Lew, Danika L.

521 Background: S0221 investigated weekly vs q 2 week dosing of doxorubicin/cyclophosphamide (AC) and paclitaxel (P) in patients (pts) with high risk early breast cancer as previously reported (JCO 33:58-64, 2015). After enrollment of 2716 pts randomization to the two AC arms was stopped for futility and an additional 578 pts received 4 cycles of q 2 week AC and were randomized to P weekly (Pw) or P q 2 weeks (P2). We report updated results of the original trial design and the first report of the 578 pts treated with AC x 4 and Pw x 12 or P2 x 6. Methods: Between December 2003 and November 2010, 2716 pts were randomized in a 2x2 factorial design to 1) 15 weeks of weekly AC (A 24 mg/m2/week and C 60 mg/m2/day po) vs 6 cycles of q 2 week AC (A 60 mg/m2 and C 600 mg/m2) and 2) Pw (paclitaxel 80 mg/m2/week x 12) vs P2 (paclitaxel 175 mg/m2 q 2 weeks x 6), with growth factor support as previously described. After study amendment 578 patients received 4 cycles of q 2 week AC followed by Pw or P2. Updated survival was assessed using log-rank tests and Cox regression models. Results: At a median follow-up of 8.5 years, among the pts treated in the original protocol, there were no significant differences among the four treatments for DFS (p=0.21) or OS (p=0.08). The triple-negative subset had worse DFS (P<0.001) than the HER2-positive or ER/PR+/HER2- subsets, with 5 year DFS of 75% vs 83% and 84%, respectively. While we previously found in the triple negative subset that the arm using q 2 weeks for both AC and paclitaxel was marginally superior, the differences among the arms are no longer significant for DFS (p=0.12) or OS (p=0.11). Among the 578 pts assigned ACx4 and randomized to Pw v P2 there were no overall differences in DFS (p=0.70) or OS (p=0.63) after 4.4 years median follow-up. Conclusions: There were no significant differences in DFS or OS between any of the schedules with extended follow-up in the original cohort and no difference in outcome by paclitaxel schedule for the 578 additional patients in the revised protocol. Either paclitaxel schedule may be recommended, with selection based on toxicity, cost, or patient preference rather than efficacy. Support: NCI grants CA32102, CA38926, CA21115, CA21076, CA77597, CA25224, CA77202, CCSRI15469, and Amgen, Inc. Clinical trial information: NCT00070564.

CRA1008 Background: S0221 is a SWOG-coordinated phase III adjuvant chemotherapy intergroup trial in node-positive and high-risk node-negative operable breast cancer which hypothesized that 1) the weekly AC+G regimen is superior to ddAC x 6 and 2) 12 weeks of weekly paclitaxel (wP) is superior to q 2 week paclitaxel x 6 (ddP). Methods: Between December 2003 and November 2010, 2,716 patients were randomized in a 2 x 2 factorial design to 1) AC+G vs ddAC and 2) P 80 mg/m2/week x 12 vs P 175 mg/m2 q 2 weeks x 6. If there was no significant interaction between the factors, the trial was powered to find a disease-free survival hazard ratio (HR) ≤ 0.82 for weekly vs q 2 week for each factor. At the first interim analysis, the AC randomization was halted for futility, and S0221 was closed to accrual 10 November 2010. S0221 reopened 15 December 2010, after which time all patients received 4 cycles of ddAC and randomization to P weekly x 12 and ddP x 6 continued. Accrual halted at a total of 3,294 in January 2012. Results: By September 7, 2012, 487 events and 340 deaths had occurred, prompting the third planned interim analysis. The Data Safety and Monitoring Committee recommended reporting the results since the futility boundary was crossed. A Cox model adjusting for the AC arms had a HR = 1.08 (95% CI 0.90-1.28; p=0.42), with the 99.5% CI excluding the original alternative hypothesis that the HR=0.82. There was no significant interaction of the two factors. Estimated 5-year progression-free survivals were 82% for weekly P and 81% for ddP. Toxicity data were available for 1,385 patients treated with ddP and 1,367 treated with weekly P. Grade 5 toxicity occurred in 4 patients on ddP and 2 on weekly P. Percent grade 3-4 toxicity per arm are shown in the Table. Conclusions: Either ddPx6 or weekly P x 12 are acceptable schedules of P administration. The differences in leukopenia likely reflect ascertainment bias against weekly P. If this is accepted, weekly P x 12 produces less overall toxicity than 6 cycles of ddP. Support: NCI grants CA32102, CA38926, CA21115, CA21076, CA77597, CA25224, CA77202, CCSRI15469, and Amgen, Inc. Clinical trial information: NCT00070564. [Table: see text]

