Safety and antitumor activity of the anti-PD-1 antibody pembrolizumab in patients with advanced, PD-L1-positive papillary or follicular thyroid cancer

BACKGROUND

Treatment options for advanced thyroid cancer refractory to standard therapies are limited. The safety and efficacy of pembrolizumab were evaluated in patients with advanced differentiated thyroid cancer expressing programmed death ligand 1 (PD-L1).

METHODS

Patients with advanced thyroid cancer were enrolled in the nonrandomized, phase Ib KEYNOTE-028 trial conducted to evaluate safety and antitumor activity of the anti-programmed death 1 (PD-1) antibody pembrolizumab in advanced solid tumors. Key eligibility criteria were advanced papillary or follicular thyroid cancer, failure of standard therapy, and PD-L1 expression in tumor or stroma cells (assessed by immunohistochemistry). Pembrolizumab 10 mg/kg was administered every 2 weeks up to 24 months or until confirmed progression or intolerable toxicity. The primary endpoint was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

Twenty-two patients were enrolled: median age was 61 years; 59% were women; and 68% had papillary carcinoma. Median follow-up was 31 months (range, 7-34 months). Treatment-related adverse events were observed in 18 (82%) patients; those occurring in ≥15% of patients were diarrhea (n = 7) and fatigue (n = 4). One grade ≥ 3 treatment-related adverse event occurred (colitis, grade 3); no treatment-related discontinuations or deaths occurred. Two patients had confirmed partial response, for an ORR of 9% (95% confidence interval [CI], 1-29%); response duration was 8 and 20 months. Median progression-free survival was 7 months (95% CI, 2-14 months); median overall survival was not reached (95% CI, 22 months to not reached).

CONCLUSIONS

Results of this phase Ib proof-of-concept study suggest that pembrolizumab has a manageable safety profile and demonstrate evidence of antitumor activity in advanced differentiated thyroid cancer in a minority of patients treated. Further analyses are necessary to confirm these findings.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02054806 . Registered 4 February 2014.

Phase I/II study of the LAG-3 inhibitor ieramilimab (LAG525) ± anti-PD-1 spartalizumab (PDR001) in patients with advanced malignancies

BACKGROUND

Lymphocyte-activation gene 3 (LAG-3) is an inhibitory immunoreceptor that negatively regulates T-cell activation. This paper presents preclinical characterization of the LAG-3 inhibitor, ieramilimab (LAG525), and phase I data for the treatment of patients with advanced/metastatic solid tumors with ieramilimab ±the anti-programmed cell death-1 antibody, spartalizumab.

METHODS

Eligible patients had advanced/metastatic solid tumors and progressed after, or were unsuitable for, standard-of-care therapy, including checkpoint inhibitors in some cases. Patients received ieramilimab ±spartalizumab across various dose-escalation schedules. The primary objective was to assess the maximum tolerated dose (MTD) or recommended phase II dose (RP2D).

RESULTS

In total, 255 patients were allocated to single-agent ieramilimab (n=134) and combination (n=121) treatment arms. The majority (98%) had received prior antineoplastic therapy (median, 3). Four patients experienced dose-limiting toxicities in each treatment arm across various dosing cohorts. No MTD was reached. The RP2D on a 3-week schedule was declared as 400 mg ieramilimab plus 300 mg spartalizumab and, on a 4-week schedule (once every 4 weeks; Q4W), as 800 mg ieramilimab plus 400 mg spartalizumab; tumor target (LAG-3) suppression with 600 mg ieramilimab Q4W was predicted to be similar to the Q4W, RP2D schedule. Treatment-related adverse events (TRAEs) occurred in 75 (56%) and 84 (69%) patients in the single-agent and combination arms, respectively. Most common TRAEs were fatigue, gastrointestinal, and skin disorders, and were of mild severity; seven patients experienced at least one treatment-related serious adverse event in the single-agent (5%) and combination group (5.8%). Antitumor activity was observed in the combination arm, with 3 (2%) complete responses and 10 (8%) partial responses in a mixed population of tumor types. In the combination arm, eight patients (6.6%) experienced stable disease for 6 months or longer versus six patients (4.5%) in the single-agent arm. Responding patients trended towards having higher levels of immune gene expression, including CD8 and LAG3, in tumor tissue at baseline.

CONCLUSIONS

Ieramilimab was well tolerated as monotherapy and in combination with spartalizumab. The toxicity profile of ieramilimab in combination with spartalizumab was comparable to that of spartalizumab alone. Modest antitumor activity was seen with combination treatment.

TRIAL REGISTRATION NUMBER

NCT02460224.

