Capecitabine versus 5-fluorouracil-based (neo-)adjuvant chemo-radiotherapy for locally advanced rectal cancer: Long term results of a randomized phase III trial R. Hofheinz, F. Wenz, S. Post, A. Matzdorff, S. Laechelt, J. Hartmann, L. Müller, H. Link, M. H. Moehler, E. Kettner, E. Fritz, U. Hieber, H. W. Lindemann, M. Grunewald, S. Kremers, C. Constantin, M. Hipp, D. Gencer, I. Burkholder, A. Hochhaus, on behalf of the German MARGIT study group

Background Capecitabine (Cape), an oral fluoropyrimidine derivative, has been shown to be equieffective with 5-fluorouracil (5-FU) / leucovorin in the adjuvant treatment of stage III colon cancer. [Twelves et al. N Engl J Med 2005] Cape was non-inferior to infusional 5-FU in combination with oxaliplatin as first-line treatment for metastatic colorectal cancer. [Cassidy et al. J Clin Oncol 2008] Cape has radiosensitizing properties. Several phase I and II trials investigated combined modality treatment using Cape in the perioperative treatment of rectal cancer. [e.g. Dunst et al. J Clin Oncol 2002] The present phase-III trial sought to compare Cape with 5-FU in the perioperative treatment of locally advanced rectal cancer.

Study design Primary aim To determine whether 5-year overall survival rate (SR5) was non-inferior in arm A (Cape) vs. arm B (5-FU) with non-inferior margin of 12.5%. Assumption: SR5 5-FU = 57.5%. Sample size calculation performed with β = 20%, α = 5% and a drop-out rate of 5%. Study was designed as a two-arm, two-strata multicenter, randomized, open phase III trial. N = 372 evaluable patients (186 per arm) required to evaluate non-inferiority with a follow-up time of 4 years.

Main inclusion & exclusion criteria Patients ≥18 years Histologically proven rectal cancer (0 – 16 cm ab ano) No distant metastases Adequate hematological parameters: Leukocytes > 3,500/µl, thrombocytes > 100,000/µl, hemoglobin > 10g/dl. Adequate liver & renal function Patients treated in adjuvant stratum Total mesorectal resection performed (R0-resection) Tumor stages pT3/4 N any M0 or pT any N+ M0 Patients treated in neoadjuvant stratum uT3/4 uN any M0 or uT any uN+ M0 (staging with EUS) Total mesorectal excision mandatory

Treatment regimen Arm AChemoradiotherapy 50.4 Gy + Cape 1,650 mg/m² days 1 – 38 plus 5 cycles of Cape 2,500 mg/m² d 1 – 14, rep. d 22 S I: 2 x Cape  CRT  3 x Cape S II: CRT  TME surgery (4 – 6 weeks after CRT)  Cape x 5 Arm BChemoradiotherapy 50.4 Gy + 5-FU 225 mg/m² c.i. daily [S I] or 5-FU 1,000 mg/m² c.i. d 1 – 5 and 29 – 33 [S II] plus 4 cycles of bolus 5-FU 500mg/m² d 1 – 5, rep. d 29 S I: 2 x 5-FU  CRT  2 x 5-FU S II: CRT  TME surgery (4 – 6 weeks after CRT)  5-FU x 4 Cape: capecitabine; CRT: chemoradiotherapy; TME: total mesorectal excision; 5-FU: 5-fluorouracil

Treatment regimen Adjuvant stratum S I Arm A Arm B Radiotherapy 50.4 Gy Capecitabine 2,500mg/m²/day (during radiotherapy 1,650mg/m²/day) Week 5-FU 500mg/m² day 1 – 5 (during radiotherapy 225 mg/m²/day) Radiotherapy 50.4 Gy

Treatment regimen Neodjuvant stratum S I Arm A Arm B Week 1020 Surgery Capecitabine 2,500mg/m²/day (during radiotherapy 1,650mg/m²/day) 5-FU 500mg/m² day 1 – 5 (during radiotherapy 1000 mg/m² d 1 – 5, d 29 – 33) Radiotherapy 50.4Gy

Patients recruitment (n = 392) 2007

Baseline characteristics Capecitabine n = FU n = 195 Age, years Median (Range)64.6 (29.6 – 84.8)64.0 (32.8 – 86.3) Gender, n (%) Male Female 129 (65.5) 68 (34.5) 131 (67.2) 64 (32.8) Stratum, n (%) Adjuvant Neoadjuvant 116 (58.9) 81 (41.1) 115 (59.0) 80 (41.0) Tumor category (cT or pT), n (%) T1 or T2 T3 T4 Missing data 29 (14.7) 150 (76.1) 15 (7.7) 3 (1.5) 36 (18.5) 140 (71.8) 14 (7.2) 5 (2.6) Nodal category (cN or pN), n (%) Node negative Node positive Missing data 78 (39.6) 112 (56.9) 7 (3.6) 69 (35.4) 120 (61.5) 6 (3.1)

Adjuvant stratum – % of patients receiving schedules cycles

Neoadjuvant stratum – % of patients receiving schedules cycles

Hematological and liver toxicity – NCI-CTC grades (v. 2.0) Capecitabine n = FU n = 195 p-value² Total 1 1/23/4Total 1 1/23/4 Hemoglobin6258– Leukocytes Platelets23 – GGT55–76–0.57 Bilirubin CTC-grade is missing in some pts. 2 p-value resulted from Chi-Square test comparing the total number of events between both treatment arms.

