A First-Time-in-Human Study of GSK2636771, a Phosphoinositide 3 Kinase Beta-Selective Inhibitor, in Patients with Advanced Solid Tumors

Background: The PI3K/protein kinase B (AKT) pathway is commonly activated in several tumor types. Selective targeting of p110β could result in successful pathway inhibition while avoiding the on- and off-target effects of pan-PI3K inhibitors. GSK2636771 is a potent, orally bioavailable, adenosine triphosphate-competitive, selective inhibitor of PI3Kβ.Methods: We evaluated the safety, pharmacokinetics, pharmacodynamics and antitumor activity of GSK2636771 to define the recommended phase II dose (RP2D). During the dose-selection and dose-escalation stages (parts 1 and 2), patients with PTEN-deficient advanced solid tumors received escalating doses of GSK2636771 (25-500 mg once daily) using a modified 3+3 design to determine the RP2D; tumor type-specific expansion cohorts (part 3) were implemented to further assess tumor responses at the RP2D.Results: A total of 65 patients were enrolled; dose-limiting toxicities were hypophosphatemia and hypocalcemia. Adverse events included diarrhea (48%), nausea (40%), and vomiting (31%). Single- and repeat-dose exposure increased generally dose proportionally. GSK2636771 400 mg once daily was the RP2D. Phospho/total AKT ratio decreased with GSK2636771 in tumor and surrogate tissue. A castrate-resistant prostate cancer (CRPC) patient harboring PIK3CB amplification had a partial response for over a year; an additional 10 patients derived durable (≥24 weeks) clinical benefit, including two other patients with CRPC with PIK3CB alterations (≥34 weeks). GSK2636771 400 mg once daily orally induced sufficient exposure and target inhibition with a manageable safety profile.Conclusions: Genomic aberrations of PIK3CB may be associated with clinical benefit from GSK2636771. Clin Cancer Res; 23(19); 5981-92. ©2017 AACR.

Safety and Activity of Varlilumab, a Novel and First-in-Class Agonist Anti-CD27 Antibody, in Patients With Advanced Solid Tumors

Purpose

CD27, a costimulatory molecule on T cells, induces intracellular signals that mediate cellular activation, proliferation, effector function, and cell survival upon binding to its ligand, CD70. Varlilumab is a novel, first-in-class, agonist CD27 antibody that stimulates the CD27 pathway, which results in T-cell activation and antitumor activity in tumor models. This first-in-human, dose-escalation and expansion study evaluated the safety, pharmacology, and activity of varlilumab in patients with advanced solid tumors.

Methods

In a 3 + 3 dose-escalation design (n = 25), patients received a single dose of varlilumab (0.1, 0.3, 1.0, 3.0, or 10 mg/kg intravenously) with a 28-day observation, followed by up to five multidose cycles (one dose per week for 4 weeks), depending on tumor response. Expansion cohorts were initiated at 3.0 mg/kg in patients with melanoma (n = 16) and renal cell carcinoma (RCC; n = 15). Primary objectives were to assess the safety and the maximum tolerated and optimal biologic doses of varlilumab. Secondary objectives were to evaluate the pharmacokinetics, pharmacodynamics, and clinical antitumor activity of varlilumab.

Results

Exposure to varlilumab was linear and dose proportional across dose groups. Only one patient experienced a dose-limiting toxicity—grade 3 transient asymptomatic hyponatremia at the 1.0-mg/kg dose level. Treatment-related adverse events were generally grade 1 or 2 in severity. Evidence of biologic activity consistent with CD27 stimulation—chemokine induction, T-cell stimulation, regulatory T cell depletion—was observed at all dose levels. A patient with metastatic RCC experienced a partial response (78% shrinkage, progression-free survival > 2.3 years). Eight patients experienced stable disease > 3 months, including a patient with metastatic RCC with progression-free survival of > 3.9 years.

Conclusion

Dose escalation of varlilumab to 10 mg/kg was well tolerated without identification of a maximum tolerated dose. Varlilumab was biologically and clinically active.

TAK-228 (formerly MLN0128), an investigational dual TORC1/2 inhibitor plus paclitaxel, with/without trastuzumab, in patients with advanced solid malignancies

PURPOSE

This phase I trial evaluated the safety, pharmacokinetic profile, and antitumor activity of investigational oral TORC1/2 inhibitor TAK-228 plus paclitaxel, with/without trastuzumab, in patients with advanced solid malignancies.

METHODS

Sixty-seven patients received TAK-228 6-40 mg via three dosing schedules; once daily for 3 days (QDx3d QW) or 5 days per week (QDx5d QW), and once weekly (QW) plus paclitaxel 80 mg/m² (dose-escalation phase, n = 47) and with/without trastuzumab 2 mg/kg (expansion phase, n = 20). Doses were escalated using a modified 3 + 3 design, based upon dose-limiting toxicities in cycle 1.

RESULTS

TAK-228 pharmacokinetics exhibited dose-dependent increase in exposure when dosed with paclitaxel and no apparent differences when administered with or 24 h after paclitaxel. Dose-limiting toxicities were dehydration, diarrhea, stomatitis, fatigue, rash, thrombocytopenia, neutropenia, leukopenia, and nausea. The maximum tolerated dose of TAK-228 was determined as 10-mg QDx3d QW; the expansion phase proceeded with 8-mg QDx3d QW. Overall, the most common grade ≥3 drug-related toxicities were neutropenia (21%), diarrhea (12%), and hyperglycemia (12%). Of 54 response-evaluable patients, eight achieved partial response and six had stable disease lasting ≥6 months.

CONCLUSION

TAK-228 demonstrated a safety profile consistent with other TORC inhibitors and promising preliminary antitumor activity in a range of tumor types; no meaningful difference was noted in the pharmacokinetics of TAK-228 when administered with or 24 h after paclitaxel. These findings support further investigation of TAK-228 in combination with other agents including paclitaxel, with/without trastuzumab, in patients with advanced solid tumors. CLINICALTRIALS.

GOV IDENTIFIER

NCT01351350.

