SAPPHIRE: A randomized phase II study of mFOLFOX6 + panitumumab versus 5-FU/LV + panitumumab after 6 cycles of frontline mFOLFOX6 + panitumumab in patients with colorectal cancer.

729Background: FOLFOX therapy, an infusion of 5-fluorouracil (5-FU) with leucovorin in combination with oxaliplatin (OXA), is a common first-line chemotherapy regimen for unresectable, advanced or recurrent colorectal carcinoma (CRC). However, long-term administration of OXA is associated with peripheral neuropathy (PN); decreasing treatment length of OXA may be beneficial without reducing its efficacy. Methods: Chemotherapy-naive pts aged ≥20 yrs with RAS wild-type advanced/recurrent CRC were enrolled to receive 6 cycles of panitumumab (Pmab) + mFOLFOX6 once every 2 wks. Pts who completed 6 cycles of Pmab + mFOLFOX6 and confirmed no progressive disease were subsequently randomized 1:1 to continue to receive Pmab + mFOLFOX6 (arm 1) or Pmab + 5-FU/LV (arm 2). The primary endpoint was progression-free survival (PFS) rate at 9 mos after randomization. The threshold PFS rate was defined as 30%, and the expected rate was set at 50%, with a 90% power and a 1-sided alpha value of 0.10. In the primary analysis, a...