Phase I/Ib Clinical Trial of Sabatolimab, an Anti-TIM-3 Antibody, Alone and in Combination with Spartalizumab, an Anti-PD-1 Antibody, in Advanced Solid Tumors

PURPOSE

Sabatolimab (MBG453) and spartalizumab are mAbs that bind T-cell immunoglobulin domain and mucin domain-3 (TIM-3) and programmed death-1 (PD-1), respectively. This phase I/II study evaluated the safety and efficacy of sabatolimab, with or without spartalizumab, in patients with advanced solid tumors.

PATIENTS AND METHODS

Primary objectives of the phase I/Ib part were to characterize the safety and estimate recommended phase II dose (RP2D) for future studies. Dose escalation was guided by a Bayesian (hierarchical) logistic regression model. Sabatolimab was administered intravenously, 20 to 1,200 mg, every 2 or 4 weeks (Q2W or Q4W). Spartalizumab was administered intravenously, 80 to 400 mg, Q2W or Q4W.

RESULTS

Enrolled patients (n = 219) had a range of cancers, most commonly ovarian (17%) and colorectal cancer (7%); patients received sabatolimab (n = 133) or sabatolimab plus spartalizumab (n = 86). The MTD was not reached. The most common adverse event suspected to be treatment-related was fatigue (9%, sabatolimab; 15%, combination). No responses were seen with sabatolimab. Five patients receiving combination treatment had partial responses (6%; lasting 12-27 months) in colorectal cancer (n = 2), non-small cell lung cancer (NSCLC), malignant perianal melanoma, and SCLC. Of the five, two patients had elevated expression of immune markers in baseline biopsies; another three had >10% TIM-3-positive staining, including one patient with NSCLC who received prior PD-1 therapy.

CONCLUSIONS

Sabatolimab plus spartalizumab was well tolerated and showed preliminary signs of antitumor activity. The RP2D for sabatolimab was selected as 800 mg Q4W (alternatively Q3W or Q2W schedules, based on modeling), with or without 400 mg spartalizumab Q4W.

Abstract CT154: Isatuximab (Isa) plus atezolizumab (Atezo) in patients (pts) with advanced malignancies: Results from a Phase 1/2 open-label multicenter study

Background: The CD38 monoclonal antibody Isa is approved for the treatment of multiple myeloma, but there are no data on its efficacy in solid tumors. A mechanism of immune resistance to anti-PD-1/PD-L1 therapy caused by CD38 expression in tumor cells has been described in the preclinical setting, providing a rationale for testing a combination of Isa+Atezo (anti-PD-L1 antibody) in the clinic to prevent therapy resistance and further enhance antitumor efficacy. The present study assessed safety and efficacy of Isa+Atezo in pts with epithelial ovarian cancer (EOC; n = 18), glioblastoma multiforme (GBM; n = 33), hepatocellular carcinoma (HCC; n = 27), or squamous cell carcinoma of the head and neck (SCCHN; n = 29), not amenable to local therapy with curative intent. Methods: Phase 1 (NCT03637764) assessed safety and confirmed the recommended Phase 2 dose (RP2D) of Isa according to a 21-day dose-limiting toxicity (DLT) observation period. Pts received Isa 10 mg/kg intravenously (IV) every week for 3 weeks followed by once every 3 weeks + Atezo 1200 mg IV every 3 weeks. Phase 2 used a Simon's 2-stage design to assess the overall response rate (ORR; EOC, HCC, SCCHN cohorts) or progression-free survival at 6 months (PFS-6; GBM cohort). Interim analysis was performed at 6 months following first treatment of the last enrolled pt in each cohort. Pharmacodynamics (PD), including analysis of CD38, PD-L1 and tumor-infiltrating lymphocytes in the tumor microenvironment (TME), were also evaluated. Results: In Phase 1, Isa+Atezo had acceptable safety and tolerability, with no new safety signals, in pts with EOC, GBM, HCC, or SCCHN. No DLTs were observed and RP2D were confirmed. Overall, 99% of pts experienced TEAEs, with >40% being Grade ≥3. The most frequently reported TEAE of any grade for all cohorts was infusion-related reactions (EOC, 83.3%; GBM, 54.5%; HCC, 63.0%; SCCHN, 31.0%). In the GBM Phase 2 cohort, the PFS-6 was 3.1%; no patients responded in Stage 1. In the EOC, HCC, and SCCHN Phase 2 cohorts, ORR was 5.6%, 7.4%, and 13.8%, respectively; therefore, the study did not continue to Stage 2. Tumor-infiltrating CD38+ immune cells were reduced by ~20% after treatment. Isa+Atezo did not lead to significant modulation of Tregs or PD-L1 in the TME. Conclusions: Isa+Atezo had acceptable safety and tolerability. Clinical PD evaluation suggested the efficient target engagement effect of Isa by demonstrating treatment-mediated reduction of CD38+ immune cells in the TME. However, significant reduction of CD38+ Tregs and restoration of T-cell proliferation was not observed. Based on clinical data, CD38 inhibition does not seem to influence response to anti-PD-L1 agents in these pts. Although no new safety signals were observed, efficacy did not fulfil criteria to expand enrollment despite the evidence of target engagement of Isa.

Citation Format: Maria Vieito Villar, Matteo Simonelli, Ferry A.L.M. Eskens, Marta Gil-Martin, Chia-Jui Yen, Radka Obermannova, Yee Chao, Vittorina Zagonel, Bohuslav Melichar, Victor Moreno, Ming-Lung Yu, Alberto Bongiovanni, Emiliano Calvo, Sylvie Rottey, Jean-Pascal Machiels, Antonio González-Martín, Luis Paz-Ares, Chih-Long Chang, Warren Mason, Chia-Chi Lin, David Reardon, Elena Garralda, Armando Santoro, Robin Meng, Giovanni Abbadessa, Fatima Menas, Helen Lee, Qianying Liu, Cécile Combeau, Nils Ternes, Christophe Massard. Isatuximab (Isa) plus atezolizumab (Atezo) in patients (pts) with advanced malignancies: Results from a Phase 1/2 open-label multicenter study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT154.

Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGFβ and PD-L1, in Patients with Esophageal Squamous Cell Carcinoma: Results from a Phase 1 Cohort in Asia

BACKGROUND

Patients with esophageal squamous cell carcinoma (SCC) have limited treatment options. Blocking transforming growth factor-β (TGFβ), which can be overexpressed in these tumors, may enhance responses to programmed cell death protein 1/programmed death-ligand 1 [PD-(L)1] inhibitors. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGFβ receptor II (TGFβRII) (a TGFβ "trap") fused to a human IgG1 monoclonal antibody blocking PD-L1.

OBJECTIVE

The objective of this study was to investigate the safety and efficacy of bintrafusp alfa in Asian patients with pretreated, PD-L1-unselected esophageal SCC.

