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

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 1 + 5-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.

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.

XELOX + placebo n=350

FOLFOX-4 + placebo n=351

XELOX + bevacizumab

n=350

FOLFOX-4 + bevacizumab

n=349

XELOX n=317

FOLFOX-4 n=317

Initial 2-arm open-label study

(n=634)

Protocol amended to 2x2 placebo-controlled design after bevacizumab phase

III data2 became available (n=1400)

RecruitmentJune 2003 – May 2004

RecruitmentFeb 2004 – Feb 2005

Figure 1. XELOX-1 / NO16966 study design

Treatment schedules

XELOX + bevacizumab (or placebo)– Bev (or placebo) 7.5 mg/kg i.v. over 30–90 min, day 1– Oxaliplatin 130 mg/m2 i.v. over 2 hrs, day 1– Capecitabine 1000 mg/m2 orally, twice daily, days 1–14– Schedule repeated every 21 days

FOLFOX-4 + bevacizumab (or placebo)– Bev (or placebo) 5 mg/kg i.v. over 30–90 min, day 1– Oxaliplatin 85 mg/m2 i.v. over 2 hrs, day 1– Folinic acid 200 mg/m2 i.v. over 2 hrs, days 1, 2– Fluorouracil 400 mg/m2 i.v. bolus, days 1, 2– Fluorouracil 600 mg/m2 i.v. inf over 22 hrs, days 1, 2– Schedule repeated every 14 days

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.

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).

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.

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.

Table 1. Baseline patient characteristics

FOLFOX-4+

placebo

(n=351)

FOLFOX-4+

bevacizumab

(n=349)

XELOX+

placebo

(n=350)

XELOX+

bevacizumab

(n=350)

Male/female, % 53/47 59/41 59/41 61/39

Median age, years 60 60 61 61

ECOG PS at baseline: 0/1, % 60/40 57/43 59/41 59/41

Alkaline phosphatase at baseline:

Abnormal/normal, % 42/58 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

9

67

23

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=0.0023 (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).

Figure 2. PFS chemotherapy + bevacizumab (ITT population)

0 5 10 15 20 25

Months

PF

S e

stim

ate

HR=0.83 [97.5% CI 0.72–0.95]p=0.0023

9.48.0

1.0

0.8

0.6

0.4

0.2

0

XELOX / FOLFOX-4 + bevacizumab n=699 (513 events)

XELOX / FOLFOX-4 + placebo n=701 (547 events)

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

Table 2. Secondary endpoints (ITT population)

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.

0 5 10 15 20

Figure 3. Separation after ~6 months in bevacizumab-containing arms between ‘general’ and ‘on treatment’ PFS

Months

PF

S e

stim

ate

XELOX / FOLFOX-4 + placebo

XELOX / FOLFOX-4 + bevacizumab

1.0

0.8

0.6

0.4

0.2

0

ON TREATMENT: HR=0.63 (97.5% CI 0.52–0.75, p<0.0001)

GENERAL: HR=0.83 (97.5% CI 0.72–0.95, p=0.0023)

Figure 4. Overall survival (ITT population)

HR=0.89 (97.5% CI 0.76–1.03)

p=0.0769

XELOX / FOLFOX-4 + bevacizumab n=699 (420 events)

XELOX / FOLFOX-4 + placebo n=701 (455 events)

1.0

0.8

0.6

0.4

0.2

0

Months

Su

rviv

al e

stim

ate

0 6 12 18 24 30 36

19.9 21.3

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 5.4 months (range 0–15.7)

– Bevacizumab + FOLFOX-4 6.3 months (0–14.9)

– Placebo + FOLFOX-4 6.0 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)

Table 3. Reasons for treatment discontinuation

582601 Discontinued treatmenta

74

53

3

140

267 (44%)

7

327

334 (56%)

Chemotherapy + placebo (n=701)

88

59

1

213

361 (62%)

16

205

221 (38%)

Chemotherapy + bevacizumab

(n=699)

Other

Refused treatment

Protocol violation

Adverse event

Non-progression eventsa

Death

Disease progression

Progression eventsa

aDuring primary treatment phase

0

10

20

30

40

50

60

1–6 7–12 13–18 19–24 25–30 31–36 37–42 43–48

FOLFOX-4 / XELOX + placebo

FOLFOX-4 / XELOX + bevacizumab

Time from randomization (weeks)

Nu

mb

er o

f p

atie

nts

Figure 5. Treatment withdrawal over time due to disease progression

Progression placebo = 334 (56%)

Progression bevacizumab = 221 (38%)

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.

0

25

50

75

100

Grade

3/4

AEs

Neutro

penia

Neuro

pathy

Diarrh

ea VTE HFS

FOLFOX-4 / XELOX + placebo

FOLFOX-4 / XELOX + bev

Figure 6. Most frequent grade 3/4 AEs with chemotherapy + placebo or bevacizumab (safety

population)

VTE = venous thromboembolism; HFS = hand-foot syndrome

AEs occuring in >5% of patients% of patients

Table 4. Grade 3/4 events with chemotherapy + placebo or bevacizumab (safety population)

Grade 3/4 event (% of patients)

FOLFOX-4 orXELOX +placebo(N=675)

FOLFOX-4 orXELOX +

bevacizumab (N=694)

All Adverse Events 75 80

GI perforations <1 <1

Bleeding 1 2

Arterial thromboembolic events 1 2

Hypertension 1 4

Proteinuria – <1

Wound-healing complications <1 <1

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 2.0

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).

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

References

1. De Gramont A, et al. J Clin Oncol 2000;18:2938−47.

2. Hurwitz H, et al. NEJM 2004;350:2335−42.

3. Saltz L, et al. Proc ASCO GI 2007 (Abstr 238).

4. Cassidy J, et al. Proc ESMO 2006 (Abstr LBA3).

Presented at the ASCO Annual Meeting, 1−5 June, 2007