Phase I trial of 40-kd branched pegylated interferon alfa-2a for patients with advanced renal cell carcinoma.
OBJECTIVE
Pegylated (40 kd) interferon alfa-2a (IFNalpha2a) (PEGASYS, Hoffman-La Roche, Nutley, NJ; PEG-IFN) is a modified form of recombinant human IFNalpha2a with sustained absorption and prolonged half-life after subcutaneous administration. A phase I study of PEG-IFN with pharmacokinetic and pharmacodynamic evaluations was conducted in previously untreated patients with advanced renal cell carcinoma (RCC).


METHODS
Twenty-seven patients were enrolled onto cohorts of three or six patients. PEG-IFN was administered on a weekly basis by subcutaneous injection. The dose was escalated from 180 microg/wk to a maximum of 540 microg/wk in 90-microg increments. Serial venous blood samples were drawn to assess concentrations of PEG-IFN and two immunologic surrogates, neopterin and 2'-5' oligoadenylate synthetase (OAS).


RESULTS
The maximum-tolerated dose was determined as 540 microg/wk, because two patients experienced dose-limiting toxicity within 28 days of starting treatment. One developed serum grade 3 ALT elevation, and a second developed grade 3 fatigue. Six patients were treated at 450 microg/wk without dose-limiting toxicity. Over the course of treatment, the side-effect profile was mostly mild to moderate in intensity. Adverse events included fatigue, fever, headache, myalgia, nausea, and decreased appetite. Five patients (19%) achieved a partial response. The mean maximum serum concentration increased from 5.0 to 27 ng/mL, and mean area under the curve increased from 247 to 2,981 ng/h/mL, with dose escalation from 180 microg/wk to 540 microg/wk. Serum concentration of PEG-IFN was sustained at close to peak during the dosing interval, and steady-state was achieved in approximately 5 weeks. The immunologic surrogates, neopterin and OAS, were induced at all doses with a sustained concentration profile similar to PEG-IFN.


CONCLUSIONS
PEG-IFN is a modified form of IFNalpha2a with distinct pharmacokinetic advantages and immunomodulatory and antitumor activity for patients with advanced RCC. A dose of 450 microg/wk by subcutaneous administration was determined as a suitable dose for further study. PEG-IFN is more convenient to administer than IFNalpha and has potential for increased efficacy, less toxicity, or both. The efficacy and toxicity of PEG-IFN will be further assessed in clinical trials and compared with IFNalpha.
Genitourinary Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
R J
RJ
Motzer
A
A
Rakhit
M
M
Ginsberg
K
K
Rittweger
J
J
Vuky
R
R
Yu
S
S
Fettner
L
L
Hooftman
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000494:pharmacology; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D011994:Recombinant Proteins
D000970:Antineoplastic Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; C100416:peginterferon alfa-2a