Tan-Chiu, Elizabeth

Abstract Purpose: This open-label, multicenter, phase IB/II study evaluated sapanisertib, a dual inhibitor of mTOR kinase complexes 1/2, plus exemestane or fulvestrant in postmenopausal women with hormone receptor–positive (HR+)/HER2-negative (HER2−) advanced/metastatic breast cancer. Patients and Methods: Eligible patients had previously progressed on everolimus with exemestane/fulvestrant and received ≤3 (phase IB) or ≤1 (phase II) prior chemotherapy regimens. Patients received sapanisertib 3 to 5 mg every day (phase IB), or 4 mg every day (phase II) with exemestane 25 mg every day or fulvestrant 500 mg monthly in 28-day cycles. Phase II enrolled parallel cohorts based on prior response to everolimus. The primary objective of phase II was to evaluate antitumor activity by clinical benefit rate at 16 weeks (CBR-16). Results: Overall, 118 patients enrolled in phase IB (n = 24) and II (n = 94). Five patients in phase IB experienced dose-limiting toxicities, at sapanisertib doses of 5 mg every day (n = 4) and 4 mg every day (n = 1); sapanisertib 4 mg every day was the MTD in combination with exemestane or fulvestrant. In phase II, in everolimus-sensitive versus everolimus-resistant cohorts, CBR-16 was 45% versus 23%, and overall response rate was 8% versus 2%, respectively. The most common adverse events were nausea (52%), fatigue (47%), diarrhea (37%), and hyperglycemia (33%); rash occurred in 17% of patients. Molecular analysis suggested positive association between AKT1 mutation status and best treatment response (complete + partial response; P = 0.0262). Conclusions: Sapanisertib plus exemestane or fulvestrant was well tolerated and exhibited clinical benefit in postmenopausal women with pretreated everolimus-sensitive or everolimus-resistant breast cancer.

Abstract Background: TAK-228 is an investigational, oral and highly selective ATP-competitive inhibitor of TORC1/2. Targeting the PI3K/AKT/mTOR pathway with the dual TORC1/2 inhibitor TAK-228 may restore sensitivity to endocrine therapies in patients (pts) with breast cancer who have progressed on the combination of an endocrine agent plus a TORC1 inhibitor. Here we report data from the phase 2 portion of a phase 1b/2 study of TAK-228 plus exemestane (E) or fulvestrant (F). Methods: Postmenopausal women with ER+ and HER2-, inoperable or metastatic breast cancer (MBC) following everolimus (EVE) plus E or F after progression, received oral TAK-228 (4 mg QD) plus E (25 mg QD) or F (500 mg monthly) for 28-day cycles until progressive disease (PD) or unacceptable toxicity (NCT02049957). Pts were enrolled into parallel cohorts based on prior response to EVE plus E or F and were given the same prior therapy (E or F) at their established dose: EVE-sensitive, defined as disease progression after complete response (CR), partial response (PR), or ≥6 mos stable disease (SD); or EVE-resistant, defined as disease progression without a CR or PR, or after <6 mos SD. Primary endpoint was clinical benefit rate at 16 wks (CR, PR, or SD at 16 wks; CBR-16). Secondary endpoints included CBR at 24 wks (CBR-24), overall response rate (ORR), progression-free survival (PFS), overall survival (OS) and safety. Results: From Oct 2015 to Dec 2017, 94 pts were enrolled. Median age was 58 y (range 32–83). At baseline, most pts (67%) had stage IV disease and others were stage IA–IIIC (24%), other (3%) or unknown (5%); 94% of EVE-sensitive (93% E vs 100% F) and 88% of EVE-resistant pts (91% E vs 75% F) had received ≥4 prior lines of therapy. Pts received a median of 3 cycles (1–15) of TAK-228. At data cutoff (24 Apr 2018), 98% of pts had discontinued treatment, mainly due to PD (76%) or adverse events (AEs; 14%). CBR-16 was 41% (n=21) in EVE-sensitive and 26% (n=11) in EVE-resistant pts (table). CBR-24 was 24% in EVE-sensitive (19% E vs 50% F) and 23% in EVE-resistant (23% E vs 25% F) pts. Eleven of 21 pts who achieved CBR-16 also achieved CBR-24 (6 SD, 5 PR) in the EVE-sensitive cohort and 8 of 11 pts in the EVE-resistant cohort (6 SD, 2 PR). The ORR was 12% in EVE-sensitive pts and 9% in EVE-resistant pts (table). Median PFS (95% CI) was 4.1 mos (2.2–5.5) and 3.4 mos (1.9–5.4), and median OS (95% CI) was 15.9 mos (14.1–19.5) and 14.0 mos (13.0–16.0) in the EVE-sensitive and -resistant cohorts, respectively. Drug-related any grade and grade ≥3 AEs were seen in 90% and 29% of pts, respectively. Most common drug-related any grade AEs were nausea (50%), fatigue (38%), hyperglycemia and diarrhea (each 29%); 22% of pts reported a serious AE. No deaths were reported. Treatment is ongoing in two pts. Conclusion: TAK-228 plus E or F showed modest clinical benefit in pts with previously treated, EVE-sensitive or -resistant MBC, with an acceptable safety profile. EVE-sensitive (N=51)EVE-resistant (N=43) TAK-228+TAK-228+Best response, n (%)E (n=43)F (n=8)E (n=35)F (n=8)ORR=CR+PR4 (9)2 (25)3 (9)1 (13)CR001 (3)0PR4 (9)2 (25)2 (6)1 (13)CBR-1617 (40)4 (50)9 (26)2 (25) Citation Format: Diamond JR, Potter D, Salkeni M, Silverman P, Haddad T, Forget F, Awada A, Canon J-L, Danso M, Lortholary A, Bourgeois H, Tan-Chiu E, Patel C, Neuwirth R, Leonard EJ, Lim B. Phase 2 safety and efficacy results of TAK-228 in combination with exemestane or fulvestrant in postmenopausal women with ER-positive/HER2-negative metastatic breast cancer previously treated with everolimus [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 PD1-09.

