Abstract P6-17-23: Randomized phase II study of lapatinib plus vinorelbine versus vinorelbine in patients with HER2 positive metastatic breast cancer progressed after lapatinib and trastuzumab treatment

Background

The continuum of anti-HER2 agents is regarded as a standard strategy for HER2 positive metastatic breast cancer patients who had progressed disease with anti-HER2 agent- containing treatments. However, there has been lack of data on which agents should be continued and how long continuous anti-HER2 therapies would be effective. This study was aimed to evaluate the efficacy of lapatinib plus vinorelbine in HER2 positive metastatic breast cancer patients who had progressed on both trastuzumab and lapatinib treatments.

Methods

A total of 149 patients were randomly assigned to lapatinib with vinorelbine (LV) (n=75; laptinib, 1000mg daily ; vinorelbine 20mg/m2 D1,D8 q3w) or vinorelbine alone (V) (n=74; 30mg/m2 D1,D8 q3w). The stratification factors were followings; 1) visceral metastasis, 2) previous response to lapatinib treatment, CR+PR vs. SD ≥ 12 weeks. The primary endpoint was progression free survival (PFS) rate at 18 weeks. The secondary endpoints were objective response rate (ORR), PFS, and overall survival (OS).

Results :

Both arms were well balanced in various clinical factors. The median number of previous anti-HER2 therapies were 2 (range 2-5). There was no significant difference in PFS rate at 18 weeks between LV and V arms (44.0% vs 36.5%, p=0.44). ORR was 19.7% in LV arm and 16.9% in V arm (p=0.881). PFS and OS did not differ between two arms (LV vs V; median PFS, 16weeks vs 12 weeks, HR= 0.86, 95% CI 0.61-1.22, p=0.41; median OS, 15.0 months vs 18.9 months, HR= 1.07, 95% CI 0.72-1.58, p=0.72). In subgroup analysis, there was no difference in PFS and OS between two arms according to previous response to lapatinib (median PFS, CR+PR vs. SD ≥ 12 weeks, 12.1weeks vs.17.4 weeks; HR= 1.242, 95% CI 0.881-1.751, p=0.215; median OS, 14.9 months vs. 19.4 months; HR= 1.179, 95% CI 0.797-1.744, p=0.41). Most common adverse events in both arms were neutropenia which was more often observed in V arm (55% vs 73%, p=0.03). Overall, the profiles of adverse events were similar in both arms and all were manageable.

Conclusion

Lapatinib plus vinorelbine treatment was tolerable, however, it did not demonstrate the clinical benefits compared to vinorelbine alone in HER2 positive metastatic breast cancer patients after progression on both trastuzumab and lapatinib.

Citation Format: Sim SH, Park IH, Jung KH, Kim S-B, Ahn J-H, Lee K-H, Im S-A, Im Y-H, Park YH, Sohn JH, Kim YJ, Lee S, Kim H-J, Chae YS, Park K-H, Nam B-H, Lee KS, Ro J. Randomized phase II study of lapatinib plus vinorelbine versus vinorelbine in patients with HER2 positive metastatic breast cancer progressed after lapatinib and trastuzumab treatment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-23.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Quality of life with palbociclib plus fulvestrant in previously treated hormone receptor-positive, HER2-negative metastatic breast cancer: patient-reported outcomes from the PALOMA-3 trial

In treating HR+, HER2− metastatic breast cancer, novel agents that enhance endocrine therapy activity but do not worsen quality of life (QoL) are clinically desired. Patient-reported outcomes data from the PALOMA-3 study suggest palbociclib plus fulvestrant allow patients to maintain good QoL in the endocrine resistance setting while experiencing a substantially delayed disease progression.

Background

In the PALOMA-3 study, palbociclib plus fulvestrant demonstrated improved progression-free survival compared with fulvestrant plus placebo in hormone receptor-positive, HER2− endocrine-resistant metastatic breast cancer (MBC). This analysis compared patient-reported outcomes (PROs) between the two treatment groups.

Patients and methods

Patients were randomized 2 : 1 to receive palbociclib 125 mg/day orally for 3 weeks followed by 1 week off (n = 347) plus fulvestrant (500 mg i.m. per standard of care) or placebo plus fulvestrant (n = 174). PROs were assessed on day 1 of cycles 1–4 and of every other subsequent cycle starting with cycle 6 using the EORTC QLQ-C30 and its breast cancer module, QLQ-BR23. High scores (range 0–100) could indicate better functioning/quality of life (QoL) or worse symptom severity. Repeated-measures mixed-effect analyses were carried out to compare on-treatment overall scores and changes from baseline between treatment groups while controlling for baseline. Between-group comparisons of time to deterioration in global QoL and pain were made using an unstratified log-rank test and Cox proportional hazards model.