PATIENTS AND METHODS

In a phase 1 study, Asian patients with pretreated esophageal SCC received bintrafusp alfa 1200 mg every 2 weeks until disease progression, unacceptable toxicity, or withdrawal. The primary endpoint was safety/tolerability with a goal of exploring clinical activity.

RESULTS

By the database cutoff of August 24, 2018, 30 patients (76.7% had two or more prior anticancer regimens) received bintrafusp alfa for a median of 6.1 weeks; two remained on treatment. Nineteen patients (63.3%) had treatment-related adverse events, seven (23.3%) with grade 3/4 events, and there were no treatment-related deaths. The confirmed objective response rate (ORR) per independent review was 10.0% (95% confidence interval [CI] 2.1-26.5); responses lasted 2.8-8.3 + months. All responses occurred in immune-excluded tumors. Investigator-assessed confirmed ORR was 20.0% (95% CI 7.7-38.6). Median overall survival was 11.9 months (95% CI 5.7-not reached).

CONCLUSIONS

Bintrafusp alfa demonstrated a manageable safety profile and efficacy in Asian patients with pretreated esophageal SCC.

CLINICAL TRIALS REGISTRATION

NCT02699515.

Moving Beyond 3+3: The Future of Clinical Trial Design

Misgivings have been raised about the operating characteristics of the canonical 3+3 dose-escalation phase I clinical trial design. Yet, the traditional 3+3 design is still the most commonly used. Although it has been implied that adhering to this design is due to a stubborn reluctance to adopt change despite other designs performing better in hypothetical computer-generated simulation models, the continued adherence to 3+3 dose-escalation phase I strategies is more likely because these designs perform the best in the real world, pinpointing the correct dose and important side effects with an acceptable degree of precision. Beyond statistical simulations, there are little data to refute the supposed shortcomings ascribed to the 3+3 method. Even so, to address the unique nuances of gene- and immune-targeted compounds, a variety of inventive phase 1 trial designs have been suggested. Strategies for developing these therapies have launched first-in-human studies devised to acquire a breadth of patient data that far exceed the size of a typical phase I design and blur the distinction between dose selection and efficacy evaluation. Recent phase I trials of promising cancer therapies assessed objective tumor response and durability at various doses and schedules as well as incorporated multiple expansion cohorts spanning a variety of histology or biomarker-defined tumor subtypes, sometimes resulting in U.S. Food and Drug Administration approval after phase I. This article reviews recent innovations in phase I design from the perspective of multiple stakeholders and provides recommendations for future trials.

Phase IA/IB study of single-agent tislelizumab, an investigational anti-PD-1 antibody, in solid tumors

Background

The programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) axis plays a central role in suppressing antitumor immunity; axis dysregulation can be used by cancer cells to evade the immune system. Tislelizumab, an investigational monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding to FcγR on macrophages to limit antibody-dependent phagocytosis, a potential mechanism of resistance to anti-PD-1 therapy. The aim of this phase IA/IB study was to investigate the safety/tolerability, antitumor effects and optimal dose and schedule of tislelizumab in patients with advanced solid tumors.

Methods

Patients (aged ≥18 years) enrolled in phase IA received intravenous tislelizumab 0.5, 2, 5 or 10 mg/kg every 2 weeks; 2 or 5 mg/kg administered every 2 weeks or every 3 weeks; or 200 mg every 3 weeks; patients in phase IB received 5 mg/kg every 3 weeks. Primary objectives were to assess tislelizumab’s safety/tolerability profile by adverse event (AE) monitoring and antitumor activity using RECIST V.1.1. PD-L1 expression was assessed retrospectively with the VENTANA PD-L1 (SP263) Assay.

Results

Between May 2015 and October 2017, 451 patients (n=116, IA; n=335, IB) were enrolled. Fatigue (28%), nausea (25%) and decreased appetite (20%) were the most commonly reported AEs. Most AEs were grade 1–2 severity; anemia (4.9%) was the most common grade 3–4 AE. Treatment-related AEs led to discontinuation in 5.3% of patients. Grade 5 AEs were reported in 14 patients; 2 were considered related to tislelizumab. Pneumonitis (2%) and colitis (1%) were the most common serious tislelizumab-related AEs. As of May 2019, 18% of patients achieved a confirmed objective response in phase IA and 12% in phase IB; median follow-up duration was 13.6 and 7.6 months, respectively. Pharmacokinetics, safety and antitumor activity obtained from both phase IA and IB determined the tislelizumab recommended dose; ultimately, tislelizumab 200 mg intravenous every 3 weeks was the dose and schedule recommended to be taken into subsequent clinical trials.

Conclusions

Tislelizumab monotherapy demonstrated an acceptable safety/tolerability profile. Durable responses were observed in heavily pretreated patients with advanced solid tumors, supporting the evaluation of tislelizumab 200 mg every 3 weeks, as monotherapy and in combination therapy, for the treatment of solid tumors and hematological malignancies.

Trial registration number

NCT02407990.

KY1044 to target the ICOS pathways inducing intratumoral Treg depletion and agonism of effector T cells: Preliminary pharmacodynamic markers from a phase 1/2 multicenter trial

2626

Background: Inducible T-cell co-stimulator (ICOS) is an important co-stimulatory receptor on effector T cells (Teffs) that also promotes tumor growth due to its high expression on regulatory T cells (Tregs). KY1044 is a fully human IgG1 that targets ICOS, acting via a dual mode of action (MoA) by depleting ICOShigh Tregs and stimulating ICOSLow Teffs. A Phase 1/2 clinical trial (NCT03829501) is currently assessing the safety and preliminary efficacy of KY1044, as a single agent and in combination with atezolizumab, in subjects with advanced relapsed/refractory malignancies. Using longitudinal blood samples and tumor biopsies, we aim to correlate KY1044 target engagement levels with pharmacodynamic (PD) properties (e.g. dual MoA) in the tumor microenvironment (TME) and the circulation. Methods: Phase 1 subjects were enrolled in dose escalation and enrichment cohorts to evaluate the effect of KY1044 as monotherapy (0.8 – 240 mg) Q3W and in combination (0.8 – 80 mg) with atezolizumab (1200 mg) Q3W. PBMCs, plasma and tumor biopsies were collected over the first 3 cycles to confirm target engagement and KY1044 MoA. The sample analysis included: immunohistochemistry (IHC) of tumor samples (ICOS, FOXP3 and CD8); circulating T cell immunoprofiling and receptor occupancy by chip-cytometry; PBMC and tumor sample pre- and post-treatment transcriptomic analysis; and the assessment of circulating cytokines (e.g. GM-CSF). Results: As assessed in PBMCs, full/prolonged ICOS target engagement on T cells was confirmed in subjects receiving a flat dose of 8 to 240 mg, while partial/transient saturation was observed at lower doses (0.8-2.4 mg). The target engagement was not affected by atezolizumab. The immune cell profiling showed changes in some populations, but there was no significant depletion of peripheral ICOS+ cells. In contrast, pre- and post-treatment IHC analysis of ICOS+/FOXP3+ cells in tumor biopsies confirmed a KY1044-dose dependent reduction of ICOS+ Tregs and maintenance of CD8+ T cells in the TME. Together, this resulted in an increased intratumoral CD8+/ICOS+ Treg ratio at all doses, plateauing from subjects receiving a flat KY1044 dose of 8 mg. KY1044-dependent agonism was indirectly assessed by measuring circulating cytokine levels. A post-dosing transient induction of GM-CSF was evident in subjects dosed with KY1044 at the 0.8 and 2.4 mg dose, whereas minimal induction was observed at dose of 8 mg and higher. Conclusions: LongitudinalPDdata confirmed the expected KY1044 MoA, namely ICOS Treg depletion and increased CD8/ICOS Treg ratio in the TME as well as T cell co-stimulation. The observed PD responses are currently being further explored in a more homogenous patient population.

