Precision medicine: Clinical outcomes including long-term survival according to the pathway targeted and treatment period–The IMPACT study.
LBA2553 Background: We evaluated the impact of pathway targeted and long-term follow-up of patients (pts) with refractory cancers referred to phase I trials. Methods: Pts referred to our program (2007-2013) had CLIA molecular testing. Pts treated with matched targeted therapy (MTT) vs. non-matched therapy (NMT) were analyzed. Results: Of 3,743 pts who had testing, 1,307 had ≥1 alteration and received therapy (MTT 711, NMT 596): med. age 57 yrs, range 16-86; 39% men; med. no. of prior therapies 4, range 0-16. The most common tumors were gastrointestinal 24.2%, gynecologic 19.4%, breast 13.5%, melanoma 11.9%, and lung 8.7%. Targeting MEK/RAF and RET pathways correlated with higher rates of CR/PR/SD≥6 months (mos), PFS and OS compared to others (all P < .001) (Table). Plateau was noted in OS (start, 38 mos): 74 of 711 (10.4%) in the MTT (max 10.7+ yrs) vs. 24 of 596 (4%) in the NMT (max 6 yrs) group were alive (p < .0001). In the MTT group, factors predicting longer PFS were non-PI3K pathway MTT (p < .001), no liver metastases (p < .001), PS < 2 (p = .006), normal LDH (p < .001) and albumin (p = .01) levels, and non-single agent therapy (p = .02). Factors predicting longer OS were non-PI3K pathway MTT (p < .001), no liver metastases (p < .001), PS < 2 (p < .001), normal LDH (p < .001) and albumin (p = .001) levels, and normal PLT counts (p = .03). Conclusions: Outcomes were superior in pts matched to RET and MEK/RAF inhibitors. Factors predicting longer PFS and OS were identified. In the MTT group, 10.4% of patients had OS ≥ 38 mos, the plateau starting point. Clinical trial information: NCT00851032. [Table: see text]