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

BACKGROUND: Patients with advanced biliary tract cancer have a poor prognosis, and first-line standard of care (gemcitabine plus cisplatin) has remained unchanged for more than 10 years. The TOPAZ-1 trial evaluated durvalumab plus chemotherapy for patients with advanced biliary tract cancer. METHODS: In this double-blind, placebo-controlled, phase 3 study, we randomly assigned patients with previously untreated unresectable or metastatic biliary tract cancer or with recurrent disease 1:1 to receive durvalumab or placebo in combination with gemcitabine plus cisplatin for up to eight cycles, followed by durvalumab or placebo monotherapy until disease progression or unacceptable toxicity. The primary objective was to assess overall survival. Secondary end points included progression-free survival, objective response rate, and safety. RESULTS: Overall, 685 patients were randomly assigned to durvalumab (n=341) or placebo (n=344) with chemotherapy. As of data cutoff, 198 patients (58.1%) in the durvalumab group and 226 patients (65.7%) in the placebo group had died. The hazard ratio for overall survival was 0.80 (95% confidence interval [CI], 0.66 to 0.97; P=0.021). The estimated 24-month overall survival rate was 24.9% (95% CI, 17.9 to 32.5) for durvalumab and 10.4% (95% CI, 4.7 to 18.8) for placebo. The hazard ratio for progression-free survival was 0.75 (95% CI, 0.63 to 0.89; P=0.001). Objective response rates were 26.7% with durvalumab and 18.7% with placebo. The incidences of grade 3 or 4 adverse events were 75.7% and 77.8% with durvalumab and placebo, respectively. CONCLUSIONS: Durvalumab plus chemotherapy significantly improved overall survival versus placebo plus chemotherapy and showed improvements versus placebo plus chemotherapy in prespecified secondary end points including progression-free survival and objective response rate. The safety profiles of the two treatment groups were similar. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT03875235.)

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.