Phase I trial of a combination of the multikinase inhibitor sorafenib and the farnesyltransferase inhibitor tipifarnib in advanced malignancies.
OBJECTIVE
We evaluated the safety, maximum tolerated dose, pharmacokinetics, and biological effects of the combination of the Raf-1, RET, KIT, platelet-derived growth factor receptor, and vascular endothelial growth factor receptor 2 kinase inhibitor sorafenib and the farnesyltransferase inhibitor tipifarnib.


METHODS
A standard 3 + 3 phase I dose-escalation design was used with a 28-day cycle (sorafenib daily and tipifarnib for 21 days, by mouth).


RESULTS
Fifty patients were treated; 43 reached restaging evaluation after cycle 2. The most common side effects were grade 1 to 2 rash, hyperglycemia, and diarrhea. Dose-limiting toxicity was rash, and the recommended phase II dose is sorafenib 400 mg p.o. qam/200 mg p.o. qpm and tipifarnib p.o. 100 mg bd. Despite the low doses of tipifarnib, one quarter of patients had > or =50% reduction in farnesyltransferase levels. Interestingly, six of eight patients with medullary thyroid cancer had durable stable disease (n = 3) or partial remissions (n = 3), lasting 12 to 26+ months. Five of the six responders had available tissue, and RET gene mutations were identified in them. Prolonged (> or =6 months) stable disease was also seen in nine patients as follows: papillary thyroid cancer (n = 4; 18+ to 27+ months), adrenocortical cancer (n = 2; 7 and 11 months), and one each of melanoma (platelet-derived growth factor receptor mutation positive; 14 months), renal (6 months), and pancreatic cancer (6 months).


CONCLUSIONS
Our study shows that the combination of tipifarnib and sorafenib is well tolerated. Activity was seen, especially in patients with medullary thyroid cancer, a tumor characterized by RET mutations.
Hong
David S
DS
Division of Cancer Medicine, Department of Investigational Therapeutics (Phase 1 Program), Unit 455, M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. dshong@mdanderson.org
Sebti
Said M
SM
Newman
Robert A
RA
Blaskovich
Michelle A
MA
Ye
Lei
L
Gagel
Robert F
RF
Moulder
Stacy
S
Wheler
Jennifer J
JJ
Naing
Aung
A
Tannir
Nizar M
NM
Ng
Chaan S
CS
Sherman
Steven I
SI
El Naggar
Adel K
AK
Khan
Rabia
R
Trent
Jon
J
Wright
John J
JJ
Kurzrock
Razelle
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001557:Benzenesulfonates / Q000008:administration & dosage*; D051231:Farnesyltranstransferase / Q000037:antagonists & inhibitors*; D005260:Female; D006801:Humans; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009154:Mutation; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D009536:Niacinamide / Q000031:analogs & derivatives; D010671:Phenylurea Compounds; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D011725:Pyridines / Q000008:administration & dosage*; D015363:Quinolones / Q000008:administration & dosage*; D000077157:Sorafenib; D016896:Treatment Outcome
D001557:Benzenesulfonates; D010671:Phenylurea Compounds; D011725:Pyridines; D015363:Quinolones; D009536:Niacinamide; D000077157:Sorafenib; D051231:Farnesyltranstransferase; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; C402769:tipifarnib