Abstract P1-12-06: UCBG intergroup: 3-years efficacy results of the Unicancer-PACS08 trial including poor prognosis patients treated with docetaxel or ixabepilone in adjuvant setting
Abstract Background: Ixabepilone, an epothilone B analog, has demonstrated single-agent activity in metastatic and neoadjuvant settings. The PACS08 trial aimed to compare adjuvant FEC100-Docetaxel regimen to FEC100-Ixabepilone in poor prognosis early breast cancer (BC) composed of patients presenting with triple-negative (TN) [i.e. estrogen receptor (ER)-/progesterone receptor (PR)-/HER2-] or ER+/PR-/HER2- tumor, which are subgroups significantly associated with worse prognosis. Patients and methods: Between 2007 and 2010, 762 patients with unilateral TNBC (n=592, 78%) or node-positive ER+/PR-/HER2- BC (n=170, 22%) were enrolled. Recruitment was interrupted due to BMS decision to stop ixabepilone development in adjuvant setting. Main inclusion criteria were: age<70 years, normal cardiac, hepatic, haematological and renal functions. Arm A: pts received 3 cycles of FEC100 (F and C, each at 500 mg/m2, E 100 mg/m2, every 3 weeks) followed by 3 cycles of Docetaxel (100 mg/m2 every 3 weeks); Arm B, Ixabepilone 40 mg/m2 replaced Docetaxel. Radiotherapy was mandatory after conservative surgery and endocrine therapy was given to ER+ pts. ER, PR and HER2 status were validated by a central pathology review on 754 cases and Immunohistochemical detection of Ki67, EGFR, cytokeratins (CK) 5/6 and 14, was performed on tissue microarray (TMA). Results: Main pts characteristics were well balanced between the 2 arms. As of September 2014, the median follow-up was 36 months. The safety profile indicates that Docetaxel is more often associated to significant haematological toxicities whereas both neurotoxicities and haematological toxicities are reported in Ixabepilone arm. Log-Rank tests indicate no difference between two arms in terms of both DFS and OS (HR=1.2, 95%CI (0.864-1.728), p=0.256 and HR=1.8, 95%CI (0.751-1.855), p=0.473, respectively). Pathological analysis of the PACS08 collection showed that TNBC displayed significantly higher proliferative activity as shown by mitotic count and Ki67 index (p<0.001). As compared to ER+/PR-/HER2- subgroup, TNBC showed distinct characteristics, and displayed a so-called basal-like phenotype in 80%. Further efficacy analyses are ongoing in order to study whether chemotherapy may have better prognosis according to pathological characteristics including tumor lymphocytic infiltrate. These additional data will be available for the SABCS2015 meeting. Conclusions: Our results indicate that Ixabepilone doesn't show higher efficiency compared to Docetaxel in adjuvant setting in poor prognosis early breast cancer. We have an unusual biological collection associated to our clinical data which will allow us to correlate efficacy data to breast cancer subgroups. Other several translational researches are still ongoing. Citation Format: Campone M, Lacroix-Triki M, Roca L, Spielmann M, Wildiers H, Cottu P, Kerbrat P, Levy C, Mayer F, Bachelot T, Wiston T, Eymard J-C, Uwer L, Machiels J-P, Verhoeven D, Jaubert D, Facchini T, Orfeuvre H, Canon J-L, Asselain B, Lemonnier J, Roché H. UCBG intergroup: 3-years efficacy results of the Unicancer-PACS08 trial including poor prognosis patients treated with docetaxel or ixabepilone in adjuvant setting. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-06.
P5-18-04: Safety Profile of Ixabepilone as Adjuvant Treatment for Poor Prognosis Early Breast Cancer: First Results of the Unicancer-PACS 08 Trial.
