1. Bevacizumab (Bev) in combination with XELOX or FOLFOX-4: updated efficacy results from XELOX-1 / NO16966, a randomized phase III trial in first-line metastatic colorectal cancer
Saltz L1, Clarke S2, Diaz-Rubio E3, Scheithauer W4, Figer A5 Wong R6, Koski S7, Lichinitser M8, Yang T9, Cassidy J10
1Memorial Sloan Kettering Cancer Center, New York, USA, 2University of Sydney and Sydney Cancer Centre, Sydney, Australia, 3Hospital Clínico San Carlos, Madrid, Spain, 4Vienna University Medical School, Vienna, Austria, 5Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 6Cancer Care Manitoba, St Boniface General Hospital, Winnipeg, MB, Canada, 7Cross Cancer Institute, Edmonton, AB, Canada, 8Russian Cancer Research Center, Moscow, Russian Federation, 9Chang-Gung Memorial Hospital, Taipei, Taiwan, 10Glasgow University, Glasgow, Scotland

2. Introduction
NO16966 (XELOX-1) started as a multinational, 2-arm, open-label, randomized phase III comparison of XELOX (oxaliplatin 130mg/m2 i.v. day 1 + capecitabine 1000mg/m2 orally bid days 1−14, every 3 weeks) vs. FOLFOX-4 (oxaliplatin 85mg/m2 i.v. day FU 400mg/m2 i.v. day 1 + folinic acid 200mg/m2 i.v. day 1)1 (Figure 1).
After pivotal phase III data for bevacizumab became available,2 the protocol was amended to a partially blinded randomized, 2 x 2 factorial design with two co-primary objectives.
Previously reported results showed that in terms of progression-free survival (PFS), bevacizumab is superior to placebo when combined with oxaliplatin-based chemotherapy (XELOX / FOLFOX-4).3
Here we present updated overall survival data with an additional 1 year of follow-up.

3. XELOX-1 / NO16966 study design
The study was double-blind with regard to bevacizumab and placebo administration, but not for capecitabine and 5-FU, since these are administered orally and intravenously, respectively (Figure 1).
Recruitment occurred in two phases as the protocol was amended to include a placebo-controlled comparison with bevacizumab.

4. Figure 1. XELOX-1 / NO16966 study design
Recruitment June 2003 – May 2004
Recruitment Feb 2004 – Feb 2005
XELOX n=317
XELOX + placebo
n=350
XELOX + bevacizumab
n=350
FOLFOX-4
n=317
FOLFOX-4 + placebo n=351
FOLFOX-4 + bevacizumab
n=349
Initial 2-arm open-label study (n=634)
Protocol amended to 2x2 placebo- controlled design after bevacizumab phase III data2 became available (n=1400)

5. Treatment schedules XELOX + bevacizumab (or placebo)
Bev (or placebo) mg/kg i.v. over 30–90 min, day 1
Oxaliplatin mg/m2 i.v. over 2 hrs, day 1
Capecitabine mg/m2 orally, twice daily, days 1–14
Schedule repeated every 21 days
FOLFOX-4 + bevacizumab (or placebo)
Bev (or placebo) mg/kg i.v. over 30–90 min, day 1
Oxaliplatin mg/m2 i.v. over 2 hrs, day 1
Folinic acid mg/m2 i.v. over 2 hrs, days 1, 2
Fluorouracil mg/m2 i.v. bolus, days 1, 2
Fluorouracil mg/m2 i.v. inf over 22 hrs, days 1, 2
Schedule repeated every 14 days

6. Main inclusion criteria
Male or female ≥18 years old
ECOG PS ≤1
Histologically confirmed adenocarcinoma of colon or rectum with metastatic disease
≥1 unidimensionally measurable lesion
No prior systemic therapy for advanced/MCRC
No prior treatment with oxaliplatin or bevacizumab
If prior adjuvant therapy patients must not have progressed during or within 6 months of completion
No CNS disease, including brain metastases
No clinically significant cardiovascular disease
No moderate or severe renal impairment
No proteinuria ≤1+
Neutrophils ≥1.5 x 109/L.

