Barone, Carlo

3637 Background: In the CORRECT phase III trial, the multikinase inhibitor REG demonstrated significant improvement in overall survival and progression-free survival vs placebo (P) in patients with mCRC whose disease had progressed on other standard therapies. The most frequent grade 3 AEs were hand–foot skin reaction (HFSR), fatigue, diarrhea, hypertension, and rash. We examined when these AEs first occurred and what impact they had on REG dosing. Methods: Adults with mCRC progressing after all standard therapies were randomized to receive REG 160 mg (n=505) or P (n=255) orally once daily for the first 3 weeks of each 4-week cycle. AEs were managed with dose modifications (reduction and interruption) according to the protocol. Results: The safety population comprised 753 pts (REG n=500, P n=253). The mean ± SD treatment duration was 12.1 ± 9.7 weeks for REG and 7.8 ± 5.2 weeks for P. Treatment-emergent AEs occurred in 99.6% of REG pts and 96.8% of P pts. AEs occurring in ≥10% more REG than P pts were fatigue, HFSR, anorexia, diarrhea, weight loss, voice changes, hypertension, rash/desquamation, oral mucositis, fever, hyperbilirubinemia, and low platelet count. The incidence of grade ≥3 HFSR, fatigue, hypertension, and rash/desquamation typically peaked in cycle 1 and tapered to a relatively stable lower incidence over later cycles, while the incidence of diarrhea remained relatively constant throughout the study; median time to first occurrence and worst grade of these AEs is shown in the table. AEs led to dose modifications in 66.6% of REG pts and 22.5% of P pts. Conclusions: The most common AEs in the REG group typically occurred early during treatment. Close early monitoring of AEs and proper management by dose modification is recommended. Clinical trial information: NCT01103323. [Table: see text]

3514 Background: In the CORRECT phase III trial, the multikinase inhibitor regorafenib (REG) demonstrated significant improvement in overall survival (OS) and progression-free survival (PFS) vs placebo (Pla) in patients with metastatic colorectal cancer (mCRC) whose disease had progressed on other standard therapies. An exploratory biomarker subanalysis was conducted to identify protein biomarkers with potential predictive or prognostic value. Methods: Fifteen proteins of interest, many of which are involved in angiogenesis, were quantified by multiplex immunoassay or ELISA in baseline plasma samples collected at study entry from 80% (611/760) of patients. Potential predictive and prognostic effects were evaluated. Results: The biomarker subpopulation was representative of the overall study population in terms of OS and PFS. Using OS as the clinical endpoint, Tie-1 was the only protein whose level demonstrated significant correlation with efficacy (low protein group: REG/Pla, HR 0.87; high protein group, HR 0.56; interaction, p=0.035). Using PFS as the clinical endpoint, von Willebrand factor (VWF) was the only protein whose level demonstrated significant correlation with efficacy (low protein group: REG/Pla, HR 0.39; high protein group, HR 0.60; interaction, p=0.02). Following correction for multiple testing, neither Tie-1 nor VWF data retained statistical significance. Baseline levels of IL-8 and placental growth factor (PlGF) were found to have prognostic value for OS (IL-8: high/low protein levels, HR 3.48, p<0.001; PIGF: HR 1.81, p=0.002). IL-8 was also prognostic for PFS (high/low protein levels: HR 1.63, p<0.001). Conclusions: None of the plasma proteins examined showed significant predictive value for REG efficacy after multiple testing correction. The association between baseline levels of Tie-1/VWF and REG efficacy may be a hypothesis to be tested in further trials. Clinical trial information: NCT01103323.

3636 Background: In the CORRECT phase III trial, the multikinase inhibitor REG demonstrated significant improvement in overall survival (OS) and progression-free survival vs placebo (Pla) in patients (pts) with mCRC whose disease progressed on other standard therapies. The most frequent REG-related grade ≥3 adverse events (AEs) of interest were hand–foot skin reaction (HFSR), fatigue, diarrhea, hypertension, and rash/desquamation. We explored whether the impact of REG in pts aged ≥65 years differed from that in younger patients. Methods: Pts with mCRC progressing following all other available therapies were randomized 2:1 to receive REG 160 mg once daily (n=505) or Pla (n=255) for the first 3 weeks of each 4-week cycle. The dose could be modified to manage AEs. The primary endpoint was OS. We report efficacy, safety, and dosing data from REG recipients by age. Results: The REG treatment group included 309 pts <65 years (307 evaluable for safety) and 196 pts ≥65 years (193 evaluable for safety). The OS hazard ratio (REG/Pla) was 0.72 (95% confidence interval [CI] 0.56–0.91) in pts <65 years and 0.86 (95% CI 0.61–1.19) in pts ≥65 years (interaction p-value = 0.405). Median OS was 6.7 vs 5 months for REG vs Pla in pts <65 years, and 6.0 vs 5.6 months, respectively, in pts ≥65 years. Most pts experienced drug-related AEs (<65 years: 93.8%; ≥65 years: 91.7%). The rates of grade ≥3 REG-related AEs of interest and dose modifications are shown in the Table. In pts <65 years vs ≥65 years, median (interquartile range [IQR]) duration of REG was 7.6 weeks (6.6–15.4) vs 7.1 weeks (5.1–17.2), median (IQR) daily REG dose was 160.0 mg (134.6–160.0) vs 160.0 mg (137.5–160.0), and median (IQR) proportion of planned REG dose was 83.3% (65.7–100.0) vs 78.6% (66.7–100.0), respectively. Conclusions: In the CORRECT trial, REG demonstrated an OS benefit in pts <65 years and ≥65 years. Safety and tolerability of REG appeared to be similar in both age subgroups. Clinical trial information: NCT01103323. [Table: see text]

467 Background: Regorafenib (REG) is an oral multikinase inhibitor that has recently demonstrated significant overall survival benefit vs placebo in the randomized phase III CORRECT study. We examined the time course of adverse events (AEs) in the CORRECT study. Methods: Regorafenib (REG) is an oral multikinase inhibitor that has recently demonstrated significant overall survival benefit vs placebo in the randomized phase III CORRECT study. We examined the time course of adverse events (AEs) in the CORRECT study. Results: The safety population comprised 753 patients (pts): REG n=500; placebo n=253. The mean treatment duration was 12.1 ± 9.7 weeks in the REG group and 7.8 ± 5.2 weeks in the placebo group. Treatment-emergent AEs occurred at any grade in 99.6% of REG pts and 96.8% of placebo pts, at grade 1/2 in 21.6% and 47.8%, respectively, at grade 3 in 56.0% and 26.5%, respectively, and at grade 4/5 in 22.0% and 22.5%, respectively. AEs occurring in ≥10% more REG than placebo pts were fatigue, hand–foot skin reaction (HFSR), anorexia, diarrhea, weight loss, voice changes, hypertension, rash/desquamation, oral mucositis, fever, hyperbilirubinemia, low platelet count. The most frequent AEs deemed to be regorafenib related were HFSR, fatigue, diarrhea, hypertension, and rash/desquamation. The frequency of these AEs over time is shown in the Table. The incidence of HFSR, fatigue, hypertension, and rash/desquamation peaked in cycle 1 and tapered to a relatively stable lower incidence over later cycles. The incidence of diarrhea remained relatively constant throughout treatment. AEs led to dose modification in 66.6% of pts in the REG group and 22.5% in the placebo group. Data on dose intensity across treatment cycles will be presented. Conclusions: In the CORRECT trial, the incidences of the most common AEs in the REG group peaked early during treatment. There appeared to be no evidence for cumulative toxicity of REG. Clinical trial information: NCT01103323. [Table: see text]