Zanidatamab, an anti-HER2 bispecific antibody, plus chemotherapy with/without tislelizumab as first-line treatment for patients with advanced HER2-positive breast cancer or gastric/gastroesophageal junction adenocarcinoma: A phase 1B/2 trial-in-progress

TPS2656

Background: Zanidatamab is a novel HER2-targeted antibody that binds two distinct extracellular domains of HER2, allowing for multiple mechanisms of action including enhanced binding, clustering, receptor internalization and downregulation; this results in inhibition of ligand-dependent and -independent proliferation and potent activation of antibody-dependent cellular cytotoxicity. Zanidatamab monotherapy is well tolerated and has shown promising anti-tumor activity in patients (pts) with pre-treated advanced HER2-positive cancers, and was well tolerated in a Phase I trial (NCT02892123). Tislelizumab is an investigational anti-programmed death-1 (PD-1) antibody engineered to minimize binding of FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, which is a potential mechanism of T-cell clearance and resistance to anti-PD-1 therapy. Tislelizumab is well tolerated and has anti-tumor activity alone and in combination with chemotherapy in pts with advanced solid tumors. The highly immunogenic nature of HER2 tumors has led to the development of therapies combining anti-HER2 therapies with immune checkpoint blockade. Methods: This open-label, two cohort Phase 1B/2 study (NCT04276493) is designed to evaluate zanidatamab as a first-line therapy with chemotherapy in pts with HER2-positive metastatic breast cancer (mBC; cohort 1) or with chemotherapy + tislelizumab in pts with HER2-positive advanced gastric/gastroesophageal junction adenocarcinoma (GC/GEJC; cohort 2). Weight-based dosing (cohorts 1a and 2a) and flat dosing (cohorts 1b and 2b) regimens of zanidatamab are being investigated. In cohort 1 (n = 20), pts with treatment-naïve HER2-positive (IHC3+ or ISH amplified) mBC will receive intravenous (IV) zanidatamab 30 mg/kg (cohort 1a) or 1800 mg (cohort 1b), plus IV docetaxel 75 mg/m2 once every 3 weeks (Q3W). In cohort 2 (n = 30), treatment-naïve pts with HER2-positive (IHC3+ or IHC2+ with ISH amplification) advanced GC/GEJC will receive IV zanidatamab 30 mg/kg (cohort 2a), or 1800 mg (pts < 70kg; cohort 2b) or 2400 mg (pts ≥ 70kg; cohort 2b), plus IV tislelizumab 200 mg and chemotherapy (CAPOX regimen: oral capecitabine 1000 mg/m2 twice daily [days 1–14] and IV oxaliplatin 130 mg/m2 [day 1]) Q3W. For cohort 2 there is a six pt safety lead-in phase, followed by dose expansion after approval by the safety monitoring committee. Primary endpoints are the safety profile and objective response rate. Secondary endpoints include duration of response, time to response, progression-free survival, disease control rate, and overall survival. Clinical trial information: NCT02892123.

Phase II study of the anti-TGF-β monoclonal antibody (mAb) NIS793 with and without the PD-1 inhibitor spartalizumab in combination with nab-paclitaxel/gemcitabine (NG) versus NG alone in patients (pts) with first-line metastatic pancreatic ductal adenocarcinoma (mPDAC)

TPS4173

Background: Overall survival remains low for pts with mPDAC despite approved therapies, highlighting the need for further innovative treatment options. Intra-tumoral fibrosis that characterizes PDAC has been associated with a state of immune exclusion and may constitute a mechanical obstacle to the penetration of chemotherapy into the tumor as well as contribute to the lack of efficacy of immunotherapy. TGF-β plays a key role in regulating the tumor microenvironment and emerging evidence points to TGF-β as a pivotal activator of cancer-associated fibroblasts, leading to the development of fibrotic networks. Preclinical data in murine models have shown that TGF-β blockade augmented the benefit of both NG and anti-PD-1 therapy, leading to tumor regression. These data provide the rationale for combining TGF-β-targeting agents with immunotherapy and chemotherapy. NIS793 is a human IgG2 mAb that binds to TGF-β. This study investigates NIS793 with and without spartalizumab combined with NG in treatment naïve mPDAC. Methods: This is a phase II open-label, randomized, multicenter study (NCT04390763) beginning with a safety run-in period followed by randomization. Eligible pts are adults with previously untreated mPDAC and an ECOG performance status ≤1. Pts are excluded if they have a tumor histology other than adenocarcinoma or microsatellite instability-high tumor. The safety run-in data will be analyzed after ≥6 pts have received NIS793 (intravenously [IV] 2100 mg Q2W) + spartalizumab (IV 400 mg Q4W) + nab-paclitaxel (IV 125 mg/m2 on Days 1, 8 and 15) + gemcitabine (IV 1000 mg/m2 on Days 1, 8 and 15) for 1 cycle (28 days) to assess the safety and tolerability of the combination and confirm the dose for the randomized part. Pts will be randomized 1:1:1 to NIS793 + spartalizumab + NG (n=50) or NIS793 + NG (n=50) or NG (n=50). Treatment will continue until unacceptable toxicity, disease progression, discontinuation by investigator’s or pt’s choice, or withdrawal of consent. The primary objective is to evaluate the progression-free survival of NIS793 + NG ± spartalizumab versus NG alone. Secondary objectives include safety and tolerability, antitumor activity, overall survival, change in CD8 and PD-L1 status, and characterization of immunogenicity and pharmacokinetics. Efficacy will be assessed locally per RECIST v1.1 and iRECIST at screening, every 8 weeks for 1 year and then every 12 weeks until disease progression. Blood and tumor samples will be taken at baseline and during study treatment for pharmacokinetic, immunogenicity and biomarker assessments. This study is ongoing and will enroll pts from 30 sites across 15 countries. The first pt was treated on October 22, 2020. Clinical trial information: NCT04390763.

