Durvalumab plus gemcitabine and cisplatin in advanced biliary tract cancer (TOPAZ-1): patient-reported outcomes from a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

In the ongoing, randomised, double-blind phase 3 TOPAZ-1 study, durvalumab, a PD-L1 inhibitor, plus gemcitabine and cisplatin was associated with significant improvements in overall survival compared with placebo, gemcitabine, and cisplatin in people with advanced biliary tract cancer at the pre-planned intermin analysis. In this paper, we present patient-reported outcomes from TOPAZ-1.

METHODS

In TOPAZ-1 (NCT03875235), participants aged 18 years or older with previously untreated, unresectable, locally advanced, or metastatic biliary tract cancer with an Eastern Cooperative Oncology Group performance status of 0 or 1 and one or more measurable lesions per Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1) were randomly assigned (1:1) to the durvalumab group or the placebo group using a computer-generated randomisation scheme. Participants received 1500 mg durvalumab or matched placebo intravenously every 3 weeks (on day 1 of the cycle) for up to eight cycles in combination with 1000 mg/m2 gemcitabine and 25 mg/m2 cisplatin intravenously on days 1 and 8 every 3 weeks for up to eight cycles. Thereafter, participants received either durvalumab (1500 mg) or placebo monotherapy intravenously every 4 weeks until disease progression or other discontinuation criteria were met. Randomisation was stratified by disease status (initially unresectable vs recurrent) and primary tumour location (intrahepatic cholangiocarcinoma vs extrahepatic cholangiocarcinoma vs gallbladder cancer). Patient-reported outcomes were assessed as a secondary outcome in all participants who completed the European Organisation for Research and Treatment of Cancer's 30-item Quality of Life of Cancer Patients questionnaire (QLQ-C30) and the 21-item Cholangiocarcinoma and Gallbladder Cancer Quality of Life Module (QLQ-BIL21). We calculated time to deterioration-ie, time from randomisation to an absolute decrease of at least 10 points in a patient-reported outcome that was confirmed at a subsequent visit or the date of death (by any cause) in the absence of deterioration-and adjusted mean change from baseline in patient-reported outcomes.

FINDINGS

Between April 16, 2019, and Dec 11, 2020, 685 participants were enrolled and randomly assigned, 341 to the durvalumab group and 344 to the placebo group. Overall, 345 (50%) of participants were male and 340 (50%) were female. Data for the QLQ-C30 were available for 318 participants in the durvalumab group and 328 in the placebo group (median follow-up 9·9 months [IQR 6·7 to 14·1]). Data for the QLQ-BIL21 were available for 305 participants in the durvalumab group and 322 in the placebo group (median follow-up 10·2 months [IQR 6·7 to 14·3]). The proportions of participants in both groups who completed questionnaires were high and baseline scores were mostly similar across treatment groups. For global health status or quality of life, functioning, and symptoms, we noted no difference in time to deterioration or adjusted mean changes from baseline were observed between groups. Median time to deterioration of global health status or quality of life was 7·4 months (95% CI 5·6 to 8·9) in the durvalumab group and 6·7 months (5·6 to 7·9) in the placebo group (hazard ratio 0·87 [95% CI 0·69 to 1·12]). The adjusted mean change from baseline was 1·23 (95% CI -0·71 to 3·16) in the durvalumab group and 0·35 (-1·63 to 2·32) in the placebo group.

INTERPRETATION

The addition of durvalumab to gemcitabine and cisplatin did not have a detrimental effect on patient-reported outcomes. These results suggest that durvalumab, gemcitabine, and cisplatin is a tolerable treatment regimen in patients with advanced biliary tract cancer.

FUNDING

AstraZeneca.

A phase I study of ATR inhibitor gartisertib (M4344) as a single agent and in combination with carboplatin in patients with advanced solid tumours

BACKGROUND

Gartisertib is an oral inhibitor of ataxia telangiectasia and Rad3-related protein (ATR), a key kinase of the DNA damage response. We aimed to determine the safety and tolerability of gartisertib ± carboplatin in patients with advanced solid tumours.

METHODS

This phase I open-label, multicenter, first-in-human study comprised four gartisertib cohorts: A (dose escalation [DE]; Q2W); A2 (DE; QD/BID); B1 (DE+carboplatin); and C (biomarker-selected patients).

RESULTS

Overall, 97 patients were enroled into cohorts A (n = 42), A2 (n = 26), B1 (n = 16) and C (n = 13). The maximum tolerated dose and recommended phase II dose (RP2D) were not declared for cohorts A or B1. In cohort A2, the RP2D for gartisertib was determined as 250 mg QD. Gartisertib was generally well-tolerated; however, unexpected increased blood bilirubin in all study cohorts precluded further DE. Investigations showed that gartisertib and its metabolite M26 inhibit UGT1A1-mediated bilirubin glucuronidation in human but not dog or rat liver microsomes. Prolonged partial response (n = 1 [cohort B1]) and stable disease >6 months (n = 3) did not appear to be associated with biomarker status. Exposure generally increased dose-dependently without accumulation.

CONCLUSION

Gartisertib was generally well-tolerated at lower doses; however, unexpected liver toxicity prevented further DE, potentially limiting antitumour activity. Gartisertib development was subsequently discontinued.

CLINICALTRIALS

GOV: NCT02278250.

A risk analysis of alpelisib-induced hyperglycemia in patients with advanced solid tumors and breast cancer

BACKGROUND

Hyperglycemia is an on-target effect of PI3Kα inhibitors. Early identification and intervention of treatment-induced hyperglycemia is important for improving management of patients receiving a PI3Kα inhibitor like alpelisib. Here, we characterize incidence of grade 3/4 alpelisib-related hyperglycemia, along with time to event, management, and outcomes using a machine learning model.

METHODS

Data for the risk model were pooled from patients receiving alpelisib ± fulvestrant in the open-label, phase 1 X2101 trial and the randomized, double-blind, phase 3 SOLAR-1 trial. The pooled population (n = 505) included patients with advanced solid tumors (X2101, n = 221) or HR+/HER2- advanced breast cancer (SOLAR-1, n = 284). External validation was performed using BYLieve trial patient data (n = 340). Hyperglycemia incidence and management were analyzed for SOLAR-1.

RESULTS

A random forest model identified 5 baseline characteristics most associated with risk of developing grade 3/4 hyperglycemia (fasting plasma glucose, body mass index, HbA1c, monocytes, age). This model was used to derive a score to classify patients as high or low risk for developing grade 3/4 hyperglycemia. Applying the model to patients treated with alpelisib and fulvestrant in SOLAR-1 showed higher incidence of hyperglycemia (all grade and grade 3/4), increased use of antihyperglycemic medications, and more discontinuations due to hyperglycemia (16.7% vs. 2.6% of discontinuations) in the high- versus low-risk group. Among patients in SOLAR-1 (alpelisib + fulvestrant arm) with PIK3CA mutations, median progression-free survival was similar between the high- and low-risk groups (11.0 vs. 10.9 months). For external validation, the model was applied to the BYLieve trial, for which successful classification into high- and low-risk groups with shorter time to grade 3/4 hyperglycemia in the high-risk group was observed.

CONCLUSIONS

A risk model using 5 clinically relevant baseline characteristics was able to identify patients at higher or lower probability for developing alpelisib-induced hyperglycemia. Early identification of patients who may be at higher risk for hyperglycemia may improve management (including monitoring and early intervention) and potentially lead to improved outcomes.

REGISTRATION

ClinicalTrials.gov: NCT01219699 (registration date: October 13, 2010; retrospectively registered), ClinicalTrials.gov: NCT02437318 (registration date: May 7, 2015); ClinicalTrials.gov: NCT03056755 (registration date: February 17, 2017).

A randomized phase II study of metronomic cyclophosphamide and methotrexate (CM) with or without bevacizumab in patients with advanced breast cancer

PURPOSE

Metronomic chemotherapy has the potential to offer tumor control with reduced toxicity when compared to standard dose chemotherapy in patients with metastatic breast cancer. As metronomic chemotherapy may target the tumor microvasculature, it has the potential for synergistic effects with antiangiogenic agents such as the VEGF-A inhibitor bevacizumab.

METHODS

In this randomized phase II study, patients with metastatic breast cancer were randomized to receive metronomic oral cyclophosphamide and methotrexate (CM) combined with bevacizumab (Arm A) or CM alone (Arm B). The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety and tolerability.