Tumour angiogenesis: its mechanism and therapeutic implications in malignant gliomas

Angiogenesis is a key event in the progression of malignant gliomas. The presence of microvascular proliferation leads to the histological diagnosis of glioblastoma multiforme. Tumour angiogenesis involves multiple cellular processes including endothelial cell proliferation, migration, reorganisation of extracellular matrix and tube formation. These processes are regulated by numerous pro-angiogenic and anti-angiogenic growth factors. Angiogenesis inhibitors have been developed to interrupt the angiogenic process at the growth factor, receptor tyrosine kinase and intracellular kinase levels. Other anti-angiogenic therapies alter the immune response and endogeneous angiogenesis inhibitor levels. Most anti-angiogenic therapies for malignant gliomas are in Phase I/II trials and only modest efficacies are reported for monotherapies. The greatest potential for angiogenesis inhibitors may lie in their ability to combine safely with chemotherapy and radiotherapy.

Dual checkpoint targeting of B7-H3 and PD-1 with enoblituzumab and pembrolizumab in advanced solid tumors: interim results from a multicenter phase I/II trial

BACKGROUND

Availability of checkpoint inhibitors has created a paradigm shift in the management of patients with solid tumors. Despite this, most patients do not respond to immunotherapy, and there is considerable interest in developing combination therapies to improve response rates and outcomes. B7-H3 (CD276) is a member of the B7 family of cell surface molecules and provides an alternative immune checkpoint molecule to therapeutically target alone or in combination with programmed cell death-1 (PD-1)-targeted therapies. Enoblituzumab, an investigational anti-B7-H3 humanized monoclonal antibody, incorporates an immunoglobulin G1 fragment crystallizable (Fc) domain that enhances Fcγ receptor-mediated antibody-dependent cellular cytotoxicity. Coordinated engagement of innate and adaptive immunity by targeting distinct members of the B7 family (B7-H3 and PD-1) is hypothesized to provide greater antitumor activity than either agent alone.

METHODS

In this phase I/II study, patients received intravenous enoblituzumab (3-15 mg/kg) weekly plus intravenous pembrolizumab (2 mg/kg) every 3 weeks during dose-escalation and cohort expansion. Expansion cohorts included non-small cell lung cancer (NSCLC; checkpoint inhibitor [CPI]-naïve and post-CPI, programmed death-ligand 1 [PD-L1] <1%), head and neck squamous cell carcinoma (HNSCC; CPI-naïve), urothelial cancer (post-CPI), and melanoma (post-CPI). Disease was assessed using Response Evaluation Criteria in Solid Tumors version 1.1 after 6 weeks and every 9 weeks thereafter. Safety and pharmacokinetic data were provided for all enrolled patients; efficacy data focused on HNSCC and NSCLC cohorts.

RESULTS

Overall, 133 patients were enrolled and received ≥1 dose of study treatment. The maximum tolerated dose of enoblituzumab with pembrolizumab at 2 mg/kg was not reached. Intravenous enoblituzumab (15 mg/kg) every 3 weeks plus pembrolizumab (2 mg/kg) every 3 weeks was recommended for phase II evaluation. Treatment-related adverse events occurred in 116 patients (87.2%) and were grade ≥3 in 28.6%. One treatment-related death occurred (pneumonitis). Objective responses occurred in 6 of 18 (33.3% [95% CI 13.3 to 59.0]) patients with CPI-naïve HNSCC and in 5 of 14 (35.7% [95% CI 12.8 to 64.9]) patients with CPI-naïve NSCLC.

CONCLUSIONS

Checkpoint targeting with enoblituzumab and pembrolizumab demonstrated acceptable safety and antitumor activity in patients with CPI-naïve HNSCC and NSCLC.

TRIAL REGISTRATION NUMBER

NCT02475213.

Systemic therapies for recurrent or metastatic nasopharyngeal carcinoma: a systematic review

BACKGROUND

The majority of published studies in recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) are single-arm trials. Reliable modelling of progression-free survival (PFS) and overall survival (OS) outcomes, therefore, is difficult. This study aim to analyse existent literature to estimate the relative efficacy of available systemic regimens in RM-NPC, as well as provide estimates of aggregate OS and PFS.

METHODS

We conducted a systematic search of MEDLINE, EMBASE and the Cochrane Library to March 2015. Clinical trials (in English only) investigating cytotoxic and molecularly targeted agents in adult patients with RM-NPC were included. All relevant studies were assessed for quality using Downs and Blacks (DB) checklist (maximum quality score of 27). Aggregate data analysis and Student's t-test were performed for all identified studies (model A). For studies that published analysable Kaplan-Meier curves, survival data were extracted and marginal proportional hazards models were constructed (model B).

