Future directions for Avastin ® in colorectal cancer (CRC) Fairooz Kabbinavar David Geffen School of Medicine at UCLA Los Angeles, USA

Optimising Avastin in metastatic CRC: ongoing clinical trial programme The current clinical trial programme will generate additional data with Avastin in combination with FOLFIRI, XELIRI, FOLFOX and XELOX in metastatic CRC Ongoing trials will provide further guidance regarding the true benefit of combining Avastin with oxaliplatin-containing therapy how best to use Avastin with oxaliplatin-containing regimens given the cumulative neurotoxicity of oxaliplatin

DREAM study mFOLFOX7 x6 XELOX4 x6 mFOLFOX7 x6 XELOX4 x6 Avastin Previously untreated patients with metastatic CRC (n=640) Primary endpoint: progression-free survival Secondary endpoints include overall survival, response rate, duration of disease control, tolerance and quality of life mFOLFOX7 or XELOX4: Avastin 5mg/kg every 2 weeks ± Tarceva 100mg/day During chemotherapy pause: Avastin 7.5mg/kg every 3 weeks ± Tarceva 150mg/day Avastin Avastin + Tarceva ® Avastin Avastin + Tarceva

CONcePT: first-line metastatic CRC phase IV optimisation Primary endpoint: time to treatment failure mFOLFOX7 + Avastin CONTINUOUS oxaliplatin ‘treat-to-failure’ ± intravenous Ca/Mg mFOLFOX = modified FOLFOX mFOLFOX7 + Avastin INTERMITTENT oxaliplatin Patients with metastatic CRC (n=532) 2x2 randomised, multicentre study

CONcePT: intermittent oxaliplatin Stage 1: Avastin 5mg/kg CI 5-FU/LVx8 cycles, months 1–4 Oxaliplatin 85mg/m 2 Stage 2: Avastin 5mg/kg CI 5-FU/LV Stage 3: Avastin 5mg/kg CI 5-FU/LVx8 cycles, months 9–12 Oxaliplatin 85mg/m 2 *Cumulative dose CI = continuous infusion x8 cycles, months 5–8 Oxaliplatin 680mg/m 2 * Oxaliplatin 1,360mg/m 2 *

OASIS - Oxaliplatin Avastin Sequence to Investigate Survival: study design Patients with metastatic CRC (n=800) FOLFOX6 + Avastin (cycles 1–8) PD Primary endpoint: first progression-free survival Secondary endpoints: duration of tumour control, overall survival and neurotoxicity Trial has 80% power to detect increase in progression-free survival from 10.5 to 14 months FOLFIRI + Avastin 5-FU/LV + Avastin FOLFOX6 re-introduction FOLFIRI FOLFOX6 re-introduction PD First lineSecond/third line* *Avastin may be used second/third line PD

Ongoing and planned trials of Avastin in CRC

Avastin in the (neo)adjuvant setting

Rationale for Avastin in the adjuvant setting The role of angiogenesis and VEGF in colorectal tumour growth is well established Using anti-VEGF therapy such as Avastin when micrometastases are dormant and potentially reliant on VEGF may prevent the ‘angiogenic switch’ Preclinical studies show that treatment with Avastin leads to regression of human tumour xenografts, 1–3 and a reduction in the number and size of liver metastases in nude mice. 4 Therefore, Avastin may have a greater impact in earlier disease stages 1 Gerber HP, et al. Cancer Res 2000;60:6253–58 2 Wildiers H, et al. Br J Cancer 2003;88:1979–86 3 Shen BQ, et al. Proc Am Assoc Cancer Res 2004;45:508 (Abstract 2203) 4 Warren RS, et al. J Clin Invest 1995;95:1789–97

Adjuvant anti-VEGF therapy may prevent the angiogenic switch Adapted from Poon RT-P, et al. J Clin Oncol 2001;19:1207–25 Stages at which angiogenesis plays a role in tumour progression Premalignant stage Malignant tumour Tumour growth Vascular invasion Dormant micrometastasis (Avascular tumour) (Angiogenic switch) (Vascularised tumour) (Tumour cell intravasation) (Seeding in distant organs)