RESULTS

A total of 55 patients were enrolled, with 34 patients treated on Arm A and 21 patients treated on Arm B. The ORR was modestly higher in Arm A (26%) than in Arm B (10%); neither met the 40% cutoff for further clinical evaluation. The median time to progression (TTP) was 5.52 months (3.22-13.6) on Arm A and 1.82 months (1.54-6.70) on Arm B (log-rank p = 0.008). The median OS was 29.6 months (17.2-NA) on Arm A and 16.2 months (15.7-NA) on Arm B (log-rank p = 0.7). Common all-grade adverse events in both arms included nausea, fatigue, and elevated AST.

CONCLUSION

The combination of metronomic CM with bevacizumab significantly improved PFS over CM alone, although there was no significant difference in OS. Oral metronomic chemotherapy alone has limited activity in advanced breast cancer.

CLINICALTRIALS

gov Identifier: NCT00083031. Date of Registration: May 17, 2004.

MyPathway Human Epidermal Growth Factor Receptor 2 Basket Study: Pertuzumab + Trastuzumab Treatment of a Tissue-Agnostic Cohort of Patients With Human Epidermal Growth Factor Receptor 2-Altered Advanced Solid Tumors

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The MyPathway multiple-basket study (ClinicalTrials.gov identifier: NCT02091141) is evaluating targeted therapies in nonindicated tumors with relevant molecular alterations. We assessed pertuzumab + trastuzumab in a tissue-agnostic cohort of adult patients with human epidermal growth factor receptor 2 (HER2)-amplified and/or -overexpressed and/or -mutated solid tumors. The primary end point was objective response rate (ORR); secondary end points included survival and safety. At data cutoff (March 2022), 346 patients with HER2 amplification and/or overexpression with/without HER2 mutations (n = 263), or HER2 mutations alone (n = 83) had been treated. Patients with HER2 amplification and/or overexpression had an ORR of 25.9% (68/263, 95% CI, 20.7 to 31.6), including five complete responses (urothelial [n = 2], salivary gland [n = 2], and colon [n = 1] cancers). Activity was higher in those with wild-type (ORR, 28.1%) versus mutated KRAS (ORR, 7.1%). Among patients with HER2 amplification, ORR was numerically higher in patients with immunohistochemistry (IHC) 3+ (41.0%; 32/78) or 2+ (21.9%; 7/32), versus 1+ (8.3%; 1/12) or no expression (0%; 0/20). In patients with HER2 mutations alone, ORR was 6.0% (5/83, 95% CI, 2.0 to 13.5). Pertuzumab + trastuzumab showed activity in various HER2-amplified and/or -overexpressed tumors with wild-type KRAS, with the range of activity dependent on tumor type, but had limited activity in the context of KRAS mutations, HER2 mutations alone, or 0-1+ HER2 expression.

Revolutionizing cancer drug development: Harnessing the potential of basket trials

The landscape of cancer therapy has been transformed by advances in clinical next-generation sequencing, genomically targeted therapies, and immunotherapies. Well designed clinical trials and efficient clinical trial conduct are crucial for advancing our understanding of cancer, improving patient outcomes, and identifying personalized treatments. Basket trials have emerged as one of the efficient modern clinical trial designs that evaluate the efficacy of these therapies across multiple cancer types based on specific molecular alterations or biomarkers, irrespective of histology or anatomic location. This review delves into the evolution of basket trials in cancer drug development, highlighting their potential prospects and current obstacles. The design of basket trials involves screening patients for specific molecular alterations or biomarkers and enrolling them in the trial to receive the targeted therapy under investigation. Statistical considerations play a crucial role in the design, analysis, and interpretation of basket trials. Several notable examples of basket trials that have led to US Food and Drug Administration approval for uncommon molecular alterations (e.g., NTRK fusions, BRAF mutations, RET and FGFR1 alterations) are discussed, including LOXO-TRK (ClinicalTrials.gov identifier NCT02122913)/SCOUT (ClinicalTrials.gov identifier NCT02637687)/NAVIGATE (ClinicalTrials.gov identifier NCT02576431)/STARTRK (ClinicalTrials.gov identifiers NT02097810, NT02568267), VE-BASKET (ClinicalTrials.gov identifier NCT01524978), ROAR Basket (ClinicalTrials.gov identifier NCT02034110), LIBRETTO-001 (ClinicalTrials.gov identifier NCT03157128), ARROW (ClinicalTrials.gov identifier NCT03037385), FIGHT-203 (ClinicalTrials.gov identifier NCT03011372), and the National Cancer Institute-Molecular Analysis for Therapy Choice trial (ClinicalTrials.gov identifier NCT02465060). Basket trials have the potential to revolutionize cancer treatment by identifying effective therapies for patients based on specific molecular alterations or biomarkers rather than traditional histology-based approaches. PLAIN LANGUAGE SUMMARY: To gain more knowledge about cancer, improve patient outcomes, and discover personalized treatments, it is crucial to conduct clinical trials efficiently. One effective type of clinical trial is called a basket trial. In basket trials, new treatments are tested on various types of cancer, regardless of their location in the body; instead, researchers focus on specific abnormalities in the cancer cells. Basket trials offer hope that we can find personalized treatments that are more effective for each individual battling cancer.

Improvements in Survival and Clinical Benefit With Gemcitabine as First-Line Therapy for Patients With Advanced Pancreas Cancer: A Randomized Trial

PURPOSE

Most patients with advanced pancreas cancer experience pain and must limit their daily activities because of tumor-related symptoms. To date, no treatment has had a significant impact on the disease. In early studies with gemcitabine, patients with pancreas cancer experienced an improvement in disease-related symptoms. Based on those findings, a definitive trial was performed to assess the effectiveness of gemcitabine in patients with newly diagnosed advanced pancreas cancer.

PATIENTS AND METHODS

One hundred twenty-six patients with advanced symptomatic pancreas cancer completed a lead-in period to characterize and stabilize pain and were randomized to receive either gemcitabine 1,000 mg/m2 weekly x 7 followed by 1 week of rest, then weekly x 3 every 4 weeks thereafter (63 patients), or to fluorouracil (5-FU) 600 mg/m2 once weekly (63 patients). The primary efficacy measure was clinical benefit response, which was a composite of measurements of pain (analgesic consumption and pain intensity), Karnofsky performance status, and weight. Clinical benefit required a sustained (> or = 4 weeks) improvement in at least one parameter without worsening in any others. Other measures of efficacy included response rate, time to progressive disease, and survival.

RESULTS

Clinical benefit response was experienced by 23.8% of gemcitabine-treated patients compared with 4.8% of 5-FU-treated patients (P = .0022). The median survival durations were 5.65 and 4.41 months for gemcitabine-treated and 5-FU-treated patients, respectively (P = .0025). The survival rate at 12 months was 18% for gemcitabine patients and 2% for 5-FU patients. Treatment was well tolerated.

CONCLUSION

This study demonstrates that gemcitabine is more effective than 5-FU in alleviation of some disease-related symptoms in patients with advanced, symptomatic pancreas cancer. Gemcitabine also confers a modest survival advantage over treatment with 5-FU.

XENERA-1: a randomised double-blind Phase II trial of xentuzumab in combination with everolimus and exemestane versus everolimus and exemestane in patients with hormone receptor-positive/HER2-negative metastatic breast cancer and non-visceral disease

BACKGROUND

Xentuzumab is a humanised monoclonal antibody that binds to IGF-1 and IGF-2, neutralising their proliferative activity and restoring inhibition of AKT by everolimus. This study evaluated the addition of xentuzumab to everolimus and exemestane in patients with advanced breast cancer with non-visceral disease.

METHODS

This double-blind, randomised, Phase II study was undertaken in female patients with hormone-receptor (HR)-positive/human epidermal growth factor 2 (HER2)-negative advanced breast cancer with non-visceral disease who had received prior endocrine therapy with or without CDK4/6 inhibitors. Patients received a weekly intravenous infusion of xentuzumab (1000 mg) or placebo in combination with everolimus (10 mg/day orally) and exemestane (25 mg/day orally). The primary endpoint was progression-free survival (PFS) per independent review.

RESULTS

A total of 103 patients were randomised and 101 were treated (n = 50 in the xentuzumab arm and n = 51 in the placebo arm). The trial was unblinded early due to high rates of discordance between independent and investigator assessment of PFS. Per independent assessment, median PFS was 12.7 (95% CI 6.8-29.3) months with xentuzumab and 11.0 (7.7-19.5) months with placebo (hazard ratio 1.19; 95% CI 0.55-2.59; p = 0.6534). Per investigator assessment, median PFS was 7.4 (6.8-9.7) months with xentuzumab and 9.2 (5.6-14.4) months with placebo (hazard ratio 1.23; 95% CI 0.69-2.20; p = 0.4800). Tolerability was similar between the arms, with diarrhoea (33.3-56.0%), fatigue (33.3-44.0%) and headache (21.6-40.0%) being the most common treatment-emergent adverse events. The incidence of grade ≥ 3 hyperglycaemia was similar between the xentuzumab (2.0%) and placebo (5.9%) arms.