RESULTS

A total of 56 studies were identified and included in model A, 26 of which had analysable Kaplan-Meier curves and were included in model B. The 26 studies in model B had significantly higher mean DB scores than the remaining 30 (17.3 vs 13.7, P=0.002). For patients receiving first line chemotherapy, the estimated median OS was 15.7 months by model A (95% CI, 12.3-19.1), and 19.3 months by model B (95% CI, 17.6-21.1). For patients undergoing second line or higher therapies (2nd+), the estimated median OS was 11.5 months by model A (95% CI 10.1-12.9), and 12.5 months by model B (95% CI 11.9-13.4). PFS estimates for patients undergoing first-line chemotherapy by model A was 7.6 months (95% CI, 6.2-9.0), and 8.0 months by model B (95% CI, 7.6-8.8). For patients undergoing therapy in the 2nd+ setting, the estimated PFS by model A was 5.4 months (95% CI, 3.8-7.0), and 5.2 months by model B (95% CI, 4.7-5.6).

CONCLUSIONS

We present the first aggregate estimates of OS and PFS for RM-NPC patients receiving first and second-line or higher treatment settings, which could inform the design of future clinical trials in this disease setting.

Antitumor immune effects of preoperative sitravatinib and nivolumab in oral cavity cancer: SNOW window-of-opportunity study

BACKGROUND

Sitravatinib, a tyrosine kinase inhibitor that targets TYRO3, AXL, MERTK and the VEGF receptor family, is predicted to increase the M1 to M2-polarized tumor-associated macrophages ratio in the tumor microenvironment and have synergistic antitumor activity in combination with anti-programmed death-1/ligand-1 agents. SNOW is a window-of-opportunity study designed to evaluate the immune and molecular effects of preoperative sitravatinib and nivolumab in patients with oral cavity squamous cell carcinoma.

METHODS

Patients with newly-diagnosed untreated T2-4a, N0-2 or T1 >1 cm-N2 oral cavity carcinomas were eligible. All patients received sitravatinib 120 mg daily from day 1 up to 48 hours pre-surgery and one dose of nivolumab 240 mg on day 15. Surgery was planned between day 23 and 30. Standard of care adjuvant radiotherapy was given based on clinical stage. Tumor photographs, fresh tumor biopsies and blood samples were collected at baseline, at day 15 after sitravatinib alone, and at surgery after sitravatinib-nivolumab combination. Tumor flow cytometry, multiplex immunofluorescence staining and single-cell RNA sequencing (scRNAseq) were performed on tumor biopsies to study changes in immune-cell populations. Tumor whole-exome sequencing and circulating tumor DNA and cell-free DNA were evaluated at each time point.

RESULTS

Ten patients were included. Grade 3 toxicity occurred in one patient (hypertension); one patient required sitravatinib dose reduction, and one patient required discontinuation and surgery delay due to G2 thrombocytopenia. Nine patients had clinical-to-pathological downstaging, with one complete response. Independent pathological treatment response (PTR) assessment confirmed a complete PTR and two major PTRs. With a median follow-up of 21 months, all patients are alive with no recurrence. Circulating tumor DNA and cell-free DNA dynamics correlated with clinical and pathological response and distinguished two patient groups with different tumor biological behavior after sitravatinib alone (1A) versus sitravatinib-nivolumab (1B). Tumor immunophenotyping and scRNAseq analyses revealed differential changes in the expression of immune cell populations and sitravatinib-targeted and hypoxia-related genes in group 1A vs 1B patients.

CONCLUSIONS

The SNOW study shows sitravatinib plus nivolumab is safe and leads to deep clinical and pathological responses in oral cavity carcinomas. Multi-omic biomarker analyses dissect the differential molecular effects of sitravatinib versus the sitravatinib-nivolumab and revealed patients with distinct tumor biology behavior.

TRIAL REGISTRATION NUMBER

NCT03575598.

Pantoprazole Affecting Docetaxel Resistance Pathways via Autophagy (PANDORA): Phase II Trial of High Dose Pantoprazole (Autophagy Inhibitor) with Docetaxel in Metastatic Castration-Resistant Prostate Cancer (mCRPC)

BACKGROUND

Enhancing the effectiveness of docetaxel for men with metastatic castration-resistant prostate cancer (mCRPC) is an unmet clinical need. Preclinical studies demonstrated that high-dose pantoprazole can prevent or delay resistance to docetaxel via the inhibition of autophagy in several solid tumor xenografts.

MATERIALS AND METHODS

Men with chemotherapy-naive mCRPC with a prostate-specific antigen (PSA) >10 ng/mL were eligible for enrolment. Men received intravenous pantoprazole (240 mg) prior to docetaxel (75 mg/m²) every 21 days, with continuous prednisone 5 mg twice daily. Primary endpoint was a confirmed ≥50% decline of PSA. The trial used a Simon's two-stage design.