Updated results from MONALEESA-2, a phase 3 trial of first-line ribociclib + letrozole in hormone receptor-positive (HR+), HER2-negative (HER2–), advanced breast cancer (ABC)

1038

Background: Endocrine therapy (ET) is the basis of first-line (1L) treatment for HR+ ABC. However, ET resistance are almost universal. At the first interim analysis (IA) of MONALEESA-2 (NCT01958021), ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) + letrozole (LET) significantly prolonged progression-free survival (PFS) vs placebo (PBO) + LET in patients (pts) with HR+, HER2– ABC.1 Here we report updated efficacy and safety data from MONALEESA-2 with a further ~11 months of follow-up. Methods: Postmenopausal women with no prior therapy for ABC were randomized 1:1 toRIB (600 mg/day, 3-weeks-on/1-week-off) + LET(2.5 mg/day, continuous) vs PBO + LET. The primary endpoint was locally assessed PFS. Secondary endpoints include overall survival (OS; key) and safety. OS significance was defined by a p-value threshold of 3.15 x 10-5. Tumor assessments were performed every 8 weeks for the first 18 months, and every 12 weeks, thereafter. Results: 668 pts were enrolled (334 in each arm). At the second IA for OS (data cut-off Jan 2, 2017), the median duration of follow-up was 26.4 months; 116 deaths and 345 PFS events had occurred. OS data remain immature, with 15.0% vs 19.8% of pt deaths in the RIB + LET vs PBO + LET arm (HR = 0.746; 95% CI: 0.517–1.078; p= 0.059). Updated PFS analyses confirmed continued treatment benefit in the RIB + LET vs PBO + LET arm. The 24-month PFS rates (RIB + LET vs PBO + LET) were 54.7% vs 35.9%. Treatment benefit was consistent across pt subgroups. The most common Grade 3/4 laboratory abnormalities (≥10% of pts; RIB + LET vs PBO + LET) were decreased neutrophils (62.6% vs 1.5%), decreased leukocytes (36.8% vs 1.5%), decreased lymphocytes (16.2% vs 3.9%), and elevated alanine aminotransferase (11.4% vs 1.2%). Conclusion: After 26+ months of follow-up, treatment benefit with 1LRIB + LET persists in postmenopausal women with HR+, HER2– ABC. The study remains immature for OS analysis. The safety profile of RIB + LET remains manageable. 1. Hortobagyi G, et al. N Engl J Med 2016;375:1738–48. Clinical trial information: NCT01958021.

First-line ribociclib plus letrozole for postmenopausal women with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC): MONALEESA-2 safety results

1047

Background: In the randomized, phase III MONALEESA-2 study (NCT01958021), first-line therapy with ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor; 600 mg/day; 3-weeks-on/1-week-off) + letrozole (LET; 2.5 mg/day) in postmenopausal women with HR+, HER2– ABC significantly prolonged progression-free survival vs placebo (PBO) + LET (hazard ratio: 0.556; p = 0.00000329; Hortobagyi GN et al. N Engl J Med 2016;375:1738–48). Here we present further safety analyses from MONALEESA-2. Methods: Adverse events (AEs) were characterized per CTCAE v4.03. Analyses of key AEs included time to first event, duration (time to AE resolution), and the rate of associated dose interruptions or reductions. Results: Safety analysis included 664 patients (pts; RIB + LET: 334; PBO + LET: 330). Neutropenia was the most common all-grade (G) and G3/4 AE in the RIB + LET arm (Table); febrile neutropenia rates were low (RIB + LET arm: 1.5%) with no associated deaths. Median time to first event for G ≥2 neutropenia in the RIB + LET arm (based on neutrophil counts) was 16 days. Other common G3/4 AEs (increased by ≥5% in the RIB + LET vs PBO + LET arm) were leukopenia (21% vs 1%), elevated alanine aminotransferase (ALT; 9% vs 1%), lymphopenia (7% vs 1%), and elevated aspartate aminotransferase (AST; 6% vs 1%). Neutropenia was the most common AE leading to dose interruptions/reductions; G3/4 neutropenia led to dose interruptions in 48% vs < 1% and reductions in 30% vs 0% of pts in the RIB + LET vs PBO + LET arm. 7.5% vs 2.1% of pts (RIB + LET vs PBO + LET) discontinued due to AEs; common AEs leading to discontinuation ( > 1% pts) were elevated ALT (5% vs < 1%), elevated AST (3% vs 1%), and vomiting (2% vs 0%). Conclusions: First-line RIB + LET had a manageable safety profile in postmenopausal women with HR+, HER2– ABC. Neutropenia was the most common AE in the RIB arm, and was transient and reversible with dose modifications. Additional AE analyses will be presented. Clinical trial information: NCT01958021. [Table: see text]

A phase I, open-label, first-time-in-patient dose escalation and expansion study to assess the safety, tolerability, and pharmacokinetics of nanoparticle encapsulated Aurora B kinase inhibitor AZD2811 in patients with advanced solid tumours

TPS2608

Background: Aurora kinase B performs key roles in the regulation of the cell cycle and represents a potential target for anticancer therapy. AZD2811, formerly designated AZD1152 hydroxy-quinazoline pyrazole anilide (AZD1152 hQPA), is a potent and selective inhibitor of Aurora B kinase activity and has been incorporated into a polymer nanoparticle carrier for intravenous (IV) administration. The phosphate pro-drug of AZD2811, known as AZD1152 (barasertib), reached Phase II of clinical development as a continuous IV infusion. While promising efficacy was seen with barasertib in elderly acute myeloid leukaemia (AML) patients ( Kantarjian HG et al., Cancer 2013;119:2611-19), continuous intravenous drug delivery precluded subsequent development in this disease setting and there were limited clinical responses in solid tumour patients due to dose-limiting myelotoxicity. AZD2811 nanoparticle has been designed to overcome these issues. Methods: Patients with relapsed advanced solid malignancies with no standard treatments are eligible for the part A dose escalation. Primary endpoint is to determine the maximum tolerated dose of AZD2811 nanoparticle using a 3+3 design. Patients with refractory/relapsed small cell lung cancer (SCLC) will be eligible for the part B expansion, where the safety, PK and anti-tumour activity of AZD2811 nanoparticle will be assessed as monotherapy and in combination with chemotherapy. Study enrolment is ongoing. Clinical trial information: NCT02579226.