A4.6.1Control MAb Warren RS, et al. J Clin Invest 1995;95:1789–97 A4.6.1 therapy and growth inhibition of colorectal liver metastases in an animal model Tumour volume (mm 3 ) Time (days) Control Control MAb (200µg) Anti-VEGF MAb (10µg) Anti-VEGF MAb (50µg) Anti-VEGF MAb (100µg) Anti-VEGF MAb (200µg) 1,600 1,

Randomised, phase III trial of adjuvant Avastin plus FOLFOX (AVANT): study design Randomised, open-label study Primary endpoint: disease-free survival Secondary endpoints: overall survival and safety Surgery for high risk stage II + stage III colon cancer (n=3,450) FOLFOX4 FOLFOX4 + Avastin (5mg/kg every 2 weeks) XELOX + Avastin (7.5mg/kg every 3 weeks) Avastin alone (7.5mg/kg every 3 weeks) Avastin alone (7.5mg/kg every 3 weeks) Observation Duration of treatment phases: 24 weeks XELOX = Xeloda ® + oxaliplatin

AVANT: eligibility criteria Histologically confirmed colon carcinoma Tumour classification according to AJCC/UICC  stage III  stage II (high-risk population) Potentially curative tumour resection within 28–56 days prior to starting treatment ECOG performance status  1 AJCC = American Joint Commission on Cancer UICC = International Union Against Cancer ECOG = Eastern Cooperative Oncology Group

AVANT: study description Primary endpoint: disease-free survival at 3 years for stage III  Statistical assumption: 80% power to demonstrate a 23% reduction in the hazard ratio (72.2% vs 77.8%)  2,880 stage III (960 per arm)  570 stage II for exploratory analysis  Recruitment period: 23 months, first patient included 21 December, 2004  Multicentre: ~350 centres planned in 36 countries First results expected in 2008 Study currently on hold for interim safety analysis

Other trials in the adjuvant setting NSABP = The National Surgical Adjuvant Breast and Bowel Project XELIRI = Xeloda + irinotecan

Avastin in the neoadjuvant setting The anti-angiogenic action of Avastin in preventing tumour growth and metastasis, and potential synergistic activity with radiotherapy, provides a strong rationale for use earlier in the treatment of CRC Avastin in the neoadjuvant setting may help reduce the size of the tumour, making it resectable Available data indicate that neoadjuvant therapy with Avastin is feasible 1 Several trials of Avastin in this setting are planned Willett CG, et al. Nat Med 2004;10:145–7

Neoadjuvant Avastin in patients with rectal cancer: phase I trial design Avastin 5mg/kg Avastin 5mg/kg + 5-FU + radiotherapy Patients with primary and non- metastatic rectal cancer Surgery 2 weeks 3 x 2-week cycles Willett CG, et al. Nat Med 2004;10:145–7 Assessment

Neoadjuvant Avastin in patients with rectal cancer: outcomes after Avastin treatment 12 days after Avastin administration tumour regression of >30% in one patient no change in tumour size in five patients Computed tomography (CT) scans (n=5) showed 40–44% decrease in tumour blood perfusion (n=4/5; p<0.05) 16–39% decrease in tumour blood volume (n=4/5; p<0.05) 25–59% reduction in tumour microvessel density (n=5/5; p<0.05) All patients underwent subsequent surgery without peri- or post-operative complications Willett CG, et al. Nat Med 2004;10:145–7

Changes in tumour vasculature following a single Avastin dose in patients with rectal cancer Blood flow (mL/min/100g tissue) PretreatmentDay 12 PS (mL/min/100g tissue) PretreatmentDay 12 Patient Willett CG, et al. Nat Med 2004;10:145–7 PS = permeability-surface area

Changes in tumour vasculature following a single Avastin dose in patients with rectal cancer (cont’d) Willett CG, et al. Nat Med 2004;10:145–7 Number of vessels per field Patient IFP (mmHg) PretreatmentDay 12 Patient IFP = interstitial fluid pressure

Trials of Avastin in the neoadjuvant setting EORTC = European Organisation for Research and Treatment of Cancer