RESULTS

Between November 2012 and March 2015, 21 men with a median age of 70 years (range, 58-81) were treated (median, 6 cycles; range, 2-11). Men had received prior systemic therapies (median, 1; range, 0-3), and 14 had received abiraterone and/or enzalutamide. PSA response rate was 52% (11/21), which did not meet the prespecified criterion (≥13/21 responders) to proceed to stage 2 of the study. At interim analysis with a median follow-up of 17 months, 18 (86%) men were deceased (15 castration-resistant prostate cancer, 2 unknown, 1 radiation complication). Of the men with RECIST measurable disease, the radiographic partial response rate was 31% (4/13). The estimated median overall survival was 15.7 months (95% confidence interval [CI], 9.3-19.6) and median PFS was 5.3 months (95% CI, 2.6-12.9). There were no toxic deaths, and all adverse events were attributed to docetaxel.

CONCLUSION

The combination of docetaxel and pantoprazole was tolerable, but the resultant clinical activity was not sufficient to meet the ambitious predefined target to warrant further testing.

IMPLICATIONS FOR PRACTICE

To date, no docetaxel combination regimen has reported superior efficacy over docetaxel alone in men with metastatic castration-resistant prostate cancer (mCRPC). The PANDORA trial has demonstrated that the combination of high dose pantoprazole with docetaxel is tolerable, but the clinical activity was not sufficient to warrant further testing. The chemotherapy standard of care for men with mCRPC remains docetaxel with prednisone. Future studies of autophagy inhibitors will need to measure autophagy inhibition accurately and determine the degree of autophagy inhibition required to produce a meaningful clinical response.

Rural oncology: overcoming the tyranny of distance for improved cancer care

Approximately one third of Australians with cancer live in regional and rural areas of the country. They have a lower rate of survival than those in city areas because of less availability of diagnostic and treatment services, later diagnosis, and lower socioeconomic status. This article explores rural oncology and how it allows patients to access specialist services usually available only to those situated in major cities. As the remoteness of hospitals increases, treatment and support are increasingly provided by less specialized staff. Rural oncology services offer patients access to an oncologist in their community. It combines research with community care. It puts together a whole team of oncologists, general practitioners, nursing and support staff, other allied health staff, and patients and their families. The use of technology, enabling teleconferencing and videoconferencing, allows contact among all members of a patient's care team and the patient. It allows for shared care of the patient with the general practitioner during follow-up and results in a reduction in hospital visits. This article gives an overview of the rural oncology experience in the New England region of Australia and of the future direction of the oncology team in this region. This includes community-oriented projects focused on improving cancer care for patients of the New England region, including one involving the Aboriginal community.

Phase I trial of alpelisib in combination with concurrent cisplatin-based chemoradiotherapy in patients with locoregionally advanced squamous cell carcinoma of the head and neck

BACKGROUND

Deregulation of the PI3K signalling pathway is frequent in squamous cell carcinoma of the head and neck (SCCHN) and may be implicated in radioresistance. We report on the results from a phase I 3 + 3 dose escalation study of alpelisib, a class I α-specific PI3K inhibitor in combination with concurrent cisplatin-based chemoradiation (CRT) in patients with locoregionally advanced SCCHN (LA-SCCHN).

METHODS

Eligible patients had previously untreated LA-SCCHN and were candidates for CRT. The primary objective was to evaluate safety and determine the recommended phase II dose (RP2D). Alpelisib was given orally once daily at two dose levels: 200 mg and 250 mg. CRT consisted of cisplatin 100 mg/m² IV every three weeks and standard fractionation radiotherapy (IMRT) 70 Gy in 35 fractions.

RESULTS

Nine patients were enrolled (six alpelisib 200 mg, three 250 mg). Oropharynx was the primary site in all patients (seven p16-positive; five T1-2N2M0, four T3-4N2-3M0 [AJCC 7th edition]). All patients completed CRT within seven weeks. Grade 3 alpelisib-related toxicities occurred in four patients. No dose-limiting toxicity (DLT) was observed at 200 mg among three DLT-evaluable patients. Two of two DLT-evaluable patients treated at 250 mg experienced DLTs (inability to complete ≥75% alpelisib secondary to radiation dermatitis and febrile neutropenia). Thus, RP2D was declared at 200 mg. After median follow-up of 39.7 months, two patients developed pulmonary metastases despite locoregional control. Three-year overall survival was 77.8% (95% CI 36.5%-93.9%).

CONCLUSION

Alpelisib at 200 mg has a manageable safety profile in combination with cisplatin-based CRT in LA-SCCHN.

Recommendations for the use of next-generation sequencing in patients with metastatic cancer in the Asia-Pacific region: a report from the APODDC working group

INTRODUCTION

Next-generation sequencing (NGS) diagnostics have shown clinical utility in predicting survival benefits in patients with certain cancer types who are undergoing targeted drug therapies. Currently, there are no guidelines or recommendations for the use of NGS in patients with metastatic cancer from an Asian perspective. In this article, we present the Asia-Pacific Oncology Drug Development Consortium (APODDC) recommendations for the clinical use of NGS in metastatic cancers.