Phase Ib study of the anti-TGF-β monoclonal antibody (mAb) NIS793 combined with spartalizumab (PDR001), a PD-1 inhibitor, in patients (pts) with advanced solid tumors

2509

Background: TGF-β plays a key role in regulating the tumor microenvironment. Emerging evidence suggests TGF-β is a key activator of cancer-associated fibroblasts, leading to fibrotic network development and immune exclusion. Preclinical data in murine models showed that TGF-β blockade alleviates intratumoral fibrosis, augmenting the efficacy of PD-1 immunotherapy. NIS793 is a human IgG2 mAb that binds to TGF-β. This study investigates NIS793 + spartalizumab in pts with advanced solid tumors. Methods: Pts initially received NIS793 (0.3–1 mg/kg Q3W) monotherapy; following evaluation of two dose levels, dose escalation continued with NIS793 + spartalizumab (NIS793 0.3–30 mg/kg Q3W + spartalizumab 300 mg Q3W; or NIS793 20–30 mg/kg Q2W + spartalizumab 400 mg Q4W) in pts with/without prior anti-PD-(L)1 therapy. In dose expansion, pts with non-small cell lung cancer (NSCLC) resistant to prior anti-PD-(L)1 or pts with microsatellite stable colorectal cancer (MSS-CRC) were treated at the recommended dose for expansion (RDE). Paired tumor biopsies were required from all pts. The primary objectives were to characterize safety and tolerability of the combination and determine the RDE. Results: By December 1, 2020, 60 pts were treated in the dose-escalation phase, mainly with NIS793 + spartalizumab (n = 49), and 60 pts were treated in dose expansion (MSS-CRC: n = 40; NSCLC: n = 20). Two pts were still receiving treatment. No dose-limiting toxicities were observed, and the RDE was established as 30 mg/kg (2100 mg) NIS793 + 300 mg spartalizumab Q3W. Overall 50% pts experienced ≥1 treatment-related AE (TRAE). The most common were rash (n = 15/120), pruritus (n = 10/120), fatigue (n = 9/120), and nausea (n = 8/120). Grade 3/4 TRAEs occurred in 11% pts, with rash (3%) being the most common. Treatment-related serious AEs were reported in 8 pts; 6 were grade 3/4 in severity. No deaths occurred due to AEs; 3 (2.5%) pts discontinued due to AEs. PK for NIS793 was linearly dose proportional with no obvious correlation between exposure and response. Two pts achieved a partial response (PR; one confirmed in clear cell renal cell carcinoma and one unconfirmed in NSCLC) during dose escalation of the combination. Two confirmed PRs were achieved in the MSS-CRC dose-expansion group. Biomarker data showed evidence of target engagement through increased TGF-β/NIS793 complexes and depleted active TGF-β in peripheral blood. Gene expression and protein analyses in tumor biopsies displayed decreased TGF-β target genes, decreased TGF-β signatures and increased immune signatures suggesting modulation of the TGF-β pathway and preliminary evidence of biological activity. Conclusions: Data showing target engagement and TGF-β pathway inhibition supported the proof of mechanism of NIS793. The RDE of the combination was established and well tolerated in pts with advanced solid tumors. Clinical trial information: NCT02947165.

A phase 1/2 open-label study of KY1044, an anti-ICOS antibody with dual mechanism of action, as single agent and in combination with atezolizumab, in adult patients with advanced malignancies

2624

Background: KY1044, is a fully human IgG1 anti ICOS antibody designed to stimulate Teffs and to deplete ICOS high Tregs in the tumor microenvironment. Methods: Patients with advanced/metastatic malignancies received escalating doses of KY1044 as a single agent and in combination with atezolizumab 1200 mg by IV infusion every 3 weeks until disease progression or unacceptable toxicity. Dose escalation was guided by a modified toxicity probability interval design. The primary objective was to determine safety, tolerability, and maximum tolerated dose. Cohorts that were tolerated were later enriched with more subjects. AEs were classified according to CTCAE v5 and efficacy measures performed according to RECIST v1.1 every 8 weeks for the first 16 weeks and then every 12 weeks. Results: As of 16-Dec-2020, a total of 103 patients have been enrolled in the study (38 patients as monotherapy in 6 cohorts at doses ranging from 0.8 to 240 mg and 65 in combination with atezolizumab in 5 cohorts at doses 0.8 – 80 mg). 63% and 55% of patients received ≥4 prior anti-cancer therapies in the single agent and combination cohorts, respectively. All cohorts were completed without DLTs during the first 21 days of treatment. In the KY1044 single agent cohorts, 47.4% of patients experienced treatment-related AEs (TRAEs), all were grades 1 or 2. In the combination cohorts, TRAEs were observed in 58% of patients. Most of the TRAEs were grade 1 or 2 apart from 8 TRAEs that were ≥grade 3 occurring in <8% of patients. Infusion-related reactions, pyrexia and lymphopenia were the most commonly occurring TRAEs in ≥10% of patients. TRAE leading to dose interruptions occurred in 1 patient in the single agent cohort and in 4 patients in the combination cohort. Only 1 patient discontinued treatment due to myositis that was considered related to the combination. Preliminary KY1044 PK data from 69 patients agree with the PK model predictions. Median treatment duration for all enrolled patients was 9 weeks. Treatment duration ≥16 weeks was observed in 24% (9/38) and 27% (17/64) patients in the single agent and combination cohorts, respectively. Five objective responses, including 1 CR in triple negative breast cancer (TNBC) and 4 PRs in TNBC, head and neck squamous cell carcinoma, penile and pancreatic cancer were observed. Four of the 5 responding patients were still on treatment at the data cut, with 3 patients on treatment for >43 weeks (range 45 to 66 weeks). Conclusions: KY1044 is well tolerated as single agent and in combination with atezolizumab. Objective responses have been observed in this phase 1 part of the study. The phase 1 expansion and phase 2 part of the study is ongoing. Clinical trial information: NCT03829501.