Abstract Background. Locally advanced breast cancer (LABC) and inflammatory breast cancer (IBC) remain difficult challenges despite progress in multimodality treatment. The SWOG trial S0800 (clinicaltrial.gov NCT00856492) compared bevacizumab in combination with weekly nab-paclitaxel followed by dose-dense AC to nab-paclitaxel followed or preceded by AC as neoadjuvant treatment for HER2-negative IBC/LABC. The rationale was based on the proposed role of angiogenesis, potential role of improved flow and oxygenation in enhancing the delivery of chemotherapy agents, and the proapoptotic effect with certain chemotherapeutic agents, particularly taxanes. Methods. This was a randomized open-label Phase II trial with an accrual goal of 200 patients equally allocated to either bevacizumab (Arm 1) or no bevacizumab.Two patients were ineligible and five withdrew consent leaving 208 for analysis. The no bevacizumab group was further randomized to two sequences (Arm 2: nab-paclitaxel - AC+PEG-G versus Arm 3: AC+PEG-G- nab-paclitaxel) with 50 patients expected in each sequence. The primary endpoint of this study was pathologic complete response (pCR) defined as no evidence of invasive tumor at the primary site and axillary lymph nodes in the surgical specimen. The power for the primary comparison of bevacizumab (bev) versus no bevacizumab (no bev) ignoring sequence was 80% with a 1-sided α = 0.10. Randomization was stratified by hormone receptor status and type of disease (IBC or LABC). Results 215 patients were accrued May 2010 - September 2012. Most had LABC (88%) versus IBC (12%) and most tumors were hormone-receptor (HR) positive (67%). Fourteen (7%) patients had no definitive surgery (included as no pCR); 135 (65%) had residual disease (no pCR) and 59 (28%) had pCR. The bevacizumab pCR rate was higher (35/96; 38%) than that in the non-bevacizumab arms (24/112; 21%) (exact p=0.021; stratified p=0.015). In HR-positive disease there was slight improvement that was not statistically significant (bev 25% vs. non-bev 18%; p=0.41) while the difference was larger in HR-negative disease (bev 59% vs. non-bev 28%; p=0.014). In LABC the overall pCR rate was 29% with a higher rate in the bevacizumab patients (37% vs. 22%; p=0.035). For IBC there was improvement (30% vs. 14%), but not statistically significant (p=0.61) in a small sample. Overall, Grade 3 and 4 events were common in both (bev 67%; non-bev 65%), but did not differ by treatment. There were 21 deaths with 3-year overall survival (OS) of 87% and 83% for bevacizumab and non-bevacizumab, respectively (log-rank p=0.57). Conclusion Compared with combination anthracycline-taxane neoadjuvant chemotherapy, the Bev-Nab-paclitaxel-AC regimen significantly improved pCR rate overall, primarily for triple negative (TNBC) patients. This neoadjuvant regimen could be a good choice for TNBC/IBC . The observed pCR rate in ER negative disease (59%) suggests that the addition of bevacizumab to a standard chemotherapy backbone may improve outcome in this subset, and justifies further testing of such an approach. Correlative science studies to further delineate the biology of TNBC and the effects of bevacizumab are ongoing. Citation Format: Zeina A Nahleh, William E Barlow, Daniel F Hayes, Anne F Schott, Julie R Gralow, Edith A Perez, William M Sikov, Sudhathi Chennuru, Hamid Mirshahidi, Sarah Vidito, Danika L Lew, Lajos Pusztai, Robert B Livingston, Gabriel N Hortobagyi. S0800: Nab-paclitaxel, doxorubicin, cyclophosphamide, and pegfilgrastim with or without bevacizumab in treating women with inflammatory or locally advanced breast cancer (NCI CDR0000636131) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-11-16.

Purpose To determine the optimal dose and schedule of anthracycline and taxane administration as adjuvant therapy for early-stage breast cancer. Patients and Methods A 2 × 2 factorial design was used to test two hypotheses: (1) that a novel continuous schedule of doxorubicin-cyclophosphamide was superior to six cycles of doxorubicin-cyclophosphamide once every 2 weeks and (2) that paclitaxel once per week was superior to six cycles of paclitaxel once every 2 weeks in patients with node-positive or high-risk node-negative early-stage breast cancer. With 3,250 patients, a disease-free survival (DFS) hazard ratio of 0.82 for each randomization could be detected with 90% power with two-sided α = .05. Overall survival (OS) was a secondary outcome. Results Interim analyses crossed the futility boundaries for demonstrating superiority of both once-per-week regimens and once-every-2-weeks regimens. After a median follow-up of 6 years, a significant interaction developed between the two randomization factors (DFS P = .024; OS P = .010) in the 2,716 patients randomly assigned in the original design, which precluded interpretation of the two factors separately. Comparing all four arms showed a significant difference in OS (P = .040) but not in DFS (P = .11), with all treatments given once every 2 weeks associated with the highest OS. This difference in OS seemed confined to patients with hormone receptor–negative/human epidermal growth factor receptor 2 (HER2) –negative tumors (P = .067), with no differences seen with hormone receptor–positive/HER2-negative (P = .90) or HER2-positive tumors (P = .40). Conclusion Patients achieved a similar DFS with any of these regimens. Subset analysis suggests the hypothesis that once-every-2-weeks dosing may be best for patients with hormone receptor–negative/HER2-negative tumors.