METHODS

The APODDC set up a group of experts in the field of clinical cancer genomics to (i) understand the current NGS landscape for metastatic cancers in the Asia-Pacific (APAC) region; (ii) discuss key challenges in the adoption of NGS testing in clinical practice; and (iii) adapt/modify the European Society for Medical Oncology guidelines for local use. Nine cancer types [breast cancer (BC), gastric cancer (GC), nasopharyngeal cancer (NPC), ovarian cancer (OC), prostate cancer, lung cancer, and colorectal cancer (CRC) as well as cholangiocarcinoma and hepatocellular carcinoma (HCC)] were identified, and the applicability of NGS was evaluated in daily practice and/or clinical research. Asian ethnicity, accessibility of NGS testing, reimbursement, and socioeconomic and local practice characteristics were taken into consideration.

RESULTS

The APODDC recommends NGS testing in metastatic non-small-cell lung cancer (NSCLC). Routine NGS testing is not recommended in metastatic BC, GC, and NPC as well as cholangiocarcinoma and HCC. The group suggested that patients with epithelial OC may be offered germline and/or somatic genetic testing for BReast CAncer gene 1 (BRCA1), BRCA2, and other OC susceptibility genes. Access to poly (ADP-ribose) polymerase inhibitors is required for NGS to be of clinical utility in prostate cancer. Allele-specific PCR or a small-panel multiplex-gene NGS was suggested to identify key alterations in CRC.

CONCLUSION

This document offers practical guidance on the clinical utility of NGS in specific cancer indications from an Asian perspective.

Phase 1 results of PTC596, a novel small molecule targeting cancer stem cells (CSCs) by reducing levels of BMI1 protein

2574

Background: PTC596 is an oral investigational new drug that reduces levels of BMI1, a protein required for CSC survival. PTC596 reduced the number of CSCs in preclinical models and slowed growth rates of tumor xenografts in rodent models. The primary objectives of this first-in-human trial of PTC596 were to determine safety, dose-limiting toxicities (DLTs), maximum tolerated dose (MTD), and pharmacokinetics (PK). Secondary objectives included exploratory assessments of biological efficacy, pharmacodynamic changes and anti-tumor activity. Methods: A Phase I multi-center, open-label study was conducted in patients with advanced solid tumors using a modified 3+3 design, followed by a dose-confirmatory 10-patient expansion. PTC596 was administered using bodyweight-adjusted twice-per-week (biw) oral dosing in 4 week cycles. Dose escalation and MTD were based on observed cycle 1 DLTs. Anti-tumor activity was assessed by RECIST 1.1. Results: A total of 31 patients with a broad range of tumor types were enrolled at dose levels of 0.65 (N = 3), 1.3 (N = 3), 2.6 (N = 3), 5.2 (N = 11), 7 (N = 8) and 10 mg/kg (N = 3). Nausea, vomiting, and diarrhea were the most common all grade adverse events, though usually mild and manageable. At 10 mg/kg one patient experienced DLTs of neutropenia, mucositis, and thrombocytopenia. The other two patients at this dose level also experienced poor tolerability with Grade 2 nausea, vomiting, and diarrhea that may be partially due to the overall pill burden and excipients. The recommended dose for the expansion and further study was 7 mg/kg. Over the dosing range, plasma concentrations of PTC596 increased in an approximately dose-proportional manner and at doses of 2.6 mg/kg and above exceeded those associated with activity in vitro and in vivo models. Best response was stable disease in 5 patients including two with minor radiographic reductions in tumor volume. Conclusions: PTC596 is tolerable with manageable gastrointestinal side effects. At 7 mg/kg biw exposures exceeded those associated with preclinical activity and future clinical studies are planned for this first-in class molecule that targets CSCs. Clinical trial information: NCT02404480.

Abstract CT302: Phase Ia/Ib dose-escalation study of the anti-TIGIT antibody tiragolumab as a single agent and in combination with atezolizumab in patients with advanced solid tumors