7. Primary and secondary objectives
Primary objectives:
Non-inferiority of XELOX vs. FOLFOX-4 for PFS:
non-inferiority was concluded if the upper limit of 97.5% confidence interval (CI) was ≤1.23.
Bevacizumab + chemotherapy (XELOX and FOLFOX-4) is superior to placebo + chemotherapy for PFS:
superiority was concluded if p≤0.025.
Secondary objectives::
Overall survival.
Response rate assessed according to RECIST criteria. Assessments made by investigators and also an independent response committee (IRC).
Safety evaluated using NCI-CTC (version 3.0).

8. Study populations ITT (intent-to-treat) = all randomized patients.
EPP (eligible patient population) = ITT minus major protocol violators and patients not receiving at least 1 dose of study drug. Used for the XELOX non-inferiority analyses due to health authority requirements.
Safety population = all patients receiving at least one dose of the respective study drug.

9. Baseline characteristics
The original 2-arm study recruited 634 patients; after transition to 2x2 factorial study design, an additional 1400 patients were recruited.
The analysis presented here is based on the 1400 patients recruited in the 2X2 factorial part of the study.
Baseline patient characteristics were well balanced between the groups (Table 1).
Most patients had 1 or 2 metastatic sites and approximately one-quarter of patients had received prior adjuvant therapy.

10. Table 1. Baseline patient characteristics
FOLFOX-4+
placebo
(n=351)
bevacizumab
(n=349)
XELOX+
(n=350)
Male/female, %
53/47
59/41
61/39
Median age, years 60 61
ECOG PS at baseline: 0/1, %
60/40
57/43
Alkaline phosphatase at baseline:
Abnormal/normal, %
42/58
43/57
45/55
Prior adjuvant chemotherapy:
No/Yes, %
76/24
75/25
74/26
78/22
Cancer type at first diagnosis, %:
Colon and rectal
Colon
Rectal 7 66 27 8 64 28 9 67 25 23

11. Efficacy
The co-primary objective was met: the addition of bevacizumab to oxaliplatin-based chemotherapy significantly improved PFS, HR=0.83 [97.5% CI 0.72–0.95, p= (Figure 2)].3,4
The overall survival analysis presented here includes 12 additional months of follow-up.
Pre-specified on-treatment definition (events occuring within 28 days of last dose only) showed significant improvement in PFS in bevacizumab-treated patients (Figure 3).

12. Figure 2. PFS chemotherapy + bevacizumab (ITT population)
XELOX / FOLFOX-4 + bevacizumab n=699 (513 events)
XELOX / FOLFOX-4 + placebo n=701 (547 events)
1.0
0.8
0.6
0.4
0.2
HR=0.83 [97.5% CI 0.72–0.95]
p=0.0023
PFS estimate
8.0
9.4
Months

13. Table 2. Secondary endpoints (ITT population)
Placebo + FOLFOX-4 or XELOX (n=701)
Bevacizumab + FOLFOX-4 or XELOX (n=699)
P value
Median PFS ‘on treatment’a, months Hazard ratio (97.5% CI)
7.9
10.4
<0.0001
Time to treatment failureb, months Hazard ratio (97.5% CI)
6.0
6.9
0.0030
Median overall survival, months Hazard ratio (97.5% CI)
19.9
21.3
0.0769
0.63 (0.52–0.75)
0.84 (0.74–0.96)
0.89 (0.76–1.03)
aOn treatment analysis includes only patients who received treatment as stated in the protocol.
bBased on safety population.
Response rate (IRC) for XELOX/FOLFOX-4+bev and XELOX/FOLFOX-4+placebo was 38% for each; response rates (investigator) were 47% and 49%, respectively.

14. Figure 3. Separation after ~6 months in bevacizumab-containing arms between ‘general’ and ‘on treatment’ PFS
XELOX / FOLFOX-4 + bevacizumab
XELOX / FOLFOX-4 + placebo
1.0
0.8
0.6
0.4
0.2
ON TREATMENT: HR=0.63 (97.5% CI 0.52–0.75, p<0.0001)
PFS estimate
GENERAL: HR= (97.5% CI 0.72–0.95, p=0.0023)
When you compare the pooled PFS general and on treatment analysis you can observe that both Avastin curves separate nicely in the begining but the PFS general Avastin curve starts to run parallel around 6 month. This reflects the observed phenomenon that a large group of patients in the 966 trial discontinued treatment at 6 month and was not treated until progression, as recommended in the protocol.
Months