Purpose Patients with inflammatory breast cancer (IBC) or locally advanced breast cancer (LABC) were randomly assigned to 21-day doxorubicin and cyclophosphamide administered for five cycles (standard arm) versus weekly doxorubicin and daily oral cyclophosphamide administered with granulocyte colony-stimulating factor support for 15 weeks (continuous arm). All patients had subsequent weekly paclitaxel for 12 weeks before surgery. Patients and Methods Patients (n = 372) were randomly assigned to the standard arm (n = 186) or the continuous arm (n = 186) stratified by disease type (LABC, n = 256; IBC, n = 116). The primary outcome was microscopic pathologic complete response (pCR) at surgery. Secondary outcomes included disease-free survival, overall survival, and toxicity. Results More patients in the standard arm had grade 3 to 4 leukopenia and neutropenia, but there were more instances of stomatitis/pharyngitis and hand-foot skin reaction in the continuous arm. Assessed among 356 eligible patients, pCR was not different between the treatment groups stratified by disease type (P = .42). In subset analysis, higher pCR rates were observed in the continuous arm versus the standard arm only for stage IIIB disease (P = .0057) and in IBC (P = .06). Comparison of overall survival and disease-free survival showed no difference between treatment groups (P = .37 and P = .87, respectively). Conclusion No significant clinical benefit was seen for the investigational arm in this trial overall.

Purpose Southwest Oncology Group (SWOG)/Intergroup study 9623 was undertaken to compare treatment with an anthracycline-based adjuvant chemotherapy regimen followed by high-dose chemotherapy (HDC) with autologous hematopoietic progenitor cell support (AHPCS) with a modern dose-dense dose-escalated (nonstandard) regimen including both an anthracycline and a taxane. Patients and Methods Participants in this phase III randomized study had operable breast cancer involving four or more axillary lymph nodes and had completed mastectomy or breast-conserving surgery. Patients were randomly assigned to receive four cycles of doxorubicin and cyclophosphamide followed by HDC with AHPCS or to receive sequential dose-dense and dose-escalated chemotherapy with doxorubicin, paclitaxel, and cyclophosphamide. The primary end point of this study was disease-free survival (DFS). Results Among 536 eligible patients, there was no significant difference between the two arms for DFS or overall survival (OS). Estimated five-year DFS was 80% (95% CI, 76% to 85%) for dose-dense therapy and 75% (95% CI, 69% to 80%) for transplantation. Estimated 5-year OS was 88% (95% CI, 84% to 92%) for dose-dense therapy and 84% (95% CI, 79% to 88%) for transplantation. Conclusion There is no evidence that transplantation was superior to dose-dense dose-escalated therapy. Transplantation was associated with an increase in toxicity and a possibly inferior outcome, although the hazard ratios were not significantly different from 1.

Purpose We conducted a phase III randomized study of two adjuvant treatment schedules of doxorubicin (A) and cyclophosphamide (C) in early-stage breast cancer to determine if administration of sequential single agents (A → C) results in superior disease-free survival (DFS) and overall survival (OS) versus the same total dose given in combination (AC). Patients and Methods High-risk node-negative or low-risk node-positive breast cancer patients received AC given: (arm I) concurrently (AC) doxorubicin 54 mg/m2 and cyclophosphamide 1.2 g/m2 intravenously (IV) every 3 weeks for six cycles; or (arm II) in sequence (A → C) doxorubicin 40.5 mg/m2 IV days 1 and 2 every 3 weeks for four cyles followed by cyclophosphamide 2.4 gm/m2 IV every 2 weeks for three cycles. Total dose and duration were identical, but the intensity of each drug was increased on A → C. Both arms included granulocyte colony-stimulating factor support and prophylactic antibiotics. All but premenopausal women with receptor negative tumors received tamoxifen after chemotherapy. Results Between 1994 and 1997, 3,176 patients were randomly assigned. Arms were well balanced; 48% of eligible patients were node-negative and 48% were estrogen receptor–positive. No significant differences in OS or DFS were observed; 5-year estimates of OS (95% CI) were 88% (87% to 90%) on AC and 89% (87% to 91%) on A → C. Grade 4 hematologic toxicity was greater on A → C, but nonhematological grade 4 was similar. Conclusion The overall result does not support superiority of dose-intense sequenced single agents. The greater toxicity of higher doses of single agents does not support their sequential use.