Results

Questionnaire completion rates were high at baseline and during treatment (from baseline to cycle 14, ≥95.8% in each group completed ≥1 question on the EORTC QLQ-C30). On treatment, estimated overall global QoL scores significantly favored the palbociclib plus fulvestrant group [66.1, 95% confidence interval (CI) 64.5–67.7 versus 63.0, 95% CI 60.6–65.3; P = 0.0313]. Significantly greater improvement from baseline in pain was also observed in this group (−3.3, 95% CI −5.1 to −1.5 versus 2.0, 95% CI −0.6 to 4.6; P = 0.0011). No significant differences were observed for other QLQ-BR23 functioning domains, breast or arm symptoms. Treatment with palbociclib plus fulvestrant significantly delayed deterioration in global QoL (P < 0.025) and pain (P < 0.001) compared with fulvestrant alone.

Conclusion

Palbociclib plus fulvestrant allowed patients to maintain good QoL in the endocrine resistance setting while experiencing substantially delayed disease progression.

Clinical Trial Registration

NCT01942135.

Abstract P4-13-03: Updated safety from a double-blind phase 3 trial (PALOMA-3) of fulvestrant with placebo or with palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy

Background: Endocrine therapy (ET) resistance remains a major clinical problem for patients (pts) with hormone receptor (HR+) breast cancer (BC). In PALOMA-3, palbociclib (P) combined with fulvestrant (F) demonstrated significant prolongation of progression-free survival (PFS) vs F plus placebo (PLB) in pre/peri and postmenopausal women with HR+/HER2– metastatic BC (MBC) whose disease progressed on prior ET (median PFS 9.2 vs 3.8 m; HR=0.422, P=0.0001).

Methods: In this double-blind phase 3 study, 521 pts with HR+/HER2– MBC were randomized 2:1 to receive P (125 mg/d orally for 3 weeks followed by 1 week off) and F (500 mg given per standard of care) or PLB plus F. Pre- and perimenopausal women also received goserelin. One previous line of chemotherapy (CT) for MBC was allowed. Safety assessments occurred at baseline and D1 of each cycle; blood counts occurred every 2 wks for the first 2 cycles and on D1 of subsequent cycles. As pts may have experienced multiple episodes of neutropenia during treatment, we analyzed all episodes in aggregate based on laboratory data per CTCAE4.0.

Results: The results reported here are from the data cutoff of Dec 2014, with a median follow-up of 5.6 m. Overall rate of any grade (G) and G3/4 AEs was 98/70% of pts in P+F vs 89/18% in PLB+F. The most commonly reported AEs in P+F (≥20%) were hematologic toxicities, fatigue, nausea, and headache. Per lab data, G3/G4 neutropenia occurred in 52.2/8.2%, G3/G4 leukopenia in 39.5/1.2%, G3/G4 anemia in 20.8/2.9% and G3/G4 thrombocytopenia in 2.1/1.2% of pts on P+F. Neutropenia occurred early, with a median onset time for first episode of ≥G3 neutropenia of 15 d (13–197) and median time from first dose to the lowest absolute neutrophil count (ANC) of 29 d (13–334). The median duration of ≥G3 episode was 7 d (1–35), suggesting that most pts can resume treatment after a 1-week cycle delay. A comparable proportion of any grade neutropenia was observed in pts with or without prior CT (prior CT 88.4% vs no prior CT 85.4%). There was no difference in the rate of G3/G4 neutropenia in the older pts (&gt;65 yrs, 51% vs ≤65 yrs, 57%) in P+F arm. Concurrent G≥3 infections occurred in 1% of pts with G≥3 neutropenia (2/192 pts). Febrile neutropenia occurred in 0.6% of pts in both arms. 21% of pts had dose reductions and 45% had dose interruption due to neutropenia. Dose intensity was maintained at 89.7% for P. Serious adverse events (SAEs) were reported in 9.6% of pts on P+F and in 14% of pts on PLB+F. The most common SAEs on P+F were pulmonary embolism (0.9%) and pyrexia (0.9%). Safety analyses with longer follow-up (data cut off, March 2015) are ongoing and will be presented.