Cabozantinib versus placebo in patients with radioiodine-refractory differentiated thyroid cancer who have progressed after prior VEGFR-targeted therapy: Results from the phase 3 COSMIC-311 trial

6001

Background: Cabozantinib (C), an inhibitor of VEGFR2, MET, AXL, and RET, showed clinical activity in patients (pts) with radioiodine (RAI)-refractory differentiated thyroid cancer (DTC) in phase 1/2 studies (Cabanillas 2017; Brose 2018). This phase 3 study (NCT03690388) evaluated the efficacy and safety of C vs placebo (P) in pts with RAI-refractory DTC who had progressed during/after prior VEGFR-targeted therapy for whom there is no standard of care. Methods: In this double-blind, phase 3 trial, pts were randomized 2:1 to receive C (60 mg QD) or P, stratified by prior lenvatinib treatment (L; yes, no) and age (≤65, > 65 yr). Pts with RAI-refractory DTC must have received L or sorafenib for DTC and progressed during or following treatment with ≤ 2 prior VEGFR inhibitors. Pts randomized to P could cross over to open-label C upon disease progression per blinded independent radiology committee (BIRC). The primary endpoints were objective response rate (ORR) in the first 100 randomized pts and progression-free survival (PFS) in all randomized pts. PFS and ORR were assessed by BIRC per RECIST v1.1. The study was designed to detect an ORR for C vs P (2-sided α = 0.01) and a hazard ratio (HR) for PFS of 0.61 (90% power, 2-sided α = 0.04). A prespecified interim PFS analysis was planned for the ITT population at the time of the primary ORR analysis. Results: As of 19 Aug 2020,125 vs 62 pts had been randomized to the C and P arms, respectively; median age was 66 yr, 55% were female and 63% received prior L. Median (m) follow-up was 6.2 months (mo). At the planned interim analysis, the trial met the primary endpoint of PFS with C demonstrating significant improvement over P (HR 0.22, 96% CI 0.13–0.36; p < 0.0001). mPFS was not reached for C vs 1.9 mo for P; PFS benefit was observed in all prespecified subgroups including prior L (yes, HR 0.26; no, HR 0.11) and age (≤65 yr, HR 0.16; > 65 yr, HR 0.31). ORR was 15% for C vs 0% for P (p = 0.0281) but did not meet the prespecified criteria for statistical significance (p < 0.01). A favorable OS trend was observed for C vs P (HR 0.54, 95% CI 0.27–1.11). Treatment-emergent adverse events (AEs) of any grade with higher occurrences in the C vs P arm included diarrhea (51% vs 3%), hand-foot skin reaction (46% vs 0%), hypertension (28% vs 5%), fatigue (27% vs 8%), and nausea (24% vs 2%); grade 3/4 AEs were experienced by 57% of pts with C vs 26% with P. Dose reductions due to any grade AEs occurred in 57% of pts with C vs 5% with P. Treatment discontinuations due to AEs not related to disease progression occurred in 5% of pts with C vs 0% with P. No treatment-related deaths occurred in either arm. Conclusions: C showed a clinically and statistically significant improvement in PFS over P in pts with RAI-refractory DTC after prior VEGFR-targeted therapy with no unexpected toxicities. C may represent a new standard of care in pts with previously treated DTC. Clinical trial information: NCT03690388.

Exposure-Response Relationships in Patients With HER2-Positive Metastatic Breast Cancer and Other Solid Tumors Treated With Trastuzumab Deruxtecan

Trastuzumab deruxtecan (T-DXd) is a HER2-targeting antibody-drug conjugate composed of a novel enzyme-cleavable linker and membrane-permeable topoisomerase I inhibitor payload. T-DXd has been approved for HER2-positive metastatic breast cancer and for HER2-positive metastatic gastric cancer. The approval in breast cancer was based on results from the DESTINY-Breast01 (U201; NCT03248492) and J101 (NCT02564900) trials. Here, we present dose justification for the approved 5.4 mg/kg every-3-weeks (Q3W) dose based on exposure-efficacy evaluated in patients with HER2-positive breast cancer (N = 337) from these 2 trials. Exposure-safety was assessed in patients with all tumor types (N = 639, n = 512 with breast cancer) across 5 trials, including J101 and DESTINY-Breast01. T-DXd doses ranged from 0.8-8.0 mg/kg Q3W; most patients received 5.4 (n = 312) or 6.4 mg/kg (n = 291). For each end point, multivariate logistic or Cox regression analysis was performed using various exposure metrics of T-DXd and released drug. A statistically significant association was observed between intact T-DXd area under the concentration-time curve (AUC) and confirmed objective response rate (ORR; P = 0.028). No significant exposure-response relationships were observed between intact T-DXd or released drug and duration of response or progression-free survival; however, follow-up was limited. All evaluated safety end points demonstrated a significant (P < 0.05) relationship with either intact T-DXd or released drug, with higher adverse event (AE) rates projected at higher exposures. Dose-response projections suggested an increase in ORR (67.5% vs. 62.9%) and toxicity (e.g., grade ≥ 3 all-cause treatment-emergent AEs: 61% vs. 54%) with T-DXd 6.4 vs. 5.4 mg/kg. Results demonstrate the benefit-risk profile at different doses and guide clinicians in the use of the 5.4-mg/kg Q3W dose in patients with HER2-positive metastatic breast cancer.

High-efficiency picosecond mode-locked laser using a thulium-doped nanoengineered yttrium-alumina-silica fiber as the gain medium

We report the theoretical and experimental investigation of a self-starting mode-locked fiber laser with a nanoengineered Tm³⁺-doped yttrium-alumina-silica (YAS) fiber as the gain medium. The YAS fiber exhibits a higher capability of Tm³⁺ cluster elimination than commercial silica fibers. The Tm³⁺ fluorescence properties and YAS dispersion are well characterized. As a result, an efficient picosecond mode-locked fiber laser is demonstrated with a slope efficiency of 14.14% and maximum pulse energy of 1.27 nJ. To the best of our knowledge, this is the first mode-locked fiber laser based on a Tm³⁺-doped YAS fiber. The experimental observation is also supported by the numerical analysis.

Clinical Development of Colony-Stimulating Factor 1 Receptor (CSF1R) Inhibitors

Macrophage infiltration has been identified as an independent poor prognostic factor for several cancers. Macrophages also orchestrate various tumor-promoting processes. This observation sparked an interest to therapeutically target these plastic innate immune cells. To date, blockade of colony-stimulating factor 1 (CSF1) or its receptor represents one of the selective approaches to manipulate tumor-associated macrophages. In this review, I discuss the efficacy and safety of various CSF1 receptor tyrosine kinase inhibitors, anti-CSF1 receptor monoclonal antibodies, and anti-CSF1 monoclonal antibodies in clinical development for patients with cancer and highlight potential combination partners, mainly anti-program cell death protein 1 (PD-1) and program cell death protein ligand 1 (PD-L1) antibodies.

Endoscopic ultrasound ablation in a patient with multiple metastatic pancreatic tumors from adrenocorticotropic hormone-producing thymic neuroendocrine neoplasm

Adrenocorticotropic hormone (ACTH)-producing neuroendocrine neoplasm (NEN) of the thymus is rare. Lymph nodes and bones are the most common metastatic sites. Most cases present with florid Cushing's syndrome (CS). Here, we reported a 58-year-old woman, who presented with intermittent flush and weight loss. Imaging studies revealed tumors in the mediastinum, pancreas, and bones. Contrast-enhanced harmonic endoscopic ultrasound (EUS) of the pancreatic tumors showed heterogeneous and hyperenhancing characteristics. EUS elastography revealed a heterogeneous stiff pattern. EUS-fine needle biopsy to the pancreatic lesion confirmed the NEN nature. Serum ACTH and cortisol levels were abnormally high. Immunohistochemical staining of the thymic and pancreatic specimens was positive for ACTH. However, the patient did not have obvious CS appearance. The patient underwent surgery, radiation, EUS-guided ethanol injection, and anti-cancer medications, but the disease still progressed. The patient died from infection 16 months after NEN was diagnosed. In conclusion, the pancreas can be a metastatic site for ACTH-producing thymic NEN. EUS-associated procedures can help in the diagnosis and treatment of pancreatic metastatic NEN.