15. Figure 4. Overall survival (ITT population)
XELOX / FOLFOX-4 + bevacizumab n=699 (420 events)
XELOX / FOLFOX-4 + placebo n=701 (455 events)
1.0
0.8
HR=0.89 (97.5% CI 0.76–1.03) p=0.0769
Survival estimate
0.6
0.4
0.2
19.9
21.3 6 12 18 24 30 36
Months

16. Treatment exposure
Duration of treatment was similar in bevacizumab- and placebo-containing arms.
Median treatment duration:
Bevacizumab + XELOX 6.1 months (range 0–15.3)
Placebo + XELOX months (range 0–15.7)
Bevacizumab + FOLFOX months (0–14.9)
Placebo + FOLFOX months (range 0–15.6).
Only 29% of bevacizumab recipients and 44–50% of placebo recipients were treated until disease progression.a
aIncludes non-progressive patients stopping treatment at week 48 (end of primary treatment phase)

17. Table 3. Reasons for treatment discontinuation
Chemotherapy
+ placebo
(n=701)
Chemotherapy
+ bevacizumab
(n=699)
Discontinued treatmenta
601
582
Progression eventsa
334 (56%)
221 (38%)
Disease progression
327
205
Death 7 16
Non-progression eventsa
267 (44%)
361 (62%)
Adverse event
140
213
Protocol violation 3 1
Refused treatment 53 59
Other 74 88
aDuring primary treatment phase

18. Figure 5. Treatment withdrawal over time due to disease progression
Number of patients
This slides give you a very good impression of the Avastin efficacy during the course of the treatment. It is impressive to see that through the complete 42 weeks the number of patients experiencing progressive disease is constantly higher in the placebo group. This underlines the PFS on treatment analysis through demonstrating a clear treatment advantage with Avastin.
Time from randomization (weeks)
Progression placebo = 334 (56%)
Progression bevacizumab = 221 (38%)

19. Safety
A higher proportion of patients discontinued therapy because of AEs in the bevacizumab-containing arms vs. the placebo-containing arms (31% vs. 21%).
Most treatment discontinuations were due to chemotherapy-rather than bevacizumab-related events.
Most common reasons for treatment discontinuation were neurotoxicity, GI events, general disorders and hematological events.
Predefined grade 3/4 AEs of interest to bevacizumab and chemotherapy are presented in Table 3.

20. AEs occuring in >5% of patients
Figure 6. Most frequent grade 3/4 AEs with chemotherapy + placebo or bevacizumab (safety population)
AEs occuring in >5% of patients
% of patients
No meaningful increase in chemotherapy related grade 3/ 4 side effect is observed with the addition of Avastin. Avastin related side effects are rare
VTE = venous thromboembolism; HFS = hand-foot syndrome

21. Table 4. Grade 3/4 events with chemotherapy + placebo or bevacizumab (safety population)
Grade 3/4 event (% of patients)
FOLFOX-4 or
XELOX +
placebo
(N=675)
bevacizumab
(N=694)
All Adverse Events 75 80
GI perforations
<1
Bleeding 1 2
Arterial thromboembolic events
Hypertension 4
Proteinuria –
Wound-healing complications
Discontinuations due to AE 21 31
All-cause 60-day mortality
1.6
2.0
Treatment-related mortality up to 28 days after last dose
1.5

22. Conclusions
The addition of bevacizumab to front-line oxaliplatin-based chemotherapy significantly improves PFS.
The overall safety profile is in line with previous trial experience in colorectal cancer.
Analysis of ‘on treatment’ PFS vs. ‘general’ PFS suggests that continuation of bevacizumab until disease progression may be necessary to optimize the effect of bevacizumab on PFS.
The observed overall survival difference did not reach statistical significance (p=0.077).

23. Acknowledgement Study sponsored by Roche Sincere thanks to:
The patients and their families
The co-investigators
The research nurses and data managers
The study management team

24. References De Gramont A, et al. J Clin Oncol 2000;18:2938−47.
Hurwitz H, et al. NEJM 2004;350:2335−42.
Saltz L, et al. Proc ASCO GI 2007 (Abstr 238).
Cassidy J, et al. Proc ESMO 2006 (Abstr LBA3).
Presented at the ASCO Annual Meeting, 1−5 June, 2007