Phase I study of peposertib and avelumab with or without palliative radiotherapy in patients with advanced solid tumors

INTRODUCTION

We report results from a phase I, three-part, dose-escalation study of peposertib, a DNA-dependent protein kinase inhibitor, in combination with avelumab, an immune checkpoint inhibitor, with or without radiotherapy in patients with advanced solid tumors.

MATERIALS AND METHODS

Peposertib 100-400 mg twice daily (b.i.d.) or 100-250 mg once daily (q.d.) was administered in combination with avelumab 800 mg every 2 weeks in Part A or avelumab plus radiotherapy (3 Gy/fraction × 10 days) in Part B. Part FE assessed the effect of food on the pharmacokinetics of peposertib plus avelumab. The primary endpoint in Parts A and B was dose-limiting toxicity (DLT). Secondary endpoints were safety, best overall response per RECIST version 1.1, and pharmacokinetics. The recommended phase II dose (RP2D) and maximum tolerated dose (MTD) were determined in Parts A and B.

RESULTS

In Part A, peposertib doses administered were 100 mg (n = 4), 200 mg (n = 11), 250 mg (n = 4), 300 mg (n = 6), and 400 mg (n = 4) b.i.d. Of DLT-evaluable patients, one each had DLT at the 250-mg and 300-mg dose levels and three had DLT at the 400-mg b.i.d. dose level. In Part B, peposertib doses administered were 100 mg (n = 3), 150 mg (n = 3), 200 mg (n = 4), and 250 mg (n = 9) q.d.; no DLT was reported in evaluable patients. Peposertib 200 mg b.i.d. plus avelumab and peposertib 250 mg q.d. plus avelumab and radiotherapy were declared as the RP2D/MTD. No objective responses were observed in Part A or B; one patient had a partial response in Part FE. Peposertib exposure was generally dose proportional.

CONCLUSIONS

Peposertib doses up to 200 mg b.i.d. in combination with avelumab and up to 250 mg q.d. in combination with avelumab and radiotherapy were tolerable in patients with advanced solid tumors; however, antitumor activity was limited.

CLINICALTRIALS

GOV IDENTIFIER

NCT03724890.

Plain language summary of the TOPAZ-1 study: durvalumab and chemotherapy for advanced biliary tract cancer

WHAT IS THIS SUMMARY ABOUT?

This is a summary describing the results of a Phase III study called TOPAZ-1. The study looked at treatment with durvalumab (a type of immunotherapy) and chemotherapy to treat participants with advanced biliary tract cancer (BTC). Advanced BTC is usually diagnosed at late stages of disease, when it cannot be cured by surgery. This study included participants with advanced BTC who had not received previous treatment, or had their cancer come back at least 6 months after receiving treatment or surgery that aimed to cure their disease. Participants received treatment with durvalumab and chemotherapy or placebo and chemotherapy. The aim of this study was to find out if treatment with durvalumab and chemotherapy could increase the length of time that participants with advanced BTC lived, compared with placebo and chemotherapy.

WHAT WERE THE RESULTS OF THE STUDY?

Participants who took durvalumab and chemotherapy had a 20% lower chance of experiencing death at any point in the study compared with participants who received placebo and chemotherapy. The side effects experienced by participants were similar across treatment groups, and less than 12% of participants in either treatment group had to stop treatment due to treatment-related side effects.

WHAT DO THE RESULTS OF THE STUDY MEAN?

Overall, these results support durvalumab and chemotherapy as a new treatment option for people with advanced BTCs. Based on the results of this study, durvalumab is now approved for the treatment of adults with advanced BTCs in combination with chemotherapy by government organizations in Europe, the United States and several other countries.

Safety, tolerability, and pharmacokinetics of Aurora kinase B inhibitor AZD2811: a phase 1 dose-finding study in patients with advanced solid tumours

BACKGROUND

AZD2811 is a potent, selective Aurora kinase B inhibitor. We report the dose-escalation phase of a first-in-human study assessing nanoparticle-encapsulated AZD2811 in advanced solid tumours.

METHODS

AZD2811 was administered in 12 dose-escalation cohorts (2-h intravenous infusion; 15‒600 mg; 21-/28-day cycles) with granulocyte colony-stimulating factor (G-CSF) at higher doses. The primary objective was determining safety and maximum tolerated/recommended phase 2 dose (RP2D).

RESULTS

Fifty-one patients received AZD2811. Drug exposure was sustained for several days post-dose. The most common AZD2811-related adverse events (AEs) were fatigue (27.3%) at ≤200 mg/cycle and neutropenia (37.9%) at ≥400 mg/cycle. Five patients had dose-limiting toxicities: grade (G)4 decreased neutrophil count (n = 1, 200 mg; Days 1, 4; 28-day cycle); G4 decreased neutrophil count and G3 stomatitis (n = 1 each, both 400 mg; Day 1; 21-day cycle); G3 febrile neutropenia and G3 fatigue (n = 1 each, both 600 mg; Day 1; 21-day cycle +G-CSF). RP2D was 500 mg; Day 1; 21-day cycle with G-CSF on Day 8. Neutropenia/neutrophil count decrease were on-target AEs. Best overall responses were partial response (n = 1, 2.0%) and stable disease (n = 23, 45.1%).

CONCLUSIONS

At RP2D, AZD2811 was tolerable with G-CSF support. Neutropenia was a pharmacodynamic biomarker.

CLINICAL TRIAL REGISTRATION

NCT02579226.

Abstract P3-07-28: SERENA-1: Updated analyses from a Phase 1 study of the next generation oral selective estrogen receptor degrader camizestrant (AZD9833) combined with abemaciclib, in women with ER-positive, HER2-negative advanced breast cancer

Background: SERENA-1 (NCT03616587) is a Phase 1, multi-part, open-label study of camizestrant in women with ER+/HER2− advanced breast cancer. Parts A/B and C/D (escalation/expansion) examined camizestrant as monotherapy and in combination with palbociclib respectively and have been presented previously.1,2 Here we present data from parts G/H which examined camizestrant in combination with abemaciclib. Methods: The primary objective was to determine the safety and tolerability of camizestrant 75 mg once daily (QD) in combination with abemaciclib 150 mg twice daily (BID). Secondary objectives included investigation of anti-tumor response and pharmacokinetics (PK). Participants were previously treated women of any menopausal status (pre-menopausal women received this combination alongside ongoing ovarian function suppressors). Prior treatment with ≤2 lines of chemotherapy in the advanced setting was permitted. There was no limit on the number of lines of prior endocrine treatment in the advanced setting; previous treatment with CDK4/6 inhibitors (CDK4/6i) and fulvestrant was permitted. Results: As of 1st June 2022, 24 patients had received camizestrant in combination with abemaciclib with a median 7.7 month follow up. Tolerability of the combination of camizestrant and abemaciclib was consistent with that of each drug individually. No patient required camizestrant dose reduction. All camizestrant-related heart rate decreases were Grade 1 (asymptomatic). PK data for camizestrant in combination with abemaciclib were consistent with camizestrant as monotherapy and published abemaciclib steady-state PK data, indicating no clinically relevant drug-drug interaction. In these heavily pre-treated patients (46% prior chemotherapy, 75% prior CDK4/6i, 54% prior fulvestrant; all in the advanced disease setting) and of whom 67% had visceral metastases, the objective response rate was 5/19 (26.3%), the clinical benefit rate at 24 weeks was 16/24 (66.7%) and the median progression-free survival had not been reached, with 8/24 patients experiencing a progression event. These data support the use of camizestrant 75 mg QD combined with the approved abemaciclib dose. Conclusions: Camizestrant 75 mg QD in combination with abemaciclib 150 mg BID was well tolerated with encouraging clinical activity. The inclusion of this regimen in the ongoing Phase 3, SERENA-6 trial 3, of camizestrant combined with CDK4/6i versus an aromatase inhibitor, will further clarify the role of this combination in the treatment of patients with ER+/HER2− advanced breast cancer with tumors expressing ESR1 mutations. References 1. Baird R, Oliveira M, Ciruelos Gil EM, et al. SABCS 2020 Virtual Meeting. Abstract PS11-05. 2. Oliveira M, Hamilton EP, Incorvati J, et al. J Clin Oncol 40, 2022 (suppl 16; abstr 1032). 3. SERENA-6 trial. Available at https://clinicaltrials.gov/ct2/show/NCT04964934 We acknowledge Helen Heffron, PhD, from InterComm International who provided medical writing support funded by AstraZeneca.

Citation Format: Nicholas Turner, Christos Vaklavas, Emiliano Calvo, Javier Garcia-Corbacho, Jason Incorvati, Manuel Ruiz Borrego, Chris Twelves, Anne Armstrong, Begoña Bermejo, Erika Hamilton, Mafalda Oliveira, Eva Ciruelos, Peter Kabos, Manish R Patel, Maria Borrell, Howard Burris, Bruno de Paula, Alejandro Falcon, Cristina Hernando, Irene Moreno, Ciara S. O’Brien, Elena Shagisultanova, Ivan Victoria Ruiz, Judy S. Wang, Mei Wei, Tim Brier, Danielle Carroll, Carmela Ciardullo, Lisa Gibbons, itziar irurzun-Arana, Tony Jack, bistra kirova, Teresa Klinowska, Justin Lindemann, Julie Maidment, Alastair Mathewson, Rhiannon Maudsley, Robert McEwen, Christopher Morrow, Andy Sykes, Richard D. Baird. SERENA-1: Updated analyses from a Phase 1 study of the next generation oral selective estrogen receptor degrader camizestrant (AZD9833) combined with abemaciclib, in women with ER-positive, HER2-negative advanced breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-07-28.

Durvalumab plus Gemcitabine and Cisplatin in Advanced Biliary Tract Cancer

Durvalumab Combination for Biliary Tract CancerThis trial randomly assigned patients with previously untreated locally advanced or metastatic biliary tract cancer to receive durvalumab or placebo in combination with gemcitabine plus cisplatin. Median overall survival (95% Cl) was 12.8 (11.1-14.0) months in the durvalumab group. Rates of grade 3 or 4 adverse events were similar between groups.

Abstract CT032: Activity and safety of alectinib for ALK-altered solid tumors from MyPathway

Purpose: Alectinib is FDA-approved for ALK-positive, metastatic non-small cell lung cancer (NSCLC). We analyzed alectinib treatment in a pan-tumor population with ALK alterations from MyPathway (NCT02091141), a multi-basket study assessing approved therapies in non-indicated advanced solid tumors with relevant alterations.

Methods: Enrolled patients (pts) were ≥18 yrs old and had metastatic tumors with ALK gene rearrangements, putative activating non-synonymous ALK mutations, and/or ALK gene amplification. Pts received alectinib 600 mg PO BID. The primary endpoint was investigator-assessed objective response rate (ORR; complete response [CR] + partial response [PR]). Other endpoints included duration of response (DOR), disease control rate (DCR; CR + PR + stable disease [SD] >4 mos), progression-free survival (PFS), and safety.

Results: By the 11-18-2021 data cutoff, 21 pts with various tumor types had been enrolled and treated (ALK mutations or amplification, n=11 [52.4%]; ALK rearrangements +/- other ALK alterations, n=10 [47.6%]). Pts had a median of 2 (range, 1-5) prior lines of therapy. In the 10 pts with ALK rearrangements, there were 3 PRs (30.0%) with a median DOR of 6.8 mos (Table). An additional 3 pts in this group had SD >4 mos; DCR was 60.0% (6/10). In contrast, there were no responses among the 11 pts with ALK mutations or amplification. Confirmed ORR for the entire group was 14.3% (3/21), and DCR was 42.9% (9/21). Median PFS was 8.2 mos in pts with ALK rearrangements vs 1.8 mos for those with other ALK alterations. Alectinib-related adverse events (AEs) were observed in 85.7% of pts, with 3 (14.3%) experiencing grade 3 AEs (anemia; hypokalemia; and changes in AST, ALT, and/or blood creatinine levels). AEs were consistent with the known alectinib safety profile.