CONCLUSIONS

While this study demonstrated that xentuzumab could be safely combined with everolimus and exemestane in patients with HR-positive/HER2-negative advanced breast cancer with non-visceral disease, there was no PFS benefit with the addition of xentuzumab. Trial registration ClinicalTrials.gov, NCT03659136. Prospectively registered, September 6, 2018.

Spleen tyrosine kinase/FMS-like tyrosine kinase-3 inhibition in relapsed/refractory B-cell lymphoma, including diffuse large B-cell lymphoma: updated data with mivavotinib (TAK-659/CB-659)

We report an updated analysis from a phase I study of the spleen tyrosine kinase (SYK) and FMS-like tyrosine kinase 3 inhibitor mivavotinib, presenting data for the overall cohort of lymphoma patients, and the subgroup of patients with diffuse large B-cell lymphoma (DLBCL; including an expanded cohort not included in the initial report). Patients with relapsed/refractory lymphoma for which no standard treatment was available received mivavotinib 60-120 mg once daily in 28-day cycles until disease progression/unacceptable toxicity. A total of 124 patients with lymphoma, including 89 with DLBCL, were enrolled. Overall response rates (ORR) in response-evaluable patients were 45% (43/95) and 38% (26/69), respectively. Median duration of response was 28.1 months overall and not reached in DLBCL responders. In subgroups with DLBCL of germinal center B-cell (GCB) and non-GCB origin, ORR was 28% (11/40) and 58% (7/12), respectively. Median progression free survival was 2.0 and 1.6 months in the lymphoma and DLBCL cohorts, respectively. Grade ≥3 treatment-emergent adverse events occurred in 96% of all lymphoma patients, many of which were limited to asymptomatic laboratory abnormalities; the most common were increased amylase (29%), neutropenia (27%), and hypophosphatemia (26%). These findings support SYK as a potential therapeutic target for the treatment of patients with B-cell lymphomas, including DLBCL. Trial registration: ClinicalTrials.gov number: NCT02000934.

First-in-Human Phase I/II ICONIC Trial of the ICOS Agonist Vopratelimab Alone and with Nivolumab: ICOS-High CD4 T-Cell Populations and Predictors of Response

PURPOSE

The first-in-human phase I/II ICONIC trial evaluated an investigational inducible costimulator (ICOS) agonist, vopratelimab, alone and in combination with nivolumab in patients with advanced solid tumors.

PATIENTS AND METHODS

In phase I, patients were treated with escalating doses of intravenous vopratelimab alone or with nivolumab. Primary objectives were safety, tolerability, MTD, and recommended phase II dose (RP2D). Phase II enriched for ICOS-positive (ICOS+) tumors; patients were treated with vopratelimab at the monotherapy RP2D alone or with nivolumab. Pharmacokinetics, pharmacodynamics, and predictive biomarkers of response to vopratelimab were assessed.

RESULTS

ICONIC enrolled 201 patients. Vopratelimab alone and with nivolumab was well tolerated; phase I established 0.3 mg/kg every 3 weeks as the vopratelimab RP2D. Vopratelimab resulted in modest objective response rates of 1.4% and with nivolumab of 2.3%. The prospective selection for ICOS+ tumors did not enrich for responses. A vopratelimab-specific peripheral blood pharmacodynamic biomarker, ICOS-high (ICOS-hi) CD4 T cells, was identified in a subset of patients who demonstrated greater clinical benefit versus those with no emergence of these cells [overall survival (OS), P = 0.0025]. A potential genomic predictive biomarker of ICOS-hi CD4 T-cell emergence was identified that demonstrated improvement in clinical outcomes, including OS (P = 0.0062).

CONCLUSIONS

Vopratelimab demonstrated a favorable safety profile alone and in combination with nivolumab. Efficacy was observed only in a subset of patients with a vopratelimab-specific pharmacodynamic biomarker. A potential predictive biomarker of response was identified, which is being prospectively evaluated in a randomized phase II non-small cell lung cancer trial. See related commentary by Lee and Fong, p. 3633.

First-In-Human Phase I Study of the OX40 Agonist MOXR0916 in Patients with Advanced Solid Tumors

PURPOSE

OX40, a receptor transiently expressed by T cells upon antigen recognition, is associated with costimulation of effector T cells and impairment of regulatory T-cell function. This first-in-human study evaluated MOXR0916, a humanized effector-competent agonist IgG1 monoclonal anti-OX40 antibody.

PATIENTS AND METHODS

Eligible patients with locally advanced or metastatic refractory solid tumors were treated with MOXR0916 intravenously once every 3 weeks (Q3W). A 3+3 dose-escalation stage (0.2-1,200 mg; n = 34) was followed by expansion cohorts at 300 mg (n = 138) for patients with melanoma, renal cell carcinoma, non-small cell lung carcinoma, urothelial carcinoma, and triple-negative breast cancer.

RESULTS

MOXR0916 was well tolerated with no dose-limiting toxicities observed. An MTD was not reached. Most patients (95%) experienced at least one adverse event (AE); 56% of AEs, mostly grade 1-2, were related to MOXR0916. Most common treatment-related AEs included fatigue (17%), diarrhea (8%), myalgia (7%), nausea (6%), decreased appetite (6%), and infusion-related reaction (5%). Pharmacokinetic (PK) parameters were dose proportional between 80 and 1,200 mg and supported Q3W administration. The recommended expansion dose based on PK and OX40 receptor saturation was 300 mg Q3W. Immune activation and upregulation of PD-L1 was observed in a subset of paired tumor biopsies. One renal cell carcinoma patient experienced a confirmed partial response. Overall, 33% of patients achieved stable disease.

CONCLUSIONS

Although objective responses were rarely observed with MOXR0916 monotherapy, the favorable safety profile and evidence of tumor immune activation in a subset of patients support further investigation in combination with complementary agents such as PD-1/PD-L1 antagonists.

Discordance in Tumor Mutation Burden from Blood and Tissue Affects Association with Response to Immune Checkpoint Inhibition in Real-World Settings

BACKGROUND

Tumor mutation burden (TMB), a biomarker for immune checkpoint inhibitor (CPI) response, is reported by both blood- and tissue-based next-generation sequencing (NGS) vendors. However, the agreement between TMB from blood (bTMB) and tissue (tTMB) in real-world settings, both in absolute value and association with CPI response, is not known.

MATERIALS AND METHODS

This study utilizes Sarah Cannon's precision medicine platform, Genospace, to harmonize clinico-genomic data from 17 206 patients with cancer with NGS results from September 2015 to August 2021. A subset of patients have both bTMB and tTMB results. Statistical analyses are performed in R and include (1) correlation (r) and concordance (ρ) between patient-matched bTMB-tTMB pairs, (2) distribution of total bTMB and tTMB values, and (3) association of bTMB and tTMB with time to CPI therapy failure.

RESULTS

In 410 patient-matched bTMB-tTMB pairs, the median bTMB (m = 10.5 mut/Mb) was significantly higher than the median tTMB (m = 6.0 mut/Mb, P < .001) leading to conflicting "high" and "low" statuses in over one-third of cases at a threshold of 10 mut/Mb (n = 410). Significant differences were observed in the distribution of bTMB values from blood-NGS vendors, with guardant health (GH) reporting higher (m = 10.5 mut/Mb, n = 2183) than Foundation Medicine (FMI, m = 3.8 mut/Mb, n = 462, P < .001). bTMB from GH required a higher threshold (≥40 mut/Mb) than bTMB from FMI (≥12 mut/Mb) in order to be associated with CPI response.

CONCLUSIONS

This study uncovers variability in bTMB reporting among commercial NGS platforms, thereby evidencing a need for assay-specific thresholds in identifying patients who may respond to CPI therapy.

Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer

BACKGROUND

In a previous analysis of this phase 3 trial, first-line ribociclib plus letrozole resulted in significantly longer progression-free survival than letrozole alone among postmenopausal patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether overall survival would also be longer with ribociclib was not known.

