Riccardo Giampieri Scuola di Specializzazione Oncologia Università Politecnica delle Marche Ancona How to manage patients with mutated KRAS tumors

Hot-spot point mutations within codons 12 or 13 of the KRAS gene  constitutively active KRAS protein Constitutively active KRAS protein  cancer cell growth and survival through the RAF-MEK-ERK and PI3K-AKT pathways independently from EGFR signaling K-ras mutation

A controversial starting point… Patient harbouring K-ras mutated tumors: Easy patient! Difficult patient! ?

Why easy patient? -We know what DO NOT give to this patient -We know what CAN be given to this patient -Treatment sequence is almost always set without difficulties

What DO NOT give: preclinical data -Anti-EGFR monoclonal antibodies + DiFi colon cancer cell lines + k-ras mutation or not Benvenuti et al. Cancer Res 2007

Moroni Lancet Oncol 2005 n=31 Lièvre Clin Cancer Res 2006 n=30 Di Fiore Br J Cancer 2007 n=59 Frattini Br J Cancer 2007 n=27 Benvenuti Cancer Res 2007 n=48 Khambata-Ford J Clin Oncol 2007 n=80 De Roock ASCO Proc 2007 n=37 Finocchiaro ASCO Proc 2007 n=81 Response rate: analysis of 8 studies available in PubMed or from ASCO Proceedings: Responders (n=82) wt (93.0%) RAS mutated (7.0%) wt (56.1%) RAS mutated (43.9%) Non-Responders (n=312) p = (Fisher’s exact test) Pre-treated patients and response rate differencies

FOLFOX FOLFOX+Cetuximab 168 pts 169 pts RR (%) p=0.06 Kras status PFS (mo.) RR (%) C+Ffox Ffox C+Ffox Ffox Wt Mutated Bokemeyer C, ASCO 2008 First line: OPUS trial (randomized phase II) Bokemeyer C. ASCO 2008, J Clin Oncol 2009; 27(5)

OPUS trial k-ras mutant population: response rates FOLFOX N=47 ERBITUX + FOLFOX N=52 CR4.3%0% PR44.7%32.7% SD36.2%51.9% PD10.6%13.5% NE4.3%1.9% RR48.9%32.7% 95% CI (exact) [34.1%, 63.9%] [20.3%, 47.1%] ERBITUX + FOLFOX FOLFOX p=0.106 Odds Ratio = (95% CI: –1.150) Response rate (%) No benefit for Erbitux p = 0.106

Stratification by: –Region –ECOG PS FOLFIRI Irinotecan (180 mg/m 2 ) + 5-FU (400 mg/m 2 bolus mg/m 2 as 46-h continuous infusion) + LV (every 2 weeks) Cetuximab + FOLFIRI Cetuximab (IV 400 mg/m 2 on day 1, then 250 mg/m 2 weekly) + irinotecan (180 mg/m 2 ) + 5-FU (400 mg/m 2 bolus mg/m 2 as 46-h continuous infusion) + LV (every 2 weeks) R EGFR-detectable mCRC Primary endpoint –Progression-free survival time (as assessed by blinded independent review) Secondary endpoints –ORR (independent review) –OS –Quality of life (EORTC QLQ-C30) –Safety First line: CRYSTAL trial (phase III)

[14.4–20.6] [15.6–20.2] 1.03 [0.74–1.44] 0.85 KRAS wild-type FOLFIRI (n=176) Cetuximab + FOLFIRI (n=172) FOLFIRI (n=87) Cetuximab + FOLFIRI (n=105) KRAS mutant Parameter Median OS [95% CI] Hazard ratio [95% CI] P-value ITT FOLFIRI (n=599) Cetuximab + FOLFIRI (n=599) [16.6–19.8] [18.5–21.3] 0.93 [0.81–1.07] 0.30 Median follow up time: 30 months [19.2–25.7] [22.2–27.8] 0.84 [0.64–1.11] 0.22 Overall survival analysis based on K-ras status

Overall survival analysis based on K-ras status

Continuous* XELOX or FOLFOX Arm A R First-line mCRC (n= 2,445) Arm B Continuous XELOX or FOLFOX + cetuximab Arm C Intermittent ‡ XELOX or FOLFOX *Treatment until disease progression or unacceptable toxicity ‡ Stop and Go treatment (12 weeks then restart at progression) MRC Sponsored study supported by Merck 109 UK and Irish Hospitals 65% XELOX; 35% FOLFOX (patient/physician choice) Maughan, et al. ESMO 2009 First line: COIN trial (phase III)