Conclusions: Although the number of pts is small, alectinib appears active in those with non-NSCLC advanced solid tumors with ALK rearrangements. As in NSCLC, cancers with ALK mutations or amplification were not responsive to ALK inhibition.

Table. Clinical outcomes Clinical Response Rearrangement (n=10) Mutation (n=7) Amplification (n=4) Median PFS, mos (all alterations) n Indications n Indications n Indications PR 3a Melanoma, Papillary urothelial carcinoma, Colon adenocarcinoma 0 NA 0 NA 9.3 SD >4 mos 3b,c Colon adenocarcinoma, Uterine leiomyosarcoma, Pancreatic adenocarcinoma 2 Squamous cell carcinoma, Soft tissue sarcoma 1 Uterine body clear cell carcinoma 5.7 SD ≤4 mos 0 NA 1 Fallopian tube serous carcinoma 0 NA PD 3d,e Colon adenocarcinoma, Esophageal adenocarcinoma, Uterine serous carcinoma 4 Anaplastic thyroid carcinoma, Esophageal adenocarcinoma, Colon adenocarcinoma (2) 3 Ovarian serous carcinoma, Gastric squamous cell carcinoma, Peritoneal non-small cell carcinoma 1.7 Non-evaluable 1f Uterine inflammatory myofibroblastic tumor 0 NA 0 NA NA aFusion gene partners: EMILIN1, DCTN1, and DIAPH2. bOne pt with ALK rearrangement and SD >4 mos also had ALK amplification. cFusion gene partners: STRN, IGFBP5, and EML4. dPts with ALK rearrangement and PD also had an ALK mutation (n=1) or ALK amplification (n=1). eFusion gene partner: STRN; fusion genes unknown for 2 pts. fPt withdrew prior to clinical assessment and was censored for PFS at 0.03 mos. NA, not applicable; PD, progressive disease; PFS, progression-free survival; PR, partial response; SD, stable disease.

Citation Format: Charles Swanton, Claire F. Friedman, Christopher J. Sweeney, Funda Meric-Bernstam, David Spigel, Ron Bose, Howard Burris, Walter C. Darbonne, Julia Malato, Jonathan Levy, Yong Wang, Tania Szado, Katja Schulze, John Hainsworth, Razelle Kurzrock. Activity and safety of alectinib for ALK-altered solid tumors from MyPathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT032.

A real-world retrospective study of the use of Ki-67 testing and treatment patterns in patients with HR+, HER2- early breast cancer in the United States

Background

The National Comprehensive Cancer Network recommends that patients with hormone receptor-positive early breast cancer be considered for adjuvant endocrine therapy (ET) after primary treatment like surgical excision. Adjuvant chemotherapy (CT) use primarily depends on risk of recurrence. Biomarkers such as Ki-67 potentially have most value in patients with intermediate risk factors, such as involvement of 1–3 positive nodes. This study evaluated the use of Ki-67 testing and treatment patterns in patients with HR+, human epidermal growth factor receptor 2-negative early breast cancer.

Methods

This was an observational retrospective cohort study of patients with electronic medical records from January 2010 to August 2018 treated for HR+, HER2− early breast cancer at Sarah Cannon sites in the United States (US). Overall, 567 patients were randomly selected after using the eligibility criteria: female or male ≥18 years, without distant metastases, and with available physician and pathology reports. Multivariable logistic regression was used to investigate factors predicting Ki-67 testing and test results. Descriptive analyses were applied to treatment patterns.

Results

Multivariable logistic regression analyses found no clinical or pathological factors that predicted whether Ki-67 testing had been ordered by physicians. Of all tested patients (N = 130), having Grade-2 tumors (OR, 7.95 [95% CI: 2.05, 30.9]; p = 0.0027) or Grade-3 tumors (OR, 95.3 [95% CI, 11.9, 760.7]; p < 0.001) at initial diagnosis was a predictor of high Ki-67 expression (≥20%). Ki-67 expression was tested in 23.6% (61/258) of patients with 1–3 positive nodes; 54.1% of them (33/61) had high Ki-67 expression (≥20%). While having a higher grade tumor predicted high Ki-67 (≥20%), 28.6% of patients with Grade-1 tumors also had high Ki-67 expression. Neo-adjuvant therapy was received by 16.0% of patients (91/567), most of whom (66/91; 72.5%) received CT alone. Adjuvant therapy, either endocrine and/or chemotherapy, was received by 92.6% (525/567) of patients and by 67.0% (61/91) of those who received neo-adjuvant therapy. Most (428/525, 81.5%) received ET in the adjuvant treatment setting.

Conclusions

High grade tumors predicted high Ki-67 (≥20%) expression, but Ki-67 testing was not widely used in these US patients. Most HR+, HER2− early breast cancers were treated with adjuvant ET, with or without CT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09557-6.

529 Phase 1 study of INCB086550, an oral PD-L1 inhibitor, in immune-checkpoint naive patients with advanced solid tumors

Background

INCB086550 is an orally administered small molecule that binds PD-L1 and inhibits PD-1/PD-L1 interaction. Translational data demonstrating markers of immune activation in patients following INCB086550 were previously reported.1 Preliminary clinical data from this phase 1 study are presented below.

Methods

Adult patients (≥18 years) with advanced solid tumors were enrolled into this open-label study. Patients had disease progression after standard available therapy or were intolerant of or ineligible for standard treatment. Measurable disease was required. A modified 3+3 dose-escalation design was employed, followed by dose expansions. The primary endpoints were safety and tolerability of INCB086550, identification of a pharmacologically active dose and/or MTD, and confirmation of the RP2D. Secondary endpoints included PK, pharmacodynamics, and efficacy as assessed by investigator-determined ORR and DCR (CR, PR, or SD ≥12 weeks).

Results

As of 9Apr2021, 79 patients received treatment (Table 1); 57.0% were female, 62.0% had ≥2 prior lines of therapy, and 16% received prior IO treatment. Forty-six (58.2%) patients had treatment-related TEAEs; those occurring in ≥5% of patients are presented in Table 2. Ten patients (12.7%) had grade ≥3 treatment-related TEAEs. Immune-related TEAEs occurred in 15 patients (19.0%); the most common (>1 patient) included peripheral sensory neuropathy (n=5), pruritus (n=3), immune-mediated neuropathy (n=2), and peripheral motor neuropathy (n=2). In total, 10 (12.7%) patients had TEAEs of peripheral neuropathy; all were grade ≤3. All grade 2 or 3 TEAEs of peripheral neuropathy resolved or improved with either study drug continuation without dose modification, dose reduction, or drug interruption/discontinuation. Patients with TEAEs leading to treatment interruption were 21 (26.6%), dose reduction 5 (6.3%), and discontinuation 13 (16.5%). Five patients (6.3%) died of a TEAE (cerebrovascular accident, dyspnea, general physical health deterioration, intestinal obstruction, intracranial hemorrhage [each n=1]); all fatal TEAEs were considered unrelated to study drug. The efficacy-evaluable population included 68 patients; ORR was 11.8% (95%CI, 5.2%–21.9%; CR, 1.5%; PR, 10.3%), and DCR was 19.1% (95%CI, 10.6%–30.5%; Table 3). Eight objective responses were observed at doses ≥400 mg BID (Table 4); 3 of these were noted among the 5 IO treatment-naive patients with MSI-H tumors who received 400 mg BID.

Conclusions

Immune-related AEs observed in this ongoing phase 1 study are consistent with those seen with antibody immune checkpoint inhibitors, with the exception of peripheral neuropathy. Preliminary efficacy of INCB086550 in tumor types known to be responsive to anti-PD-(L)1 therapy is encouraging and warrants further investigation.

Trial Registration

Clinicaltrials.

gov identifier NCT03762447

References

Piha-Paul S, et al. J Immunother Cancer. 2020;8(suppl 3):A255.

Ethics Approval

The study protocol was approved by institutional review boards (IRB) or independent ethics committees at participating centers. All study participants gave informed consent before taking part. The approval numbers were: Integ Review IRB (Austin, TX), RM 598; MD Anderson Cancer Center Office of Human Subject Protection (Houston, TX), IRB ID 2018-0765; ADVARRA (Columbia, MD), IRB# 00000971; Ethisch Comité/Comité d’ Ethique Hospital (Brussels, Belgium), A2021/085; Hôpital Saint-Louis (Paris, France), Prof Le Tourneau – 2020-118/Ref. of the Promoter 0.09.22.72214; NHS Health Research Authority London - City & East Research Ethics Committee (Bristol, UK), IRAS project ID:282291/REC reference: 20/LO/1001; Comitato Etico IRCCS Pascale (Milan, Italy), ISS Validation Protocol Number 29111(2020)-PRE21-1835; Comitato Etico Della Fondazione IRCCS ”Istituto Nazionale Dei Tumori”- Milano CE150053 (Milan, Italy), INT 230/20; Comitato Etico Regione Toscana - Area Vasta Sud Est CE150047, 18064; Comitato Etico Indipendente Istituto Clinico Humanitas CE150081, 940/20; Regulatory Pharma Net (Pisa, Italy), IEC 1393.

Abstract 529 Table 1

Number of patients per dose level

BID, twice daily; QD, once daily.

The tumor types in the study included breast, cervical, colorectal, endometrial, esophageal, gastric, hepatocellular, melanoma, mesothelioma, ovarian, small cell lung cancer, squamous cell carcinoma of the head and neck, renal cell, urothelial, adrenal, anal, cholangiocarcinoma, gall bladder, pancreatic, penile, salivary gland, sarcoma, vaginal, prostate, basal cell, pleomorphic sarcoma, fallopian, carcinoma of parotid gland, well-differentiated liposarcoma, myoepithelial, castrate-resistant prostate cancer, cancer of unknown primary, neuroendocrine, prostate adenocarcinoma with neuroendocrine differentiation, glioblastoma, anal canal, angiosarcoma, and gastroesophageal junction.

Abstract 529 Table 2

Treatment-related TEAEs reported by ≥5% of patients (N=79)

TEAE, treatment-emergent adverse event.

Abstract 529 Table 3

Summary of best overall response by RECIST v1.1 or RANO*

CR, complete response; DCR, disease control rate; GBM, glioblastoma; ORR, objective response rate; PR, partial response; RANO, Response Assessment of Neuro-Oncology; RECIST, Response Evaluation Criteria in Solid Tumors; SD, stable disease.

* 1 patient with GBM was assessed by RANO and had best overall response of progressive disease.

† The efficacy-evaluable population included all solid tumor participants enrolled in the study who received at least 1 dose of INCB086550, completed a baseline scan, and met at least 1 of the following criteria: ≥1 postbaseline scan, participant had been on the study for a minimum of 63 days of follow-up, or participant had discontinued from treatment.

‡ ”Not evaluable” indicates participants in the efficacy-evaluable population that did not have valid postbaseline overall response assessments by RECIST or RANO.

§ ”Not assessed” indicates participants in the efficacy-evaluable population that did not have any postbaseline overall response assessments by RECIST or RANO.

Abstract 529 Table 4

Tumor types with investigator-assessed objective response per RECIST v1.1 (n=8)

BID, twice daily; dMMR, deficient mismatch repair; IO, immuno-oncology; MSI-H, high microsatellite instability; RECIST, Response Evaluation Criteria in Solid Tumors.

+Ongoing response.

Infigratinib in Early-Line and Salvage Therapy for FGFR3-Altered Metastatic Urothelial Carcinoma

The optimal sequencing of systemic treatments for metastatic urothelial cancer (mUC) is unknown. We assessed the efficacy of infigratinib, a fibroblast growth factor receptor (FGFR) 1 to 3 inhibitor, in 67 patients with FGFR3-altered mUC by line of therapy. Objective response rates were 31% (early-line setting) and 24% (≥2nd-line setting). Infigratinib has notable activity in mUC regardless of line of therapy.