Phase I study of AG-120, an IDH1 mutant enzyme inhibitor: Results from the cholangiocarcinoma dose escalation and expansion cohorts

4015

Background: Mutations in the metabolic enzyme isocitrate dehydrogenase 1 (mIDH1) occur in patients (pts) with cholangiocarcinoma (CC) and are detected in up to 25% of intrahepatic CC. mIDH1 produce the oncometabolite, D-2-hydroxyglutarate (2-HG), resulting in epigenetic and genetic dysregulation and oncogenesis. AG-120 is a first-in-class, potent, oral inhibitor of mIDH1 tested in this phase I study in mIDH1 solid tumors, including CC. Methods: AG-120 was escalated in a 3+3 design from 100 mg twice daily to 1200 mg once daily (QD) in 28-day cycles (N = 60, mIDH1 advanced solid tumors). Key eligibility for CC: recurrence of progressive mIDH1 CC following standard therapy (dose escalation) or at least a prior gemcitabine-based regimen (expansion cohort). Response (RECIST 1.1) was assessed every 8 weeks. Plasma and tumor tissue were collected for exploratory analyses. Results: Based on the safety, pharmacokinetic, and pharmacodynamic data from dose escalation, the 500 mg QD dose was selected for expansion in mIDH1 CC and other mIDH1 solid tumors. As of Dec 16, 2016, 73 pts with mIDH1 CC had been dosed in the dose escalation (n = 24) and expansion (n = 49) cohorts. Demographics: M/F = 24/49, median number of prior therapies = 2 (range 1–5), ECOG 0–1 = 26/47. There were no dose-limiting toxicities. Treatment-related adverse events (AEs) in ≥5% pts: fatigue (21%), nausea (18%), vomiting (12%), diarrhea (10%), decreased appetite (8%), dysgeusia (5%), QT prolongation (5%). Two (3%) pts experienced related grade 3 AEs: fatigue and low phosphorus. There were no AG-120-related AEs leading to discontinuation. Among the 72 efficacy evaluable (≥1 post baseline response assessment or discontinued prematurely) mIDH1 CC pts (24 in escalation and 48 in expansion cohort), 6% (n = 4) had a confirmed partial response and 56% (n = 40) experienced stable disease. The progression-free survival rate at 6 months was 40%, and 8 pts have been treated with AG-120 for ≥1 year. Conclusions: In this pretreated mIDH1 CC population, AG-120 was associated with a favorable safety profile and prolonged stable disease. A global, phase III, randomized, placebo-controlled study of AG-120 in mIDH1 CC has been initiated (ClarIDHy). Clinical trial information: NCT02073994.

Phase III, randomized study of first-line trastuzumab emtansine (T-DM1) ± pertuzumab (P) vs. trastuzumab + taxane (HT) treatment of HER2-positive MBC: Final overall survival (OS) and safety from MARIANNE

1003

Background: In MARIANNE (NCT01120184), patients with HER2-positive advanced breast cancer were randomized to trastuzumab + docetaxel or paclitaxel (HT; n=365), T-DM1 + placebo (T-DM1; n=367), or T-DM1 + P (T-DM1 + P; n=363) as first-line therapy. In the primary analysis, T-DM1–based treatment exhibited noninferior, but not superior, progression-free survival relative to HT (Perez EA, et al. J Clin Oncol 2016). OS was similar between treatments in the first interim analysis. Here we report OS from the final descriptive analysis. Methods: Enrolled patients had centrally assessed HER2-positive (IHC3+ or ISH+) progressive/recurrent locally advanced breast cancer or previously untreated MBC with a ≥6-month interval since (neo)adjuvant treatment with taxanes or vinca alkaloids. Results: At the clinical cutoff date of May 15, 2016, median follow-up was 54 months and 512 patients had died. Median OS was 50.9, 53.7, and 51.8 months with HT, T-DM1, and T-DM1 + P, respectively (Table). A sensitivity analysis in which HT-treated patients who received T-DM1 and/or P after disease progression (n=85) were censored prior to treatment switch found similar results. There were numerically fewer grade ≥3 adverse events (AEs) with T-DM1. Conclusions: With this longer follow-up, the T-DM1 safety profile was consistent with the primary analysis and prior experience. While OS was similar across treatment arms, a median OS of 53.7 months and fewer grade ≥3 AEs (vs other arms) supports T-DM1 as an effective and tolerable alternative first-line treatment for HER2-positive MBC patients. Clinical trial information: NCT01120184. [Table: see text]

A phase Ib, first-in-human, dose escalation and expansion study of XMT-1522, a novel antibody-drug conjugate (ADC) directed against HER2, in patients with advanced breast cancer and other advanced tumors expressing HER2

TPS2606

Background: XMT-1522 is an ADC consisting of a novel human IgG1 anti-HER2 monoclonal antibody conjugated to an auristatin-based cytotoxic payload (AF-HPA). An average of 12 AF-HPA molecules is conjugated to each antibody via a biodegradable polymer. In pre-clinical xenograft experiments XMT-1522 achieved complete, durable tumor regressions in models of HER2-positive and HER2 1+/2+ breast cancer, HER2 2+/3+ NSCLC, and HER2-positive and HER2 1+ gastric cancer. Methods: This study (NCT02952729) is comprised of two parts: a dose escalation segment (DES) and an expansion segment (EXP). The primary objectives of the DES are determination of the maximum tolerated dose and recommended Phase 2 dose (RP2D) and assessment of safety and tolerability. The DES will enroll patients with advanced or metastatic breast cancer who have progressed following standard therapies and have HER2 protein at least 1+ by IHC. XMT-1522 will be administered intravenously every 3 weeks. DES uses a 3+3 design. Post-dose assessments include LVEF measurement at the end of cycles 1, 3, then every 3 cycles, ophthalmologic exams at the end of cycles 1, 2, then every 2 cycles, and re-staging CT scans every 2 cycles. Pharmacokinetics of antibody, AF-HPA payload and an AF-HPA metabolite will be measured. Two patients have completed dose level 1 without DLT. The EXP segment will open at the RP2D and will further assess safety and tolerability of XMT-1522 and assess efficacy in selected patient populations. EXP will enroll 4 cohorts (N = 20 each). Cohort 1: HER2 1+/2+ advanced breast cancer with 2-3 prior chemotherapy regimens Cohort 2: HER2-positive advanced breast cancer with prior pertuzumab and ado-trastuzumab emtansine (T-DM1) Cohort 3: HER2-positive advanced gastric cancer with prior trastuzumab Cohort 4: HER2 2+/3+ NSCLC with at least 1 prior platinum regimen The protocol requires archival tumor tissue for central confirmation of HER2 status, alternative HER2 measurements, and targeted gene expression and sequencing studies. Tumor biopsies will be requested at the time of progression from patients who responded to XMT-1522. Clinical trial information: NCT02952729.