Maughan, et al. ESMO 2009 COIN trial: response rates based on K-ras status All patientsKRAS wild-typeKRAS mutant FOLFOX /XELOX (n=815) Cetuximab + FOLFOX /XELOX (n=815) FOLFOX /XELOX (n=367) Cetuximab + FOLFOX /XELOX (n=362) FOLFOX /XELOX (n=268) Cetuximab + FOLFOX /XELOX (n=297) ORR at 12 weeks (%) Odds ratio1.17 (p=0.124)1.44 (p=0.015)0.97 (p=0.877) Best overall response (%) Odds ratio1.08 (p=0.428)OR=1.35 (p=0.049)OR=0.88 (p=0.449)

The 045 Phase I: Study Design FOLFIRI: irinotecan 180 mg/m 2 over 30–90 min; FA 400 mg/m 2 over 2 hours; 5-fluorouracil 200 mg/m 2 as bolus and 2400 mg/m 2 over 46 hours given every 2 weeks CONTROL ARM (GROUP A) 10-patient cohort ERBITUX (400 mg/m 2 on day 1, then 250 mg/m 2 weekly) EXPERIMENTAL ARM (GROUP B) 10-patient cohorts ERBITUX at escalating doses for successive cohorts: 400, 500, 600, 700 mg/m 2 once every second week 6 weeks’ treatment Complete PK profile obtained during this period FOLFIRI added to patients’ current ERBITUX regimen Evaluate best overall response Progression-free survival PART I PART II 1º endpoint DLT assessment 2º endpoints Tabernero et al. ASCO GI 2008 (Abstract No. 435) Study AIO 045 Maybe it is dose related…

KRAS status MonotherapyCombination therapy Wild-type n=29 Mutation n=19 Wild-type n=29 Mutation n=19 RR, n (%) [95% CI] 8 (27.6) [12.7–47.2] 0 (0) [0–17.7] 16 (55.2) [35.7–73.6] 6 (31.6) [12.6–56.6] p=0.015p=0.144 Median PFS, months [95% CI] —— 9.4 [7.0–11.3] 5.6 [3.3–12.2] HR: 0.47, p= KRAS mutations were detected in 19 samples (40%) of KRAS evaluable population Tabernero J, et al. ASCO GI 2008 (Abstract No. 435) … Of course not

Panitumumab anyone?

KRAS wild-type Amado et al. J Clin Oncol 2008;26 Panitumumab single agent Amado RG, et al. J Clin Oncol 2008;26:

181 Trial (PFS) (2°line FOLFIRI+/-panitumumab) Peeters et al. J Clin Oncol 2010

181 Trial (OS) Peeters et al. J Clin Oncol 2010

PRIME trial (PFS) (1°line FOLFOX+/-Panitumumab) Douillard et al. J Clin Oncol 2010

PRIME trial (OS) Douillard et al. J Clin Oncol 2010

So, we can’t give THAT… But WHAT can we give?

Bevacizumab: IFL+/- Bevacizumab and K-ras status (PFS) Hurwitz et al. The Oncologist Duration of PFS (Months) Proportion Progression-Free Duration of PFS (Months) Proportion Progression-Free Group: Mutant (n = 78)Group: Wild-type (n = 152) Median PFS (mo) IFL + placebo 5.5 IFL + BV 9.3 Median PFS (mo) IFL + placebo 7.4 IFL + BV 13.5 HR :0.44; P <.0001HR: 0.41; P =.0008

Bevacizumab: IFL+/- Bevacizumab and K-ras status (OS) Hurwitz et al. The Oncologist Duration of Survival (Months) Proportion Surviving Group: Mutant (n = 78)Group: Wild-type (n = 152) Duration of Survival (Months) Proportion Surviving Median OS (mo) IFL + placebo 13.6 IFL + BV 19.9 Median OS (mo) IFL + placebo 17.6 IFL + BV 27.7 HR: 0.58; P =.04HR: 0.69; P =.26

Primary endpoint –6-month PFS Secondary endpoints –OS, PFS, toxicity, secondary resection of liver or lung metastases Reinacher-Schick, et al. ESMO 2010 (Abstract 584PD) R = randomisation; WT = wild-type; MT = mutant Bevacizumab + CAPIRI (n=120) [KRAS WT=44; KRAS MT=21] Bevacizumab + CAPOX (n=127) [KRAS WT=56; KRAS MT=21] Previously untreated mCRC (n=247) R AIO 0604 study: design of the trial