Pertuzumab and trastuzumab for HER2-positive, metastatic biliary tract cancer (MyPathway): a multicentre, open-label, phase 2a, multiple basket study

BACKGROUND

Systemic therapies for metastatic biliary tract cancers are few, and patients have a median overall survival of less than 1 year. MyPathway evaluates the activity of US Food and Drug Administration-approved therapies in non-indicated tumours with potentially actionable molecular alterations. In this study, we present an analysis of patients with metastatic biliary tract cancers with HER2 amplification, overexpression, or both treated with a dual anti-HER2 regimen, pertuzumab plus trastuzumab, from MyPathway.

METHODS

MyPathway is a non-randomised, multicentre, open-label, phase 2a, multiple basket study. Patients aged 18 years and older with previously treated metastatic biliary tract cancers with HER2 amplification, HER2 overexpression, or both and an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled from 23 study sites in the USA and received intravenous pertuzumab (840 mg loading dose, then 420 mg every 3 weeks) plus trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks). The primary endpoint was investigator-assessed objective response rate according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. The primary outcome and adverse events were analysed in all patients who received at least one dose of pertuzumab and trastuzumab. This trial is registered with ClinicalTrials.gov, NCT02091141, and is ongoing.

FINDINGS

39 patients enrolled in the MyPathway HER2 biliary tract cancer cohort between Oct 28, 2014, and May 29, 2019, were evaluable for anti-tumour activity by the March 10, 2020, data cutoff date. Median follow-up was 8·1 months (IQR 2·7-15·7). Nine of 39 patients achieved a partial response (objective response rate 23% [95% CI 11-39]). Grade 3-4 treatment-emergent adverse events were reported in 18 (46%) of 39 patients, most commonly increased alanine aminotransferase and increased aspartate aminotransferase (each five [13%] of 39). Treatment-related grade 3 adverse events were reported in three (8%) of 39 patients, including increased alanine aminotransferase, aspartate aminotransferase, blood alkaline phosphatase, and blood bilirubin. Serious treatment-emergent adverse events were observed in ten (26%) of 39 patients, of which only abdominal pain occurred in more than one patient (two [5%] of 39). There were no treatment-related serious adverse events, treatment-related grade 4 events, or deaths.

INTERPRETATION

Treatment was well tolerated in patients with previously treated HER2-positive metastatic biliary tract cancer. The response rate is promising for the initiation of randomised, controlled trials of pertuzumab plus trastuzumab in this patient population.

FUNDING

F Hoffmann-La Roche-Genentech.

First-In-Human, First-In-Class, Phase I Trial of the Fucosylation Inhibitor SGN-2FF in Patients with Advanced Solid Tumors

LESSONS LEARNED

Inhibition of glycoprotein fucosylation, as monotherapy and in combination with immune checkpoint blockade, is a promising therapeutic strategy for treating a broad range of cancers. In this first-in-human, first-in-class, phase I study in advanced solid tumors, SGN-2FF demonstrated dose-proportional pharmacokinetics, evidence of pharmacodynamic target inhibition of glycoprotein fucosylation, and preliminary antitumor activity. SGN-2FF was associated with thromboembolic events that led to study termination.

BACKGROUND

We conducted a first-in-human, first-in-class, phase I study of SGN-2FF, a potent small molecule inhibitor of glycoprotein fucosylation, in patients with advanced solid tumors.

METHODS

The study consisted of four parts: SGN-2FF monotherapy dose-escalation (Part A) and expansion (Part B), and SGN-2FF + pembrolizumab dose-escalation (Part C) and expansion (Part D). The objectives were to evaluate safety and tolerability, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity of SGN-2FF monotherapy and SGN-2FF + pembrolizumab.

RESULTS

Forty-six patients were enrolled (Part A, n=33; Part B, n=6; Part C, n=7; Part D did not enroll any patients). During Part A (n=32) exploring 1-15 g QD and 2-5 g BID, grade 3 dose-limiting toxicities were diarrhea (2 g and 15 g QD) and increased lipase (2 g QD). The MTD was 10 g daily. In Part A, common toxicities were grades 1-2 diarrhea, fatigue, and nausea (each 47%); thromboembolic events (grades 2-5) occurred in 5/32 patients (16%). Safety measures implemented included concurrent prophylactic anticoagulation with low-molecular weight heparin (LMWH). In Part C, despite the safety measures implemented, a thromboembolic event occurred in 1/7 patients (14%) during the SGN-2FF lead-in period. Of 28 evaluable patients in Part A, 1 patient with advanced head and neck squamous cell carcinoma achieved RECIST v1.1 complete response (CR) and 10 (36%) had RECIST v1.1 stable disease, including 1 patient with advanced triple negative breast cancer with 51% tumor burden reduction. SGN-2FF administration led to dose-proportional increases in exposure and PD reduction in protein fucosylation.

CONCLUSION

SGN-2FF demonstrated proof-of-mechanism and preliminary antitumor activity but was associated with thromboembolic events leading to study termination.

OncoAlert Round Table Discussions: The Global COVID-19 Experience

The speed and spread of the COVID-19 pandemic has been affecting the entire world for the past several months. OncoAlert is a social media network made up of more than 140 oncology stakeholders: oncologists (medical, radiation, and surgical), oncology nurses, and patient advocates who share the mission of fighting cancer by means of education and dissemination of information. As a response to the COVID-19 pandemic, OncoAlert hosted The Round Table Discussions. We have documented this effort along with further discussion about the COVID-19 pandemic and the consequences on patients living with cancer to disseminate this information to our colleagues worldwide.

First-in-human study of the safety, pharmacokinetics, and pharmacodynamics of first-in-class fatty acid synthase inhibitor TVB-2640 alone and with a taxane in advanced tumors

BACKGROUND

We conducted a first-in-human dose-escalation study with the oral FASN inhibitor TVB-2640 to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D), as monotherapy and with a taxane.

METHODS

This completed open-label outpatient study was conducted at 11 sites in the United States and United Kingdom. Patients with previously-treated advanced metastatic solid tumors and adequate performance status and organ function were eligible. TVB-2640 was administered orally daily until PD. Dose escalation initially followed an accelerated titration design that switched to a standard 3 + 3 design after Grade 2 toxicity occurred. Disease-specific cohorts were enrolled at the MTD. Statistical analyses were primarily descriptive. Safety analyses were performed on patients who received at least 1 dose of study drug. (Clinicaltrials.gov identifier NCT02223247).

FINDINGS

The study was conducted from 21 November 2013 to 07 February 2017. Overall, 136 patients received TVB-2640, 76 as monotherapy (weight-based doses of 60 mg/m² to 240 mg/m² and flat doses of 200 and 250 mg) and 60 in combination, (weight-based doses of 60 mg/m² to 100 mg/m² and flat dose of 200 mg) (55 paclitaxel, 5 docetaxel). DLTs with TVB-2640 were reversible skin and ocular effects. The MTD/RP2D was 100 mg/m². The most common TEAEs (n,%) with TVB-2640 monotherapy were alopecia (46; 61%), PPE syndrome (35; 46%), fatigue (28; 37%), decreased appetite (20; 26%), and dry skin (17; 22%), and with TVB-2640+paclitaxel were fatigue (29 ; 53%), alopecia (25; 46%), PPE syndrome (25; 46%), nausea (22; 40%), and peripheral neuropathy (20; 36%). One fatal case of drug-related pneumonitis occurred with TVB-2640+paclitaxel; no other treatment-related deaths occurred. Target engagement (FASN inhibition) and inhibition of lipogenesis were demonstrated with TVB-2640. The disease control rate (DCR) with TVB-2640 monotherapy was 42%; no patient treated with monotherapy had a complete or partial response (CR or PR). In combination with paclitaxel, the PR rate was 11% and the DCR was 70%. Responses were seen across multiple tumor types, including in patients with KRAS^MUT NSCLC, ovarian, and breast cancer.

INTERPRETATION

TVB-2640 demonstrated potent FASN inhibition and a predictable and manageable safety profile, primarily characterized by non-serious, reversible adverse events affecting skin and eyes. Further investigation of TVB-2640 in patients with solid tumors, particularly in KRAS^MUT lung, ovarian, and breast cancer, is warranted.

FUNDING

This trial was funded by 3-V Biosciences, Inc. (now known as Sagimet Biosciences Inc.).

Abstract PS18-34: Physician adoption and molecular landscape of next-generation sequencing in breast cancer patients from community-based clinics

Background: Molecular biomarkers such as the expression status of hormone receptors (HR) and HER2 influence disease diagnosis, prognosis, and treatment decisions in breast cancer patients. Recent advances in genetic sequencing technologies and targeted therapies have revealed additional actionable biomarkers including PIK3CA, ESR1, and BRCA1/2; however, it remains unclear whether physicians in community-based clinics are universally adopting molecular profiling practices. Here, we describe the utility of next generation sequencing (NGS) in the care of breast cancer patients in community-based clinics with a focus on physician behaviors and molecular landscapes.

Methods: Sarah Cannon provides clinical research services to medical oncology practices who order NGS panels as part of standard of care. Genospace, Sarah Cannon’s web-based precision medicine platform, links NGS test results with electronic medical records to identify and analyze clinico-genomic data of molecularly-profiled cancer patients. Here, a total of 2,673 NGS reports from 2,313 unique patients dated between January 2014 and December 2019 were analyzed. Hormone statuses were abstracted from physician notes using natural language processing capabilities and manual abstraction. Linear regression modeling was used for statistical analysis.

Results: Physician ordering of NGS tests for breast cancer patients increased 6.3-fold from 2014 to 2019. Ordering of plasma-based NGS tests increased from 0.6% (versus 99.4% tissue) in 2014 to 47.0% (versus 53.0% tissue) in 2019. The time from initial diagnosis to NGS results increased from a median of 1008 days in 2015 to 1296 days in 2019 (p &lt; 0.05), while the time from specimen collection to NGS test results (tissue only) decreased from 53 days in 2015 to 28 days in 2019 (p &lt; 0.01). The majority of NGS-tested breast cancer patients were HR+/HER2- (62.6%), followed by HR-/HER2- (21.5%), HR+/HER2+ (8.4%), HR-/HER2+ (4.4%), and HER2 equivocal (3.0%). Plasma-based NGS testing was utilized more commonly in HR+ cancers (43.4% of HR+; 25.3% of HR-). In agreement with published studies, BRCA1 alterations were enriched in HR- cancers (1.7% of HR+; 6.6% of HR-) and BRCA2 alterations were enriched in HR+ cancers (6.4% of HR+; 3.2% of HR-). Amplifications in CCND1 (21.7% of HR+; 2.2% of HR-) and FGFR1 (18.1% of HR+; 6.2% of HR-) were also enriched in HR+ cancers, as were mutations in ESR1 (18.9% of HR+; 1.0% of HR-). PIK3CA mutations occurred most frequently in HR+ cancers (45.0%), but were also present in HR- cancers (20.9%). TP53 mutations were comparatively high in HR- cancers (42.9% of HR+; 94.8% of HR-).

Conclusions: The usage of NGS for the care of breast cancer patients is increasing in community settings. Plasma-based NGS tests are ordered more frequently in HR+ cancers, likely as a result of difficult-to-biopsy and poor yield bone-only disease. Despite increased testing frequencies, NGS tests are ordered later-in-care which may be a reflection of earlier diagnosis or the development of more efficacious standard of care therapies in front line settings. The tissue specimens sent for sequencing are collected closer to the test date, indicating improved tissue processing systems and prioritization of fresh specimen collection for NGS testing. Overall, physicians are adopting NGS-testing as part of standard of care for breast cancer patients in the community setting and are discovering actionable mutations.

