In a study comparing the unblinded NRTI combinations (with or without blinded nelfinavir) in children, a greater proportion treated with abacavir and lamivudine (71%) or abacavir and zidovudine (60%) had HIV-1 RNA ≤ 400 copies/ ml at 48 weeks, compared with those treated with lamivudine and zidovudine (47%)[ p=0.09, intention to treat analysis].