Phase 2 randomized, flexible crossover, double-blinded, placebo-controlled trial of the farnesyltransferase inhibitor tipifarnib in children and young adults with neurofibromatosis type 1 and progressive plexiform neurofibromas

Authors

Brigitte C. Widemann, National Institutes of Health
Eva Dombi, National Institutes of HealthFollow
Andrea Gillespie, National Cancer Institute, Bethesda, MD
Pamela L. Wolters, Johns Hopkins University
Jean Belasco, Children's Hospital of Philadelphia
AeRang Kim, George Washington University
+13 additional authors

Document Type

Journal Article

Publication Date

2-2014

Journal

Neuro-Oncology

Abstract

Background

RAS is dysregulated in neurofibromatosis type 1 (NF1) related plexiform neurofibromas (PNs). The activity of tipifarnib, which blocks RAS signaling by inhibiting its farnesylation, was tested in children and young adults with NF1 and progressive PNs.

Methods

Patients aged 3–25 years with NF1-related PNs and imaging evidence of tumor progression were randomized in a double-blinded fashion to receive tipifarnib (200 mg/m² orally every 12 h) or placebo (phase A) and crossed over to the opposite treatment arm at the time of tumor progression (phase B). PN volumes were measured with MRI, and progression was defined as ≥20% volume increase. Time to progression (TTP) in phase A was the primary endpoint, and the trial was powered to detect whether tipifarnib doubled TTP compared with placebo. Toxicity, response, and quality of life were also monitored.

Results

Sixty-two patients were enrolled. Tipifarnib and placebo were well tolerated. On phase A, the median TTP was 10.6 months on the placebo arm and 19.2 months on the tipifarnib arm (P = .12; 1-sided). Quality of life improved significantly compared with baseline on the tipifarnib arm but not on the placebo arm. Volumetric tumor measurement detected tumor progression earlier than conventional 2-dimensional (WHO) and 1-dimensional (RECIST) methods.

Conclusions

Tipifarnib was well tolerated but did not significantly prolong TTP of PNs compared with placebo. The randomized, flexible crossover design and volumetric PN assessment provided a feasible and efficient means of assessing the efficacy of tipifarnib. The placebo arm serves as an historical control group for phase 2 single-arm trials directed at progressive PNs.

Comments

This work is written by U.S. Government employees and is in the public domain in the U.S.

Originally published in Oxford University Press, Neuro-Oncology.

Creative Commons License

This work is free of known copyright restrictions.

APA Citation

[Epub ahead of print]

Peer Reviewed

1

Open Access

1