Avastin plus targeted therapies

Rationale for combining anti-VEGF and anti-HER1/EGFR agents Both HER1/EGFR and VEGF are overexpressed in many tumours 1 VEGF has been implicated in resistance to anti-HER1/EGFR therapy Treatment with two agents targeting two different critical pathways may be more effective than a single one 2 Preclinical studies have shown that anti-VEGF and anti-HER1/EGFR therapies have at least additive effects 3 Clinical trials in various indications (RCC, 4 NSCLC, 5 HNSCC 6 ) have shown that the combination of Avastin ® and Tarceva TM is active 1 Viloria-Petit A, et al. Cancer Res 2001;61:5090–101; 2 Herbst RS, et al. Eur J Cancer Suppl 2003;1:S293; 3 Ciardiello F, et al. Clin Cancer Res 2000;6:3739–47; 4 Spigel DR, et al. J Clin Oncol 2005;23(June 1 Suppl.):387s (Abstract 4540); 5 Sandler AB, et al. J Clin Oncol 2004;22(July 15 Suppl.): Abstract 2000; 6 Vokes EE, et al. J Clin Oncol 2005;23(June 1 Suppl.):501s (Abstract 5504) HER = human epidermal growth factor receptor EGFR = epidermal growth factor receptor VEGF = vascular endothelial growth factor RCC = renal cell cancer NSCLC = non-small cell lung cancer HNSCC = head and neck squamous cell carcinoma

Experimental evidence for combined EGFR and VEGF inhibition Jung YD, et al. Eur J Cancer 2002;38:1133–40 Ciardiello F, et al. Clin Cancer Res 2000;6:3739–47 GEO colon cancer xenograft TMK-1 gastric cancer xenograft DC101: Anti-VEGF receptor MAb C225: Anti-EGFR MAb Tumour weight (kg) ControlDC101C225DC101/ C225 Control VEGF-AS MAbC225 Combination Control-AS Tumour volume (cm 3 ) Days MAb = monoclonal antibody

Clinical data to support dual VEGF and EGFR inhibition 1 Cunningham D, et al. N Engl J Med 2004;351:337–45 2 Saltz LB, et al. J Clin Oncol 2005;23(June 1 Suppl.):248s (Abstract 3508) Inter-trial analysis shows that Avastin plus cetuximab improves response rate and time to progression in previously treated metastatic CRC patients

Avastin with other anti-HER1/EGFR agents in CRC FOLFOX = 5-fluorouracil (5-FU)/leucovorin (LV) + oxaliplatin FOLFIRI = 5-FU/LV + irinotecan XELOX = Xeloda ® + oxaliplatin PFS = progression-free survival

Combinations with biological agents: summary Several agents targeting the VEGF pathway or EGFR have received regulatory approval or are in the late stages of clinical development for the treatment of various cancer types Evidence suggests that combined blockade of the two pathways may provide better efficacy than blocking either pathway alone

Avastin in multiple lines of treatment First line Avastin + IFL / FOLFIRI (XELIRI) Avastin + 5-FU/LV (Xeloda) Avastin + FOLFOX (XELOX) 5-FU/LV = 5-fluorouracil/leucovorin; IFL/FOLFIRI = irinotecan, 5-FU/LV; FOLFOX = 5-FU/LV + oxaliplatin; XELOX = Xeloda + oxaliplatin; XELIRI = Xeloda + irinotecan Second line FOLFOX ± Avastin FOLFIRI / FOLFOX ± Avastin FOLFIRI ± Avastin Cetuximab ± irinotecan Cetuximab ± irinotecan Cetuximab + irinotecan 5-FU/LV?Cetuximab Clinical trial

Conclusions Avastin is being evaluated in combination with all active chemotherapy regimens, such as FOLFIRI, XELIRI, FOLFOX and XELOX, to further optimise the treatment for metastatic CRC The potential of Avastin as an effective option in the (neo)adjuvant setting is being evaluated in phase III clinical trials Ongoing trials are examining the efficacy and safety of combining first-line Avastin with EGFR-targeted therapies in patients with metastatic CRC