Frequency of detection of molecular biomarkers in NGS-tested breast cancer patientsTissueTissueTissueTissuePlasmaPlasmaPlasmaPlasmaGeneAlterationHR+/HER2-HR-/HER2-HR+/HER2+HR-/HER2+HR+/HER2-HR-/HER2-HR+/HER2+HR-/HER2+ERBB2Amp1.1%0.5%45.4%67.9%0.0%0.8%10.4%45.5%CCND1Amp21.3%1.7%21.8%5.1%7.5%1.7%5.2%0.0%MYCAmp9.3%15.5%18.5%17.9%1.3%5.8%1.3%9.1%FGFR1Amp17.4%6.8%18.5%3.8%6.5%3.3%2.6%0.0%PIK3CAMutation43.8%19.1%49.6%32.1%49.5%25.0%50.6%30.3%ESR1Mutation19.4%1.2%13.4%0.0%41.7%4.2%31.2%0.0%BRCA1Mutation1.9%7.2%0.8%3.8%5.1%5.0%2.6%9.1%BRCA2Mutation6.7%3.6%5.9%1.3%8.8%5.8%14.3%3.0%ERBB2Mutation3.4%1.4%11.8%6.4%9.5%1.7%15.6%12.1%TP53Mutation42.2%94.7%51.3%93.6%65.8%96.7%68.8%93.9%PTENMutation8.8%10.6%2.5%3.8%12.6%10.8%7.8%6.1%PALB2Mutation1.6%1.2%0.8%0.0%0.2%0.0%0.0%0.0%MTORMutation0.7%0.2%0.8%0.0%2.7%0.0%0.0%0.0%ARID1AMutation9.0%4.8%12.6%2.6%11.0%11.7%7.8%3.0%KRASMutation3.2%3.1%0.8%2.6%6.5%8.3%5.2%6.1%AKT1Mutation6.5%3.4%2.5%1.3%7.5%6.7%1.3%0.0%n=856n=414n=119n=78n=602n=120n=77n=33

Citation Format: Emma Sturgill, Amanda Misch, Rebecca Lachs, Carissa Jones, Dan Schlauch, Suzanne Jones, Mythili Shastry, Denise Yardley, Howard Burris, David Spigel, Erika Hamilton, Andrew McKenzie. Physician adoption and molecular landscape of next-generation sequencing in breast cancer patients from community-based clinics [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS18-34.

Extended RAS Analysis of the Phase III EPIC Trial: Irinotecan + Cetuximab Versus Irinotecan as Second-Line Treatment for Patients with Metastatic Colorectal Cancer

BACKGROUND

The multicenter, open-label, randomized, phase III EPIC study (EMR 062202-025) investigated cetuximab plus irinotecan versus irinotecan in patients with epidermal growth factor receptor-detectable metastatic colorectal cancer (mCRC) that progressed on first-line fluoropyrimidine- and oxaliplatin-based chemotherapy; we report the outcomes of patients with RAS-wild-type (wt) disease.

MATERIALS AND METHODS

Available DNA samples from RAS-unselected patients (n = 1,164 of 1,298 [89.7%]) were reanalyzed for RAS mutations using beads, emulsion, amplification, and magnetics. Baseline characteristics, efficacy, safety, and poststudy therapy were assessed. RAS-wt status was defined as a mutated RAS allele frequency of ≤5%, with all relevant alleles being analyzable.

RESULTS

Baseline characteristics were comparable between the groups (n = 452 patients with RAS-wt mCRC; cetuximab plus irinotecan n = 231, irinotecan n = 221) and between the RAS-wt and RAS-unselected populations. In the cetuximab plus irinotecan versus irinotecan arms, median overall survival was 12.3 versus 12.0 months, median progression-free survival (PFS) was 5.4 versus 2.6 months, and objective response rate (ORR) was 29.4% versus 5.0%, respectively. Quality of life (QoL) was improved in the cetuximab plus irinotecan arm. Serious adverse events occurred in 45.4% (cetuximab plus irinotecan) and 42.4% (irinotecan) of patients. In total, 47.1% of patients in the irinotecan arm received subsequent cetuximab therapy.

CONCLUSION

PFS, ORR, and QoL were improved with cetuximab plus irinotecan as a second-line treatment in patients with RAS-wt mCRC, confirming that cetuximab-based therapy is suitable in this population. Almost half of patients in the irinotecan arm received poststudy cetuximab, masking a potential overall survival benefit of cetuximab addition.

IMPLICATIONS FOR PRACTICE

Cetuximab is approved for the treatment of RAS-wild-type metastatic colorectal cancer (mCRC). In this retrospective analysis of the phase III EPIC study (cetuximab plus irinotecan vs. irinotecan alone as second-line treatment in patients with RAS-unselected mCRC), the subgroup of patients with RAS-wild-type mCRC who received cetuximab plus irinotecan had improved progression-free survival, objective response rate, and quality of life compared with the RAS-unselected population. These findings suggest that cetuximab-based therapy is a suitable second-line treatment for patients with RAS-wild-type mCRC.

Hyperphosphatemia Secondary to the Selective Fibroblast Growth Factor Receptor 1-3 Inhibitor Infigratinib (BGJ398) Is Associated with Antitumor Efficacy in Fibroblast Growth Factor Receptor 3-altered Advanced/Metastatic Urothelial Carcinoma

BACKGROUND

Infigratinib (BGJ398) is a potent, selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor with significant activity in metastatic urothelial carcinoma (mUC) bearing FGFR3 alterations. It can cause hyperphosphatemia due to the "on-target" class effect of FGFR1 inhibition.

OBJECTIVE

To investigate the relationship between hyperphosphatemia and treatment response in patients with mUC.

INTERVENTION

Oral infigratinib 125 mg/d for 21 d every 28 d.

DESIGN, SETTING, AND PARTICIPANTS

Data from patients treated with infigratinib in a phase I trial with platinum-refractory mUC and activating FGFR3 alterations were retrospectively analyzed for clinical efficacy in relation to serum hyperphosphatemia. The relationship between plasma infigratinib concentration and phosphorous levels was also assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical outcomes were compared in groups with/without hyperphosphatemia.

RESULTS AND LIMITATIONS

Of the 67 patients enrolled, 48 (71.6%) had hyperphosphatemia on one or more laboratory tests. Findings in patients with versus without hyperphosphatemia were the following: overall response rate 33.3% (95% confidence interval [CI] 20.4-48.4) versus 5.3% (95% CI 0.1-26.0); disease control rate 75.0% (95% CI 60.4-86.4) versus 36.8% (95% CI 16.3-61.6). This trend was maintained in a 1-mo landmark analysis. Pharmacokinetic/pharmacodynamic analysis showed that serum phosphorus levels and physiologic infigratinib concentrations were correlated positively. Key limitations include retrospective design, lack of comparator, and limited sample size.

CONCLUSIONS

This is the first published study to suggest that hyperphosphatemia caused by FGFR inhibitors, such as infigratinib, can be a surrogate biomarker for treatment response. These findings are consistent with other reported observations and will need to be validated further in a larger prospective trial.

PATIENT SUMMARY

Targeted therapy is a new paradigm in treating bladder cancer. In a study using infigratinib, a drug that targets mutations in a gene called fibroblast growth factor receptor 3 (FGFR3), we found that elevated levels of phosphorous were associated with greater clinical benefit. In the future, these data may help inform treatment strategies.

Abstract CT062: Efficacy and safety of larotrectinib in patients with cancer and NTRK gene fusions or other alterations

Introduction: A variety of alterations in NTRK genes have been identified in various cancers, including amplifications, rearrangements, deletions, splice variants as well as fusions. Larotrectinib is a highly selective TRK inhibitor that is active in patients (pts) with TRK fusion cancer. Here, we report post hoc efficacy and safety outcomes of larotrectinib treatment in pts with cancer and NTRK gene fusions (Fusion) vs those with Non-fusion alterations. Methods: Data were pooled from three clinical trials of adult and pediatric pts with TRK fusion cancer treated with larotrectinib (NCT02122913, NCT02576431, NCT02637687). NTRK gene status was assessed using local molecular testing; two studies (NCT02122913 and NCT02637687) initially enrolled pts regardless of TRK fusion status. Efficacy outcomes included objective response rate (ORR), assessed by investigators using RECIST 1.1, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Adverse events (AEs) were also assessed. The data cut-off was February 19, 2019. Results: This analysis included 159 pts (153 evaluable for efficacy) with NTRK fusions, with 17 different tumor types, and 73 Non-fusion pts with various genomic alterations, with 25 different tumor types. NTRK alterations reported in the Non-fusion pts included point mutations in 8 pts, amplifications in 7, rearrangements in 4 and deletions in 1. The ORR was 79% (95% confidence interval [CI] 72-85) in the Fusion group, with complete responses (CR) in 24 (16%), partial responses (PR) in 97 (63%), stable disease (SD) in 19 (12%), and progressive disease (PD) in 9 (6%). Median DOR was 35.2 months (95% CI 22.8-not estimable [NE]). In the Non-fusion group treated with larotrectinib, there were no responses except for one pt with NTRK1 amplification who had a PR of short duration (3.7 months); 17 Non-fusion pts (23%) had SD and 48 (66%) had PD as best response. Similarly, differences were seen in survival endpoints between pts in the overall Fusion and Non-fusion groups: median PFS 28.3 mo vs 1.8 mo and median OS 44.4 mo vs 10.7 mo, respectively. Median time of treatment was 7.9 months in the Fusion group and 1.7 months in the Non-fusion group. Incidences of Grade 3 or 4 AEs were lower in the Fusion group (49%) vs the Non-fusion group (58%). Discontinuation due to AEs occurred in 6% of pts in the Fusion group vs 25% in the Non-fusion group. Conclusion: Larotrectinib is highly efficacious in pts with TRK fusion cancer and has demonstrated durable responses. Pts with other NTRK alterations, including point mutations and amplifications, had only limited benefit from larotrectinib.

Citation Format: David S. Hong, Afshin Dowlati, Howard Burris, Edward Chu, Marcia S. Brose, Anna F. Farago, Cornelis M. van Tilburg, Shivaani Kummar, Leo Mascarenhas, John A. Reeves, Marion Rudolph, Patricia Maeda, Barrett H. Childs, Theodore W. Laetsch, Alexander Drilon. Efficacy and safety of larotrectinib in patients with cancer and NTRK gene fusions or other alterations [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT062.

JSCO-ESMO-ASCO-JSMO-TOS: international expert consensus recommendations for tumour-agnostic treatments in patients with solid tumours with microsatellite instability or NTRK fusions

A Japan Society of Clinical Oncology (JSCO)-hosted expert meeting was held in Japan on 27 October 2019, which comprised experts from the JSCO, the Japanese Society of Medical Oncology (JSMO), the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO), and the Taiwan Oncology Society (TOS). The purpose of the meeting was to focus on what we have learnt from both microsatellite instability (MSI)/deficient mismatch repair (dMMR) biomarkers in predicting the efficacy of anti-programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) immunotherapy, and the neurotrophic tyrosine receptor kinase (NTRK) gene fusions in predicting the efficacy of inhibitors of the tropomyosin receptor kinase (TRK) proteins across a range of solid tumour types. The recent regulatory approvals of the anti-PD-1 antibody pembrolizumab and the TRK inhibitors larotrectinib and entrectinib, based on specific tumour biomarkers rather than specific tumour type, have heralded a paradigm shift in cancer treatment approaches. The purpose of the meeting was to develop international expert consensus recommendations on the use of such tumour-agnostic treatments in patients with solid tumours. The aim was to generate a reference document for clinical practice, for pharmaceutical companies in the design of clinical trials, for ethics committees in the approval of clinical trial protocols and for regulatory authorities in relation to drug approvals, with a particular emphasis on diagnostic testing and patient selection.

Ivosidenib in Isocitrate Dehydrogenase 1-Mutated Advanced Glioma

PURPOSE

Diffuse gliomas are malignant brain tumors that include lower-grade gliomas (LGGs) and glioblastomas. Transformation of low-grade glioma into a higher tumor grade is typically associated with contrast enhancement on magnetic resonance imaging. Mutations in the isocitrate dehydrogenase 1 (IDH1) gene occur in most LGGs (> 70%). Ivosidenib is an inhibitor of mutant IDH1 (mIDH1) under evaluation in patients with solid tumors.

METHODS

We conducted a multicenter, open-label, phase I, dose escalation and expansion study of ivosidenib in patients with mIDH1 solid tumors. Ivosidenib was administered orally daily in 28-day cycles.