Safety and Clinical Activity of a New Anti-PD-L1 Antibody as Monotherapy or Combined with Targeted Therapy in Advanced Solid Tumors: The PACT Phase Ia/Ib Trial

PURPOSE

This phase Ia/Ib PACT study evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of a new programmed cell death ligand 1 (PD-L1) inhibitor, LY3300054, as monotherapy or in combination with ramucirumab, abemaciclib, or merestinib (a type II MET kinase inhibitor) in patients with advanced, refractory solid tumors (NCT02791334).

PATIENTS AND METHODS

Patients were enrolled into cohorts of escalating LY3300054 dose (phase Ia) as monotherapy (N = 15) or combined with ramucirumab (N = 10), abemaciclib (N = 24), or merestinib (N = 12). The phase Ib dose expansion enrolled 8 patients with melanoma in the monotherapy arm and 12 patients with pancreatic cancer in the merestinib combination arm. Combination treatments were administered concurrently from day 1 of each cycle. A 14-day lead-in abemaciclib arm was also explored. Primary endpoints were dose-limiting toxicity (DLT) and safety.

RESULTS

Treatment-related adverse events included fatigue and nausea in the monotherapy arm (13% for each), hypothyroidism (30%) in the ramucirumab arm, diarrhea (54%) in the abemaciclib arm, and nausea (25%) in the merestinib arm. DLTs associated with hepatoxicity were observed in 3 of 4 patients in the abemaciclib lead-in cohorts. No DLTs or grade 3 or 4 hepatoxicity were reported in the concurrent abemaciclib arm. Pharmacokinetic characteristics were comparable with other PD-L1 inhibitors. One patient in each arm experienced a partial response per RECIST v1.1 lasting ≥7 months.

CONCLUSIONS

LY3300054 was well tolerated without unexpected safety concerns when administered alone or concurrently with ramucirumab, abemaciclib, or merestinib. Lead-in abemaciclib before combining with LY3300054 was not feasible due to hepatotoxicity. Durable clinical benefits were seen in all regimens.

Updated Integrated Analysis of the Efficacy and Safety of Entrectinib in Locally Advanced or Metastatic ROS1 Fusion-Positive Non-Small-Cell Lung Cancer

Genetic rearrangements of the tyrosine receptor kinase ROS proto-oncogene 1 (ROS1) are oncogenic drivers in non-small-cell lung cancer (NSCLC). We report the results of an updated integrated analysis of three phase I or II clinical trials (ALKA-372-001, STARTRK-1, and STARTRK-2) of the ROS1 tyrosine kinase inhibitor, entrectinib, in ROS1 fusion–positive NSCLC.

Overcoming the impact of the COVID-19 pandemic on oncology early phase trials and drug development in Asia-Experiences and perspectives of the Asian Oncology Early Phase 1 Consortium

Aim

The significance and prioritization of early phase oncology trial continuation during a global pandemic is unknown. This study reported the outcomes, multiple challenges, and broad recommendations associated with the impact of the novel coronavirus disease 2019 (COVID‐19) on oncology early phase 1 trials—and on drug development in Asia—based on the experiences and perspectives of Asian oncology phase 1 centers.

Methods

Between March and April 2020 during the initial period of outbreak, the impact of COVID‐19 across oncology phase 1 sites in five Asian countries—China (Hong Kong), Japan, South Korea, Taiwan, and Singapore—was retrospectively analyzed.

Results

There was no trial termination or treatment discontinuation in all five countries. Although the most common impact was new patient enrollment being placed on hold, which was based on pharmaceutical sponsors’ decision‐making, the situation varied per site. Most sites had no restrictions in place that would limit their ability to fully comply with the requirements of conducting the early phase studies. The number of protocol deviations during the pandemic was largely dependent on domestic transportation status during the outbreak rather than the ability of the clinical trial centers.

Conclusion

Determining the risk to benefits ratio of patients with cancer who are enrolled in early phase 1 clinical trials under the unusual circumstances of a global pandemic is important. Specific guidance or guidelines on the conduct of early phase 1 clinical trials during public health emergencies that are based on the recent lessons learned is urgently required.

A Solution Processable Dithioalkyl Dithienothiophene (DSDTT) Based Small Molecule and Its Blends for High Performance Organic Field Effect Transistors

The 3,5-dithiooctyl dithienothiophene based small molecular semiconductor DDTT-DSDTT (1), end functionalized with fused dithienothiophene (DTT) units, was synthesized and characterized for organic field effect transistors (OFET). The thermal, optical, electrochemical, and computed electronic structural properties of 1 were investigated and contrasted. The single crystal structure of 1 reveals the presence of intramolecular locks between S(alkyl)···S(thiophene), with a very short S-S distance of 3.10 Å, and a planar core. When measured in an OFET device compound 1 exhibits a hole mobility of 3.19 cm² V^-1 s^-1, when the semiconductor layer is processed by a solution-shearing deposition method and using environmentally acceptable anisole as the solvent. This is the highest value reported to date for an all-thiophene based molecular semiconductor. In addition, solution-processed small molecule/insulating polymer (1/PαMS) blend films and devices were investigated. Morphological analysis reveals a nanoscopic vertical phase separation with the PαMS layer preferentially contacting the dielectric and 1 located on top of the stack. The OFET based on the blend comprising 50% weight of 1 exhibits a hole mobility of 2.44 cm² V^-1 s^-1 and a very smaller threshold voltage shift under gate bias stress.