Reinacher-Schick, et al. ESMO 2010 (Abstract 584PD) AIO 0604 study: CAPIRI arm

Reinacher-Schick, et al. ESMO 2010 (Abstract 584PD) AIO 0604 study: CAPOX arm

Masi, et al. Lancet Oncology 2010 Avastin 5 mg/kg Irinotecan 165 mg/m 2 Oxaliplatin 85 mg/m 2 L-LV 200 mg/m 2 5-FU continuous infusion 3200 mg/m 2 Day 1Days 2–3 Cycles repeated every 2 weeks for 12 cycles followed by maintenance Avastin until PD FOIB study: design

K-ras a B-raf b WT (n=34) MT (n=21) WT (n=45) MT (n=10) Responders, n (%)28 (82)15 (71)34 (75)9 (90) Non-responders, n (%) 6 (18)6 (29)11 (25)1 (10) a Responders vs non-responders: p=0.503 (Fischer’s exact test) b Responders vs non-responders: p=0.430(Fischer’s exact test) Masi et al. Lancet Oncology 2010 FOIB study: retrospective analysis on K-ras status, RR

Masi et al. Lancet Oncology 2010 Time (months) Progression-free (%) K-ras WT: median PFS: 13.4 months K-ras MT: median PFS: 12.6 months Log-rank test: p=0.433 HR= % CI: 0.38–1.51 FOIB study: retrospective analysis on K-ras status, PFS

Possible 1°line therapeutic options –Bevacizumab+FOLFOX (XELOX) –Bevacizumab+FOLFIRI (XELIRI) –FOLFOXIRI To sum up…

So… Where is the “Difficult” part?

Starting in a “knee-deep in trouble” situation… K-ras is not only a PREDICTIVE factor… It is also a PROGNOSTIC factor Of a WORSE prognosis

K-ras prognostic: RASCAL

CRYSTAL study OS: K-ras also prognostic?

K-ras mutated: a name fits all? 7 more frequent mutations >98% Rare mutations 2% The only mutation with prognostic value? RASCAL II Br J Cancer 2001

The G13D case: someone begs to differ…

So… not every Kras mutated tumor doesn’t respond to anti-EGFR…?

NORDIC VII: trial design

NORDIC VII: PFS according to K-ras status

NORDIC VII: OS according K-ras status

Cetuximab + FOLFIRI Cetuximab + FOLFOX4 Cetuximab + FOLFIRI Cetuximab + OxFp Cetuximab + FOLFOX 6 or FOLFIRI Cetuximab + FOLFIRI Cetuximab + FOLFOX 6 Cetuximab + capecitabine Cetuximab (continuous) + FLOX Cetuximab + capecitabine + oxaliplatin + bevacizumab Difference (wt-mt) Response Rate NORDIC VII: Comparison with other studies (OS)

Cetuximab + FOLFIRI Cetuximab + FOLFOX4 Cetuximab + FOLFIRI Cetuximab + OxFp Cetuximab + FOLFIRI Cetuximab + FOLFOX 6 Cetuximab + capecitabine Cetuximab (continuous) + FLOX Cetuximab + capecitabine + oxaliplatin + bevacizumab Difference (wt-mt) PFS NORDIC VII: Comparison with other studies (PFS)

CAPIRI + cetuximab (n=93) CAPOX + cetuximab (n=92) Previously untreated mCRC (n=185) R Stintzing, et al. ESMO 2010 (Abstract 582PD) Primary endpoint –response rate Secondary endpoints –TTP, disease control rate, tolerability AIO KRK-0204: CAPIRI/CAPOX+Cetuximab

CAPOX + cetuximab and CAPIRI + cetuximab are feasible, with acceptable toxicity profiles Both regimens are effective, with comparable efficacy KRAS status did not influence ORR KRAS WT patients showed only a trend towards longer OS and PFS vs KRAS MT patients Stintzing, et al. ESMO 2010 (Abstract 582PD) AIO KRK-0204: Conclusions

What is then the MOST predictive factor for anti-EGFR efficacy?

Douillard, et al. ASCO 2010 PRIME trial: efficacy by SKIN TOXICITY

Thanks for the attention…