RESULTS

In 66 patients with advanced gliomas, ivosidenib was well tolerated, with no dose-limiting toxicities reported. The maximum tolerated dose was not reached; 500 mg once per day was selected for the expansion cohort. The grade ≥ 3 adverse event rate was 19.7%; 3% (n = 2) were considered treatment related. In patients with nonenhancing glioma (n = 35), the objective response rate was 2.9%, with 1 partial response. Thirty of 35 patients (85.7%) with nonenhancing glioma achieved stable disease compared with 14 of 31 (45.2%) with enhancing glioma. Median progression-free survival was 13.6 months (95% CI, 9.2 to 33.2 months) and 1.4 months (95% CI, 1.0 to 1.9 months) for the nonenhancing and enhancing glioma cohorts, respectively. In an exploratory analysis, ivosidenib reduced the volume and growth rates of nonenhancing tumors.

CONCLUSION

In patients with mIDH1 advanced glioma, ivosidenib 500 mg once per day was associated with a favorable safety profile, prolonged disease control, and reduced growth of nonenhancing tumors.

A Phase Ib Study to Evaluate the MEK Inhibitor Cobimetinib in Combination with the ERK1/2 Inhibitor GDC-0994 in Patients with Advanced Solid Tumors

LESSONS LEARNED

Despite strong preclinical rationale, combined cobimetinib-mediated MEK inhibition and GDC-0994-mediated ERK inhibition was not tolerable on two 28-day dosing schedules in which GDC-0994 was given for 21 days continuously and cobimetinib administered over 21 days either continuously or intermittently. Adverse events were as expected for mitogen-activated protein kinase pathway inhibition, but overlapping and cumulative toxicities could not be managed on either dosing schedule. Pharmacokinetic parameters of cobimetinib and GDC-0994 given in combination were similar to those previously observed in monotherapy studies, so that there was no evidence of drug-drug interaction. Cycle 1 metabolic responses were observed by 18F-fluorodeoxyglucose-positron emission tomography but were not predictive of outcome measured by RECIST 1.1.

BACKGROUND

Simultaneous targeting of multiple nodes in the mitogen-activated protein kinase (MAPK) pathway offers the prospect of enhanced activity in RAS-RAF-mutant tumors. This phase Ib trial evaluated the combination of cobimetinib (MEK inhibitor) and GDC-0994 (ERK inhibitor) in patients with locally advanced or metastatic solid tumors.

METHODS

Cobimetinib and GDC-0994 were administered orally on two separate dosing schedules. Arm A consisted of concurrent cobimetinib and GDC-0994 once daily for 21 days of a 28-day cycle; Arm B consisted of intermittent dosing of cobimetinib on a 28-day cycle concurrent with GDC-0994 daily for 21 days of a 28-day cycle.

RESULTS

In total, 24 patients were enrolled. For Arm A, owing to cumulative grade 1-2 toxicity, the dose of cobimetinib was decreased. For Arm B, dose increases of GDC-0994 and cobimetinib were intolerable with grade 3 dose-limiting toxicities of myocardial infarction and rash. Pharmacokinetic data did not show evidence of a drug-drug interaction. Overall, seven patients had a best overall response of stable disease (SD) and one patient with pancreatic adenocarcinoma had an unconfirmed partial response.

CONCLUSION

The safety profile of MEK and ERK inhibition demonstrated classic MAPK inhibitor-related adverse events (AEs). However, overlapping AEs and cumulative toxicity could not be adequately managed on either dosing schedule, restricting the ability to further develop this combination.

Phase I Study of the Mutant IDH1 Inhibitor Ivosidenib: Safety and Clinical Activity in Patients With Advanced Chondrosarcoma

PURPOSE

Surgery is the primary therapy for localized chondrosarcoma; for locally advanced and/or metastatic disease, no known effective systemic therapy exists. Mutations in the isocitrate dehydrogenase 1/2 (IDH1/2) enzymes occur in up to 65% of chondrosarcomas, resulting in accumulation of the oncometabolite D-2-hydroxyglutarate (2-HG). Ivosidenib (AG-120) is a selective inhibitor of mutant IDH1 approved in the United States for specific cases of acute myeloid leukemia. We report outcomes of patients with advanced chondrosarcoma in an ongoing study exploring ivosidenib treatment.

PATIENTS AND METHODS

This phase I multicenter open-label dose-escalation and expansion study of ivosidenib monotherapy enrolled patients with mutant IDH1 advanced solid tumors, including chondrosarcoma. Ivosidenib was administered orally (100 mg twice daily to 1,200 mg once daily) in continuous 28-day cycles. Responses were assessed every other cycle using RECIST (version 1.1).

RESULTS

Twenty-one patients (escalation, n = 12; expansion, n = 9) with advanced chondrosarcoma received ivosidenib (women, n = 8; median age, 55 years; range, 30-88 years; 11 had received prior systemic therapy). Treatment-emergent adverse events (AEs) were mostly grade 1 or 2. Twelve patients experienced grade ≥ 3 AEs; only one event was judged treatment related (hypophosphatemia, n = 1). Plasma 2-HG levels decreased substantially in all patients (range, 14%-94.2%), to levels seen in healthy individuals. Median progression-free survival (PFS) was 5.6 months (95% CI, 1.9 to 7.4 months); the PFS rate at 6 months was 39.5%. Eleven (52%) of 21 patients experienced stable disease.

CONCLUSION

In patients with chondrosarcoma, ivosidenib showed minimal toxicity, substantial 2-HG reduction, and durable disease control. Future studies of ivosidenib monotherapy or rational combination approaches should be considered in patients with advanced mutant IDH1 chondrosarcoma.

Targeted therapy for advanced salivary gland carcinoma based on molecular profiling: results from MyPathway, a phase IIa multiple basket study

BACKGROUND

Systemic therapy options for salivary cancers are limited. MyPathway (NCT02091141), a phase IIa study, evaluates targeted therapies in non-indicated tumor types with actionable molecular alterations. Here, we present the efficacy and safety results for a subgroup of MyPathway patients with advanced salivary gland cancer (SGC) matched to targeted therapies based on tumor molecular characteristics.

PATIENTS AND METHODS

MyPathway is an ongoing, multiple basket, open-label, non-randomized, multi-center study. Patients with advanced SGC received pertuzumab + trastuzumab (HER2 alteration), vismodegib (PTCH-1/SMO mutation), vemurafenib (BRAF V600 mutation), or atezolizumab [high tumor mutational burden (TMB)]. The primary endpoint is the objective response rate (ORR).

RESULTS

As of January 15, 2018, 19 patients with SGC were enrolled and treated in MyPathway (15 with HER2 amplification and/or overexpression and one each with a HER2 mutation without amplification or overexpression, PTCH-1 mutation, BRAF mutation, and high TMB). In the 15 patients with HER2 amplification/overexpression (with or without mutations) who were treated with pertuzumab + trastuzumab, 9 had an objective response (1 complete response, 8 partial responses) for an ORR of 60% (9.2 months median response duration). The clinical benefit rate (defined by patients with objective responses or stable disease >4 months) was 67% (10/15), median progression-free survival (PFS) was 8.6 months, and median overall survival was 20.4 months. Stable disease was observed in the patient with a HER2 mutation (pertuzumab + trastuzumab, n = 1/1, PFS 11.0 months), and partial responses in patients with the PTCH-1 mutation (vismodegib, n = 1/1, PFS 14.3 months), BRAF mutation (vemurafenib, n = 1/1, PFS 18.5 months), and high TMB (atezolizumab, n = 1/1, PFS 5.5+ months). No unexpected toxicity occurred.

CONCLUSIONS

Overall, 12 of 19 patients (63%) with advanced SGC, treated with chemotherapy-free regimens matched to specific molecular alterations, experienced an objective response. Data from MyPathway suggest that matched targeted therapy for SGC has promising efficacy, supporting molecular profiling in treatment determination.

A First-in-Human Phase I Study to Evaluate the ERK1/2 Inhibitor GDC-0994 in Patients with Advanced Solid Tumors

PURPOSE

ERK1/2 signaling can be dysregulated in cancer. GDC-0994 is an oral inhibitor of ERK1/2. A first-in-human, phase I dose escalation study of GDC-0994 was conducted in patients with locally advanced or metastatic solid tumors.

PATIENTS AND METHODS

GDC-0994 was administered once daily on a 21-day on/7-day off schedule to evaluate safety, pharmacokinetics, and preliminary signs of efficacy. Patients with pancreatic adenocarcinoma and BRAF-mutant colorectal cancer were enrolled in the expansion stage.

RESULTS

Forty-seven patients were enrolled in six successive cohorts (50-800 mg). A single DLT of grade 3 rash occurred at 600 mg. The most common drug-related adverse events (AE) were diarrhea, rash, nausea, fatigue, and vomiting. Pharmacokinetic data showed dose-proportional increases in exposure, with a mean half-life of 23 hours, supportive of once daily dosing. In evaluable paired biopsies, MAPK pathway inhibition ranged from 19% to 51%. Partial metabolic responses by FDG-PET were observed in 11 of 20 patients across dose levels in multiple tumor types. Overall, 15 of 45 (33%) patients had a best overall response of stable disease and 2 patients with BRAF-mutant colorectal cancer had a confirmed partial response.

CONCLUSIONS

GDC-0994 had an acceptable safety profile and pharmacodynamic effects were observed by FDG-PET and in serial tumor biopsies. Single-agent activity was observed in 2 patients with BRAF-mutant colorectal cancer.

Everolimus Plus Exemestane vs Everolimus or Capecitabine Monotherapy for Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer: The BOLERO-6 Randomized Clinical Trial

Importance

Everolimus plus exemestane and capecitabine are approved second-line therapies for advanced breast cancer.

Objective

A postapproval commitment to health authorities to estimate the clinical benefit of everolimus plus exemestane vs everolimus or capecitabine monotherapy for estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer.

Design

Open-label, randomized, phase 2 trial of treatment effects in postmenopausal women with advanced breast cancer that had progressed during treatment with nonsteroidal aromatase inhibitors.

Interventions

Patients were randomized to 3 treatment regimens: (1) everolimus (10 mg/d) plus exemestane (25 mg/d); (2) everolimus alone (10 mg/d); and (3) capecitabine alone (1250 mg/m2 twice daily).

Main Outcomes and Measures

Estimated hazard ratios (HRs) of progression-free survival (PFS) for everolimus plus exemestane vs everolimus alone (primary objective) or capecitabine alone (key secondary objective). Safety was a secondary objective. No formal statistical comparisons were planned.

Results

A total of 309 postmenopausal women were enrolled, median age, 61 years (range, 32-88 years). Of these, 104 received everolimus plus exemestane; 103, everolimus alone; and 102, capecitabine alone. Median follow-up from randomization to the analysis cutoff (June 1, 2017) was 37.6 months. Estimated HR of PFS was 0.74 (90% CI, 0.57-0.97) for the primary objective of everolimus plus exemestane vs everolimus alone and 1.26 (90% CI, 0.96-1.66) for everolimus plus exemestane vs capecitabine alone. Between treatment arms, potential informative censoring was noted, and a stratified multivariate Cox regression model was used to account for imbalances in baseline characteristics; a consistent HR was observed for everolimus plus exemestane vs everolimus (0.73; 90% CI, 0.56-0.97), but the HR was closer to 1 for everolimus plus exemestane vs capecitabine (1.15; 90% CI, 0.86-1.52). Grade 3 to 4 adverse events were more frequent with capecitabine (74%; n = 75) vs everolimus plus exemestane (70%; n = 73) or everolimus alone (59%; n = 61). Serious adverse events were more frequent with everolimus plus exemestane (36%; n = 37) vs everolimus alone (29%; n = 30) or capecitabine (29%; n = 30).

Conclusions and Relevance

These findings suggest that everolimus plus exemestane combination therapy offers a PFS benefit vs everolimus alone, and they support continued use of this therapy in this setting. A numerical PFS difference with capecitabine vs everolimus plus exemestane should be interpreted cautiously owing to imbalances among baseline characteristics and potential informative censoring.

Trial Registration

ClinicalTrials.gov identifier: NCT01783444.