Conclusions: Findings suggest P+F has a favorable safety profile characterized mainly by asymptomatic hematologic toxicity. Overall SAE rates were low and comparable between the 2 arms. Palbociclib-related neutropenia differs from that seen with CT, consistent with proposed mechanism of action, in that it is not commonly associated with fever, and can be effectively managed by a dose interruption or cycle delay.

Funding: Pfizer, Inc.

Citation Format: Verma S, DeMichele AM, Loi S, Ro J, Colleoni M, Iwata H, Harbeck N, Stearns V, Cristofanilli M, Huang Bartlett C, Schnell P, Zhang K, Thiele A, Turner NC, Rugo HS. Updated safety from a double-blind phase 3 trial (PALOMA-3) of fulvestrant with placebo or with palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy. [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 P4-13-03.

Abstract P4-13-27: A phase Ib dose de-escalation study of combined tamoxifen and goserelin acetate with alpelisib (BYL719) or buparlisib (BKM120) in premenopausal patients with HR+/HER2– locally advanced or metastatic breast cancer

Background: Growing evidence suggests that concomitant inhibition of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin pathway could enhance and extend the clinical benefit of endocrine therapies in hormone receptor-positive (HR+) metastatic breast cancer (mBC). In this Phase Ib study (NCT02058381), alpelisib (a p110α-selective inhibitor) or buparlisib (a pan-PI3K inhibitor) was combined with tamoxifen and goserelin acetate in premenopausal women with mBC, a more prevalent patient population in Asian vs Western countries.

Methods: Premenopausal women with HR+/human epidermal growth factor receptor 2-negative (HER2–) locally advanced or mBC and no prior endocrine therapy for metastatic disease were recruited in Taiwan, Republic of Korea, and Thailand. Patients (pts) received tamoxifen (20 mg once daily [QD]) and goserelin (3.6 mg Q28D) with either alpelisib (350 mg QD; Group 1) or buparlisib (100 mg QD; Group 2) on a continuous dosing schedule in 28-day cycles. The primary objective was to define the recommended Phase II dose (RP2D) for each combination, based on dose-limiting toxicities (DLTs) observed during Cycle 1, using a dose de-escalation design. Secondary objectives included pharmacokinetics, safety and tolerability (per Common Terminology Criteria for Adverse Events v4.03), efficacy (per Response Evaluation Criteria In Solid Tumors v1.1), and impact on quality of life.

Results: As of February 2, 2015, 12 pts, all Asian, have been treated in the first cohort. In Group 1, 6 pts with a median age of 43 were treated with alpelisib (350 mg starting dose), and no DLTs were observed in Cycle 1. In Group 2, 6 pts with a median age of 47 were treated with buparlisib (100 mg starting dose), and 1 DLT of Grade (G) 3 alanine aminotransferase/aspartate aminotransferase elevation was observed. In Group 1, significant toxicities included hypokalemia (G3: 1 pt), rash (G3: 1 pt; G1/2: 2 pts), anemia (G3: 1 pt), leukopenia (G3: 1 pt), and infections (G3: 1 pt; G1/2: 1 pt); no G4 toxicities were reported. In Group 2, significant toxicities included liver toxicity (G4: 1 pt; G3: 1 pt; G1/2: 2 pts), psychiatric disorders (G4: 1 pt; G3: 1 pt; G1/2: 1 pt), rash (G3: 1 pt; G1/2: 2 pts), hypertension (G3: 1 pt; G1/2: 1 pt), and hyperglycemia (G3: 1 pt). No pts in Group 1, and 5/6 pts in Group 2, have discontinued treatment due to adverse events (AEs). Median treatment duration was 110 days in Group 1 and 71 days in Group 2.

Conclusions: The combination of alpelisib (350 mg) with tamoxifen and goserelin resulted in a manageable toxicity profile. Meanwhile, the same combination with full-dose buparlisib (100 mg) was less well tolerated; despite the appearance of only one DLT during Cycle 1, the majority of pts subsequently stopped treatment due to AEs. An expansion phase is ongoing, and results will be integrated with safety, tolerability, and efficacy results for the first 15 pts enrolled in each group. PIK3CA status at baseline will also be assessed.

Citation Format: Lu Y-S, Ro J, Tseng L-M, Chao T-Y, Chitapanarux I, Valenti R, Canatar A, Salomon H, Park YH. A phase Ib dose de-escalation study of combined tamoxifen and goserelin acetate with alpelisib (BYL719) or buparlisib (BKM120) in premenopausal patients with HR+/HER2– locally advanced or metastatic breast cancer. [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 P4-13-27.

