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NSABP C08 adjuvant colon cancer Best of ASCO, Beirut, July 2009. Prof Eric Van Cutsem, MD, PhD Digestive Oncology Leuven, Belgium. A phase III trial assessing bevacizumab in stage II and III carcinoma of the colon: Results of NSABP Protocol C-08.
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NSABP C08 adjuvant colon cancer Best of ASCO, Beirut, July 2009 Prof Eric Van Cutsem, MD, PhD Digestive Oncology Leuven, Belgium
A phase III trial assessing bevacizumab in stage II and III carcinoma of the colon: Results of NSABP Protocol C-08 N.WolmarkG.YothersM.J.O’ConnellS.Sharif N.Atkins T.E.SeayL.FeherenbacherS.O’Reilly and C.J.Allegra
NSABP C-08 Stage ll + lll Strat: # Pos. N Randomize mFF6 mFF6 + B
NSABP C-08 mFF6 q2wk X 6 mo R Bev* q2wk X 1 yr *5mg/K
NSABP C-08 Duration: 09-04 - 10-06 Accrual: 2710 Med F-U: 35.6 mo End Pt: DFS (592 /603 ev) Stats:25% ↓ ev rate (HR = 0.75)
mFF6 mFF6+B Randomized Lost / Ineval Analysis 1356 18 1338 1354 16 1334 NSABP C-08Accrual
NSABP C-08 Patient Characteristics
mFF6 mFF6+B P Hypertension 1.8 12 <0.0001 Pain 6.3 11.1 <0.0001 Proteinuria 0.8 2.7 <0.001 Wound Comp 0.3 1.7 <0.001 NSABP C-08Grade 3+ Toxicities Increased with Bevacizumab (%) Median Duration of Bev = 11.5 months Allegra et al JCO May 4, 2009
NSABP C-08 DFS % Ev 3yDFS mFF6+B 291 77.4 mFF6 312 75.5 HR 0.89 P 0.15 Yrs
NSABP C-08 DFS HR 0.89 P 0.15 mFF6+B mFF6
NSABP C-08 Was there a significant transient effect ofbevacizumab? Cumulative HR over time
NSABP C-08 HR HR Yrs
NSABP C-08 HR 0.0004
NSABP C-08 HR 0.004 0.0004
NSABP C-08 HR 0.02 0.004 0.0004
NSABP C-08 HR 0.05 0.02 0.004 0.0004
NSABP C-08 HR 0.08 0.05 0.02 0.004 0.0004
NSABP C-08 Was there a significant interaction between the effect of Bev and time?
Event-free at 1 Yr DFS at 1 Yr Ev 1yDFS mFF6+B 75 94.3 mFF6 122 90.7 Ev mFF6+B 216 mFF6 190 ∆ 3.6 HR 0.60 P 0.0004 HR 1.07 P 0.48 Time-Treatment Interaction P = 0.001 NSABP C-08
NSABP C-08 DFS and Stage
DFS Stage III DFS Stage II Ev 3yDFS mFF6+B 40 87.4 mFF6 47 84.7 Ev 3yDFS mFF6+B 251 74.2 mFF6 265 72.4 Δ 2.7 Δ 1.8 HR 0.90 P 0.25 HR 0.82 P 0.35 NSABP C-08
NSABP C-08 Status at 36 mo Med Follow-up Primum non nocere
Conclusions The addition of bevacizumab to mFF6 did not result in an overall statistically significant prolongation in DFS There was a transient benefit in DFS during the one year that bevacizumab was utilized
Conclusions Consideration should be given to clinical trials assessing longer duration of bevacizumab administration
Finding the NicheBevacizumab in Adjuvant CRCor... “What if Norman’s Right?” Lee M. Ellis, MD Departments of Surgical Oncology and Cancer Biology UT MD Anderson Cancer Center Houston, Texas, USA
What Can We Learn From This Negative Trial? • >2,500 patients participated in this trial • It is our responsibility to extract as much information and insight from this trial in order to advance the field • The most interesting finding in this trial…. • There “appeared” to be an early benefit in the FOLFOX + Bev arm • What is the biology behind this observation? • Can we use the knowledge of biology to design future trials?
The addition of bevacizumab to FOLFOX does not add benefit…..at all There is some benefit to adding Bev to FOLFOX, but this is dependent upon the longer duration of bevacizumab + chemotherapy There is some benefit to adding Bev to FOLFOX, but this is dependent upon the longer duration of bevacizumab therapy Three Hypotheses/Possibilities Are Raised By The C08 Trial
Is The Early Improvement in HR a Statistical Fluke? • I do not think so • There is biology to explain this observation • AVANT trial for validation
If The Early Benefit is Real, It Should Also be Observed in the AVANT Adjuvant Colon Cancer Study 3451 patients were enrolled between November 2004 and June 2007 Primary analysis: compare DFS between control and each treatment arm in stage III patients Projected final analysis time: Q3, 2010 48 Weeks 24 Weeks FOLFOX4 q2wk n=3451 Stage III or high-risk stage II colon cancer 1:1:1 FOLFOX4 q2wk Bev 5 mg/kg, q2wk Bev 7.5 mg/kg q3wk Stratified by stage and region XELOX q3wk Bevacizumab 7.5 mg/kg q3wk
Several Preclinical Studies Suggest That Anti-VEGF Therapy Can Accelerate Metastasis Could the initial benefit of Bev be offset by a later increase in metastasis?
NO: It Does Not Appear That Bev Lead to a Paradoxical Increase in Metastasis BUT We Will Need Longer Follow-up to See If the Curves Cross 100 80 60 The percent of patients with recurrence at multiple sites was the same in both arms (18/18%). 40 There is no evidence from other CRC trials that Bev could lead to an increase in metastasis in CRC. But…..longer follow-up is necessary!! 20 0 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 More on the need for longer follow-up later in this presentation
Three Hypotheses/Possibilities Are Raised By The C08 Trial The addition of bevacizumab to FOLFOX does not add benefit…..at all There is some benefit to adding Bev to FOLFOX, but this is dependent upon the longer duration of bevacizumab + chemotherapy This implies that a longer duration of Bev + chemotherapy (if feasible) could lead to prolonged improvement in DFS There is some benefit to adding Bev to FOLFOX, but this is dependent upon the longer duration of bevacizumab therapy
The Purpose of Adjuvant CHEMOTHERAPY is to Increase the Cure Rate by Eradicating Microscopic Tumor Deposits! Did The Addition of Bevacizumab to FOLFOX Increase the Cure Rate? Sargent et al. “Evidence for Cure by Adjuvant Therapy in Colon Cancer……” JCO, 2009
No! The Addition of Bevacizumab to FOLFOX Did Not Increase the Cure Rate - Eventually the Microscopic Tumor Deposits Became Macroscopic 100 80 In the metastatic setting, the vast majority of patients who experience a response, do so within the first 4 months. There is no reason to believe that longer term combination therapy (or single agent Bev) will lead to more cures. 60 40 20 This is important and I will come back to this later in this talk. 0 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5
Hypothesis #3 There Is Some Benefit To Adding Bev To FOLFOX, But This Is Dependent Upon The Longer Duration Of Bevacizumab Therapy • If so, bevacizumab should be administered longer • But…..there are issues! • How much longer? • How much will it cost? • What are the long term adverse events? • Is this feasible?????