plasma HIV-1 RNA <400 copies/ml from 17% (9/52 patients on zidovudine/lamivudine) to 50% (13/26 patients who switched to zidovudine/lamivudine/nelfinavir). Incidence of drug-related adverse events was similar in the two groups, except for nausea (more common in zidovudine/lamivudine group; 40 versus 17%) and diarrhoea (more common in zidovudine/lamivudine/nelfinavir group; 45 versus 14%). In conclusion, our study confirms the efficacy of triple combination therapy with two nucleoside analogues and a protease inhibitor compared with double-nucleoside therapy. Interestingly, the addition of nelfinavir to zidovudine/lamivudine, even after 6 months of double nucleoside therapy, led to a substantial virological benefit that was sustained over 24weeks in a subset of patients.