METHODS

Here we report the results of the protocol-specified final analysis of overall survival, a key secondary end point. Patients were randomly assigned in a 1:1 ratio to receive either ribociclib or placebo in combination with letrozole. Overall survival was assessed with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods after 400 deaths had occurred. A hierarchical testing strategy was used for the analysis of progression-free survival and overall survival to ensure the validity of the findings.

RESULTS

After a median follow-up of 6.6 years, 181 deaths had occurred among 334 patients (54.2%) in the ribociclib group and 219 among 334 (65.6%) in the placebo group. Ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole. Median overall survival was 63.9 months (95% confidence interval [CI], 52.4 to 71.0) with ribociclib plus letrozole and 51.4 months (95% CI, 47.2 to 59.7) with placebo plus letrozole (hazard ratio for death, 0.76; 95% CI, 0.63 to 0.93; two-sided P = 0.008). No new safety signals were observed.

CONCLUSIONS

First-line therapy with ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole in patients with HR-positive, HER2-negative advanced breast cancer. Median overall survival was more than 12 months longer with ribociclib than with placebo. (Funded by Novartis; MONALEESA-2 ClinicalTrials.gov number, NCT01958021.).

Abemaciclib in Combination With Endocrine Therapy for Patients With Hormone Receptor-Positive, HER2-Negative Metastatic Breast Cancer: A Phase 1b Study

Background

Cyclin-dependent kinases (CDK) 4 and 6 regulate G1 to S cell cycle progression and are often altered in cancers. Abemaciclib is a selective inhibitor of CDK4 and CDK6 approved for administration on a continuous dosing schedule as monotherapy or as combination therapy with an aromatase inhibitor or fulvestrant in patients with advanced or metastatic breast cancer. This Phase 1b study evaluated the safety and tolerability, pharmacokinetics, and antitumor activity of abemaciclib in combination with endocrine therapy for metastatic breast cancer (MBC), including aromatase inhibitors (letrozole, anastrozole, or exemestane) or tamoxifen.

Patients and Methods

Women ≥18 years old with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) MBC were eligible for enrollment. Eligibility included measurable disease or non-measurable but evaluable bone disease by Response Evaluation Criteria in Solid Tumours (RECIST) v1.1, Eastern Cooperative Oncology Group performance status 0–1, and no prior chemotherapy for metastatic disease. Adverse events were graded by the National Cancer Institute Common Terminology Criteria for Adverse Events v4.0 and tumor response were assessed by RECIST v1.1.

Results

Sixty-seven patients were enrolled and received abemaciclib 200 mg every 12 hours in combination with letrozole (Part A, n=20), anastrozole (Part B, n=16), tamoxifen (Part C, n=16), or exemestane (Part D, n=15). The most common treatment-emergent adverse events (TEAE) were diarrhea, fatigue, nausea, and abdominal pain. Grade 4 TEAEs were reported in five patients (one each with hyperglycemia, hypertension, neutropenia, procedural hemorrhage, and sepsis). There was no effect of abemaciclib or endocrine therapy on the pharmacokinetics of any combination study drug. Across all treated patients, the median progression-free survival was 25.4 months (95% confidence interval: 18.0, 35.8). The objective response rate was 38.9% in 36 patients with measurable disease.

Conclusions

Abemaciclib in combination with multiple endocrine therapy options exhibited manageable safety and promising antitumor activity in patients with HR+, HER2- MBC.

Clinical Trial Registration

https://clinicaltrials.gov/, identifier NCT02057133

Abstract GS2-01: Overall survival subgroup analysis by metastatic site from the phase 3 MONALEESA-2 study of first-line ribociclib + letrozole in postmenopausal patients with advanced HR+/HER2− breast cancer

Background: MONALEESA-2 (ML-2) recently reported a statistically significant overall survival (OS) benefit with first-line ribociclib (RIB) + letrozole (LET) over placebo (PBO) + LET in postmenopausal patients with HR+/HER2- advanced breast cancer (ABC) (median, 63.9 vs 51.4 months; hazard ratio, 0.76; 95% CI, 0.63-0.93; P = .004). Understanding OS outcomes in clinically relevant subgroups of patients is important for improving personalized care and prognosis. Here, we report the results of a prespecified exploratory OS analysis in select patient subgroups by baseline location and number of metastatic sites.. Methods: Postmenopausal patients with HR+/HER2− ABC were randomized 1:1 to receive first-line RIB or PBO with LET. Prespecified exploratory OS analyses were performed for subgroups of special interest by baseline location (bone only [yes or no], liver involvement [yes or no], liver or lung involvement [yes or no]) and number of metastatic sites (&lt; 3 or ≥ 3). The data are hypothesis generating since this analysis was exploratory and not powered for statistical significance.. Results: A total of 668 patients were included in the analysis. A consistent improvement in OS was observed with RIB + LET vs PBO + LET in all subgroups regardless of baseline metastatic site (Table). RIB + LET demonstrated an OS benefit over PBO + LET in clinically relevant subgroups by baseline location and number of metastatic sites, including subgroups of patients with liver metastases, liver or lung metastases, and ≥ 3 metastatic sites, who generally have a worse prognosis.. Conclusion: Consistent with the intent-to-treat population of ML-2, the results of this prespecified exploratory analysis demonstrated an OS benefit with RIB + LET independent of the site and number of metastatic lesions.

TableTreatment Arm (n)HR (95% CI)Bone-only metastasisYesRIB + LET (69)0.78 (0.50-1.21)PBO + LET (79)NoRIB + LET (265)0.77(0.61-0.96)PBO + LET (255)Liver involvementYesRIB + LET (59)0.81 (0.54-1.24)PBO + LET (72)NoRIB + LET (275)0.77 (0.62-0.97)PBO + LET (262)Liver or lung involvementYesRIB + LET (182)0.81(0.62-1.05)PBO + LET (190)NoRIB + LET (152)0.71 (0.53-0.96)PBO + LET (144)No. of metastatic sites&lt; 3RIB + LET (220)0.78(0.61-1.00)PBO + LET (222)≥ 3RIB + LET (114)0.71(0.51-0.98)PBO + LET (112)

Citation Format: Joyce O'Shaughnessy, Salomon M Stemmer, Howard A Burris, Yoon-Sim Yap, Gabe Sonke, Lowell Hart, Mario Campone, Katarina Petrakova, Eric P Winer, Wolfgang Janni, Pierfranco Conte, David A Cameron, Fabrice André, Carlos Arteaga, Juan Pablo Zarate, Arunava Chakravartty, Tetiana Taran, Fabienne Le Gac, Paolo Serra, Gabriel N Hortobagyi. Overall survival subgroup analysis by metastatic site from the phase 3 MONALEESA-2 study of first-line ribociclib + letrozole in postmenopausal patients with advanced HR+/HER2− breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-01.

Tumor-Specific and Tumor-Agnostic Molecular Signatures Associated With Response to Immune Checkpoint Inhibitors

PURPOSE

Next-generation sequencing (NGS) testing is being incorporated into routine standard of care for patients with cancer. Immune checkpoint inhibitors (CPIs) are approved for use in both tumor-specific and tumor-agnostic indications. We sought to determine tumor type-specific or tumor-agnostic correlations between mutations detected by NGS and response to CPIs.

MATERIALS AND METHODS

A retrospective analysis of 26,004 patient records with NGS data available was conducted. Time to treatment failure and overall survival analyses were performed. Hazard ratios and associated statistics were computed in the R programming language. The study was considered exempt from internal review board review and data were considered nonhuman subjects.

RESULTS

Response to CPIs varied between tumor types with melanoma and lung cancer performing relatively better on CPIs than other tumor types. Within tumor types, response to CPIs was stratified by mutations in specific genes. Tumor-agnostic markers including high tumor mutation burden and microsatellite instability-high were also associated with longer time to treatment failure on CPIs. Importantly, within the high tumor mutation burden and microsatellite instability-high groups, mutations in individual genes correlate with response to CPIs.

CONCLUSION

The results from commercial NGS panels may be used to stratify patients for response to CPIs. In tumors where CPIs show relatively low efficacy, there may be distinct patient populations-based on gene mutation status-that are predicted to have better response to CPIs. Likewise, there may be distinct patient populations who do relatively worse on CPIs within tumor types known to respond well to CPIs.

Next-Generation Sequencing of Patients With Breast Cancer in Community Oncology Clinics

PURPOSE

Molecular biomarkers informing disease diagnosis, prognosis, and treatment decisions in patients with breast cancer are being uncovered by next-generation sequencing (NGS) technologies. In this study, we survey how NGS is used for patients with breast cancer in real-world settings with a focus on physician behaviors and sequencing results.