Abstract P5-08-25: CKAP2 (cytoskeleton associated protein 2) is a new prognostic marker in HER2-negative luminal breast cancer

Background: Ki-67 has been increasingly used as a prognostic marker in spite of debates on the evaluation methods and inconsistent results on its clinical values. CKAP2 is a microtubule-associated protein which plays key roles in microtubule assembly and disassembly. In the present study, the clinical significance of CKAP2-positive cells was evaluated and compared with the results of Ki-67 positive cells.

Methods: A total of 579 early breast cancer patients who underwent surgery at the National Cancer Center Hospital between 2001 and 2005 were accrued. The proliferation activity was measured by CKAP2-positive cell count (CPCC) and Ki-67 labeling index (Ki-67 LI) using CKAP2 and Ki-67 antibodies, respectively, by immunohistochemcial staining on FFPE tumor tissue. The correlation of CPCC or Ki-67 LI with recurrence free survival (RFS) was analyzed. The immunofluorescent staining was performed on HeLa cells after synchronization by double thymidine block to compare the patterns between CKAP2 and Ki-67.

Results: The CPCC (median, 8 with the range of 0- 170) and Ki-67 LI (median, 10.2 with the range of 0%- 91.7%) were highly correlated (R = 0.754, P &lt; 0.001). While CPCC was marginally significant in multivariate analysis for RFS in all cases, it was a significant variable for RFS in the subset analysis with HER2-negative luminal breast cancer patients (HR, 3.154; 95% CI, 1.154-10.693; P = 0.027). On the contrary, Ki-67 LI failed to show any correlation with RFS in all or any subgroups. In the analysis on HeLa cells, CKAP2 staining was more specific to cells in metaphase than Ki-67 staining.

Conclusions: CPCC can be an independent prognostic factor specifically in a HER2-negative luminal type of breast cancer. In addition, CPCC appears to be superior to Ki-67 LI as a survival indicator which may be related to the restricted expression pattern of CKAP2 in metaphase cells. Further study is warranted.

Citation Format: Sim SH, Bae C-D, Kwon Y, Park IH, Lee KS, Jung S-Y, Lee S, Kang H-S, Lee ES, Kim H-S, Hong K-M, Ro J. CKAP2 (cytoskeleton associated protein 2) is a new prognostic marker in HER2-negative luminal breast cancer. [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 P5-08-25.

Abstract P4-13-01: PALOMA3: Phase 3 trial of fulvestrant with or without palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy—confirmed efficacy and safety

Background: Selective estrogen receptor modulators and aromatase inhibitors (AI) (+LHRH agonists [premenopausal]) are standard of care (SOC) for hormone–receptor–positive (HR+) metastatic breast cancer (MBC). Many HR+ MBC patients (pts) get limited benefit from adjuvant or advanced endocrine therapy (ET) and develop endocrine resistance, refractory disease. HR+ BC growth relies on cyclin dependent kinases 4/6 that promote G1–S phase cell cycle progression. Palbociclib (PAL) with ET showed efficacy in HR+/HER2– MBC (Turner et al, 2015). We report updated safety and efficacy from PALOMA3 with longer follow–up, focusing on degrees of clinically defined endocrine resistance.

Methods: Pts with HR+/HER2– MBC that progressed on prior ET were randomized 2:1 to PAL (125 mg/d oral [3 wks drug, 1 wk off]) + fulvestrant (F, 500 mg, SOC) +/– goserelin or placebo (PLB)+F. One line of chemotherapy (CT) for MBC was allowed. Pt stratification: prior ET sensitivity; visceral metastases; menopausal status. Primary endpoint (EP) was investigator–assessed progression–free survival (PFS). Secondary EP: overall survival, response assessment, patient–reported outcomes, safety.