Health-related quality of life (HRQoL) of postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) treated with ribociclib + letrozole: Results from MONALEESA-2

1020

Background: In the MONALEESA-2 trial, ribociclib + letrozole significantly improved progression-free survival (PFS) and showed higher overall response rates vs letrozole alone in HR+, HER2– ABC. To place these clinical results in the context of patient experience, here we present key patient-reported outcomes (PROs) including HRQoL. Methods: 668 patients were randomized (1:1); 334 each to the ribociclib + letrozole and placebo + letrozole arms. PROs were evaluated during treatment and at progression using the EORTC QLQ-C30, QLQ-BR23, and EQ-5D-5L questionnaires. Changes from baseline in all subscales were analyzed using a linear mixed-effect model and time to 10% deterioration was compared between treatment arms using the stratified log-rank test. Results: Questionnaire compliance rates were high (≥90%). During treatment, HRQoL (global health status/QoL score) was maintained and similar in both treatment arms. At progression/end of treatment, HRQoL worsened numerically in both arms. Time to definitive 10% deterioration of HRQoL was similar between treatment groups, slightly favoring the ribociclib + letrozole arm (hazard ratio: 0.89; 95% confidence interval: 0.67–1.18). No statistically or clinically relevant differences were observed for key symptoms using EORTC QLQ-C30 including fatigue, nausea, and vomiting. There was a clinically relevant ( > 5 points) improvement in pain from baseline to post-baseline (up to Cycle 15) in the ribociclib + letrozole arm while there was only mild improvement ( < 5 points) observed in the placebo + letrozole arm. Conclusions: In addition to significantly improving PFS, ribociclib + letrozole maintains HRQoL when compared with letrozole + placebo. A numerical trend was observed favoring ribociclib + letrozole for pain reduction. Clinical trial information: NCT01958021.

A phase Ib dose escalation study of combined inhibition of IDO1 (GDC-0919) and PD-L1 (atezolizumab) in patients (pts) with locally advanced or metastatic solid tumors

105

Background: GDC-0919, a small molecule inhibitor of indoleamine-2,3-dioxygenase 1 (IDO1), reduces tryptophan catabolism and kynurenine production within the tumor microenvironment that may promote normal effector T cell activity and an immunogenic state. IDO1 inhibition may complement targeting of PD-L1 with atezolizumab. Methods: A Phase Ib, open-label, study assessed safety, pharmacokinetics (PK), pharmacodynamics (PD), and anti-tumor activity (RECIST v1.1) of GDC-0919 and atezolizumab in pts with locally advanced or metastatic solid tumors. Pts were given escalating doses of GDC-0919 (50-1000 mg orally twice daily, for 21 days) and atezolizumab (1200 mg IV, every 3 weeks) using a standard 3+3 design. Results: As of 14Dec2016, 52 pts were treated in 6 cohorts of GDC-0919 plus atezolizumab. The median number of prior systemic therapies was 3 (range 1-9); 2 pts received prior immunotherapy. Pts received a median of 4 cycles of GDC-0919 and atezolizumab (range 1-17). No MTD was identified. Across all dose levels, 1 DLT was observed (Grade [G] 3 sepsis syndrome at GDC-0919 200 mg); no G4/5 AEs were attributed to study treatment. G3+ AEs, regardless of causality were reported in 34 (65%) pts. Related G3 AEs were reported in 7 (13%) pts, included nausea, rash, sepsis syndrome, fatigue, and pneumonitis. Two pts (4%) had AEs leading to treatment discontinuation, related in 1/2 (G3 pneumonitis). Combination PK was consistent with single agent observations and supports BID dosing of GDC-0919. Peripheral PD showed dose-dependent decreases in plasma kynurenine, consistent with systemic modulation of IDO1. Preliminary efficacy data from 45 pts with ≥ 1 on-treatment tumor assessments included 4 patients (9%) with partial response and 11 (24%) pts with stable disease. Conclusions: The combination of GDC-0919 and atezolizumab was generally well-tolerated and demonstrated peripheral IDO1 modulation and preliminary efficacy in a heterogeneous patient population during dose escalation. The study is currently enrolling pts with select tumor types in expansion cohorts to assess tumor PD and combination efficacy. Clinical trial information: NCT02471846.

Phase 1 safety of ICOS agonist antibody JTX-2011 alone and with nivolumab (nivo) in advanced solid tumors; predicted vs observed pharmacokinetics (PK) in ICONIC

3033

Background: JTX-2011 is an agonist monoclonal antibody that targets ICOS, Inducible CO-Stimulator of T cells. A dual mechanism of action is intended to activate antigen-specific CD4 T effector cells and selectively deplete intratumoral T regulatory cells. JTX-2011 is equally potent across human, rodent, and non-human primate species. Methods: A quantitative systems pharmacology (QSP) model describing target binding by JTX-2011 and target mediated drug disposition in blood, tumor and non-tumor tissues was based on preclinical potency and non-linear PK data across species. The model was translated to predict PK and target engagement (TE) in humans to facilitate dose selection. The QSP model predicts > 95% TE for 21 days at the top planned dose. We present safety and actual/predicted PK from a Phase 1 study of JTX-2011 alone (Part A) and safety in combination with nivo (Part B). Results: 25 subjects have been dosed, 19 in 4 cohorts of JTX-2011 alone at .003, .01, .03, and .1 mg/kg IV q 21 days, and 6 in 2 cohorts of JTX-2011 .01 mg/kg and .03 mg/kg IV plus nivo 240 mg IV q21 days. Safety data from ≥ 1 cycle is available for 12 subjects in Part A (7 ≥ 3 cycles), and 3 in Part B (all ≥ 3 cycles). PK data is available for cycle 1 of Part A. Mean age (±SD) is 60 (±10.6). Mean prior systemic therapies is > 5 (range 1-11). Tumor types include endometrial, triple negative breast, melanoma, lung, pancreatic and colorectal cancers. No dose limiting toxicities have been reported. 3 Grade 3 adverse events (AEs) were reported in 2 Part A subjects: anemia and hypoxia (unrelated SAE) at .003 mg/kg and JTX-2011 related diarrhea at .1 mg/kg. Grade 1-2 AEs in ≥2 subjects are chills, pyrexia, neck pain, dizziness, and nausea. 5 subjects had JTX-2011 related Grade 1-2 infusion reactions up to 6 hours post infusion. Non-linear exposure increase was observed. While PK at lower doses is consistent with model predictions, AUC and t1/2at 0.03 and 0.1 mg/kg doses are higher than predicted, suggesting higher than predicted TE. Conclusions: JTX-2011 has been well tolerated up to 0.1 mg/kg and with nivo at .01 mg/kg IV q 21 days. Greater than linear exposure increase was observed and TE may be higher than QSP model prediction. Clinical trial information: NCT02904226.