Abstract Abstract #2131 Introduction: TAS-108 is an oral steroidal anti-estrogen agent that selectively inhibits ERα and is mainly metabolized by CYP3A4. The purpose of this study is to investigate the efficacy and safety of TAS-108 administrated orally in three dose levels in patients with locally advanced, locally recurrent inoperable or metastatic breast carcinoma (BC) in four countries (USA, Russia, Mexico and Chile).
 Methods: Postmenopausal women with confirmed ER and/or PgR positive BC who had previously responded to one or two standard endocrine therapies, with or without one prior chemotherapy were randomly assigned to three doses of TAS-108, 40 mg, 80 and 120 mg daily. Using a modified Panageas' optimal two-stage trinomial design, the enrollment of 60 evaluable patients (first-stage: 19) was required to each individual dose group. Tumor response was assessed every 8 weeks according to RECIST criteria. Adverse events (AEs) were graded by CTC-AE v3.0.
 Results: A total of 146 patients with mean age of 63 years old were enrolled with 61 patients in the 40 mg group and 66 in the 80 mg group. The 120 mg group was terminated at the end of stage 1 with 19 patients enrolled due to lack of efficacy. The mean duration of study treatment was 172 days for the 40 mg group and 160 days for the 80 mg group. Partial response (PR) was documented in 6 (10%) patients in the 40 mg group and 4 (6.7%) patients in the 80 mg group. The rate of disease stabilization (CR+PR+SD) reported by the investigators was 43% (95%CI, 31%,56%) in the 40 mg group and 45% (95%CI, 32%,58%) in the 80 mg group. Adjudicated clinical benefit (CR+PR+SD more than 24 wks) was observed in 22% of patients in the 40 mg group and 20% of patients in the 80 mg group. Clinical benefit was achieved in 25% of patients with 1 prior hormonal therapy and 15% of patients with more than one line of prior hormonal therapy. Median time to progression (TTP): 15 weeks for the 40 mg group and 15.9 weeks for the 80 mg group. Median duration of clinical benefit was 32 weeks in the 40 mg group and 64 weeks in the 80 mg group. In the 40/80/120 mg groups, the commonly reported treatment-related AEs included nausea (15%/11%/16%), fatigue (10%/11%/16%), headache (10%/6%/16%), hot flushes (10%/5%/32%), diarrhea (2%/6%/5%), constipation (3%/3%/5%), and arthralgia (2%/5%/11%). No endometrial cancer and treatment-related deaths occurred during the study.
 Conclusions: TAS-108 has demonstrated anti-tumor activity in this population and was generally well tolerated. The 40 mg dose was chosen as the recommended dose for future clinical evaluation in patients with advanced breast cancer. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2131.

Purpose Treatment with aromatase inhibitors decreases bone mineral density (BMD) and may increase the risk of fractures in postmenopausal women with early-stage breast cancer. The addition of zoledronic acid to adjuvant letrozole therapy may protect against bone loss. Patients and Methods Patients receiving adjuvant letrozole were randomly assigned to receive either upfront or delayed-start zoledronic acid (4 mg intravenously every 6 months). The delayed group received zoledronic acid when lumbar spine (LS) or total hip (TH) T score decreased to less than −2.0 or when a nontraumatic fracture occurred. The primary end point of this study was to compare the change in LS BMD at month 12 between the groups. Secondary end points included change in TH BMD and changes in serum bone turnover markers at month 12. Results The upfront and delayed groups each included 301 patients. At month 12, LS BMD was 4.4% higher in the upfront group than in the delayed group (95% CI, 3.7% to 5.0%; P < .0001), and TH BMD was 3.3% higher (95% CI, 2.8% to 3.8%; P < .0001). In the upfront group, mean serum N-telopeptide and bone-specific alkaline phosphatase concentrations decreased by 15.1% (P < .0001) and 8.8% (P = .0006), respectively, at month 12, whereas concentrations increased significantly in the delayed group by 19.9% (P = .013) and 24.3% (P < .0001), respectively. Conclusion With 1 year of follow-up, results of the primary end point of the Zometa-Femara Adjuvant Synergy Trial (Z-FAST) indicate that upfront zoledronic acid therapy prevents bone loss in the LS in postmenopausal women receiving adjuvant letrozole for early-stage breast cancer.