Prescribing decision drivers in patients with recurrent gastrointestinal stromal tumor (GIST) previously treated with adjuvant imatinib: A retrospective chart extract-based approach.

Abstract

e21515 Background: Adjuvant imatinib (IM) is the standard of care for primary resectable GIST. However, little is known about prescribing habits following disease recurrence. This study identifies main prescribing decision drivers in recurrent GIST pts following completion of adjuvant IM treatment. Methods: Using an online data collection system, clinical information was retrieved on 410 pts treated with adjuvant IM for ≥6 months for primary resectable KIT+GIST, who discontinued IM treatment, had a recurrence (while off IM), and subsequently restarted IM or initiated sunitinib. Pt-level data were collected at primary diagnosis and at first recurrence. Prescribing decision drivers were identified using logistic regression models. Physicians were also surveyed to identify factors that influence their prescribing decisions. Results: Following initial disease recurrence, 77% of pts restarted IM and 23% initiated sunitinib. IM duration at primary diagnosis was the main prescribing decision driver; pts treated with IM for a shorter period of time (≤18 months) were 7.0 times more likely to restart IM than pts with longer IM duration (p<.01). Pts who took longer (≥12 months) to develop recurrence after IM discontinuation (Odds ratio [OR]=3.4; p=<.01 ), had a low mitotic rate at recurrence (OR=2.8; p=<.01), or had a recurrence inside the gastrointestinal system (OR=2.7; p=<.01) were also more likely to be prescribed IM following recurrence. These findings were consistent with the top survey responses on factors influential to prescribing decisions after recurrence: time to develop recurrence (55%), pt risk profile (53%), and IM duration prior to recurrence (51%). Conclusions: Based on information of pts who restarted IM or initiated sunitinib, IM treatment duration at primary diagnosis, time to develop recurrence after IM discontinuation, tumor location and mitotic rate at recurrence seem to be the main prescribing decision drivers. These findings were consistent with physicians’ main factors reported to influence their prescribing decisions following recurrence.