Targeted therapy for advanced salivary cancer with HER2 or hedgehog alterations: Interim data from MyPathway

6086

Background: Salivary gland cancers comprise <1% of cancers. Advanced cases have a 40% 5-year survival rate. Due to their rarity, no standard treatment guidelines exist. However, salivary duct carcinomas have morphological and gene expression profiles similar to breast cancers, and 20–40% of this subset have HER2 alterations. MyPathway (NCT02091141) is an ongoing, phase 2, multi-basket study evaluating the efficacy of targeted treatments in nonindicated tumor types with alterations in the HER2, BRAF, Hedgehog (Hh), or EGFR pathways. We present interim data for patients with salivary cancer. Methods: Patients had advanced salivary cancer with HER2 (amplification, overexpression, and/or mutation) or Hh (SMO or PTCH-1) alterations, locally assessed by gene sequencing, FISH, or IHC, as applicable. Patients received standard doses of pertuzumab + trastuzumab or vismodegib, respectively, until disease progression or unacceptable toxicity. The primary endpoint is investigator-assessed objective response rate (ORR) by RECIST v1.1. Results: As of Nov 30, 2016, 8 patients had been treated for salivary cancer, all carcinomas (7 had HER2 alterations; 1 had an Hh alteration). One HER2 patient without a post-baseline tumor assessment by data cut-off was not evaluable for efficacy. Characteristics and outcomes are shown (Table). Of 6 patients with a complete response (CR) or partial response (PR), 5 patients were still receiving study treatment by the data cut-off, with a median time on treatment of 4.6 months (range 1.4–12.5). There were no new safety signals. Conclusions: Six of 7 patients (86%) with advanced salivary carcinoma achieved CR or PR by targeting HER2 (n=5) or Hh (n=1) alterations. These promising results merit study of these treatments in additional patients. Accrual to MyPathway is ongoing. Clinical trial information: NCT02091141. [Table: see text]

Targeted therapy for non-small cell lung cancer (NSCLC) with HER2, BRAF, or hedgehog alterations: Interim data from MyPathway

9073

Background: Treatments targeting critical molecular alterations (EGFR, ALK, and ROS1) in NSCLC are highly effective. MyPathway (NCT02091141) is an ongoing, phase 2, multi-basket study evaluating the efficacy of targeted treatment in non-indicated tumor types harboring alterations in the HER2, BRAF, Hedgehog (Hh), or EGFR pathways. Interim results in NSCLC are presented. Methods: Patients with previously treated advanced NSCLC and alterations in the HER2 (amplification and/or mutation), BRAF (V600E or other mutations), Hh (SMO or PTCH-1 mutations), or EGFR (mutations other than known activating mutations) pathways received standard doses of pertuzumab + trastuzumab, vemurafenib, vismodegib, or erlotinib, respectively, until disease progression or unacceptable toxicity. The HER2, BRAF, and Hh cohorts are included in this analysis. The primary endpoint is investigator-assessed objective response rate (ORR, defined as complete response [CR] + partial response [PR]) by RECIST v1.1. Results: As of November 30, 2016, 61 patients with NSCLC and HER2 (n = 36), BRAF (n = 22), or Hh (n = 3) alterations have been treated (median age of 64 years, 49% male, 85% adenocarcinoma, and a median of 2 previous regimens). Median treatment duration was 1.8 (range, 0–21.4) months. Efficacy in the 55 patients with the minimum required follow-up for efficacy analysis is summarized in the table. Conclusions: Targeted therapy is active in patients with previously treated NSCLC harboring BRAF V600E mutations or HER2 alterations (amplifications and/or mutations). These cohorts have been expanded as MyPathway accrual continues. Additional efficacy data and details regarding molecular alterations will be presented. Clinical trial information: NCT02091141. [Table: see text]

TITAN: phase III study of doxorubicin/cyclophosphamide followed by ixabepilone or paclitaxel in early-stage triple-negative breast cancer

PURPOSE

Ixabepilone is a microtubule stabilizer with activity in taxane-refractory metastatic breast cancer and low susceptibility to taxane-resistance mechanisms including multidrug-resistant phenotypes and high β-III tubulin expression. Since these resistance mechanisms are common in triple-negative breast cancer (TNBC), ixabepilone may have particular advantages in this patient population. This study evaluated the substitution of ixabepilone for paclitaxel following doxorubicin/cyclophosphamide (AC) in the adjuvant treatment of early-stage TNBC.

METHODS

Patients with operable TNBC were eligible following definitive breast surgery. Patients were randomized (1:1) to receive four cycles of AC followed by either four cycles (12 weeks) of ixabepilone or 12 weekly doses of paclitaxel.

RESULTS

614 patients were randomized: 306 to AC/ixabepilone and 308 to AC/paclitaxel. At a median follow-up of 48 months, 59 patients had relapsed (AC/ixabepilone, 29; AC/paclitaxel, 30). The median time from diagnosis to relapse was 20.8 months. The 5-year disease-free survival (DFS) rates of the two groups were similar [HR 0.92; ixabepilone 87.1% (95% CI 82.6-90.5) vs. paclitaxel 84.7% (95% CI 79.7-88.6)]. The estimated 5-year overall survival (OS) rates were also similar [HR 1.1; ixabepilone 89.7% (95% CI 85.5-92.7) vs. paclitaxel 89.6% (95% CI 85.0-92.9)]. Peripheral neuropathy was the most common grade 3/4 event. Dose reductions and treatment discontinuations occurred more frequently during paclitaxel treatment.

