Penny Phillips

Phase II Randomized Study of Neoadjuvant Everolimus Plus Letrozole Compared With Placebo Plus Letrozole in Patients With Estrogen Receptor-Positive Breast Cancer

PURPOSE Cross-talk between the estrogen receptor (ER) and the phosphoinositide-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathways is a mechanism of resistance to endocrine therapy, and blockade of both pathways enhances antitumor activity in preclinical models. This study explored whether sensitivity to letrozole was enhanced with the oral mTOR inhibitor, everolimus (RAD001). PATIENTS AND METHODS Two hundred seventy postmenopausal women with operable ER-positive breast cancer were randomly assigned to receive 4 months of neoadjuvant treatment with letrozole (2.5 mg/day) and either everolimus (10 mg/day) or placebo. The primary end point was clinical response by palpation. Mandatory biopsies were obtained at baseline and after 2 weeks of treatment (ie, day 15). Samples were assessed for PI3K mutation status (PIK3CA) and for pharmacodynamic changes of Ki67, phospho-S6, cyclin D1, and progesterone receptor (PgR) by immunohistochemistry. RESULTS Response rate by clinical palpation in the everolimus arm was higher than that with letrozole alone (ie, placebo; 68.1% v 59.1%), which was statistically significant at the preplanned, one-sided, alpha = 0.1 level (P = .062). Marked reductions in progesterone receptor and cyclin D1 expression occurred in both treatment arms, and dramatic downregulation of phospho-S6 occurred only in the everolimus arm. An antiproliferative response, as defined by a reduction in Ki67 expression to natural logarithm of percentage positive Ki67 of less than 1 at day 15, occurred in 52 (57%) of 91 patients in the everolimus arm and in 25 (30%) of 82 patients in the placebo arm (P < .01). The safety profile was consistent with historical results of everolimus monotherapy; grades 3 to 4 adverse events occurred in 22.6% of patients who received everolimus and in 3.8% of patients who received placebo. CONCLUSION Everolimus significantly increased letrozole efficacy in neoadjuvant therapy of patients with ER-positive breast cancer.

Abstract CT116: BMS-986205, an optimized indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, is well tolerated with potent pharmacodynamic (PD) activity, alone and in combination with nivolumab (nivo) in advanced cancers in a phase 1/2a trial

Background: IDO1 is highly expressed in multiple cancers and may be an immunosuppressive mechanism for tumor escape via its production of metabolites that inhibit T-cell function. Nivo, a mAb that targets PD-1, causes IDO1 upregulation, supporting a rationale for combining it with an IDO1 inhibitor. Our preclinical program aimed to identify a best in class IDO1 inhibitor with favorable pharmacokinetic (PK) characteristics (Hunt J, et al. AACR 2017 [abst 6774]). Here we present BMS-986205, a selective IDO1 inhibitor validated in a novel phase 1/2a trial alone and in combination with nivo. Methods: During dose escalation, patients (pts) with advanced cancers were treated in escalating cohorts with BMS-986205 (25-200 mg as of Jan 5, 2017) orally once daily (QD) for 2 wk, followed by BMS-986205 + nivo 240 mg IV every 2 wk. Objectives included safety (primary), PK, and PD. Preclinical analyses included measurement of enzyme inhibition in HEK293 cells overexpressing human IDO1 or tryptophan 2,3-dioxygenase (TDO) and IFNγ-stimulated HeLa cells. Results: In support of clinical testing, BMS-986205 was evaluated preclinically. In vitro characteristics included potent inhibition of kynurenine (kyn) production in IDO1-HEK293 cells (IC50 = 1.1 nM) but not in TDO-HEK293 cells, sustained inhibition in IDO1 cell-based assays after washout, and single-digit nM potency in human tolerogenic MLR assays. Based on preclinical data, a 150 mg QD human dose was projected to maximally inhibit IDO1. In the ongoing clinical study, 42 pts have been treated. All treatment-related adverse events were grade 1/2 except three grade 3 toxicities (autoimmune hepatitis [dose limiting; BMS-986205 100 mg/nivo 240 mg], rash, and asymptomatic hypophosphatemia). Day 14 individual trough concentrations began exceeding the human whole blood IC50 starting with 25 mg QD, and the IC90 starting with 50 mg QD; all pts treated at 200 mg QD exceeded the IC90. Serum kyn was substantially reduced at all doses (> 45% mean reduction at each dose), with > 60% mean reduction at the 100 and 200 mg QD doses. Importantly, intratumoral kyn was reduced up to 90% in evaluable paired pre- and on-treatment samples. Conclusions: BMS-986205 is an optimized, once-daily, selective and potent oral IDO1 inhibitor at clinically relevant concentrations. It is well tolerated up to at least 200 mg in combination with nivo in this novel trial. Evidence of substantial serum kyn reduction was observed at doses as low as 25 mg QD; inhibition at 100 and 200 mg QD appears greater than that reported for other in-class compounds. In addition, we have presented the first evidence of intratumoral kyn reduction by an IDO1 inhibitor. These data suggest the potential of BMS-986205 as an IDO1 inhibitor with superior PD properties and support further evaluation in combination with nivo. Citation Format: Lillian L. Siu, Karen Gelmon, Quincy Chu, Russell Pachynski, Olatunji Alese, Paul Basciano, Justine Walker, Priyam Mitra, Li Zhu, Penny Phillips, John Hunt, Jayesh Desai. BMS-986205, an optimized indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, is well tolerated with potent pharmacodynamic (PD) activity, alone and in combination with nivolumab (nivo) in advanced cancers in a phase 1/2a trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT116. doi:10.1158/1538-7445.AM2017-CT116