Phase II study of pembrolizumab after chemoradiotherapy (CRT) as adjuvant therapy for locally advanced esophageal squamous cell carcinoma (LA-ESCC) patients at high risk of recurrence following preoperative CRT plus surgery

TPS259

Background: LA-ESCC is a potentially curable disease, for which preoperative CRT followed by esophagectomy is a standard-of-care. Previous studies have identified that close/involved margin and lymph node metastasis with extranodal invasion (ENI) in post-CRT surgical specimens are associated with increased risk of recurrence. In CheckMate-577 trial, adjuvant nivolumab significantly improved disease-free survival (DFS) in patients with esophageal cancer treated with preoperative CRT and surgery; in another trial (the “PACIFIC” trial), adjuvant durvalumab has significantly improved overall survival (OS) in stage III non-small cell lung cancer treated with definitive CRT. We hypothesize that adding pembrolizumab to CRT as an adjuvant therapy would improve the outcomes of LA-ESCC patients who are treated with preoperative CRT plus esophagectomy and with high-risk of recurrence. Methods: This single institution single-arm phase II study include patients with histologically confirmed LA-ESCC (AJCC 7th staging system:cT3-4aN0M0 or T1-4aN1-3M0) harboring at least one risk factor (closed/involved margin, ENI, or ypN2-3) in post-CRT surgical specimens. Patients with adenocarcinoma of esophagus or gastroesophageal junction or synchronously diagnosed with a squamous cell carcinoma of aero-digestive way other than ESCC are excluded. Patients enrolled will receive adjuvant weekly cisplatin–CRT (cisplatin, 30mg/m2 for 2 cycles every week; radiotherapy, 180-200 cGy/fraction for 10-13 times) followed by pembrolizumab (200 mg, every 3 weeks, for 18 cycles). The primary endpoint of this study is 1-year relapse-free survival (RFS) rate; and the key secondary endpoints include RFS, 3-year RFS rate, OS, 3-yr OS rate, toxicity and safety. The study, registered with clinical trial ID of NCT03322267, started patient enrollment in Aug 2018. As of Aug of 2020, 11 of 46 planned patients have been enrolled. Clinical trial information: NCT03322267.

Open-label, phase II study of ladiratuzumab vedotin (LV) for advanced gastric and gastroesophageal junction adenocarcinoma (SGNLVA-005, Trial-in-Progress)

TPS256

Background: LIV-1 is a transmembrane protein expressed in a variety of cancer types. SGN-LIV1A, or ladiratuzumab vedotin (LV), is a novel investigational humanized IgG1 antibody-drug conjugate (ADC) directed against LIV-1. LV mediates delivery of monomethyl auristatin E (MMAE), which drives antitumor activity through cytotoxic cell killing and induces immunogenic cell death. In a phase 1 study, LV was tolerable and active in heavily pretreated patients with metastatic breast cancer at a recommended dose of 2.5 mg/kg every 21 days (Modi 2017). More frequent, fractionated dosing has improved the activity and/or safety of other ADCs. Thus, this study is currently evaluating the safety and efficacy of weekly LV dosing (Days 1, 8, and 15 of every 3-week cycle) in different advanced solid tumors with various LIV-1 expression, including advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma, esophageal squamous cell carcinoma, small cell lung cancer (SCLC), non-small cell lung cancer (squamous and nonsquamous), head and neck squamous cell carcinoma, castration resistant prostate cancer, and melanoma. Methods: SGNLVA-005 (NCT04032704) is an open-label, phase 2 study evaluating LV monotherapy in patients with 8 different advanced solid tumors in two parts (administered as a 30 minute intravenous infusion [IV]: Part A LV 2.5 mg/kg IV every 3 weeks [up to n = 72 total]; Part B LV 1.0 or 1.25 mg/kg every 1 week [up to n = 252 total]). The study is enrolling previously treated patients with unresectable locally advanced or metastatic disease. Patients must have measurable disease per RECIST v1.1, an Eastern Cooperative Oncology Group (ECOG) score of 0 or 1, and adequate organ function. Cohort specific inclusion criteria require that patients in the gastric and GEJ adenocarcinoma and esophageal squamous cell carcinoma cohorts must have received and progressed during or after no more than 1 prior line of platinum based cytotoxic chemotherapy. Patients in the gastric and GEJ adenocarcinoma cohort may have received prior anti-programmed cell death (ligand) 1 (anti-PD[L]1) therapy (unless contraindicated), and patients with known human epidermal growth factor receptor 2 (HER2) overexpression must have received prior HER2-targeted therapy. Patients are not preselected based on tumor LIV-1 expression. Tumor samples will be analyzed for correlation between LIV-1 expression and tumor response. Safety and efficacy will be monitored throughout the study. Study objectives include objective response rate (primary); safety and tolerability, disease control rate, duration of response, progression-free and overall survival, and pharmacokinetics and immunogenicity (all secondary); and pharmacodynamics. Study accrual is ongoing in the USA, Italy, South Korea, Taiwan, Australia, and the UK. Clinical trial information: NCT04032704.

Association of B cells in tumor microenvironment (TME) with clinical benefit to programmed cell death protein-1 (PD-1) blockade therapy in esophageal squamous cell carcinoma (ESCC)

237

Background: Previous studies have indicated B cells as potential predictive markers for anti-PD-1 blockade therapy in several cancer types. The study explored whether B cells in TME and B cell related gene signatures are associated with clinical benefit (CB) for ESCC patients receiving anti-PD-1/PD-ligand 1 (PD-L1) therapy. Methods: Sixty-six ESCC patients treated with PD-1/PD-L1 blockade-based immunotherapy were enrolled. Tumor response was evaluated per RECIST 1.1, and CB was defined as complete response, partial response or stable disease at least 6 months. Transcriptome of formalin-fixed paraffin-embedded ESCC tissues were generated by NanoString nCounter platform with Human PanCancer Immune Profiling panel (n=25), Gene Set Enrichment Analysis (GSEA) was performed to identify the differential immune-related pathways, and CIBERSORT was applied to estimate the levels of infiltrating immune cells. The expression of CD20 was evaluated by immunohistochemistry (IHC) (n=66). Results: Of 66 enrolled patients (M: F= 65: 1, median age of 59), 44 and 22 were of recurrent and de novo metastatic ESCC. Forty and 26 received PD-1/PD-L1 blockade alone and PD-1/PD-L1-based combination immunotherapy, respectively. The response rate was 17%, and the CB rate was 24%. The median progression-free-survival (PFS) and overall survival are 1.8 and 5.5 months, respectively. B cell signature was significantly increased in patients with CB ( P < 0.05) and associated with longer progression-free survival and overall survival (both P < 0.05). The genes related to B cells, B cell functions, and T cell functions were up-regulated in patients with CB compared to that with non-CB (all P < 0.05). Naïve B cells and plasma cells were significantly increased in patients with CB (both P < 0.05). The expression levels of stromal CD20 by IHC trended to increase in patients with CB ( P = 0.08). Conclusions: B cells in tumor microenvironment may be associated with CB of anti-PD-1/PD-L1 therapy in patients with ESCC. (Funded by MOST 105-2314-B-002 -186 -MY3; MOHW107-TDU-B-211-114017; MOST 108-2314-B-002 -076 -MY3; MOST 107-2314-B-002-199 -).