METHODS

We conducted a retrospective analysis of patients with breast cancer who received NGS testing from commercial vendors as part of standard of care from 2014 to 2019. A total of 2,635 NGS reports from 2,316 unique breast cancer patients were assessed. Hormone receptor and human epidermal growth factor receptor 2 statuses were abstracted from patient medical records. Comparative gene amplification and mutation frequencies were analyzed using Pearson's correlation and Lin's concordance statistics.

RESULTS

The number of physicians ordering NGS tests for patients with breast cancer increased more than six-fold from 2014 to 2019. Tissue- and plasma-based tests were ordered roughly equally by 2019, with plasma-based testing ordered most frequently in hormone receptor-positive subtypes. Patients with triple-negative breast cancer were most likely to receive NGS testing. Gene amplifications including ERBB2 were detected less frequently in our real-world data set as compared to previous genomic landscape studies, whereas the opposite was true for gene mutations including ESR1. Pathogenic mutations in the PI3K pathway (38.6%) and DNA damage repair pathway (11.0%) were frequently reported. Alterations were also reported across other cellular pathways.

CONCLUSION

Overall, we found that an increasing number of physicians in community settings are adopting NGS in the care of patients with breast cancer. Discrepancies between our real-world NGS data and previous genomic landscape studies are likely owed to the prevalence of plasma-based testing in community oncology clinics, as the reference data were from tissue-based NGS alone.

Atezolizumab Treatment of Tumors With High Tumor Mutational Burden From MyPathway, a Multicenter, Open-label, Phase 2a Multiple Basket Study

High tumor mutational burden (TMB-H) correlates with improved immunotherapy response. We assessed atezolizumab 1,200 mg every 3 weeks for TMB-H tumors from MyPathway (NCT02091141), a phase IIa multibasket study. One hundred twenty-one patients had advanced solid tumors with TMB ≥10 mut/Mb by any Clinical Laboratory Improvement Amendments (CLIA)–certified assay. The preplanned primary endpoint was objective response rate (ORR) in patients with TMB ≥16 mut/Mb tumors by FoundationOne TMB testing [F1(CDx)]. Patients with F1(CDx) TMB ≥10 and <16 mut/Mb were also evaluated. Ninety patients with 19 tumor types and F1(CDx) TMB ≥10 mut/Mb were efficacy evaluable. In 42 patients with F1(CDx) TMB ≥16 mut/Mb, confirmed ORR was 38.1% [16/42; 95% confidence interval (CI), 23.6–54.4], and disease control rate was 61.9% (26/42; 95% CI, 45.6–76.4) versus 2.1% (1/48; 95% CI, 0.1–11.1) and 22.9% (11/48; 95% CI, 12.0–37.3) for 48 patients with TMB ≥10 and <16 mut/Mb. Responses were observed in nine different tumor types (47%; 9/19).

A Phase II Study Evaluating Orteronel, an Inhibitor of Androgen Biosynthesis, in Patients With Androgen Receptor (AR)-Expressing Metastatic Breast Cancer (MBC)

BACKGROUND

AR is a targetable pathway with AR modulation inhibiting estrogen- and androgen-mediated cell proliferation. Orteronel is an oral, selective, nonsteroidal inhibitor of 17, 20-lyase, a key enzyme in androgen biosynthesis. This study evaluated single-agent orteronel in AR+ metastatic breast cancer (MBC).

METHODS

Male/female patients with AR+ MBC were grouped in Cohort 1: AR+ TNBC with l-3 prior chemotherapy regimens or Cohort 2: AR+ HR+ (estrogen [ER+]/ progesterone receptor [PR+] positive) HER2+/- with 1 to 3 prior hormonal and at least 1 prior chemotherapy regimen. Patients with HER2+ MBC must have received at least 2 lines of HER2-targeted therapy. Orteronel was administered at 300 mg BID; response rate was the primary endpoint.

RESULTS

Seventy patients were enrolled (Cohort 1, n = 26 and Cohort 2, n = 44). Median treatment duration was 7.1 weeks. Seven patients were on treatment for ≥6 months. One of the 21 evaluated patients in Cohort 1 (4.8%) had an objective response. In Cohort 2, none of the first 23 patients to be evaluated had a response and accrual was stopped. Median progression-free and overall survival were 1.8 and 8.3 months, respectively. Toxicities were predominantly Grade 1 or 2 nausea/vomiting (36%) and fatigue (31%). Grade 3 or 4 events in ≥5% of patients included increased amylase/lipase (10%) and hypertension (6%).

CONCLUSIONS

Orteronel demonstrated limited clinical activity in heavily pre-treated AR+ MBC. Further development of orteronel in MBC is not recommended. Further efforts to validate the AR as a therapeutic target should focus on identifying new markers predictive of sensitivity to AR-targeted agents.

Convalescent plasma associates with reduced mortality and improved clinical trajectory in patients hospitalized with COVID-19

BACKGROUNDEvidence supporting convalescent plasma (CP), one of the first investigational treatments for coronavirus disease 2019 (COVID-19), has been inconclusive, leading to conflicting recommendations. The primary objective was to perform a comparative effectiveness study of CP for all-cause, in-hospital mortality in patients with COVID-19.METHODSThe multicenter, electronic health records-based, retrospective study included 44,770 patients hospitalized with COVID-19 in one of 176 HCA Healthcare-affiliated community hospitals. Coarsened exact matching (1:k) was employed, resulting in a sample of 3774 CP and 10,687 comparison patients.RESULTSExamination of mortality using a shared frailty model, controlling for concomitant medications, date of admission, and days from admission to transfusion, demonstrated a significant association of CP with lower mortality risk relative to the comparison group (adjusted hazard ratio [aHR] = 0.71; 95% CI, 0.59-0.86; P < 0.001). Examination of patient risk trajectories, represented by 400 clinico-demographic features from our real-time risk model (RTRM), indicated that patients who received CP recovered more quickly. The stratification of days to transfusion revealed that CP within 3 days after admission, but not within 4 to 7 days, was associated with a significantly lower mortality risk (aHR = 0.53; 95% CI, 0.47-0.60; P < 0.001). CP serology level was inversely associated with mortality when controlling for its interaction with days to transfusion (HR = 0.998; 95% CI, 0.997-0.999; P = 0.013), yet it did not reach univariable significance.CONCLUSIONSThis large, diverse, multicenter cohort study demonstrated that CP, compared with matched controls, is significantly associated with reduced risk of in-hospital mortality. These observations highlight the utility of real-world evidence and suggest the need for further evaluation prior to abandoning CP as a viable therapy for COVID-19.FUNDINGThis research was supported in whole by HCA Healthcare and/or an HCA Healthcare-affiliated entity, including Sarah Cannon and Genospace.

Characterization of patients with long-term responses to rucaparib treatment in recurrent ovarian cancer

OBJECTIVE

To describe molecular and clinical characteristics of patients with high-grade recurrent ovarian carcinoma (HGOC) who had long-term responses to the poly(ADP-ribose) polymerase (PARP) inhibitor rucaparib.

METHODS

This post hoc analysis pooled patients from Study 10 (NCT01482715; Parts 2A and 2B; n = 54) and ARIEL2 (NCT01891344; Parts 1 and 2; n = 491). Patients with investigator-assessed complete or partial response per RECIST were classified based on duration of response (DOR): long (≥1 year), intermediate (6 months to <1 year), or short (<6 months). Next-generation sequencing was used to detect deleterious mutations and loss of heterozygosity (LOH) in tumors.

RESULTS

Overall, 25.3% (138/545) of enrolled patients were responders. Of these, 27.5% (38/138) had long-term responses; 28.3% (39/138) were intermediate- and 34.8% (48/138) were short-term responders. Most of the long-term responders harbored a BRCA1 or BRCA2 (BRCA) mutation (71.1%, 27/38), and BRCA structural variants were most frequent among long-term responders (14.8%; 4/27). Responders with HGOC harboring a BRCA structural variant (n = 5) had significantly longer DOR than patients with other mutation types (n = 81; median not reached vs 0.62 years; HR, 0.21; 95% CI, 0.10-0.43; unadjusted p = 0.014). Among responders with BRCA wild-type HGOC, most long- and intermediate-term responders had high genome-wide LOH: 81.8% (9/11) and 76.9% (10/13), respectively, including 7 with deleterious RAD51C, RAD51D, or CDK12 mutations.