CONCLUSIONS

Treatment with AC/ixabepilone provided similar DFS and OS in patients with operable TNBC when compared to treatment with AC/paclitaxel. The two regimens had similar toxicity, although treatment discontinuation, dose modifications, and overall peripheral neuropathy were more frequent with AC/paclitaxel.

TRIAL REGISTRATION

Clinical Trials.gov Identifier, NCT00789581.

First-in-human phase 1 study of margetuximab (MGAH22), an Fc-modified chimeric monoclonal antibody, in patients with HER2-positive advanced solid tumors

Background

Margetuximab is an anti-HER2 antibody that binds with elevated affinity to both the lower and higher affinity forms of CD16A, an Fc-receptor important for antibody dependent cell-mediated cytotoxicity (ADCC) against tumor cells. A Phase 1 study was initiated to evaluate the toxicity profile, maximum tolerated dose (MTD), pharmacokinetics, and antitumor activity of margetuximab in patients with HER2-overexpressing carcinomas.

Patients and methods

Patients with HER2-positive breast or gastric cancer, or other carcinomas that overexpress HER2, for whom no standard therapy was available, were treated with margetuximab by intravenous infusion at doses of 0.1-6.0 mg/kg for 3 of every 4 weeks (Regimen A) or once every 3 weeks (10-18 mg/kg) (Regimen B).

Results

Sixty-six patients received margetuximab (34 patients for Regimen A and 32 patients for Regimen B). The MTD was not reached for either regimen. Treatment was well-tolerated, with mostly Grade 1 and 2 toxicities consisting of constitutional symptoms such as pyrexia, nausea, anemia, diarrhea, and fatigue. Among 60 response-evaluable patients, confirmed partial responses and stable disease were observed in 7 (12%) and 30 (50%) patients, respectively; 26 (70%) of these patients had received prior HER2-targeted therapy. Tumor reductions were observed in over half (18/23, 78%) of response-evaluable patients with breast cancer including durable (>30 weeks) responders. Ex vivo analyses of patient peripheral blood mononuclear cell samples confirmed the ability of margetuximab to support enhanced ADCC compared with trastuzumab.

Conclusions

Margetuximab was well-tolerated and has promising single-agent activity. Further development efforts of margetuximab as single agent and in combination with other therapeutic agents are ongoing.

Trial Registration ID

NCT01148849.

A phase I dose-escalation study of Selumetinib in combination with Erlotinib or Temsirolimus in patients with advanced solid tumors

Background Combinations of molecularly targeted agents may provide optimal anti-tumor activity and improve clinical outcomes for patients with advanced cancers. Selumetinib (AZD6244, ARRY-142886) is an oral, potent and highly selective, allosteric inhibitor of MEK1/2, a component of the RAS/RAF/MEK/ERK pathway which is constitutively activated in many cancers. We investigated the safety, tolerability, and pharmacokinetics (PK) of selumetinib in combination with molecularly targeted drugs erlotinib or temsirolimus in patients with advanced solid tumors. Methods Two-part study: dose escalation, to determine the maximum tolerated dose (MTD) of selumetinib in combination with erlotinib 100 mg once daily (QD) or temsirolimus 25 mg once weekly, followed by dose expansion at the respective combination MTDs to further investigate safety and anti-tumor effects. Results 48 patients received selumetinib plus erlotinib and 32 patients received selumetinib plus temsirolimus. The MTD with erlotinib 100 mg QD was selumetinib 100 mg QD, with diarrhea being dose limiting. The most common all grade adverse events (AEs): diarrhea, rash, nausea, and fatigue. Four (8.3%) patients had ≥12 weeks stable disease. The MTD with temsirolimus 25 mg once weekly was selumetinib 50 mg twice daily (BID), with mucositis and neutropenia being dose limiting. The most commonly reported AEs: nausea, fatigue, diarrhea, and mucositis. Ten (31.3%) patients had ≥12 weeks stable disease. The combination PK profiles were comparable to previously observed monotherapy profiles. Conclusions MTDs were established for selumetinib in combination with erlotinib or temsirolimus. Overlapping toxicities prevented the escalation of selumetinib to its recommended phase II monotherapy dose of 75 mg BID.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00600496; registered 8 July 2009.

A Phase I/Ib Study of Enzalutamide Alone and in Combination with Endocrine Therapies in Women with Advanced Breast Cancer

Purpose: Several lines of evidence support targeting the androgen signaling pathway in breast cancer. Enzalutamide is a potent inhibitor of androgen receptor signaling. Preclinical data in estrogen-expressing breast cancer models demonstrated activity of enzalutamide monotherapy and enhanced activity when combined with various endocrine therapies (ET). Enzalutamide is a strong cytochrome P450 3A4 (CYP3A4) inducer, and ETs are commonly metabolized by CYP3A4. The pharmacokinetic (PK) interactions, safety, and tolerability of enzalutamide monotherapy and in combination with ETs were assessed in this phase I/Ib study.Experimental Design: Enzalutamide monotherapy was assessed in dose-escalation and dose-expansion cohorts of patients with advanced breast cancer. Additional cohorts examined effects of enzalutamide on anastrozole, exemestane, and fulvestrant PK in patients with estrogen receptor-positive/progesterone receptor-positive (ER⁺/PgR⁺) breast cancer.Results: Enzalutamide monotherapy (n = 29) or in combination with ETs (n = 70) was generally well tolerated. Enzalutamide PK in women was similar to prior data on PK in men with prostate cancer. Enzalutamide decreased plasma exposure to anastrozole by approximately 90% and exemestane by approximately 50%. Enzalutamide did not significantly affect fulvestrant PK. Exposure of exemestane 50 mg/day given with enzalutamide was similar to exemestane 25 mg/day alone.Conclusions: These results support a 160 mg/day enzalutamide dose in women with breast cancer. Enzalutamide can be given in combination with fulvestrant without dose modifications. Exemestane should be doubled from 25 mg/day to 50 mg/day when given in combination with enzalutamide; this combination is being investigated in a randomized phase II study in patients with ER⁺/PgR⁺ breast cancer. Clin Cancer Res; 23(15); 4046-54. ©2017 AACR.