Results: By March 2015, median follow–up was 8.9 mo. 521 pts were randomized (PAL+F, 347; PLB+F, 174). Baseline characteristics were balanced. Median PFS was 9.5 (95% CI 9.2–11.0) mo (PAL+F) vs 4.6 (3.5–5.6) mo (PLB+F) (HR 0.46 [0.36–0.59], P&lt;0.001). Overall response (CR+ PR) was significantly improved with PAL+F (ITT: 19% vs 8.6%, P=0.001; pts with measurable disease: 24.6% vs 10.9%, P&lt;0.001). Clinical benefit (CBR=CR+PR+SD ?24wks) was 66.6% vs 39.7% (P&lt;0.001). Benefit from PAL was confirmed in pre– and postmenopausal pts with PFS in premenopausal 9.5 vs 5.6 mo (HR=0.50 [0.29–0.87], P=0.006) and in postmenopausal 9.9 vs 3.9 mo (HR=0.45 [0.34–0.59], P&lt;0.001). Common adverse events (AEs) for PAL+F vs PLB+F were neutropenia (80.9 vs 3.5%), leukopenia (49.6 vs 4.1%), and fatigue (39.1 vs 28.5%); febrile neutropenia occurred in 0.9% (P+ F) vs 0.6% pts (PLB+F). Discontinuation due to AEs was 4.0% on P vs 1.7% on PLB. The benefit of PAL+F vs PLB+F was compared in pts with various degrees of endocrine resistance: a) progression ≤12 mo of adjuvant ET completion, PFS 9.5 vs 5.4 mo (HR 0.55 [0.32–0.92], P=0.01); b) failed 1 line of ET, 10.2 vs 5.4 mo (HR 0.42 [0.29–0.59], P&lt;0.001); c) failed 2 lines of ET, 9.9 vs 1.8 mo (HR=0.20 [0.10– 0.39, P&lt;0.001); d) proven endocrine sensitive, 10.2 vs 4.2 mo (HR 0.42 [0.32–0.56], P&lt;0.001); e) proven no prior endocrine sensitivity, 7.5 vs 5.4 mo (HR 0.64 [0.39–1.07], P=0.04) f) AI most recent therapy, 9.5 vs 3.7 mo (HR 0.42 [0.31–0.56], P&lt;0.001).

Conclusion: Mature efficacy confirmed superior PFS and demonstrated significantly improved clinical response and CBR by the combination of ET and Palbociclib. It also consistently showed therapeutic benefit irrespective of menopausal status and various degrees of endocrine sensitivity. Safety profile is favorable. PAL+F may be an effective option for HR+ MBC pts.

Funding: Pfizer.

Citation Format: Cristofanilli M, Bondarenko I, Ro J, Im S-A, Masuda N, Colleoni M, DeMichele AM, Loi S, Verma S, Iwata H, Huang Bartlett C, Zhang K, Puyana Theall K, Turner NC, Slamon DJ. PALOMA3: Phase 3 trial of fulvestrant with or without palbociclib in pre- and postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer that progressed on prior endocrine therapy—confirmed efficacy and safety. [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 P4-13-01.

Abstract P5-12-08: Time course of changes in serum FSH, serum estradiol, and menstruation in premenopausal patients with breast cancer taking tamoxifen after completing chemotherapy: A report from the ASTRRA study

BACKGROUND

Ovarian suppression with tamoxifen after chemotherapy is a promising therapeutic approach, particularly in young, high-risk breast cancer patients. Assessment of restoration of ovarian function is important with respect to the initiation of ovarian suppression.

METHODS

In total, 1289 women who remained or resumed premenopausal status after chemotherapy were randomized to receive 5 years of tamoxifen or 5 years of tamoxifen plus 2 years of ovarian suppression. Prospectively collected hormone data were available for 24 months after completing chemotherapy for 267 breast cancer patients without ovarian suppression.

RESULTS

At 6 months, a premenopausal status was identified in 56.6%, 36%, and 16.2% of patients using serum FSH, E2, and with menstruation bleeding, respectively, and about 30% more women achieved ovarian restoration using all three parameters during the 24-month follow-up. Ovarian function restoration differed significantly according to age group (log-rank, P&lt;0.001 for all definitions). At 6 months, the distribution of patients according to hormone levels was as follows: group 1 (FSH &lt;30 mIU/ml, E2 &gt;20 pg/ml), 28.0%; group 2 (FSH &lt;30 mIU/ml, E2 ≤20 pg/ml), 28.4%; group 3 (FSH ≥30 mIU/ml, E2 &gt;20 pg/ml), 8.0%; and group 4 (FSH ≥30 mIU/ml, E2 ≤20 pg/ml), 35.6%. During the 24-month follow-up, the prevalence of menstruation restoration was higher in group 1 (71.6%) than in the other three groups. Restoration of serum E2 and menstrual bleeding occurred in 44% and 33% of patients in group 2, respectively; the corresponding percentages in group 4 were 40.6% and 28.7% (P&lt;0.001).

CONCLUSIONS

Ovarian function should be monitored using serum FSH, serum E2, and menstruation history for at least 24 months after completing chemotherapy during tamoxifen treatment to establish eligibility for ovarian suppression.