Anti-PD-1 monoclonal antibody MEDI0680 in a phase I study of patients with advanced solid malignancies

BACKGROUND

The safety, efficacy, pharmacokinetics, and pharmacodynamics of the anti-programmed cell death-1 antibody MEDI0680 were evaluated in a phase I, multicenter, dose-escalation study in advanced solid malignancies.

METHODS

MEDI0680 was administered intravenously once every 2 weeks (Q2W) or once every 3 weeks at 0.1, 0.5, 2.5, 10 or 20 mg/kg. Two cohorts received 20 mg/kg once a week for 2 or 4 weeks, then 20 mg/kg Q2W. All were treated for 12 months or until progression. The primary endpoint was safety. Secondary endpoints were efficacy and pharmacokinetics. Exploratory endpoints included pharmacodynamics.

RESULTS

Fifty-eight patients were treated. Median age was 62.5 years and 81% were male. Most had kidney cancer (n = 36) or melanoma (n = 9). There were no dose-limiting toxicities. Treatment-related adverse events occurred in 83% and were grade ≥ 3 in 21%. Objective clinical responses occurred in 8/58 patients (14%): 5 with kidney cancer, including 1 with a complete response, and 3 with melanoma. The relationship between dose and serum levels was predictable and linear, with apparent receptor saturation at 10 mg/kg Q2W and all 20 mg/kg cohorts.

CONCLUSIONS

MEDI0680 induced peripheral T-cell proliferation and increased plasma IFNγ and associated chemokines regardless of clinical response. CD8+ T-cell tumor infiltration and tumoral gene expression of IFNG, CD8A, CXCL9, and granzyme K (GZMK) were also increased following MEDI0680 administration.

TRIAL REGISTRATION

NCT02013804 ; date of registration December 12, 2013.

Abstract LB-185: Preliminary results of PROCLAIM-CX-2009, a first-in-human, dose-finding study of the Probody drug conjugate CX-2009 in patients with advanced solid tumors

Background: CX-2009 is a Probody™ drug conjugate (PDC) directed against CD166 (ubiquitously expressed in normal epithelium and overexpressed in carcinomas) that incorporates DM4, a potent but toxic microtubulin inhibitor (MTI). PDCs are preferentially activated by tumor microenvironment proteases with minimal binding in the inactive/masked state in nonmalignant tissue. Preclinically, CX-2009 led to significant tumor growth inhibition or regression in multiple solid tumor types. CX-2009 (masked) had extended exposure compared with the corresponding CD166-targeting ADC (unmasked), consistent with significantly reduced target-mediated drug disposition. These results indicate CX-2009 is efficiently activated in the tumor with low nonmalignant tissue engagement. Preliminary safety and antitumor activity from a first-in-human investigational dose escalation study are reported.

Methods: In the dose escalation of this ongoing phase 1/2 study (NCT03149549), 37 patients (pts) with advanced solid tumors received CX-2009 0.25-10 mg/kg IV every 21 days. 7 tumor types were enrolled in this study because of their high CD166 expression and MTI sensitivity: breast carcinoma (BC), castration-resistant prostate carcinoma, non-small cell lung carcinoma (NSCLC), epithelial ovarian carcinoma (EOC), endometrial carcinoma, head and neck squamous cell carcinoma, and cholangiocarcinoma. The study was initiated with accelerated dose titration in 1 single-subject cohort (0.25 mg/kg), followed by a standard 3+3 design up to 10 mg/kg to determine MTD.

Results: As of 30 Nov 2018, 37 pts were enrolled with advanced solid tumors (27% BC 27% EOC, 46% other) and a median of 6 (range 1-15) prior therapies. High CD166 by IHC was found in 14/24 tumors; median number of doses was 2 (range, 1-11), 19% of pts remain on treatment. One dose-limiting toxicity (grade 3 vomiting, 8 mg/kg) was observed. MTD was not reached at 10 mg/kg. Grade 1-2 treatment-related adverse events (TRAEs) occurred in 57% of pts and the most common (&gt;10%) were fatigue, anorexia (16% each), infusion-related reaction, diarrhea, and nausea (14% each). Grade 3-4 TRAEs were seen in 22% of pts (most frequently keratitis: 4 pts; 8, 9, and 10 mg/kg groups) and were managed and reversed with topical steroids. Of 25 pts evaluable for radiographic response, 3 had unconfirmed partial responses (BC, 8 and 9 mg/kg; EOC, 9 mg/kg; 2 CD166 high, 1 unknown; greatest tumoral shrinkage 85%) and 1 had durable stable disease for 24 weeks (NSCLC, 6 mg/kg, CD166 low).

Conclusions: CX-2009 was tolerable at dose levels up to 10 mg/kg. Preliminary antitumor activity is observed at dose levels starting at 6 mg/kg and above, warranting further investigation. The study is ongoing, enrolling translational cohorts. PK data and data on Probody integrity in the periphery will be presented. Probody is a trademark of CytomX Therapeutics, Inc.

Source of Funding: CytomX Therapeutics, Inc.

Citation Format: Funda Meric-Bernstam, Valentina Boni, Alexander I. Spira, Rachel E. Sanborn, H-Tobias Arkenau, Randy Sweis, Howard Burris, Rachel Li, Sreeni Yalamanchili, Matthias Will, Joyce F. Liu, James J. Harding, Pratigya Gautam. Preliminary results of PROCLAIM-CX-2009, a first-in-human, dose-finding study of the Probody drug conjugate CX-2009 in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-185.

Phase I Study of the Indoleamine 2,3-Dioxygenase 1 (IDO1) Inhibitor Navoximod (GDC-0919) Administered with PD-L1 Inhibitor (Atezolizumab) in Advanced Solid Tumors

PURPOSE

IDO1 induces immune suppression in T cells through l-tryptophan (Trp) depletion and kynurenine (Kyn) accumulation in the local tumor microenvironment, suppressing effector T cells and hyperactivating regulatory T cells (Treg). Navoximod is an investigational small-molecule inhibitor of IDO1. This phase I study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics of navoximod in combination with atezolizumab, a PD-L1 inhibitor, in patients with advanced cancer.

PATIENTS AND METHODS

The study consisted of a 3+3 dose-escalation stage (n = 66) and a tumor-specific expansion stage (n = 92). Navoximod was given orally every 12 hours continuously for 21 consecutive days of each cycle with the exception of cycle 1, where navoximod administration started on day -1 to characterize pharmacokinetics. Atezolizumab was administered by intravenous infusion 1,200 mg every 3 weeks on day 1 of each cycle.

RESULTS

Patients (n = 157) received navoximod at 6 dose levels (50-1,000 mg) in combination with atezolizumab. The maximum administered dose was 1,000 mg twice daily; the MTD was not reached. Navoximod demonstrated a linear pharmacokinetic profile, and plasma Kyn generally decreased with increasing doses of navoximod. The most common treatment-related AEs were fatigue (22%), rash (22%), and chromaturia (20%). Activity was observed at all dose levels in various tumor types (melanoma, pancreatic, prostate, ovarian, head and neck squamous cell carcinoma, cervical, neural sheath, non-small cell lung cancer, triple-negative breast cancer, renal cell carcinoma, urothelial bladder cancer): 6 (9%) dose-escalation patients achieved partial response, and 10 (11%) expansion patients achieved partial response or complete response.

CONCLUSIONS

The combination of navoximod and atezolizumab demonstrated acceptable safety, tolerability, and pharmacokinetics for patients with advanced cancer. Although activity was observed, there was no clear evidence of benefit from adding navoximod to atezolizumab.

Pertuzumab plus trastuzumab for HER2-amplified metastatic colorectal cancer (MyPathway): an updated report from a multicentre, open-label, phase 2a, multiple basket study

BACKGROUND

Therapies targeting HER2 have improved clinical outcomes in HER2-positive breast and gastric cancers, and are emerging as potential treatments for HER2-positive metastatic colorectal cancer. MyPathway evaluates the activity of targeted therapies in non-indicated tumour types with potentially predictive molecular alterations. We aimed to assess the activity of pertuzumab and trastuzumab in patients with HER2-amplified metastatic colorectal cancer.

METHODS

MyPathway is an ongoing, phase 2a, multiple basket study. Patients in this subset analysis were aged 18 years or older and had treatment-refractory, histologically confirmed HER2-amplified metastatic colorectal cancer with measurable or evaluable disease and an Eastern Cooperative Oncology Group performance status score of 2 or less, enrolled from 25 hospitals or clinics in 16 states of the USA. Patients received pertuzumab (840 mg loading dose, then 420 mg every 3 weeks, intravenously) and trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks, intravenously). The primary endpoint was the proportion of patients who achieved an objective response based on investigator-reported tumour responses. Analyses were done per protocol. This ongoing trial is registered with ClinicalTrials.gov, number NCT02091141.

FINDINGS

Between Oct 20, 2014, and June 22, 2017, 57 patients with HER2-amplified metastatic colorectal cancer were enrolled in the MyPathway study and deemed eligible for inclusionin this cohort analysis. Among these 57 evaluable patients, as of Aug 1, 2017, one (2%) patient had a complete response and 17 (30%) had partial responses; thus overall 18 of 57 patients achieved an objective response (32%, 95% CI 20-45). The most common treatment-emergent adverse events were diarrhoea (19 [33%] of 57 patients), fatigue (18 [32%] patients), and nausea (17 [30%] patients). Grade 3-4 treatment-emergent adverse events were recorded in 21 (37%) of 57 patients, most commonly hypokalaemia and abdominal pain (each three [5%] patients). Serious treatment-emergent adverse events were reported in ten (18%) patients and two (4%) of these adverse events (ie, chills and infusion-related reaction) were considered treatment related. There were no treatment-related deaths.

INTERPRETATION

Dual HER2-targeted therapy with pertuzumab plus trastuzumab is well tolerated and could represent a therapeutic opportunity for patients with heavily pretreated, HER2-amplified metastatic colorectal cancer.

FUNDING

F Hoffmann-La Roche/Genentech.

Abstract P6-18-11: Long-term responders to single-agent margetuximab, an Fc-modified anti-HER2 monoclonal antibody, in metastatic HER2+ breast cancer patients with prior anti-HER2 therapy

Background

Margetuximab is an Fc-optimized anti-HER2 antibody that recognizes the same epitope as trastuzumab. Margetuximab has increased affinity for the activating CD16A Fc-receptor on NK cells and macrophages as well as decreased affinity for the inhibitory CD32B receptor compared to trastuzumab. In a Phase 1 study (NCT01148849) of 66 patients with relapsed or metastatic HER2+ cancer across multiple indications, margetuximab was well tolerated at all doses. Among 60 response-evaluable patients, confirmed partial response (PR) and stable disease (SD) were seen in 7 (12%) and 30 (50%) patients, respectively. Tumor reductions occurred in 18/23 (78%) evaluable breast cancer patients. Ex-vivo analyses of patient peripheral blood mononuclear cell samples confirmed margetuximab's ability to enhance antibody dependent cell-mediated cytotoxicity over that from trastuzumab. We report on 3 breast cancer patients with prior anti-HER2 therapy failure with durable (≥ 3.5 years) SD (1) or PR (2).

Methods

Enrolled patients had histologically/cytologically-confirmed carcinoma with documented HER2 overexpression by immunohistochemistry (2+ or 3+) and disease progression during/following last therapy. Eligibility included life expectancy ≥3 months; performance status ≤1; measurable disease by Response Criteria for Solid Tumors 1.1; adequate bone marrow, renal, hepatic function; and left ventricular ejection fraction ≥50%. Margetuximab was given by intravenous infusion at 0.1 – 6.0 mg/kg for 3 of every 4 weeks or once every 3 weeks (10 – 18 mg/kg).

