Racivir [RCV; (؉/؊)-␤-2,3-dideoxy-5-fluoro-3-thiacytidine], a 50:50 racemic mixture of the two ␤ nucleoside enantiomers, is currently in development for the treatment of human immunodeficiency virus type 1 (HIV-1) infections. RCV was administered once a day orally for 14 days at doses of 200, 400, or 600 mg in combination with stavudine and efavirenz to HIV-1-infected treatment-naïve male volunteers in a phase Ib/IIa study. Six volunteers at each dose were monitored for a total of 35 days for tolerance, pharmacokinetics, and plasma HIV RNA levels. RCV in combination with stavudine and efavirenz was well tolerated at all doses tested. Pharmacokinetic parameters were dose proportional, and the maximum concentration of drug in serum at all doses exceeded the 90% effective concentration for wild-type HIV-1. Viral loads dropped as expected in all dosage groups, with mean reductions from 1.13 to 1.42 log 10

PurposeCombined immunomodulatory and antiviral treatment was administered to three patients with newly diagnosed HIV-associated primary central nervous system lymphoma (PCNSL) in an attempt to improve outcomes.Patients and methodsThree patients from our institution who were recently diagnosed with HIV-associated PCNSL received intravenous azidothymidine (AZT) 1.6 gr. bid for two weeks, followed by oral AZT 250 mg bid from day 15. In addition, complementary highly active antiretroviral therapy (HAART) with a second nucleoside reverse transcriptase inhibitor (NRTI) plus one protease inhibitor (PI) and interleukin 2 (IL-2) subcutaneously 2 million units twice daily (bid) plus foscarnet 90 mg/kg bid were administered on days 1-14. One patient received anti-EpsteinBarr virus (EBV)-maintenance therapy with ganciclovir, followed by cidofovir [1].ResultsAll patients experienced progressive disease while on induction therapy, and switched early to whole-brain radiation therapy (WBRT) as second linetreatment. No grade 3 or 4 toxicities were observed. Two patients died on days 50 and 166 respectively due to progressive disease. The third patient with histologically proven lymphoproliferation and only suspected PCNSL remained alive at 53 months. He was on HAART and remained clinically and neurologically stable.ConclusionAlthough IL-2, HAART, high-dose AZT and foscarnet are used for other HIV-related conditions, they did not demonstrate benefit in lymphoma remission for 2 HIVassociated PCNSL patients. The third patient went into delayed remission after additional radiotherapy and was in good clinical and neurological health status over 53 months after diagnosis.