Abstract Purpose: PACS 01 trial demonstrated that the sequential adjuvant chemotherapy with FEC100 followed by docetaxel (D) significantly improves disease-free and overall survival in node-positive(N+) early breast cancer (BC). However, Triple negative (TN) and ER+/ PR-/HER2− subgroups are significantly associated to a worse prognosis even after adjunction of D. As Ixabepilone (Ixa) has notable preclinical and clinical activity in these subgroups, the PACS 08 trial aims to compare standard FEC100-D regimen to 3 cycles of FEC100 followed by 3 cycles of Ixa. We report the preliminary results of the toxicity profile. Patients and methods: Patients (pts) had localized resectable unilateral ER-/PR-/HER2− or ER+/PR-/HER2− BC. Main inclusion criteria were: age<70 years, normal cardiac, hepatic, haematological and renal functions. Arm A: pts received 3 cycles of FEC100 (F and C, each at 500 mg/m2, E 100 mg/m2, every 3 weeks) followed by 3 cycles of D (100 mg/m2 every 3 weeks); Arm B, Ixa 40 mg/m2 replaced D. Radiotherapy was mandatory after conservative surgery and endocrine therapy was given to ER+ pts. A 5% absolute difference in disease-free survival at 5 years is the main statistical end-point. Results: Between October 2007 and September 2010, 762 pts with TNBC or ER+/PR-/HER2− BC were enrolled. Recruitment was interrupted due to BMS decision to stop Ixa development in adjuvant setting. Main pts characteristics were well balanced between the 2 arms: median age 53 years, postmenopausal 57.8%, conservative surgery 68.4%, node positive 59.5%. A total of 755 pts were evaluable for safety. Treatment was completed for 93.4% and 86.1% of pts in arms A and B, respectively. During FEC100 sequence, toxicities were well balanced between the two arms. From cycle 4, whereas Gr3/4 sensory neurotoxicity (12pts; 3.5%) and thrombopenia (7pts; 2%) were reported in Ixa arm, none of these toxicities was reported in the D arm (p0.001). There were significantly more Gr3/4 neutropenia on day 21 in Ixa arm (13pts, 6.6% vs 4pts, 1.9%; p<10.005). No significant difference was observed for febrile neutropenia. Fewer cutaneous toxicities were observed in Ixa arm (2pts, 0.6% vs 10pts, 2.6%; p<0.05). No significant difference was observed neither for motor neurotoxicity or hepatic function between two arms. More pts discontinued treatment in Ixa arm compared to D arm (49pts (13%) vs 26pts (7%), p<0.05). Main reasons were Gr3/4 haematological adverse events (AE) and Gr3/4 neurotoxicities for Ixa arm and due to GR3/4 haematological AE for D arm. One non expected Gr4 bullous dermatitis was reported during the first Ixa cycle. 2 deaths due to septic shock occured in Ixa arm (both at cycle 4 for a 56- and a 66-year-old woman). However, according to the IDMC no obvious precipitating factor questioning the Ixa arm was identified. Conclusion: Our results indicate that D arm is more often associated to significant haematological toxicities, whereas both neurotoxicities and haematological toxicities are reported in the Ixa arm. Although significantly more pts discontinued treatment due to adverse events in Ixa arm compared to D arm, Ixa may still represent a promising therapeutic option for pts in the adjuvant setting especially for poor prognosis BC. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-18-04.
Ixabepilone plus capecitabine improves overall survival in symptomatic patients with metastatic breast cancer previously treated with anthracycline and taxane in 2 large phase III studies.
Abstract Abstract #6114 Introduction:
 Symptomatic patients (pts) with performance status (KPS) 70-80 with locally advanced or metastatic breast cancer (MBC) have worse prognosis than pts with good performance status and are often excluded from clinical trials. Ixabepilone (ixa), the first in a new class of antineoplastic agents, showed clinical benefit in 2 large clinical trials in combination with capecitabine (C) in MBC pts with tumors resistant to (study 046; JCO; 2007) or pretreated with anthracycline (A) and taxane (T) (study 048). In 048, ixa + C, compared to C alone, showed significant increases in PFS (HR 0.79 [0.69-0.90] and ORR (43% vs 29%). A trend toward increased OS was seen in 048 (HR 0.90 [0.78-1.03]) and 046 (HR 0.90 [0.77-1.05]) which did not reach statistical significance. In 046 and 048 trials, a survival benefit was seen with ixa + C in a predefined analysis in a subset of symptomatic KPS 70-80 pts (HR: 0.75 [0.58-0.98], 0.76 [0.60-0.96], respectively). We present a predefined pooled analysis of clinical outcomes in symptomatic pts from both studies to better evaluate the treatment effect in this subset.
 Methods:
 1973 pts with MBC previously treated with an A and T were randomized in phase III trials 046 and 048 to receive ixa (40mg/m2 IV over 3h Q3w) + C (1000mg/m2 PO BID x14d Q3w) or C alone (1250mg/m2 PO BID x14d Q3w). 606 pts from the 2 studies were KPS 70-80. Study outcomes included ORR, PFS and OS.
 Results:
 ORR, PFS and OS favored ixa + C in this pt population.
 
 In asymptomatic pts (KPS 90-100), similar improvement was observed in PFS and ORR; no benefit in OS was seen. Incidence of key treatment related grade 3/4 AEs for ixa + C in this subset of pts was similar to the overall population.
 Conclusions:
 In the pooled analysis, ixa + C demonstrates a survival benefit (2.8 mo) for symptomatic pts (KPS 70-80) failing A and T, which was consistently seen in this pt population in the individual studies as well, indicating that symptomatic pts can benefit from management of their disease and achieve overall clinical benefit with ixa combination. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6114.