A phase I dose-escalation study of selumetinib in combination with docetaxel or dacarbazine in patients with advanced solid tumors

Background

The RAS/RAF/MEK/ERK pathway is constitutively activated in many cancers. Selumetinib (AZD6244, ARRY-142886) is an oral, potent and highly selective, allosteric MEK1/2 inhibitor with a short half-life that has shown clinical activity as monotherapy in phase I and II studies of advanced cancer. Preclinical data suggest that selumetinib may enhance the activity of chemotherapeutic agents. We assessed the safety, tolerability, and pharmacokinetics (PK) of selumetinib (AZD6244, ARRY-142886) in combination with docetaxel or dacarbazine in patients with advanced solid tumors.

Methods

This study was a phase I, open-label, multicenter study in patients aged ≥18 years with advanced solid tumors who were candidates for docetaxel or dacarbazine treatment. Part A of the study (dose escalation) evaluated safety, tolerability, PK, and maximum tolerated dose (MTD) of selumetinib twice daily (BID) with docetaxel 75 mg/m² or dacarbazine 1000 mg/m² administered every 21 days. Patients receiving docetaxel could be administered primary prophylactic granulocyte-colony stimulating factor according to standard guidelines. Part B of the study (dose expansion) further evaluated safety, tolerability, and PK in 12 additional patients at the MTD combinations determined in part A.

Results

A total of 35 patients received selumetinib plus docetaxel, and 25 received selumetinib plus dacarbazine. The MTD of selumetinib was 75 mg BID in combination with either docetaxel (two dose-limiting toxicity [DLT] events: neutropenia with fever, and thrombocytopenia) or dacarbazine (one DLT event: thrombocytopenia). Common adverse events occurring with each treatment combination were diarrhea, peripheral/periorbital edema, fatigue, and nausea. PK parameters for selumetinib and docetaxel or dacarbazine were similar when administered alone or in combination. Partial responses were reported in 6/35 patients receiving selumetinib plus docetaxel and 4/25 patients receiving selumetinib plus dacarbazine.

Conclusions

The combinations of selumetinib plus docetaxel and selumetinib plus dacarbazine demonstrated manageable safety and tolerability profiles and preliminary signs of clinical activity in patients with advanced solid tumors.

Trial registration

ClinicalTrials.gov NCT00600496; registered 8 July 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3143-6) contains supplementary material, which is available to authorized users.

Safety and activity of IT-139, a ruthenium-based compound, in patients with advanced solid tumours: a first-in-human, open-label, dose-escalation phase I study with expansion cohort

OBJECTIVE

This phase I clinical study (NCT01415297) evaluated the safety, tolerability, maximum-tolerated dose (MTD), pharmacokinetics and pharmacodynamics of IT-139 (formerly NKP-1339) monotherapy in patients with advanced solid tumours. IT-139, sodium trans-(tetrachlorobis(1H-indazole)ruthenate(III)), is a novel small molecule that suppresses the stress induction of GRP78 in tumour cells. GRP78 is a key regulator of misfolded protein processing, and its upregulation in tumours is associated with intrinsic and drug-induced resistance.

METHODS

Forty-six patients with advanced solid tumours refractory to treatment received intravenous infusions of IT-139 on days 1, 8 and 15 for every 28 days, and doses were evaluated across nine cohorts at 20, 40, 80, 160, 320, 420, 500, 625 and 780 mg/m².

RESULTS

Overall, IT-139 was well tolerated. The treatment-emergent adverse events (AEs) occurring in ≥20% of patients were nausea, fatigue, vomiting, anaemia and dehydration. The majority of patients had AEs that were ≤grade 2, regardless of relationship with the study drug. Of the total 38 efficacy-evaluable patients, one patient with a carcinoid tumour achieved a durable partial response. Nine additional patients achieved stable disease . The MTD was determined to be 625 mg/m². IT-139 exhibited first-order linear pharmacokinetics.

CONCLUSIONS

IT-139 demonstrated a manageable safety profile at the MTD and modest anti-tumour activity in this study of patients with solid tumours refractory to treatment. The lack of dose-limiting haematological toxicity and the absence of neurotoxicity position IT-139 well for use in combination with a broad spectrum of anticancer drugs.

TRIAL REGISTRATION NUMBER

NCT01415297.

Pertuzumab plus trastuzumab for HER2-positive metastatic urothelial cancer (mUC): Preliminary data from MyPathway

348

Background: Patients (pts) with mUC have few treatment options beyond the second-line setting. HER2 gene amplification has been reported in a minority of pts with UC, but there have been anecdotal reports of the activity of HER2-targeted agents. MyPathway is a multi-basket study evaluating the efficacy and safety of targeted therapies in non-indicated tumor types harboring relevant molecular alterations. We present preliminary data for pts with HER2-positive mUC receiving HER2-targeted treatment with pertuzumab + trastuzumab. Methods: MyPathway (NCT02091141) is an open-label, multicenter, phase IIA study. Pts in this subset analysis had refractory mUC with HER2 amplification or putative activating mutations by gene sequencing, FISH, or IHC. Pts received standard doses of pertuzumab + trastuzumab without chemotherapy until disease progression or unacceptable toxicity. The primary endpoint is investigator-assessed overall response rate (RECIST v1.1). Results: As of July 31, 2016, 12 pts with platinum-resistant HER2-positive mUC (HER2-amplified, n=9; HER2-mutated, n=3) have been enrolled. At a median follow-up of 5.4 (range 0.9–14.5) mos, 1 pt had complete response (CR, ongoing at 12.5 mos), 2 had partial responses (PR; duration of response, 3.7 and 5.5 mos), and 2 had stable disease (SD) for >4 mos (Table). Safety was consistent with the product labels. Conclusions: Preliminary results indicate that the combination of pertuzumab + trastuzumab has activity in previously treated HER2-amplified mUC, including a durable CR in a pt with peritoneal metastases. Accrual to MyPathway is ongoing. Clinical trial information: NCT02091141. [Table: see text]

Atezolizumab (atezo) in patients with metastatic urothelial carcinoma (mUC): A 2-year clinical update from a phase Ia study