Background: The immunomodulatory receptor TIGIT (T-cell Immunoreceptor with Ig and ITIM domains) is a novel inhibitory immune checkpoint present on activated T cells and NK cells in multiple cancers. In preclinical models, co-inhibition of the TIGIT and PD-L1/PD-1 pathways improved anti-tumor activity compared to either agent alone. Tiragolumab (tira or MTIG7192A) is a humanized IgG1/kappa monoclonal antibody (mAb) that binds TIGIT to prevent its interaction with its ligand PVR (CD155). In this first-in-human dose-escalation study, we report the preliminary safety and anti-tumor activity of tira as a single agent and in combination with atezolizumab (atezo) in patients with advanced solid tumors. Methods: Enrolled patients, ECOG PS 0-1, had advanced tumors for whom standard therapy did not exist or was ineffective. Patients received escalating doses of tira alone IV Q3W alone (Phase Ia) or in combination with atezo 1200 mg IV Q3W (Phase Ib) to determine the maximum tolerated dose (MTD) and continued until disease progression, intolerable toxicity, or patient/investigator decision. Study objectives included evaluation of safety and tolerability, pharmacokinetics (PK), pharmacodynamics, and anti-tumor activity of tira alone or tira + atezo. Data cut-off date was April 2019. Results: 73 patients with multiple tumor types were treated in dose-escalation (24 in Phase Ia, 49 in Ib with tira + atezo). In Phase Ia and Phase Ib, median age was 60 and 54 years, ECOG 0 for 29% and 27% of patients, and those who received ≥ 3 prior therapies were 67% and 57%, respectively. No DLTs were observed. Across doses, treatment-related AEs occurred in 67% in Phase Ia and 59% in Phase Ib (Grade ≥ 3: 4% and 4%, respectively), and most common AEs were fatigue (38%) in Phase Ia and anemia (31%) in Phase Ib. Exposure of tira increased with increasing dose, and saturation of nonlinear PK occurred at tira doses ≥ 100 mg Q3W. Complete and sustained occupancy of peripheral TIGIT receptors was observed at tira doses ≥ 30 mg Q3W. In Phase Ia, there were no objective responses, but SD of &gt; 4 months duration was observed (n=4). In Phase Ib, there were 3 responses, which all occurred in PD-L1 positive tumors (2 non-small cell lung cancer [NSCLC]: 1 CR, 1 PR; and 1 head/neck squamous cell carcinoma: PR) with two patients not receiving prior immunotherapy (CIT-naïve). Therefore, expansion cohorts were initiated in PD-L1-positive CIT-naïve indications in Phase Ib. In the metastatic NSCLC expansion cohort (n=14) ORR was 50%, with 1 CR and 6 PRs; DCR was 79%, and the safety profile was similar. Conclusions: Tira monotherapy or combined with atezo was well-tolerated and had an acceptable safety profile across all dose levels. Preliminary anti-tumor activity was observed in Phase Ib with tira + atezo in CIT-naïve PD-L1-positive tumors, including NSCLC, and enrollment is ongoing in these expansion cohorts.

Citation Format: Johanna C. Bendell, Philippe Bedard, Yung-Jue Bang, Patricia LoRusso, Stephen Hodi, Michael Gordon, Sandra D'Angelo, Sandra D'Angelo, Jayesh Desai, Elena Garralda, Antoine Italiano, Myung-Ju Ahn, Andres Cervantes, Zev Wainberg, Emiliano Calvo, Marta Gil-Martin, Maria Martinez-Garcia, Rastilav Bahleda, Philippe Cassier, Jean-Pierre Delord, Amy Prawira, Ignacio Melero, Leisha Emens, Emanuela Romano, Karen Miller, Robert W. Hsieh, Cloris Xue, Kari Morrissey, Patrick Twomey, Kelly Gash, Namrata S. Patil, Jane Grogan, Raymond Meng, Byoung Cho, Tae Won Kim. Phase Ia/Ib dose-escalation study of the anti-TIGIT antibody tiragolumab as a single agent and in combination with atezolizumab in patients with advanced solid tumors [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 CT302.

A Survey of Medical Oncology Training in Australian Medical Schools: Pilot Study

BACKGROUND

Oncology is a rapidly evolving field with continuous advancements in the diagnosis and treatment of cancer. Therefore, it is important that medical students are provided with the knowledge and experience required to care for oncology patients and enable them to diagnose and manage toxicities of novel therapeutic agents.

OBJECTIVE

This study was performed to understand the medical students' perspective of the oncology education provided in universities across Australia and identify areas of education that could potentially be modified or improved to ultimately attract more students to a career in oncology.

METHODS

This pilot cross-sectional study consisted of an 18-question survey that was submitted online to medical students in their final year and interns rotating to the Tamworth Hospital.

RESULTS

The survey was completed by 94 fifth-year medical students and interns. Oncology was taught both theoretically and clinically for 68% (63/93) of participants, and 48% (44/92) had an exclusive oncology rotation. Both theoretical and clinical oncology assessments were conducted for only 21% (19/92) of participants. Overall, 42% (38/91) of participants were satisfied with their oncology education, and 78% (40/51) were dissatisfied with the number of oncology teaching hours. The importance of a career in oncology was rated as low by 46% (41/90) of participants.

CONCLUSIONS

This pilot study indicates that there are potential areas to improve oncology teaching in Australian universities. The majority of surveyed students were dissatisfied with the number of teaching hours they receive in oncology. More global assessment of students and/or interns from other Australian institutes may yield further useful information.