Results

Three of 17 HER2 3+ metastatic breast cancer patients received long-term margetuximab. Patient 35 had 3 prior regimens (adjuvant doxorubicin+cyclophosphamide followed by docetaxol+trastuzumab; gemcitabine+vinorelbine; lapatinib+capecitabine) and received margetuximab at 10 mg/kg q3wk, 88 cycles to date, with PR achieved Cycle 1 Day 43, maintained 4.4 years. Patient 44 had 3 prior regimens for metastatic disease (docetaxel+trastuzumab+pertuzumab; doxorubicin+cyclophosphamide; lapatinib+capecitabine) and received margetuximab at 15 mg/kg q3wk, 79 cycles to date with SD for 4.3 years. Patient 50 had 4 prior regimens for recurrent/metastatic disease (tamoxifen; anastrozole; capecitabine+trastuzumab; lapatinib+capecitabine) and received margetuximab dose of 18 mg/kg q3wk with PR achieved Cycle 1 Day 43, maintained 3.5 years. Progression was noted at Cycle 57, and margetuximab continues at 63 cycles to date. No cardiac toxicities were found during long-term follow-up for these 3 patients and there were no treatment-related adverse events ≥Grade 3.

Conclusions

Margetuximab is well-tolerated without cardiac toxicities in long-term responders, with single-agent activity including durable responses in heavily pre-treated metastatic breast cancer. A Phase 3, randomized, multi-center clinical trial (SOPHIA; NCT02492711) is enrolling patients with metastatic breast cancer, comparing margetuximab plus chemotherapy to trastuzumab plus chemotherapy in patients who have received 1 to 3 lines of therapy for advanced disease.

Citation Format: Im S-A, Bang Y-J, Oh D-Y, Giaccone G, Bauer T, Nordstrom J, Li H, Moore P, Hong S, Baughman J, Rock E, Burris H. Long-term responders to single-agent margetuximab, an Fc-modified anti-HER2 monoclonal antibody, in metastatic HER2+ breast cancer patients with prior anti-HER2 therapy [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 P6-18-11.

Abstract 5551: SGN-2FF: A small-molecule inhibitor of fucosylation modulates immune cell activity in preclinical models and demonstrates pharmacodynamic activity in early phase 1 analysis

SGN-2FF, an orally bioavailable small molecule inhibitor of glycoprotein fucosylation, demonstrates encouraging preclinical antitumor activity in mouse models with suggested multiple mechanisms of action, including direct and indirect effects on immune cells, tumor cells, and the tumor microenvironment. The effects of SGN-2FF were evaluated on tumors implanted in multiple strains of mice to determine how differences in the immune repertoire affect the antitumor activity. SGN-2FF treatment of nude mice, which maintain functional B cells and antibody production, resulted in a delay in LS174T tumor growth compared with untreated mice, while LS174T tumors in SCID mice, which lack B cells, were unaffected by SGN-2FF. These data suggest that activity of SGN-2FF in nude mice may be dependent on residual B cells and circulating antibodies. The antitumor effect of SGN-2FF in syngeneic mouse models with intact immune systems also appears to be dependent on T cell activity. Transfer of T cells isolated from SGN-2FF-treated tumor-bearing mice to naïve tumor-bearing mice was sufficient to delay tumor growth. T cells isolated from untreated tumor-bearing mice did not have the same effect. These results demonstrate that afucosylated immune cells play a key role in the preclinical activity of SGN-2FF.

Various preclinical assays were used to detect SGN-2FF-mediated changes in cellular and IgG fucosylation important for biological activity. These assays are being applied in evaluating patient samples in the ongoing phase 1, multicenter, dose-escalation study investigating the safety, tolerability, PK, and biomarkers of antitumor activity of SGN-2FF administered orally to adult patients with advanced solid tumors (NCT# 02952989). Changes in peripheral IgG fucosylation, absolute neutrophil count, and immune cell surface fucosylation were identified as initial biomarkers for proof of pharmacodynamic activity. Preliminary data following daily doses of SGN-2FF demonstrate that cell surface fucosylation on granulocytes was significantly reduced and neutrophil count was significantly increased in 6 of 7 treated subjects; additionally, IgG fucosylation was significantly decreased in 7 of 7 subjects. PK have been characterized, and preliminary results are within the expected range as predicted from preclinical studies. Following daily administration of SGN-2FF, accumulation of the active metabolite, GDP-2FF, was observed intracellularly, while no accumulation of SGN-2FF was observed in plasma. Collectively, these data demonstrate robust biological effects of SGN-2FF. The pharmacodynamic biomarkers and PK analysis are informing next steps in identifying an optimal dose and dosing schedule for SGN-2FF.

Citation Format: Nicole M. Okeley, Ryan A. Heiser, Weiping Zeng, Shawna Mae Hengel, Jason Wall, Peter C. Haughney, Timothy Anthony Yap, Francisco Robert, Rachel E. Sanborn, Howard Burris, Laura Q. Chow, Khanh T. Do, Martin Gutierrez, Karen Reckamp, Amy Weise, D Ross Camidge, John Strickler, Conor Steuer, Zejing Wang, Megan M. O'Meara, Stephen C. Alley, Shyra J. Gardai. SGN-2FF: A small-molecule inhibitor of fucosylation modulates immune cell activity in preclinical models and demonstrates pharmacodynamic activity in early phase 1 analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5551.

Abstract PD3-14: Phase 1 study of the antibody-drug conjugate SGN-LIV1A in patients with heavily pretreated triple-negative metastatic breast cancer

Background

LIV-1, a transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells. It is associated with lymph node involvement and metastatic progression. SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which disrupts microtubulin and induces apoptosis.

Methods

This ongoing, phase 1 study evaluates safety, tolerability, pharmacokinetics, and antitumor activity of SGN-LIV1A (q3wks IV) in women with LIV-1-positive, unresectable, locally advanced or metastatic breast cancer (LA/MBC) (NCT01969643). Patients (pts) with measurable disease and ≥2 prior cytotoxic regimens for LA/MBC are eligible. Pts with ≥ Grade 2 neuropathy are excluded. Response is assessed per RECIST v1.1; pts with stable disease (SD) or better can continue treatment until disease progression or intolerable toxicity. At completion of dose escalation in hormone receptor-positive/HER2-negative (HR+/HER2–) and triple-negative (TN) pts, expansion cohorts were opened to further evaluate safety and antitumor activity of monotherapy in TN pts. Tumor biopsies are evaluated for LIV-1 expression.

Results

To date, 69 pts (18 HR+/HER2–, 51 TN) have received a median of 3 cycles (range, 1–12) of SGN-LIV1A at doses of 0.5–2.8 mg/kg. Median age was 56 yrs. Pts had a median of 3 prior cytotoxic regimens for LA/MBC; 58 had visceral disease and 37 had bone metastases. No dose-limiting toxicities (DLTs) occurred in 19 DLT-evaluable pts; maximum tolerated dose was not exceeded at 2.8 mg/kg. Expansion cohorts of TN pts were opened at 2.0 and 2.5 mg/kg. Treatment-emergent adverse events (AEs) reported in ≥25% of pts were fatigue (59%), nausea (51%), peripheral neuropathy (44%), alopecia (36%), decreased appetite (33%), constipation (30%), abdominal pain, diarrhea, and neutropenia (25% each). Most AEs were Grade 1/2; AEs ≥ Grade 3 included neutropenia (25%) and anemia (15%). Febrile neutropenia occurred in 2 pts whose total dose exceeded 200 mg per cycle, including 1 treatment-related death due to sepsis. No other treatment-related deaths occurred on-study. Seven pts discontinued treatment due to AEs. In dose escalation, activity was observed in 17 efficacy evaluable (EE) HR+/HER2- pts, with a disease control rate (DCR= CR+PR+SD) of 59% (10 SD), including 1 pt with SD ≥24 wks. Among the 44 EE TN pts (dose escalation plus expansion cohorts), the objective response rate (ORR) was 32% (14 PR) with a confirmed PR rate of 21%, DCR was 64% (14 PR, 14 SD), and clinical benefit rate (CBR=CR+PR+SD ≥24 wks) was 36% (16 pts). For TN pts, median PFS was 11.3 wks (95% CI: 6.1, 17.1); 10 pts remain on treatment.

Of 631 MBC tumor samples of all clinical subtypes evaluated for LIV-1, 91% were positive; 75% had moderate-to-high expression (H-score ≥100).

Conclusions

LIV-1 is expressed in almost all MBC tumors. SGN-LIV1A monotherapy was generally well tolerated and showed encouraging antitumor activity in heavily pretreated TN MBC, with a PR rate of 32%, confirmed PR rate of 21%, and CBR (≥24 wks) of 36%. Response duration data continue to evolve. Enrollment continues in the TN monotherapy expansion cohort.

Citation Format: Modi S, Pusztai L, Forero A, Mita M, Miller KD, Weise A, Krop I, Burris III H, Kalinsky K, Tsai M, Liu MC, Hurvitz SA, Wilks S, Ademuyiwa F, Diab S, Han HS, Kato G, Nanda R, O'Shaughnessy J, Kostic A, Li M, Specht J. Phase 1 study of the antibody-drug conjugate SGN-LIV1A in patients with heavily pretreated triple-negative metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-14.

Targeted Therapy for Advanced Solid Tumors on the Basis of Molecular Profiles: Results From MyPathway, an Open-Label, Phase IIa Multiple Basket Study

Purpose Detection of specific molecular alterations in tumors guides the selection of effective targeted treatment of patients with several types of cancer. These molecular alterations may occur in other tumor types for which the efficacy of targeted therapy remains unclear. The MyPathway study evaluates the efficacy and safety of selected targeted therapies in tumor types that harbor relevant genetic alterations but are outside of current labeling for these treatments. Methods MyPathway ( ClinicalTrials.gov identifier: NCT02091141) is a multicenter, nonrandomized, phase IIa multiple basket study. Patients with advanced refractory solid tumors harboring molecular alterations in human epidermal growth factor receptor-2, epidermal growth factor receptor, v-raf murine sarcoma viral oncogene homolog B1, or the Hedgehog pathway are treated with pertuzumab plus trastuzumab, erlotinib, vemurafenib, or vismodegib, respectively. The primary end point is investigator-assessed objective response rate within each tumor-pathway cohort. Results Between April 1, 2014 and November 1, 2016, 251 patients with 35 different tumor types received study treatment. The efficacy population contains 230 treated patients who were evaluated for response or discontinued treatment before evaluation. Fifty-two patients (23%) with 14 different tumor types had objective responses (complete, n = 4; partial, n = 48). Tumor-pathway cohorts with notable objective response rates included human epidermal growth factor receptor-2-amplified/overexpressing colorectal (38% [14 of 37]; 95% CI, 23% to 55%) and v-raf murine sarcoma viral oncogene homolog B1 V600-mutated non-small-cell lung cancer (43% [six of 14]; 95% CI, 18% to 71%). Conclusion The four currently approved targeted therapy regimens in the MyPathway study produced meaningful responses when administered without chemotherapy in several refractory solid tumor types not currently labeled for these agents.

Cabozantinib in hepatocellular carcinoma: results of a phase 2 placebo-controlled randomized discontinuation study

Background

Cabozantinib, an orally bioavailable inhibitor of tyrosine kinases including MET, AXL, and VEGF receptors, was assessed in patients with hepatocellular carcinoma (HCC) as part of a phase 2 randomized discontinuation trial with nine tumor-type cohorts.

Patients and methods

Eligible patients had Child-Pugh A liver function and ≤1 prior systemic anticancer regimen, completed ≥4 weeks before study entry. The cabozantinib starting dose was 100 mg daily. After an initial 12-week cabozantinib treatment period, patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 were randomized to cabozantinib or placebo. The primary endpoint of the lead-in stage was objective response rate (ORR) at week 12, and the primary endpoint of the randomized stage was progression-free survival (PFS).

Results

Among the 41 HCC patients enrolled, the week 12 ORR was 5%, with 2 patients achieving a confirmed partial response (PR). The week 12 disease control rate (PR or SD) was 66% (Asian subgroup: 73%). Of patients with ≥1 post-baseline scan, 78% had tumor regression, with no apparent relationship to prior sorafenib therapy. Alpha-fetoprotein (AFP) response (>50% reduction from baseline) occurred in 9 of the 26 (35%) patients with elevated baseline AFP and ≥1 post-baseline measurement. Twenty-two patients with SD at week 12 were randomized. Median PFS after randomization was 2.5 months with cabozantinib and 1.4 months with placebo, although this difference was not statistically significant. Median PFS and overall survival from Day 1 in all patients were 5.2 and 11.5 months, respectively. The most common grade 3/4 adverse events, regardless of attribution, were diarrhea (20%), hand-foot syndrome (15%), and thrombocytopenia (15%). Dose reductions were utilized in 59% of patients.