CONCLUSION

Among patients who responded to rucaparib, a substantial proportion achieved responses lasting ≥1 year. These analyses demonstrate the relationship between DOR to PARP inhibitor treatment and molecular characteristics in HGOC, such as presence of reversion-resistant BRCA structural variants.

Vorasidenib, a Dual Inhibitor of Mutant IDH1/2, in Recurrent or Progressive Glioma; Results of a First-in-Human Phase I Trial

PURPOSE

Lower grade gliomas (LGGs) are malignant brain tumors. Current therapy is associated with short- and long-term toxicity. Progression to higher tumor grade is associated with contrast enhancement on MRI. The majority of LGGs harbor mutations in the genes encoding isocitrate dehydrogenase 1 or 2 (IDH1/IDH2). Vorasidenib (AG-881) is a first-in-class, brain-penetrant, dual inhibitor of the mutant IDH1 and mutant IDH2 enzymes.

PATIENTS AND METHODS

We conducted a multicenter, open-label, phase I, dose-escalation study of vorasidenib in 93 patients with mutant IDH1/2 (mIDH1/2) solid tumors, including 52 patients with glioma that had recurred or progressed following standard therapy. Vorasidenib was administered orally, once daily, in 28-day cycles until progression or unacceptable toxicity. Enrollment is complete; this trial is registered with ClinicalTrials.gov, NCT02481154.

RESULTS

Vorasidenib showed a favorable safety profile in the glioma cohort. Dose-limiting toxicities of elevated transaminases occurred at doses ≥100 mg and were reversible. The protocol-defined objective response rate per Response Assessment in Neuro-Oncology criteria for LGG in patients with nonenhancing glioma was 18% (one partial response, three minor responses). The median progression-free survival was 36.8 months [95% confidence interval (CI), 11.2-40.8] for patients with nonenhancing glioma and 3.6 months (95% CI, 1.8-6.5) for patients with enhancing glioma. Exploratory evaluation of tumor volumes in patients with nonenhancing glioma showed sustained tumor shrinkage in multiple patients.

CONCLUSIONS

Vorasidenib was well tolerated and showed preliminary antitumor activity in patients with recurrent or progressive nonenhancing mIDH LGG.

Abstract LB050: Modulation of innate and adaptive immunity in blood and tumor of patients receiving the SHP2 inhibitor RMC-4630

RMC-4630 is a potent, selective, orally bioavailable allosteric inhibitor of SHP2, a central node in the RAS signaling pathway. In preclinical models, SHP2 inhibition not only directly inhibited tumor growth through suppression of tumor-intrinsic RAS signaling, but also resulted in transformation of the tumor immune microenvironment, characterized by an increase in CD8+T cell infiltrates and selective depletion of pro-tumorigenic M2 macrophages.

In this study, we evaluated pharmacodynamic biomarkers in blood and tumors from patients in the RMC-4630 phase I monotherapy clinical trial (NCT 03634982) by using flow cytometry and immunohistochemistry (IHC). Safety, PK and efficacy data are reported in a separate abstract.

Longitudinal analysis of immune cell phenotyping in blood was conducted in 35 patients. There was a trend for lower pre-study monocytic myeloid-derived suppressor cell (mMDSC) to be associated with a better clinical outcome on RMC-4630 therapy. While the proportion of circulating T cell and B cell populations did not change, both blood mMDSC and total monocytes were significantly reduced during RMC-4630 administration. Furthermore, tumor volumes changes, and the proportion of patients with SD versus PD, positively correlated with the ratio of mMDSCs to total monocytes on RMC-4630 treatment.

Inhibition of pERK was observed in a subset of patients. Three paired tumor biopsies from efficacy-evaluable patients, including 1 PR, 1 SD and 1 PD, were available for tumor microenvironment analysis by multiplexed-IHC assays. Increase in tumor infiltrating T cells in the tumors of one patient with a PR and another with SD was observed on RMC-4630 therapy. Inhibition of tumor PD-L1 expression and a decrease in M2 macrophages was also observed on treatment in the tumor biopsy of the PR patient.

Collectively, the preliminary clinical biomarker data supports the preclinical observations that SHP2 inhibition with RMC-4630 modulates both innate and adaptive anti-tumor immunity.

Citation Format: Ariel Yung-Chia Chen, Eric Haura, Jose Pacheco, Marianna Koczywas, Michael Gordon, Susanna Ulahannan, Howard A. Burris, Sai-Hong Ignatius Ou, Judy S. Wang, Jonathan W. Riess, Caroline McCoach, Anna Capasso, Elsa Quintana, Josie Hayes, Richa Dua, Bojena Bitman, Martha Guerra, Hongfang Wang, Xiaolin Wang, Pasi A. Janne. Modulation of innate and adaptive immunity in blood and tumor of patients receiving the SHP2 inhibitor RMC-4630 [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 LB050.

Abstract LB054: Confirmation of target inhibition and anti-tumor activity of the SHP2 inhibitor RMC-4630 via longitudinal analysis of ctDNA in a phase 1 clinical study

RMC-4630 is a potent, selective, orally bioavailable allosteric inhibitor of SHP2, a central node in the RAS signaling pathway. Preclinical data have demonstrated that RMC-4630 can shrink tumors carrying certain mutations in the RAS pathway such as KRASG12C, NF1LOF, and BRAFClass3. Longitudinal circulating tumor DNA (ctDNA) was isolated from blood using GuardantOMNI in 80 patients with relapsed/refractory solid tumors in the phase 1 dose-escalation trial of RMC-4630 (NCT03634982) to characterize and confirm RAS pathway mutations and to evaluate molecular responses in patients receiving RMC-4630 monotherapy. Safety, PK and efficacy findings from this study are reported in a separate abstract. 78 of 80 patients had baseline somatic mutations detected in plasma, of which 60 were either KRASG12X, NF1LOF, or BRAFClass3; 48 of these 60 patients also had on-treatment ctDNA assessments and these patients constitute the population reported here. 9 of 48 patients (19%) had KRASG12C detected at baseline, available scan results and a ctDNA sample after 4 weeks of receiving RMC-4630. A decrease in KRASG12C variant allele frequency (VAF) was detected in 5/9 patients (56%) with clearance in 1 patient with a partial response. Decrease in KRASG12C VAF was associated with change in tumor volume (PCC=0.85, p=0.008), preceding scan results by approximately 1 month, suggesting that change in KRASG12C VAF may be an early measure of drug activity or possibly response. 5 of 48 patients (10%) had NF1LOF detected at baseline. A decrease, or stability in NF1LOF VAF on treatment compared to baseline was detected in 4 (80% of all NF1LOF patients). The decrease in NF1LOF VAF was not associated with change in tumor volume and may represent effects of RMC-4630 on a subclone harboring NF1LOF. One patient had a detectable BRAFClass3 mutation at baseline, which decreased in VAF on treatment compared to baseline. Of the remaining patients there were 12 KRASG12D, 9 KRASG12V and other KRASG12X. The majority progressed with an increase in VAF of all mutations including KRASG12X, suggesting that the KRASG12X-containing clone is responsible for escape from single agent RMC-4630. In most instances the increase in KRASG12X VAF in blood preceded determination of clinical progression. Longitudinal assessment of ctDNA indicates that some patients with RAS-addicted tumors undergo a molecular response on treatment with the SHP2 inhibitor RMC-4630.

Citation Format: Josie L. Hayes, Marianna Koczywas, Sai-Hong Ignatius Ou, Pasi A. Janne, Jose M. Pacheco, Susanna Ulahannan, Judy S. Wang, Howard A. Burris, Jonathan W. Riess, Caroline McCoach, Michael S. Gordon, Anna Capasso, Ariel Chen, Richa Dua, Bojena Bitman, Martha Guerra, Hongfang Wang, Xiaolin Wang, Eric Haura. Confirmation of target inhibition and anti-tumor activity of the SHP2 inhibitor RMC-4630 via longitudinal analysis of ctDNA in a phase 1 clinical 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 LB054.

