Erlotinib for progressive vestibular schwannoma in neurofibromatosis 2 patients.

OBJECTIVE

In vitro treatment of Nf2-deficient cells with epidermal growth factor receptor (EGFR) inhibitors can reduce cellular proliferation. We sought to determine the activity of erlotinib for progressive vestibular schwannoma (VS) associated with neurofibromatosis 2 (NF2).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Eleven NF2 patients with progressive VS who were poor candidates for standard therapy.

INTERVENTION

Erlotinib 150 mg daily.

MAIN OUTCOME MEASURES

A radiographic response was defined as >or= 20% decrease in tumor volume compared with baseline. A hearing response was defined as a statistically significant increase in word recognition score (WRS) compared with baseline; a minor hearing response was defined as a 10 dB improvement in pure-tone average with stable WRS.

RESULTS

: Before treatment, the median and mean annual volumetric growth rate for 11 index VS were 26% and 46%, respectively. Among 10 evaluable patients, the median time-to-tumor progression was 9.2 months. Three patients with stable disease experienced maximum tumor shrinkage of 4%, 13%, and 14%. Nine patients underwent audiologic evaluations. One experienced a transient hearing response, 2 experienced minor hearing responses, 3 remained stable, and 2 developed progressive hearing loss. The median time-to-progressive hearing loss was 9.2 months and to either tumor growth or progressive hearing loss was 7.1 months. Adverse treatment effects included mild-to-moderate rash, diarrhea, and hair thinning, with 2 episodes of grade 3 toxicity.

CONCLUSION

Erlotinib treatment was not associated with radiographic or hearing responses in NF2 patients with progressive VS. Because a subset of patients experienced prolonged stable disease, time-to-progression may be more appropriate than radiographic or hearing response for anti-EGFR agents in NF2-associated VS.