Citation Format: Kim HJ, Ahn SH, Nam SJ, Park SH, Ro JS, Im SA, Jung YS, Noh WC. Time course of changes in serum FSH, serum estradiol, and menstruation in premenopausal patients with breast cancer taking tamoxifen after completing chemotherapy: A report from the ASTRRA study. [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 P5-12-08.

Impact of pharmaceutical excipients on in vitro association of saquinavir to chylomicrons

This study was performed to investigate the impact of pharmaceutical excipients commonly used for lymphatic transport on in vitro drug association with chylomicrons (CM). A CM association study was conducted using saquinavir solubilized in four different pharmaceutical excipients. We observed a linear relationship between saquinavir solubility and drug association, suggesting that the solubility of saquinavir in excipients is a key determinant for successful lymphatic delivery. Broadly, these results suggest that excipients with good solubilization properties may be advantageous for enhancing lymphatic drug delivery.

Abstract OT2-6-13: A randomized phase 2 study of the triplet combination of ridaforolimus (RIDA), dalotuzumab (DALO) and exemestane (EX) compared to the ridaforolimus, exemestane doublet in high proliferation, estrogen receptor positive (ER+) advanced breast cancer

Background: The clinical benefit of combination of mTOR inhibition and anti-hormonal therapy has been previously established and represents a new standard of care for patients with hormone receptor positive (HR+) advanced breast cancer (ABC). Preclinical evaluation of the mTOR pathway demonstrates that dual inhibition of IGFR and mTOR may be additive or synergistic and abrogates the feedback activation of AKT due to rapamycin analog mTOR inhibitors. A completed phase 1 study of the combination of the mTOR inhibitor, RIDA and the anti-IGFR antibody, DALO demonstrated preliminary signals of anti-tumor activity. This was further evaluated in a recently completed phase 2 study of RIDA-DALO compared to exemestane in ER+ ABC. Final safety and efficacy results from that phase 2 study will be reported at this meeting (see Baselga et al). Building upon the clinical synergies of mTOR and EX as well as the biologic relationship of the mTOR and IGFR pathways, a clinical study has been initiated to evaluate the triplet combination of RIDA-DALO-EX compared to RIDA-EX. Methods: This is a multicenter, international, randomized phase 2 study of the triplet combination of RIDA (10 mg by mouth daily for 5 out of every 7 days), DALO (10 mg/kg IV weekly), and EX (25 mg QD) compared to RIDA (30 mg by mouth daily for 5 out of every 7 days) and EX (25 mg QD) in high KI67 (≥15%) expressing ER+, ABC. Approximately 84 patients will be randomized 1:1 to either triplet or doublet therapy. Key eligibility criteria include: HR+ and HER-2 negative measurable ABC, prior therapy with a non-steroidal aromatase inhibitor, and KI67 labeling index ≥15%. The primary endpoint of the study is progression free survival (PFS). Key secondary endpoints include evaluation of percent (%) reduction from baseline in the sum of imaging measurements (target lesion diameters or volumes) at 16 weeks between the two arms, and overall response rates. The sample size is event driven with a target of 38 PFS events, which provides approximately 80% power, at 1-sided alpha of 0.1, to detect a HR of 0.5, corresponding to an approximate 100% improvement in median PFS, from 10.6 to 21.2 months. Safety parameters or adverse experiences of special interest include hyperglycemia, stomatitis, mucosal inflammation, pneumonitis and hearing loss. Accrual has been completed with results expected in May 2014.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-13.

Abstract OT3-1-08: The PROCEED trial KCSG BR11-01: Phase III multicenter randomized open label study of irinotecan plus capecitabine versus capecitabine in patients previously treated with anthracycline and taxane for HER2 negative metastatic breast cancer

Background: Most patients with metastatic breast cancer (MBC) experience disease progression after being treated with an anthracycline or taxane. Irinotecan, a semisynthetic agent derived from the natural alkaloid camptothecin is metabolized to the active metabolite SN-38 which targets topoisomerase I leading to single and double strand DNA breaks. Irinotecan as a single agent demonstrated tumor activity with an objective response rate ranging from 5 to 23% in patients with MBC refractory to taxane and anthracycline. Irinotecan increased the activity of 5-FU, the active metabolite of capecitabine, and overcomes the negative effect of thymidylate synthase overexpression, which is the main target of an active metabolite of 5-FU. A phase II study that evaluated the efficacy and safety of irinotecan and capecitabin combination (IX) showed that the median progression free survival (PFS) was 7.6 months (95% CI, 5.0-10.2months), and the median OS was 22.6 months (95% CI, 15.4 – 29.8 months) with good tolerability in anthracycline and taxane pretreated MBC patients. Based on these results, we planned to conduct a multicenter, randomized phase III study which assesses the efficacy of irinotecan and capecitabine combination therapy compared with capecitabine alone in patients with anthracycline and taxane resistant MBC.