Conclusions

Cabozantinib has clinical activity in HCC patients, including objective tumor responses, disease stabilization, and reductions in AFP. Adverse events were managed with dose reductions.

Trial registration number

NCT00940225.

Hybrid capture-based genomic profiling of circulating tumor DNA from patients with estrogen receptor-positive metastatic breast cancer

BACKGROUND

Genomic changes that occur in breast cancer during the course of disease have been informed by sequencing of primary and metastatic tumor tissue. For patients with relapsed and metastatic disease, evolution of the breast cancer genome highlights the importance of using a recent sample for genomic profiling to guide clinical decision-making. Obtaining a metastatic tissue biopsy can be challenging, and analysis of circulating tumor DNA (ctDNA) from blood may provide a minimally invasive alternative.

PATIENTS AND METHODS

Hybrid capture-based genomic profiling was carried out on ctDNA from 254 female patients with estrogen receptor-positive breast cancer. Peripheral blood samples were submitted by clinicians in the course of routine clinical care between May 2016 and March 2017. Sequencing of 62 genes was carried out to a median unique coverage depth of 7503×. Genomic alterations (GAs) in ctDNA were evaluated and compared with matched tissue samples and genomic datasets of tissue from breast cancer.

RESULTS

At least 1 GA was reported in 78% of samples. Frequently altered genes were TP53 (38%), ESR1 (31%) and PIK3CA (31%). Temporally matched ctDNA and tissue samples were available for 14 patients; 89% of mutations detected in tissue were also detected in ctDNA. Diverse ESR1 GAs including mutation, rearrangement and amplification, were observed. Multiple concurrent ESR1 GAs were observed in 40% of ESR1-altered cases, suggesting polyclonal origin; ESR1 compound mutations were also observed in two cases. ESR1-altered cases harbored co-occurring GAs in PIK3CA (35%), FGFR1 (16%), ERBB2 (8%), BRCA1/2 (5%), and AKT1 (4%).

CONCLUSIONS

GAs relevant to relapsed/metastatic breast cancer management were identified, including diverse ESR1 GAs. Genomic profiling of ctDNA demonstrated sensitive detection of mutations found in tissue. Detection of amplifications was associated with ctDNA fraction. Genomic profiling of ctDNA may provide a complementary and possibly alternative approach to tissue-based genomic testing for patients with estrogen receptor-positive metastatic breast cancer.

Abstract CT153: First in human study of the first-in-class fatty acid synthase (FASN) inhibitor TVB-2640

Introduction

FASN inhibition causes selective disruption of palmitate biosynthesis that, in tumor cells, leads to apoptosis. TVB-2640 is an oral, first-in-class, small molecule reversible inhibitor of FASN that demonstrated in vivo antitumor effects. We previously reported the results of dose escalation and now present evidence of activity in patients (pts) treated in the dose expansion cohorts.

Methods

This fully enrolled multicenter phase I trial included pts with advanced solid tumors. TVB-2640 was given PO once daily at the MTD (100 mg/m2) as monotherapy (mono) or in combination (combo) with weekly IV paclitaxel (80 mg/m2).

Results

The most common related AEs observed in both groups (mono, N=44, combo, N=43) included alopecia (41%), palmar-plantar erythrodysesthesia (PPE) (47%), and decreased appetite (13%). Additional common AEs in the mono group included dry skin (19%) and in the combo group included nausea (28%). Gr3 related AEs included decreased appetite (8%) and PPE (9%); all other related AEs were ≤ Gr2. All related AEs were reversible on dose interruption. No enhancement of paclitaxel toxicity was observed with TVB-2640. Pneumonitis in the combo arm was observed uncommonly (9%), but the contribution of TVB-2640 to this effect is uncertain.

Pharmacokinetic analyses showed that TVB-2640 had a similar half-life whether given alone or in combo with paclitaxel. Clearance rates were similar on days 1 and 8 (or day 15 for combo). Multiple pharmacodynamic markers demonstrated potent inhibition of FASN and lipogenesis in pts.

With respect to clinical activity, overall, 5 confirmed RECIST partial responses (cPR) were seen. Among pts with NSCLC, 18 of 31 were KRASmut, and KRASmut pts achieved longer progression-free survival on TVB-2640 monotherapy, with 60% of KRASmut pts vs. 0% of KRASwt pts on study &gt; 12 wks. Among 18 KRASmut pts, 11 achieved prolonged SD (≥16 wks), including 6 mono pts (SD=19-46 wks) and 5 combo pts (SD=23-54 wks), whereas no KRASwt pts achieved prolonged SD. One NSCLC combo pt achieved cPR at wk 12 and remained on study for 39 wks. Of 14 breast cancer pts, 3 pts achieved cPR and 8 pts achieved prolonged SD (≥16 wks), despite extensive previous treatment, including taxane resistance. One ongoing breast cancer pt with SD, entering her 78th wk of treatment, discontinued paclitaxel at wk 35 and remains on monotherapy . One pt with peritoneal carcinoma (combo) achieved cPR and a 58% decrease in CA125. Reductions in CA125 were seen in 5 out of 12 ovarian cancer pts, who were typically heavily pretreated and taxane-resistant.

Summary

TVB-2640 demonstrated antitumor activity, including objective responses when combined with weekly paclitaxel, as well as prolonged SD as monotherapy or in combination with paclitaxel. Further studies are planned to evaluate the efficacy of TVB-2640 in NSCLC and breast cancer pts.

Citation Format: Gerald Falchook, Manish Patel, Jeffrey Infante, Hendrik-Tobias Arkenau, Emma Dean, Andrew Brenner, Erkut Borazanci, Juanita Lopez, Kathleen Moore, Peter Schmid, Arthur Frankel, Suzanne Jones, William McCulloch, George Kemble, Howard Burris. First in human study of the first-in-class fatty acid synthase (FASN) inhibitor TVB-2640 [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 CT153. doi:10.1158/1538-7445.AM2017-CT153

Abstract 311: Development of AZD2811, an aurora kinase B inhibitor, incorporated into an AccurinTM nanoparticle for use in haematological and solid cancers

A nanoparticle formulation of AZD2811, a selective aurora kinase B inhibitor, is currently under clinical development for the treatment of both haematological and solid tumour disease. AZD2811 is the active derivative of the prodrug Barasertib (AZD1152) which gave promising clinical activity in elderly AML patients delivered as a 7-day infusion (Kantarjian et al, Cancer, 119, 2611-2619, 2013). To address the limitations associated with the clinical utility of Barasertib and other cell cycle inhibitors in the clinic, AZD2811 has been incorporated into an AccurinTM nanoparticle using a pamoic acid ion pairing approach to optimise drug release rate (Song et al, Journal of Controlled Release, 229, 106-119, 2016), improve the drug exposure to tumour and reduce the duration of administration. A proof of principle formulation of AZD2811 as an AccurinTM nanoparticle established the principle that anti-tumour activity and improved therapeutic index could be achieved (Ashton et al, Science Translational Medicine, 325, 1-10, 2016). The clinical nanoparticle formulation of AZD2811 has been optimised for drug loading and release rate. In pre-clinical models, the clinical formulation can be used flexibly to optimise drug delivery for use in both haematological disease such as AML, or in solid tumour settings. Anti-tumour activity in solid tumours can be achieved at doses where bone marrow toxicity is reduced compared to Barasertib. In sensitive xenograft and PDX solid tumour models greater than 90% tumour regression is observed after a total dose of 50mg/kg with no tumour progression for greater than 40 days. In contrast, for AML, increasing the dose intensity by 2-4 fold leads to neutropenia and to complete tumour regression in a range of AML xenograft models for greater than 60 days. These data establish the concept that drug delivery using nanoparticles is able to resolve therapeutic index challenges, and is able to do so across different disease types. AZD2811 is currently in Phase 1 clinical trial (D6130C0000). The current pre-clinical and clinical data with this novel approach to inhibition of the cell cycle will be discussed.

Citation Format: Susan Ashton, Nicholas Floch, Paula Taylor, Colin Howes, Doug Ferguson, Matthew Ling, Maureen Hattersley, Shenghua Wen, Kim Maratea, Adina Hughes, Sean Redmond, Wolfram Brugger, Simon Smith, Alexander MacDonald, Keith Parry, Howard Burris, Young-Ho Song, Jim Nolan, Elizabeth Pease, Simon T. Barry. Development of AZD2811, an aurora kinase B inhibitor, incorporated into an AccurinTM nanoparticle for use in haematological and solid cancers [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 311. doi:10.1158/1538-7445.AM2017-311

Abstract CT035: ICONIC: Phase 1/2 trial of ICOS agonist JTX-2011 alone and in combination with nivolumab (nivo)

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 induce proliferation and stimulation of CD4 T effector cells and selectively deplete intratumoral T regulatory cells. JTX-2011 has shown preclinical antitumor effects both as a single agent and in combination with anti-PD-1 antibodies, with single agent efficacy correlated with % of ICOS expressing T cells in tumors. An ICOS IHC assay was used to identify human tumor types with the highest levels of ICOS expressing T cells.

Methods: ICONIC is a first-in-human Phase 1/2, open label, adaptive clinical study of JTX-2011 alone or in combination with a fixed dose of nivo in subjects with advanced solid tumors. It is designed to assess safety and tolerability, determine the maximal tolerated dose (MTD) and recommended Phase 2 dose, and evaluate preliminary efficacy.

Part A: 3+3 dose escalation of JTX-2011, with Safety/PK/PD expansion cohorts at 2 or more dose levels.

Part B: 3+3 dose escalation of JTX-2011 in combination with nivo, with Safety/PK/PD expansion cohorts at two or more dose levels.

Part C: ≥3 JTX-2011 cohorts in tumors expected to have higher levels of ICOS expressing T cells (non small cell lung cancer [NSCLC], head and neck squamous cell cancer [HNSCC], and others), with ICOS enrichment by IHC.

Part D: ≥ 5 JTX-2011 + nivo cohorts in tumors expected to have higher levels of ICOS expressing T cells NSCLC, HNSCC, triple negative breast cancer, melanoma, gastric, and others), with ICOS enrichment by IHC.

Major Inclusion Criteria

Confirmed cancer that is recurrent, metastatic, or persistent after at least one line of therapy and with no further standard treatment optionsA&B: available and consent to provide archival tumor tissueC&D: available and consent to provide archival tumor tissue, have a lesion that can be biopsied at acceptable clinical risk (as judged by the investigator), and agree to a fresh biopsy

Major Exclusion Criteria

Refused standard therapy Hx of intolerance, hypersensitivity, or treatment discontinuation due to severe immune adverse events on prior immunotherapyImmunodeficiencyActive or prior history of autoimmune diseaseSymptomatic or uncontrolled brain metastases, leptomeningeal disease, or spinal cord compression

Endpoints

Safety and tolerability PK, target engagement, and other PD markers Efficacy by RECIST 1.1 and irR

Overall response rateDuration of ResponseDisease Control RateProgression Free Survival (PFS)Landmark PFSOverall Survival

Trial Progress

Enrollment began in August 2016 and is continuing as planned.

Citation Format: Olivia Sears, Howard Burris, Anthony Tolcher, Margaret Callahan, Timothy Yap, Shivanni Kummar, Gerald Falchook, Russell Pachynski, Scott Tykodi, Tanguy Siewert, Geoffrey Gibney, Justin Gainor, Patricia LoRusso, Emmanuel Lazaro, Myles Clancy, Ella Li, Baoyu Ding, Elizabeth Trehu. ICONIC: Phase 1/2 trial of ICOS agonist JTX-2011 alone and in combination with nivolumab (nivo) [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 CT035. doi:10.1158/1538-7445.AM2017-CT035