Phase I and pharmacokinetic study of tomudex combined with 5-fluorouracil plus levofolinic acid in advanced head and neck cancer and colorectal cancer.
In vitro studies have shown a schedule-dependent synergism between Tomudex and 5-fluorouracil (5-FU). Incubation of different types of head and neck and colorectal cancer cells with levofolinic acid (LFA) plus 5-FU for 4 or 24 h, after 24-h incubation with Tomudex, produces a clear synergism. The purpose of this study was to evaluate the tolerability and activity of a combination of Tomudex, LFA, and 5-FU in advanced head and neck and colorectal cancer. Furthermore, the potential for 5-FU pharmacomodulation by Tomudex was also evaluated through an intrapatient assessment of dihydropyrimidine dehydrogenase (DPD) activity and 5-FU AUC with and without pretreatment with Tomudex. Eligible patients were treated with Tomudex at the starting dose of 1.5 mg/m2 on day 1, LFA at a fixed dose of 250 mg/m2 on day 2, immediately followed by bolus 5-FU at the starting dose of 600 mg/m2. Tomudex and 5-FU doses were alternately escalated. Courses were repeated every 2 weeks. In the second course, LFA and 5-FU were administered on day 1 and Tomudex on day 2; further treatment was given according to the sequence used in the first course. Plasma 5-FU concentrations were analyzed on courses 1 and 2 using a high-performance liquid chromatography assay with UV detection. DPD activity was measured in peripheral blood mononuclear cells on courses 1 and 2 using incubation of cytosol with [14C]FU and quantitation of metabolite formation. Fifty-eight patients were enrolled in the study. Dose escalation was stopped at step 8, because of the occurrence of dose-limiting toxicity in two of three patients. The dose level immediately before (3 mg/m2 Tomudex, 1050 mg/m2 5-FU) was selected for further evaluation. Tomudex and 5-FU mean dose intensities actually delivered at the seventh step were 1.32 and 462 mg/m2/week, respectively. Six of 40 patients with metastatic colorectal cancer obtained an objective response (15%; 95% confidence interval, 6-30%). In particular, three complete responses and three partial responses were observed. Six of 17 patients with locally advanced or metastatic head and neck cancer obtained an objective response (1 complete response + 5 partial responses; 35%; 95% confidence interval, 14-62%). Median duration of response in colorectal cancer patients was 12 months. 5-FU AUC was not significantly different between the two courses (median intrapatient difference, 9.3%; P = 0.28). DPD activity in course 1 was significantly higher than course 2 (P = 0.041) in the 16 patients in which values were evaluable. The combination of Tomudex, LFA, and 5-FU is well tolerated and active in colorectal and head and neck cancer. The Tomudex mean dose intensity actually delivered is higher than usually achieved in monotherapy. The absence of a clear pharmacokinetic interaction suggests that the synergism of Tomudex and 5-FU might occur at the cellular level.
Caponigro
F
F
Divisione Oncologia Medica A, Istituto Nazionale Tumori Napoli, Italy. fracap@sirio-oncology.it
Avallone
A
A
McLeod
H
H
Cartenì
G
G
De Vita
F
F
Casaretti
R
R
Morsman
J
J
Blackie
R
R
Budillon
A
A
De Lucia
L
L
Gravina
A
A
Catalano
G
G
Comella
P
P
Comella
G
G
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011799:Quinazolines / Q000008:administration & dosage / Q000009:adverse effects; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects
D011799:Quinazolines; D013876:Thiophenes; C068874:raltitrexed; D002955:Leucovorin; D005472:Fluorouracil