Methods: In this trial, patients with HER2 normal tumor who previously received anthracycline and taxane based chemotherapies are enrolled. Eligible patients are randomly assigned in a 1:1 ratio to receive irinotecan plus capecitabine or capecitabine alone. The primary end point of this trial is PFS and a total number of accrual patients will be 222. Randomization is done using a random block size permutation method and stratified by hormone receptor status (negative vs. positive), first line vs. ≥second lines, visceral metastasis (negative vs. positive). Patients receive irinotecan at 80 mg/m2 on day 1 and 8 every 3 weeks and capecitabine 1000mg/m2 bid from day 1 to day 14 every 3 weeks. In control arm, patients receive capecitabine 1250mg/m2 bid from day 1 to day 14 every 3 weeks. Response will be assessed using RECIST1.1 criteria and toxicity will be graded according to NCI-CTCAE 4.0 criteria. Study Status: A total of 107 patients consented for the study since June 2011, and accrual is ongoing. Clinical trial information: NCT01501669.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT3-1-08.

Abstract P3-08-14: Could the preoperative systemic therapy be a risk factor for breast cancer-related lymphedema in stage II/III breast cancer?

Background: The breast cancer-related lymphedema (LE) has been known to be closely related to axillary lymph nodes dissection (ALND), chemotherapy, and radiation therapy. In this study, we evaluated whether the sequence of systemic chemotherapy and surgery could be a predictive factor in stage II/III breast cancer.

Methods and Materials: A total of 867 patients with stage II/III breast cancer, who underwent curative surgery with adequate systemic therapy from 2004 to 2009, were retrospectively analyzed. Adjuvant chemotherapy (ACT) was performed in 571 patients (65.9%) and preoperative systemic chemotherapy (PSC) in 296 (34.1%). We evaluated the incidence of LE by clinicopathologic factors and treatments.

Results: At a median follow-up of 5.1 years (range, 3.0-8.3 years), 360 patients (41.5%) had experienced LE, 244 patients have retained LE (permanent LE), and 116 patents were normalized. The overall 5-year cumulative incidence of LE was 17%. LE occurred in 188 patients (32.9%) in patients with ACT, 172 patients (58.1%) with PSC (P&lt;0.001), permanent LE in 121 (21.2%) with ACT, 123 (41.6%) with PSC (P&lt;0.001), respectively. Multivariate analysis showed that PSC (hazard ratio [HR], 1.65; P&lt;.001), radiotherapy (HR, 2.24; P&lt;0.01), ALND (HR, 1.41; P = 0.04), and nodal stage (HR, 1.93; P = 0.04) were independent risk factors for LE occurrence. For the permanent LE, PSC (HR, 1.44; P = 0.05), radiotherapy (HR, 2.79; P&lt;0.01), ALND (HR, 1.77; P&lt;0.01), and nodal stage (HR, 3.01; P = 0.02) showed the associations.

Conclusions: The risk factors associated with LE were advanced stage, ALND and radiotherapy. PSC was one of predictors for transients LE. However, further evaluation should be done whether it is a risk factor for permanent LE.

This research was supported by National Cancer Center Grant NCC-1210181-2 by the National Cancer Center, Republic of Korea.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-08-14.

Abstract P5-01-12: Prognostic implications of tumor-infiltrating lymphocytes (TIL) in association with PD-L1 expression, and serum cytokine levels in early breast cancer

Background

Immune system has been known to influence the prognosis of breast cancer (BC). However, the relationship between immune modulating factor (PD-L1) and tumor infiltrating lymphocyte (TIL) profiles in breast cancer has yet to be revealed according to breast cancer subtypes. In addition, the effects of circulating cytokines on TILs have not been addressed.

Patients and methods

We investigated the relationship between the profiles of TILs and PD-L1 expression of the primary tumor tissue by immunohistochemistry with clinical outcomes in 253 patients who underwent surgery for early breast cancer at National Cancer Center from January 2001 to December 2005. Besides, the serum cytokines including IL-10, IL-18, IL-6, IFN-g, and TGF-β1 were measured at diagnosis. Clinical data including hormone receptors status, HER2 expression, disease free survival (DFS), and overall survival (OS) were collected.