Phase I study of BI 754091 plus BI 754111 in Asian patients with gastric/gastroesophageal junction or esophageal cancer

212

Background: Dual blockade of immune checkpoint molecules, PD-1 and LAG-3, has been proposed to restore T-cell function and thus enhance antitumor responses. This Phase I trial evaluated BI 754091 (anti-PD-1) with BI 754111 (anti-LAG-3) antibodies in Asian pts with advanced solid tumors (NCT03433898). Here, we present results from pts with anti-PD-(L)1 inhibitor-naïve gastric/gastroesophageal junction or esophageal cancer (Cohorts A and B). Methods: In Parts 1 and 2 (dose escalation), the recommended dose for the combination was determined as BI 754091 240 mg + BI 754111 600 mg IV Q3W. In Part 3, the combination was assessed in expansion cohorts including pts with gastric/gastroesophageal junction cancer (Cohort A) and esophageal cancer (Cohort B). Eligible pts had received ≥1 line of prior systemic therapy but no prior anti-PD-(L)1 therapy. The primary endpoint in Part 3 was objective response (OR; confirmed complete response or partial response [PR]) per RECIST 1.1. Results: In Cohort A/B, 36/37 pts were treated:26/31 (72/84%) male, median age 60/63 years. Patients were enrolled in Taiwan (1/7 pts, 3/19%), Japan (12/27 pts, 33/73%) or Korea (23/3 pts, 64/8%). The median number of regimens of prior systemic therapy was 2/2 (Cohorts A/B, range: 1–6/1–4). All pts in Cohort B had squamous cell carcinoma. At the time of analysis, pts in Cohort A/B had undergone a median of 84/73 days on treatment (range: 31–346/8–325), from the start of treatment until the date of snapshot, death or discontinuation. Confirmed OR (PR) was observed in 4/7 pts in Cohorts A/B; overall response rate (ORR) was 11% and 19%. Stable disease (SD) was observed in 10/8 (28/22%) pts in Cohorts A/B and overall disease control rate was 39/41%. In Cohorts A/B, adverse events (AEs) and treatment-related AEs were experienced by 30/34 (83/92%) and 12/22 (33/59%) pts, respectively. The most commonly reported AEs were pyrexia (25/19%), decreased appetite (17/19%), increased aspartate aminotransferase (11/14%), anemia (11/11%) and nausea (6/14%). In Cohort A/B, 9/15 (25/41%) pts experienced immune-related AEs, most commonly rash in Cohort A (4 pts; 11%) and hyperthyroidism in Cohort B (4 pts; 11%). In Cohorts A/B, 2/6 (6/16%) patients experienced AEs leading to discontinuation of treatment. Conclusions: Treatment was well tolerated and preliminary antitumor activity was seen. Addition of LAG3 did not improve ORR beyond that expected for an anti-PD-1 monotherapy in gastric and esophageal cancer without patient selection. Clinical trial information: NCT03433898. [Table: see text]

Phase I Dose-Escalation Study of SCB01A, a Microtubule Inhibitor with Vascular Disrupting Activity, in Patients with Advanced Solid Tumors

LESSONS LEARNED

SCB01A is a novel microtubule inhibitor with vascular disrupting activity. This first-in-human study demonstrated SCB01A safety, pharmacokinetics, and preliminary antitumor activity. SCB01A is safe and well tolerated in patients with advanced solid malignancies with manageable neurotoxicity.

BACKGROUND

SCB01A, a novel microtubule inhibitor, has vascular disrupting activity.

METHODS

In this phase I dose-escalation and extension study, patients with advanced solid tumors were administered intravenous SCB01A infusions for 3 hours once every 21 days. Rapid titration and a 3 + 3 design escalated the dose from 2 mg/m² to the maximum tolerated dose (MTD) based on dose-limiting toxicity (DLT). SCB01A-induced cellular neurotoxicity was evaluated in dorsal root ganglion cells. The primary endpoint was MTD. Safety, pharmacokinetics (PK), and tumor response were secondary endpoints.

RESULTS

Treatment-related adverse events included anemia, nausea, vomiting, fatigue, fever, and peripheral sensorimotor neuropathy. DLTs included grade 4 elevated creatine phosphokinase (CPK) in the 4 mg/m² cohort; grade 3 gastric hemorrhage in the 6.5 mg/m² cohort; grade 2 thromboembolic event in the 24 mg/m² cohort; and grade 3 peripheral sensorimotor neuropathy, grade 3 elevated aspartate aminotransferase, and grade 3 hypertension in the 32 mg/m² cohort. The MTD was 24 mg/m² , and average half-life was ~2.5 hours. The area under the curve-dose response relationship was linear. Nineteen subjects were stable after two cycles. The longest treatment lasted 24 cycles. SCB01A-induced neurotoxicity was reversible in vitro.

CONCLUSION

The MTD of SCB01A was 24 mg/m² every 21 days; it is safe and tolerable in patients with solid tumors.

Ramucirumab and durvalumab for previously treated, advanced non-small-cell lung cancer, gastric/gastro-oesophageal junction adenocarcinoma, or hepatocellular carcinoma: An open-label, phase Ia/b study (JVDJ)

BACKGROUND

Emerging evidence supports combining immune checkpoint inhibitors (ICIs) with conventional or targeted therapies to enhance ICI antitumour activity and broaden the spectrum of patients who respond to ICIs. Here, we present the safety and preliminary efficacy of ramucirumab, an anti-VEGFR2 IgG1, plus durvalumab, an anti-PD-L1 IgG1, in previously treated patients with advanced non-small-cell lung cancer (NSCLC), gastric/gastro-oesophageal junction adenocarcinoma (gastric/GEJ), or hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

A 25-centre, phase Ia/b single-arm, non-randomised, multi-cohort study was undertaken in patients with advanced/metastatic disease, Eastern Cooperative Oncology Group performance status, 0-1, progression on prior therapy, no prior ramucirumab or immunotherapy and any PD-L1 status. Patients received ramucirumab (10 mg/kg) plus durvalumab (1125 mg) intravenously Q3W (NSCLC), or ramucirumab (8 mg/kg) plus durvalumab (750 mg) Q2W (gastric/GEJ, HCC).

RESULTS

Phase Ia treatment was found safe for phase Ib expansion; final enrolment was NSCLC (n = 28), gastric/GEJ (n = 29), HCC (n = 28). Grade ≥3 treatment-related adverse events occurred in 32.1%, 37.9% and 42.9% of patients, respectively. The most common were fatigue (35.7%), hypertension (34.5%) and diarrhoea (28.6%), respectively. Two patients died owing to an adverse event; one was treatment-related (hepatitis acute, HCC cohort). Objective response rate was 11% for NSCLC and HCC and 21% for gastric/GEJ. Median progression-free survival and overall survival were, respectively, 2.7 and 11 months in NSCLC; 2.6 and 12.4 months in gastric/GEJ; 4.4 and 10.7 months in HCC, with more prolonged survival in patients with high PD-L1 expression.

CONCLUSION

Ramucirumab/durvalumab exhibited manageable safety. The combination showed antitumour activity in all cohorts, particularly in patients with high PD-L1 expression.