SNOW: Sitravatinib and nivolumab in oral cavity cancer (OCC) window of opportunity study

6569

Background: Sitravatinib (receptor TKI against TYRO3, AXL, MERTK and VEGF family of receptors) is predicted to increase M1-type tumor-associated macrophages (TAMs) and decrease MDSCs in the tumor microenvironment. SNOW is a window-of-opportunity study evaluating the immunogenic and antitumor effects of preoperative sitravatinib and nivolumab in patients (pts) with OCC. Early results demonstrated the combination was safe and active (Oliva et al, SITC 2019). Biomarker analyses and updated results are presented. Methods: Pts with untreated T2-4a, N0-2 or T1>1cm-N2 OCC are eligible. All pts receive oral sitravatinib 120mg daily from day (D) 1 up to 48h pre-surgery and 1 dose of Nivolumab 240mg on D15. Surgery planned between D23-D30. Standard of care adjuvant radiotherapy given based on clinical stage. Tumor pictures, fresh tumor biopsies, blood samples taken at baseline, D15 and pre-surgery. Tumor flow cytometry and multiplex immunofluorescence staining performed on all biopsies to study changes in immune-cell populations. Tumor whole-exome sequencing (WES) performed on baseline biopsies. Results: As of Jan 31st 2020, 10 out of 12 planned pts were enrolled. Study treatment was well-tolerated: only 1 pt had grade (G) >3 toxicity (hypertension) and 1 pt required surgery delay due to G2 thrombocytopenia. None had intraoperative complications. 1 pt had wound infection and tracheostomy bleeding 11 days post-surgery, possibly-related to study drugs. All pts had tumor reduction, 9/10 had pathological downstaging, including 1 complete response (Table). All had clear margins with no extranodal extension; none required adjuvant chemotherapy. All pts are alive with no recurrence (median follow-up= 69 weeks). Lower % of MDSCs and increased % of M1-TAMs and M1:M2 ratio trend was seen at D15 and pre-surgery, with stronger effect in major responders. Best responders (Pts S1-S2) had higher % of PD-L1+ TAMs at baseline. Tumor WES revealed an HRAS G12D mutation in pt S2 and a BLM mutation (DNA repair) in pt S6 (no downstaging). Conclusions: Pharmacodynamic analyses support the antitumor and immune effects of sitravatinib and nivolumab in OCC. Immune pathological response assessment and transcriptomics are on-going. Clinical trial information: NCT03575598 . [Table: see text]

A phase I dose escalation and dose expansion study of the anti-programmed cell death-1 (PD-1) antibody AK105

e14006

Background: AK105 is a humanized IgG1 mAb that blocks PD-1 binding to PD-L1 allowing T-cells to recognize and kill tumor cells. Key attributes of AK105 include antibody engineering to eliminate Fc mediated effector function, and a slower off-rate on antigen binding resulting in improved receptor occupancy (RO). These features offer more robust biological effect and enhance anti-tumor activity of AK105. Methods: A multicenter, Phase I, open-label dose escalation and expansion study in solid tumors (NCT03352531) began in Dec 2017, evaluating the safety and efficacy of AK105 administered IV q2w till confirmed progression (RECIST v1.1). For dose escalation, pts were enrolled at dose cohorts of 1, 3, and 10 mg/kg. Expansion of AK105 at the RP2D of 200 mg q2w is ongoing in pts with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma; esophageal squamous-cell carcinoma; hepatocellular carcinoma (HCC); microsatellite instability-high (MSI-H) colorectal cancer. Results: As of 1 Feb, 2019, 34 pts (median age 66.5 years [30–79], female 44%, ECOG 0/1 ([68%/32%]) in cohorts of 1 mg/kg (n = 3), 3 mg/kg (n = 6), 10 mg/kg (n = 7), and 200 mg q2w (n = 18), received a median of 5 (1–29) doses of AK105. No DLTs were reported. Treatment-related adverse events (TRAEs) occurred in 41% of pts (G3 in 12% [4/34], no G4, treatment interruption in 9% [3/34]). Most frequent TRAEs ( > 5%) were hyperthyroidism (9%), hypothyroidism (6%), fatigue (6%), and rash (6%). PD-1 RO analysis showed that pts maintained full occupancy ( > 80%) for all dose levels. Of 25 evaluable heavily pretreated pts, ORR was 24% (6/25; 29% [4/14] in dose escalation and 18% [2/11] in expansion phase) and disease control rate (DCR) was 56% (14/25). Five responses are confirmed and ongoing (HCC, pancreatic carcinoma, cholangiocarcinoma, GBM, gastric adenocarcinoma), one is pending confirmatory scan (GEJ). Conclusions: The RP2D obtained from the dose escalation phase, reported safety profile and encouraging antitumor activity of AK105 supports continued clinical development, which include: pivotal studies in classic Hodgkin lymphoma and nasopharyngeal carcinoma, phase 2/3 combination studies with chemotherapy in NSCLC and combination study with anlotinib, a multi-targeting tyrosine kinase inhibitor in HCC. PD analysis is ongoing and expansion is ongoing at the RP2D. Clinical trial information: NCT03352531.