Results

Median age of patients was 49 years (range, 32-74) and median follow-up was 8.5 years. One hundred eighty five (73.1%) patients had hormone receptor (HR) positive and 101 (39.9%) patients had node positive BC. CD8+ TILs were more abundant in low PD-L1 expressed tumor (P = 0.027), though there was no association between FOXP3+ TILs and PD-L1 expression (P = 0.585). A total number of TILs was higher in HR negative compared with HR positive BC (P = 0.061) and the expression of PD-L1 was more frequent in HR positive BC (P&lt;0.001). In HR negative BC, there was a trend of longer DFS in patients with higher CD8+ TILs and low PD-L1 expression (P = 0.097). However, such association was not detected in HR positive BC patients. Among serum cytokines we examined, the higher levels of IL-18 were significantly associated with shorter DFS in HR negative BC (P = 0.006). In HR negative BC, higher CD8+ TILs with low PD-L1 expression and lower IL-18 were significantly related with better clinical outcomes when adjusted with other clinical factors (DFS, P = 0.032; OS, P = 0.048).

Conclusions

Lower PD-L1 expression in breast tumor was associated with higher CD8+ lymphocyte infiltration. Especially in HR negative BC, increasing CD8+ TILs with lower PD-L1 expression and lower serum IL-18 level were good prognostic factors. Further validation will be needed to establish the role of immune profiles in BC patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-01-12.

Abstract P4-12-28: HER2-related biomarkers in HER2+ breast cancer patients in Asia Pacific

Recent findings suggest that HER2-related molecular markers such as PTEN deletion or downregulation, PIK3CA mutation, truncated HER2 receptor (p95HER2), and tumor HER2 mRNA levels, have the potential to predict anti-HER2 treatment response. We evaluated the distribution of these biomarkers at the time of primary diagnosis and their relationship to responsiveness to lapatinib treatment in the metastatic setting in HER2+ breast cancer patients.

We conducted an observational study of female HER2+ breast cancer patients who were initiated on lapatinib treatment following recurrence or metastases in five Asia Pacific countries. Patients were enrolled between August 2010 and December 2012. Eligible patients had a tumor biopsy specimen available from their primary breast cancer diagnosis or before they started on any anti-HER2 treatment, had not been exposed to more than two lines of anti-HER2 treatment in the metastatic setting or other experimental anti-HER2 treatment, and had no other primary tumor. Biomarkers levels at primary diagnosis were measured; PTEN levels were assessed by immunohistochemistry and PIK3CA mutations were detected by a mass spectroscopy-based approach. The primary endpoint was progression-free survival (PFS) from the initiation of first lapatinib-based regimen given in metastatic setting to disease progression from that regimen or death from any cause. PFS analysis was conducted with a data cut-off date of 31 December 2012.

A total of 162 patients were included in this study and 96% have confirmed HER2+ breast cancer primary tumor. The mean age was 52±10 years and 97% had metastases at study entry, with bone being the most common site of metastasis (48%). About a quarter had PTEN protein loss (24%), 30% had PIK3CA mutation, and 7% had both at primary diagnosis. No significant association was observed between both biomarkers or between each biomarker and estrogen receptor status or HER2 status.

Table 1. Relationship between PTEN and PIK3CA PIK3CA mutation, n (%)PIK3CA wild-type, n (%)p-valuePTEN status  0.674Loss11 (29)27 (71) Normal33 (33)68 (67) 

Patients with altered PTEN expression, or PIK3CA mutation showed comparable PFS with lapatinib-based treatment as those with normal PTEN or PIK3CA expression at analysis cut-off date (median PFS 7.5 and 8.5 months respectively vs. 8.9 and 9.0 months respectively; p = 0.502 and p = 0.268 respectively). There remained no significant difference in PFS after having adjusted for significant confounders (HR 1.2 and 1.1 respectively; 95% CI 0.7–1.9 and 0.7–1.8 respectively; p = 0.481 and p = 0.730 respectively). The distribution of p95HER2 expression and tumor HER mRNA levels and their association with PFS will be included at the time of presentation.

Our preliminary findings suggest that PTEN alteration, or PIK3CA mutation may not be predictive of clinical response to lapatinib treatment in HER2+ breast cancer patients. The final PFS results with additional markers will provide more clues regarding their relationship to treatment response.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-28.