Effects of interferon-alpha in patients with AIDS-associated Kaposi's sarcoma are related to blood interferon levels and dose.
Definition of improved therapeutic regimens of interferon-alpha (IFN-alpha) for the treatment of Kaposi's sarcoma (KS) would be useful since currently recommended doses are sometimes associated with unacceptable toxicity. IFN concentrations were measured in serum samples from men with AIDS-associated KS who were enrolled in a trial of IFN-alpha alone (16 patients) or a trial of IFN-alpha combined with zidovudine (25 patients). Analyses were done to examine the relationship between the dose of IFN-alpha, blood level of IFN, and the patient's clinical response to treatment. There was no correlation between dose of zidovudine given and response. As expected, there was a high correlation between dose of IFN-alpha and blood level in both studies (p less than 0.001). Furthermore, we found relationships between clinical response and both dose of IFN-alpha and blood level achieved. In the two studies combined, among men with greater than 200 CD4+ cells/mm3 of blood at baseline on average daily doses of greater than or equal to 10 million international units (MIU) of IFN-alpha, 13/19 (68%) responded compared to 6/17 (35%) on less than MIU (p = 0.05). Similarly, of men with IFN blood levels greater than or equal to 100 IU/mL 12/16 (75%) responded compared to 7/20 (35%) of those with blood levels less than 100 IU/mL (p = 0.02). The dose and blood levels of IFN achieved and maintained may be important factors in determining responses of KS. Additional clinical trials of IFN-alpha treatment of KS at doses about 10 MIU/day appear warranted.
Sawyer
L A
LA
Laboratory of Retrovirus Research, Food and Drug Administration, Bethesda, MD 20892.
Metcalf
J A
JA
Zoon
K C
KC
Boone
E J
EJ
Kovacs
J A
JA
Lane
H C
HC
Quinnan
G V
GV
D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy*; D000328:Adult; D004305:Dose-Response Relationship, Drug; D006679:HIV Seropositivity / Q000188:drug therapy; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins; D012514:Sarcoma, Kaposi / Q000188:drug therapy*; D015215:Zidovudine / Q000008:administration & dosage
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D015215:Zidovudine