290

Background: Atezo (anti–PD-L1) has demonstrated safety and efficacy in a broad range of cancers and is approved in the United States for mUC previously treated with platinum-based chemotherapy. Here we report long-term results in mUC from Phase Ia study NCT01375842 (PCD4989g). Methods: Previously treated mUC patients received atezo 15 mg/kg or 1200 mg IV q3w. Enrollment in this Phase Ia expansion cohort initially required PD-L1–selected status and later opened to patients regardless of PD-L1 expression on tumor-infiltrating immune cells. The primary endpoint was safety/tolerability. Secondary endpoints included investigator-assessed RECIST v1.1 ORR (confirmed), DOR and OS. Results: 95 patients were safety evaluable (Table). Median age was 66 years, 76% were male and 80% had primary bladder tumors. 61% had ECOG PS 1. 52% received ≥ 3 prior systemic therapies for mUC (70% platinum). Median treatment duration was 3 months (range: 0-32 months); 24% were treated for ≥ 1 year. Treatment-related AEs occurred in 66% (all Grade) and 8% (Grade 3-4) of patients. No treatment-related deaths were reported. In 94 objective response–evaluable patients (follow-up ≥ 12 weeks), the ORR was 27% (95% CI: 18, 37%), and the CR rate was 10%; the SD rate was 19%. mDOR was 22.1 months (95% CI: 12.1, NE months) in all patients; 56% of responses (7/9 CRs and 7/16 PRs) were ongoing at the December 15, 2015 data cutoff. With a 24-month median follow-up duration (range: 1+ to 32 months), the 1-year OS rate was 47% (95% CI: 36, 58%), and the 2-year rate was 29% (19, 40%); mOS is in the Table. Updated clinical data with further follow-up and analyses by PD-L1 status will be presented. Conclusions: Long-term treatment with atezo was well tolerated, without new safety signals in heavily pre-treated mUC patients. The durability of responses, including CRs, along with extended OS, confirm atezo as a new standard for previously treated mUC patients. Clinical trial information: NCT01375842. [Table: see text]

Abstract P4-22-16: First-line ribociclib + letrozole in patients with HR+, HER2– advanced breast cancer (ABC) presenting with visceral metastases or bone-only disease: A subgroup analysis of the MONALEESA-2 trial

Background: Patients with ABC who present with visceral metastases have a worse outcome than patients with non-visceral disease, while patients with bone-only disease tend to have a better prognosis. Ribociclib (LEE011) is an oral, selective inhibitor of cyclin-dependent kinase (CDK) 4/6. In a Phase 3, placebo-controlled, randomized trial (MONALEESA-2; NCT01958021), first-line ribociclib (R) + letrozole (L) significantly prolonged progression-free survival (PFS) vs placebo (P) + L in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) ABC, with a hazard ratio of 0.556 (95% confidence interval [CI]: 0.429–0.720; p=0.00000329) at the interim analysis cut-off date (Jan 29, 2016). Here, we present subgroup analyses in patients with visceral metastases, and those with bone-only disease.

Methods: Postmenopausal women with HR+, HER2– ABC were randomized 1:1 to receive R (600 mg/day; 3-weeks-on/1-week-off) + L (2.5 mg/day; continuous) or P+L, stratified by the presence of liver and/or lung metastases. No prior CDK4/6 inhibitors or systemic therapy for ABC were allowed. Eligible patients had Eastern Cooperative Oncology Group performance status ≤1, baseline alanine/aspartate aminotransferase levels &lt;5× upper limit of normal (ULN) or &lt;2.5× ULN for patients with or without liver metastases, respectively, and ≥1 predominantly lytic bone lesion at baseline for patients with bone-only disease. Locally assessed PFS was analyzed for all patients (primary endpoint), and for predefined patient subgroups.

Results: Overall, 668 patients were randomized; 393 had visceral metastases and 147 had bone-only disease.

 Visceral metastasesBone-only disease n=393n=147 R+LP+LR+LP+L n=197n=196n=69n=78Median age, years (range)63 (23–91)63 (29–88)65 (37–85)63 (37–84)De novo metastatic disease, n (%)53 (27)55 (28)28 (41)24 (31)Non-de novo disease-free interval, n (%)≤24 months12 (6)15 (8)5 (7)6 (8)&gt;24 months132 (67)126 (64)36 (52)48 (62)Discontinued treatment, n (%)83 (42)111 (57)29 (42)40 (51)Reason for discontinuation, n (%)Disease progression56 (28)93 (47)17 (25)31 (40)Patient/physician decision10 (5)15 (8)7 (10)6 (8)Adverse events16 (8)3 (2)4 (6)2 (3)Protocol deviation001 (1)1 (1)Death1 (&lt;1)000

In patients with visceral metastases: Median PFS was not reached in the R+L arm (95% CI: 19.3–not estimable [NE]) vs 13.0 months (95% CI: 12.6 –16.5) in the P+L arm, with hazard ratio 0.535 (95% CI: 0.385–0.742). Median duration of exposure was 12.0 and 13.0 months (R and L, respectively) in the R+L arm, and 12.1 and 12.2 months (P and L, respectively) in the P+L arm.

In patients with bone-only disease: Median PFS was not reached in the R+L arm (95% CI: NE–NE) vs 15.3 months (95% CI: 13.8–NE) in the P+L arm, with hazard ratio 0.690 (95% CI: 0.381–1.249). Median duration of exposure was 12.1 and 12.6 months (R and L, respectively) in the R+L arm, and 12.7 and 12.9 months (P and L, respectively) in the P+L arm.

Conclusions: First-line R+L was well tolerated and significantly prolonged PFS vs P+L in postmenopausal women with HR+, HER2– ABC, both in patients with visceral metastases and those with bone-only disease.

Keywords: Advanced breast cancer; CDK4/6 inhibitor; Letrozole; Ribociclib

Citation Format: Burris HA, Chan A, Campone M, Blackwell KL, Winer EP, Janni W, Verma S, Burdaeva O, Alba E, Favret AM, Mondal S, Miller M, Germa C, Hirawat S, Yap YS. First-line ribociclib + letrozole in patients with HR+, HER2– advanced breast cancer (ABC) presenting with visceral metastases or bone-only disease: A subgroup analysis of the MONALEESA-2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-16.