Gastrointestinal Toxicity – NCI-CTC grades (v. 2.0) Capecitabine n = FU n = 195 p-value² Total 1 1/23/4Total 1 1/23/4 Nausea –0.69 Vomiting Diarrhea Mucositis Stomatitis88–1211–0.37 Abdominal pain –0.17 Proctitis < CTC-grade is missing in some pts. 2 p-value resulted from Chi-Square test comparing the total number of events between both treatment arms.

Diarrhea – NCI-CTC grades (v. 2.0) Capecitabine n = FU n = 195 p-value Diarrhea Capecitabine n = FU n = 195 p-value Diarrhea8862< Cycles without radiotherapy Cycles with radiotherapy (Cycle 3 in adjuvant strata & cycle 1 in neoadjuvant strata )

Other Toxicity – NCI-CTC grades (v. 2.0) Capecitabine n = FU n = 195 p-value² Total 1 1/23/4Total 1 1/23/4 Fatigue5550– Anorexia13 – Alopecia44–1110–0.07 Hand-foot skin reaction –< Radiation dermatitis Thrombosis / Embolism CTC-grade is missing in some pts. 2 p-value resulted from Chi-Square test comparing the total number of events between both treatment arms.

Neoadjuvant stratum – CONSORT diagram Informed consent withdrawn, n = 1 Refused port implantation, n = 1 Protocol violation (sigma CA), n = 1 Primary resection, n = 2 No start (worsening renal function), n = 1 No surgery (refusal, n = 2; PD, n = 1) Deep anterior resection, n = 58 Abdominoperineal resection, n = 16 Not resectable, n = 1 No surgery (pCR n = 1, PD n = 1) Died during RChT (accident, n = 1; heart attack, n = 1) Deep anterior resection, n = 53 Abdominoperineal resection, n = 19 Local excision, n = 1 Randomized n = 161 Capecitabine, n = 815-Fluorouracil, n = 80 Commenced RChT, n = 78Commenced RChT, n = 77 Surgery, n = 75 Died ≤ 30 days post surgery, n = 3 Surgery, n = 73 Died ≤ 30 days post surgery, n = 1

Neoadjuvant stratum Comparison Arm A & Arm B Capecitabine5-FU p-value (  ² test) Type of resection, % Deep anterior Abdominoperineal Local excision n = n = p = 0.56 Resection status, % R0 R1/R2 Unknown n = n = p = 1.00 ypT- status, % ypT 0 ypN 0 (pCR) ypT 0 – 2 ypT 3 – 4 n = n = p = 0.16 p = 0.07 pCR: pathological complete remission

Neoadjuvant stratum Comparison Arm A & Arm B Capecitabine5-FU Clinical stagingPathohistologyClinical stagingPathohistology T status 0, 1, 2 3, 4 n = % 91.2% n = % 44.6% n = % 94.7% n = % 60.8% N status 0, X 1, 2, 3 n = % 52.0% n = % 28.8% n = % 48.0% n = % 43.2%

Neoadjuvant stratum – Trend of improved downstaging with Capecitabine Patients receiving capecitabine exhibited less ypN-positive tumors (p = 0.09) improved T-downstaging (i.e. ypT0 – 2) (p = 0.07) more pCR (ypT0 ypN0): 13.2 % vs. 5.4% (p = 0.16) Comparison (  ² test) Clinical stagingPathohistology T statusp = 0.5p = 0.07 N statusp = 0.7p = 0.09

Disease related events Localization of recurrence and death Capecitabine n = FU n = 195 p-value  ² test Local recurrence12 (6.1)14 (7.2)p = Distant metastases37 (18.8)54 (27.7)p = Deaths, n (%) Disease related Other causes Unknown 38 (19.3) 26 (13.2) 12 (6.1) 0 55 (28.2) 37 (19.0) 15 (7.7) 3 (1.5) p =

Disease free survival (DFS) Secondary endpoint (Median Follow-up 52 mon.)

Overall survival (OS) Primary endpoint (Median Follow-up 52 mon.)

Hand-foot skin reaction (HFS) and survival Comparison of 3-y DFS and 5-y OS Capecitabine Any grade HFS n = 62 Capecitabine No HFS n = FU All patients n = y DFS83.2% %66.6% 95%-CI (%)71.0 – – – y OS91.4% %66.6% 95%-CI (%)80.5 – – – Test for superiority: p = versus Cape no-HFS (n = 135) & p = versus remaining population (n = 330) 2 Test for superiority: p = versus Cape no-HFS (n = 135) & p < versus remaining population (n = 330)

Conclusions Both treatment regimens were well tolerated. Cape patients had more all grade HFS, proctitis, diarrhea and fatigue, while alopecia and leukopenia were more frequently observed with 5-FU. In the neo-adjuvant stratum Cape led by trend to improved downstaging and a numerical higher rate of pCR. Cape was non-inferior to 5-FU regarding 5-year survival. –Exploratory test for superiority was borderline significant. 3-year DFS was significantly better with Cape. HFS indicated superior 3-year DFS and 5-year OS. Capecitabine may replace 5-FU in the perioperative treatment of locally advanced rectal cancer.