Abstract PS11-29: A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic triple-negative breast cancer (TNBC)

Background: Treatment options for TNBC are limited by the lack of estrogen and progesterone receptors as well as the absence of HER2 overexpression. AR is present in all breast cancer subtypes and up to 40% of TNBC have AR overexpression (AR+). Thus AR positivity in TNBC represents a potential targetable signaling pathway. Preclinical studies demonstrated that AR modulation inhibits cell proliferation, and clinical activity with anti-androgen monotherapy has been reported in breast cancer. Orteronel is a novel, oral, selective, nonsteroidal inhibitor of 17, 20-lyase, a key enzyme in androgen biosynthesis under evaluation as a potential therapeutic strategy in hormone-sensitive cancers. In this phase 2 study, we evaluated androgen blockade with single agent orteronel in AR+ metastatic breast cancer (MBC). Methods: Male or female pts with AR+ MBC (≥10% staining by central immunohistochemistry) were eligible. Pts were grouped into 2 cohorts for analysis: Cohort 1-TNBC (AR+/ER-/PR-/HER2-) and Cohort 2-ER+ (AR+/ER+/HER2 +/-). Results in Cohort 2 (ER+) have been previously reported; here we report results in the AR+ TNBC cohort. TNBC pts must have been previously treated with standard therapy (1-3 chemotherapy regimens for MBC). All pts received 300 mg orteronel PO BID over a 4 week cycle and underwent response assessment every 2 cycles. Treatment continued until disease progression or unacceptable toxicity. The hypothesized response rate for pts with previously treated metastatic AR+ TNBC was 11%. Results: From 7/2014 to 2/2019 a total of 26 AR+ TNBC pts were enrolled on cohort 1. The trial closed early due to slow accrual. Median age was 57 years (range, 33-92); 96% ECOG 0-1; all pts had ≥ 1 prior chemotherapy; 42% prior targeted therapy; 8% prior immunotherapy. All tumors were ER and PR negative per institutional standards. PI3K was mutated in 16% (3/19) tumors tested and 65% (13/20) were PTEN-negative. Median duration of treatment was 8 weeks (range 0.7-35.7) with 15% of pts on treatment ≥ 6 months (mo). All pts have discontinued treatment, 85% due to disease progression, and 15% due to AEs. Nausea and fatigue [8 pts each (31%)] were the most common AEs noted. G 3/4 AEs included hypertension, increased amylase and lipase [2 pts each (8%)] with 4 patients reporting SAEs (G2 pneumonitis, G2 chest pain and G2 peripheral edema, G4 prolonged QT and G4 hypokalemia). The ORR was 4% and DCR was 15%. Median PFS was 2.0 mo and median OS was 10.2 mo. Conclusions: Orteronel monotherapy was well tolerated but demonstrated limited clinical activity in this heavily pre-treated metastatic AR+ TNBC patient population. As novel AR targeting agents are being developed, future studies are needed to identify AR+ breast cancer patients most likely to benefit from AR inhibition.

Citation Format: Denise A Yardley, Robyn R Young, Kerin B Adelson, Andrea L Silber, Michael D Kommor, Jose E Najera, Davey B Daniel, Nancy W Peacock, Mythili Shastry, John D Hainsworth, Howard A Burris, III. A phase 2 study evaluating orteronel, an inhibitor of androgen biosynthesis, in patients with androgen receptor (AR)-expressing metastatic triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS11-29.

American Society of Clinical Oncology Road to Recovery Report: Learning From the COVID-19 Experience to Improve Clinical Research and Cancer Care

This report presents the American Society of Clinical Oncology's (ASCO's) evaluation of the adaptations in care delivery, research operations, and regulatory oversight made in response to the coronavirus pandemic and presents recommendations for moving forward as the pandemic recedes. ASCO organized its recommendations for clinical research around five goals to ensure lessons learned from the COVID-19 experience are used to craft a more equitable, accessible, and efficient clinical research system that protects patient safety, ensures scientific integrity, and maintains data quality. The specific goals are: (1) ensure that clinical research is accessible, affordable, and equitable; (2) design more pragmatic and efficient clinical trials; (3) minimize administrative and regulatory burdens on research sites; (4) recruit, retain, and support a well-trained clinical research workforce; and (5) promote appropriate oversight and review of clinical trial conduct and results. Similarly, ASCO also organized its recommendations regarding cancer care delivery around five goals: (1) promote and protect equitable access to high-quality cancer care; (2) support safe delivery of high-quality cancer care; (3) advance policies to ensure oncology providers have sufficient resources to provide high-quality patient care; (4) recognize and address threats to clinician, provider, and patient well-being; and (5) improve patient access to high-quality cancer care via telemedicine. ASCO will work at all levels to advance the recommendations made in this report.

Research Amidst the Pandemic

Description Cancer patients need access to promising investigational therapies, available only through clinical trials, and the emergence of COVID-19 and the resulting pandemic became an emerging threat to fulfilling that need. Many academic medical centers were pausing their clinical research programs, diverting their resources and sheltering their teams. Sarah Cannon, the Cancer Institute of HCA Healthcare, made the decision to stay safe, but stay the course.

First-in-human phase I study of ARV-110, an androgen receptor (AR) PROTAC degrader in patients (pts) with metastatic castrate-resistant prostate cancer (mCRPC) following enzalutamide (ENZ) and/or abiraterone (ABI)

3500

Background: Proteolysis Targeting Chimera (PROTAC) protein degraders induce selective degradation of targeted proteins by engaging the ubiquitin proteasome system. ARV-110 is an orally bioavailable PROTAC that specifically degrades AR ≥ 95% and achieves anti-tumor activity in ENZ-naïve and -resistant prostate cancer xenograft models. Methods: To define the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of ARV-110, pts with ≥ 2 prior therapies for mCRPC, including ENZ and/or ABI, received ARV-110 orally once daily. Dose escalation is per 3+3 design. Endpoints include dose limiting toxicities (DLTs), adverse events (AEs), pharmacokinetics (PK), biomarkers (e.g., AR mutation analysis), RECIST and PSA response. Results: By January 2020, 18 pts were dosed: 35 mg (N = 3), 70 mg (N = 4), 140 mg (N = 8), 280 mg (N = 3). 12 pts received both ENZ and ABI; 14 received prior chemotherapy. 1 of 18 pts experienced a DLT (280 mg) of Grade (Gr) 4 elevated AST/ALT followed by acute renal failure while taking rosuvastatin (ROS). A 2nd pt had Gr 3 AST/ALT with ROS that resolved off ROS, permitting ARV-110 retreatment. ROS plasma concentrations demonstrated significant increases concurrent with AST/ALT elevations in both pts. Subsequently, ROS was prohibited without further ≥Gr 2 AST/ALT AEs. No other related Gr 3/4 AEs were reported. ARV-110 PK was generally dose proportional and at 140 mg reached levels associated with preclinical anti-tumor activity. 15 pts were evaluable for PSA response (excludes 1 pt stopped after 1 dose for early progression and 2 pts initiated 2 weeks before cutoff, all at 140 mg). Of these, 8 pts initiated dosing at ≥140 mg. 2 pts achieved confirmed PSA declines of >50%, both at 140 mg. Prior therapy in both pts included ENZ and ABI, chemotherapy, bicalutamide and radium-223 plus other regimens. 1 pt had 2 AR mutations known to confer ENZ resistance. The 2nd pt also achieved an unconfirmed RECIST partial response (confirmatory scan pending). Both responses were ongoing at data cutoff (8+ and 21+ weeks of treatment). Conclusions: To date, ARV-110 has an acceptable safety profile. Concurrent ROS is now prohibited. MTD has not yet been established; determination of RP2D continues. ARV-110 demonstrates antitumor activity in mCRPC after ENZ/ABI with 2 ongoing confirmed PSA responses, one of which was associated with tumor reduction. Updated data for this first PROTAC in clinical testing will be presented. Clinical trial information: NCT03888612 .

Infigratinib in upper tract urothelial carcinoma versus urothelial carcinoma of the bladder and its association with comprehensive genomic profiling and/or cell-free DNA results

BACKGROUND

Infigratinib (BGJ398) is a potent and selective fibroblast grown factor receptor 1 to 3 (FGFR1-3) inhibitor with significant activity in patients with advanced or metastatic urothelial carcinoma bearing FGFR3 alterations. Given the distinct biologic characteristics of upper tract urothelial carcinoma (UTUC) and urothelial carcinoma of the bladder (UCB), the authors examined whether infigratinib had varying activity in these settings.

METHODS

Eligible patients had metastatic urothelial carcinoma with activating FGFR3 mutations and/or fusions. Comprehensive genomic profiling was performed on formalin-fixed, paraffin-embedded tissues. Blood was collected for cell-free DNA analysis using a 600-gene panel. Patients received infigratinib at a dose of 125 mg orally daily (3 weeks on/1 week off) until disease progression or intolerable toxicity occurred. The overall response rate (ORR; partial response [PR] plus complete response [CR]) and disease control rate (DCR; CR plus PR plus stable disease [SD]) were characterized.