A signal-seeking trial of olaparib and durvalumab in homologous repair-deficient tumors: A sub-study of the cancer molecular screening and therapeutics (MoST) program

3073

Background: Data on the utility of a PARP inhibitor in combination with a checkpoint inhibitor remain limited, particularly in the histology agnostic setting with homologous recombination deficiency (HRD). This study evaluated the clinical activity of the combination of olaparib and durvalumab with the primary study endpoint of progression-free survival (PFS) at 6 months (PFS6m). Methods: This was a phase II, single-arm, signal-seeking study of the MoST program. Patients were recruited into two cohorts based on HRD genes, agnostic to histology: (1) BRCA 1/2 deficient tumours, excluding breast, prostate, ovarian cancers, and (2) other HRD related genes. Molecular testing was performed using in-house and commercial panels on archival tumour tissue centrally adjudicated by a molecular tumour board. All patients were treated with olaparib 300mg bid for 1 month, followed by combination with durvalumab 1500mg q4 weekly for 13 cycles. Olaparib treatment was then continued until disease progression. Results: Between Nov 2017-Feb 2019, 48 patients were enrolled (16 to BRCA 1/2 cohort 1 and 32 to HRD related genes cohort 2). Most common tumour sites were bone/soft tissue (15%, N=7), pancreas (13%, N=6) and stomach (8%, N=4). Overall best response in cohort 1 was PR (25%, N=4) and SD 4 (25%, N=4), and cohort 2 was PR (6%, N=2) and SD (56%, N=18). Median PFS was 3.65m (Cohort 1) and 3.56m (Cohort 2) respectively. PFS6m was 35% (Cohort 1) and 38% (Cohort 2) respectively. PDL1 status was not predictive of olaparib and durvalumab benefit. The most common grade 3/4 adverse events were anemia (11%%, N=4), abdominal pain (9%, N=3), increased lipase (9%,N=3), increased amylase (9%, N=3), dyspnea (6%, N=2), Hyperglycemia dyspnea (6%, N=2), Pancreatitis dyspnea (6%, N=2) and hematuria (6%, N=2). Conclusions: Olaparib and durvalumab show promising activity in a histology agnostic setting, particularly in BRCA deficient tumours. Further research is needed to identify biomarkers that correlate with treatment benefit. Results from longer clinical follow-up and additional biomarker analyses will be presented. Clinical trial information: ACTRN12617001000392 .

FPT155-001: A phase Ia/Ib study of FPT155 (CD80-FC) in patients with advanced solid tumors

TPS42

Background: Despite recent advances in immunotherapy, many patients with advanced solid tumors are refractory to available therapies or eventually relapse. Novel immune therapies are needed with differentiated mechanisms of action that result in improved response rates and durability across a broad range of tumors. FPT155 is a first-in-class therapeutic being developed to meet this need. FPT155 is a recombinant fusion protein composed of the extracellular domain of human CD80 fused with the Fc domain of human immunoglobulin G1. It is designed to act as a potent stimulator of anti-tumor immunity through CD28 and thereby co-stimulate T cell responses only in the presence of antigenic T cell receptor (TCR) signaling. FPT155 alone does not induce spontaneous cytokine release by primary human immune cells, in contrast to a CD28 superagonist antibody that exerts TCR stimulus-independent activity. FPT155 also blocks CTLA-4 from competing for endogenous CD80, allowing CD28 signaling to prevail in T cell activation. A murine surrogate of FPT155 is a potent inhibitor of tumor growth that induces complete tumor regression in multiple tumor models, including models that are insensitive to anti-PD1 or anti-CTLA4. Methods: The FPT155-001 study is a Phase 1a/1b open-label, multicenter, dose escalation and expansion study to evaluate the safety and tolerability of FPT155 monotherapy. Phase 1a dose escalation includes an accelerated titration design followed by a standard 3+3 design until the recommended dose for Phase 1b is determined by evaluation of all available safety, pharmacokinetic (PK), and pharmacodynamic (PD) data. Eligible patients with advanced solid tumors who are refractory to all standard therapy for their malignancy will be enrolled in Phase 1a. Phase 1b dose expansion will enroll patients with select tumor types. The primary endpoint is safety in both phases. Key secondary endpoints in Phase 1a include characterization of the FPT155 PK profile and immunogenicity. Key secondary endpoints in Phase 1b include objective response rate, duration of response, progression free survival, and disease control rate. The FPT155-001 trial opened for enrollment in October 2018 and is in progress. Clinical trial information: Submitted - awaiting registration number.