RESULTS

A total of 67 patients were enrolled; the majority (70.1%) had received ≥2 prior antineoplastic therapies. In 8 patients with UTUC, 1 CR and 3 PRs were observed (ORR, 50%); the remaining patients achieved a best response of SD (DCR, 100%). In patients with UCB, 13 PRs were observed (ORR, 22%), and 22 patients had a best response of SD (DCR, 59.3%). Notable differences in genomic alterations between patients with UTUC and those with UCB included higher frequencies of FGFR3-TACC3 fusions (12.5% vs 6.8%) and FGFR3 R248C mutations (50% vs 11.9%), and a lower frequency of FGFR3 S249C mutations (37.5% vs 59.3%).

CONCLUSIONS

Differences in the cumulative genomic profile were observed between patients with UTUC and those with UCB in the current FGFR3-restricted experience, underscoring the distinct biology of these diseases. These results support a planned phase 3 adjuvant study predominantly performed in this population.

Relationship between hyperphosphatemia with infigratinib (BGJ398) and efficacy in FGFR3-altered advanced/metastatic urothelial carcinoma (aUC)

576

Background: Infigratinib (BGJ398) is a potent and selective FGFR1–3 inhibitor with significant clinical activity in aUC bearing FGFR3 alterations. A common adverse event is hyperphosphatemia, a class effect associated with FGFR1 inhibition. We sought to better understand the relationship between hyperphosphatemia and response to infigratinib in patients with aUC. Methods: Eligible patients had aUC with activating FGFR3 mutations/fusions and had received prior platinum-based chemotherapy, unless contraindicated. Patients received infigratinib 125 mg orally daily (3w on/1w off) until disease progression or unacceptable toxicity. Calcium and phosphate levels within normal limits were required at enrollment. Efficacy was assessed by overall response rate (ORR) and disease control rate (DCR) based on RECIST 1.0 criteria. All patients received prophylaxis with the oral phosphate binder sevelamer. Hyperphosphatemia was defined as serum phosphorous >5.5 mg/dL, consistent with the threshold for action in the protocol. Results: Of the 67 patients enrolled, 48 (71.6%) had hyperphosphatemia on ≥1 post-baseline lab test. Efficacy findings in patients with vs without hyperphosphatemia were: ORR 33.3% (95% CI 20.4–48.4) vs 5.3% (95% CI 0.1–26.0), mPFS 4.9 months (95% CI 3.65–5.98) vs 1.84 months (95% CI 1.28–3.48), and mOS 8.74 months (95% CI 5.72–13.67) vs 7.62 months (95% CI 2.53–15.57). Median treatment length was 4.1 vs 1.4 months and mDOR was 5.0 vs 3.7 months for patients with vs without hyperphosphatemia, respectively. A landmark analysis at the 1-month mark was performed, and hyperphosphatemia (Y/N) was determined based on lab tests within the first month. The differences in efficacy outcomes were still observed. Conclusions: Hyperphosphatemia is a well-described class effect and pharmacodynamic biomarker of FGFR inhibitors, including infigratinib, and is generally reversible/easily managed with diet and phosphate binders. Our data support prior observations with FGFR inhibitors, suggesting that hyperphosphatemia is associated with treatment response and is not negatively associated with treatment length. Clinical trial information: NCT01004224.

Safety, dose tolerance, pharmacokinetics, and pharmacodynamics of fosciclopirox (CPX-POM) in patients with advanced solid tumors

518

Background: Fosciclopirox (CPX-POM) is being developed for the treatment of non-muscle invasive and muscle invasive bladder cancer. CPX-POM selectively delivers its active metabolite, ciclopirox (CPX), to the entire urinary tract following systemic administration. In a chemical carcinogen mouse model of bladder cancer, CPX-POM treatment resulted in significant decreases in bladder weight, migration to lower stage tumors, inhibition of cell proliferation as well as Notch 1 and Wnt signaling pathways. Methods: Study CPX-POM-001 (NCT03348514) is US multi-site, Phase I, open-label, dose escalation study characterizing the safety, dose tolerance, pharmacokinetics (PK) and pharmacodynamics of IV CPX-POM in advanced solid tumor patients. The PK of CPX-POM, CPX and ciclopirox glucuronide (CPX-G), were characterized in plasma and urine. Circulating biomarkers of Wnt and Notch, IL-6, IL-8 and VEGF were determined. Results: Nineteen patients were enrolled in the study. The starting dose of 30 mg/m2 was administered once daily on Days 1-5 of each 21-day treatment cycle. Doses were escalated to 1200 mg/m2. The MTD was determined to be 900 mg/m2. Overall, the number of treatment-related AE's tended to increase in frequency with dose, nausea and vomiting being the most common. Grade 3 confusion was observed in the 1200 mg/m2 cohort. Four AE's of Grade 1 confusion at 600 and 900 mg/m2. There was no evidence of QTc prolongation or other ECG abnormality. One patient in the 240 mg/m2 dose cohort, with a diagnosis of indolent primary fallopian tube tumor, achieved a partial response per RECIST 1.1. Metabolism of CPX-POM was rapid and complete. The clearance of CPX was dose proportional and time-independent. At MTD, steady-state 24-hour urine CPX concentrations of 215 µM were achieved. Evidence of Notch and Wnt inhibition was observed. Conclusions: IV CPX-POM was well tolerated with treatment-related AEs primarily CNS-related. At MTD, systemic and urinary CPX exposures exceeding in vitro IC50 values by several-fold. The 900 mg/m2 dose is currently being evaluated in an expansion cohort study in cisplatin-ineligible muscle invasive bladder cancer patients scheduled for cystectomy. Clinical trial information: NCT03348514.

Abstract PD5-11: Association of immune gene expression with outcome in the MARIANNE phase 3 clinical trial in HER2-positive metastatic breast cancer (MBC)

Introduction: Although HER2+ breast cancer (BC) is considered a moderately immunogenic tumor, several studies have shown a role of pre-existing immunity associated with favorable long-term prognosis and better response to treatment. In this study, we performed exploratory analyses to assess whether the efficacy of HER2 targeted treatment in the MARIANNE trial correlated with immune gene expression. Methods: MARIANNE (NCT01120184) is a phase 3 study in patients (pts) with centrally confirmed HER2+ local advanced/metastatic BC naïve to prior treatments in the advanced disease. Pts were randomized (1:1:1) to trastuzumab+taxane (HT), T-DM1, or T-DM1+Petuzumab (P) and the trial showed noninferior PFS of T-DM1 and T-DM1+P vs HT. Gene expression (RNA) analysis was performed on tumor samples by a custom 800-gene codeset on the nCounter platform. PD-L1, CD8 expressions and immune gene signatures (sign) analyses were assessed by multivariate Cox regression models using median (cut-off) as categorical variable and adjusted by prior HT, presence of visceral disease, world region, baseline ECOG, measureable disease at baseline, therapy setting, HER2 mRNA expression, PIK3CA mutation status. Results: MARIANNE randomized 1095 pts (HT, n=365; T-DM1, n=367; T-DM1+P, n=363). Gene expression results were available for 671 pts (61.3% of the intent-to-treat [ITT] population) which was representative of ITT. In ITT, HR below 1 was observed when comparing pts with high (&gt;median) vs low (≤median) immune gene expression by clinical outcome suggesting a potential association of high immune marker expression with improved PFS (Table 1) and to some extent with OS (data not shown). This association was primarily observed in the T-DM1 arm where the HR suggested a risk reduction of disease progression(PD)/death especially in the high Teff, high PD-L1 and high CD8 subgroups, and to some extent in the HT arm (Table 1). When assessing the predictive impact on PFS by comparing T-DM1 vs HT, HR below 1 was observed especially in pts with high Teff signature, high PD-L1 and high CD8 expressions (HR 0.67 (95% CI (0.47-0.95)), HR 0.68 (95% CI (0.48-0.97), and HR 0.64 (95%CI 0.44-0.93), respectively). When comparing T-DM1+P vs. HT, HR below 1 was observed especially in pts with low Teff signature and low PD-L1 expression (HR 0.70 (95% CI (0.50-0.99), and HR 0.68 (95% CI (0.48-0.96) respectively). No clear differences between immune gene expression subgroups was observed when comparing treatment arms in regards to OS (data not shown). Conclusions: In the exploratory analysis from the MARIANNE study, high immune gene expression, especially in the high PD-L1, CD8 and Teff subgroups, showed an association with improved clinical benefit with HRs reflecting for a risk reduction of PD/death for PFS and partially for OS. This association was less obvious in the T-DM1+P arm. When comparing the treatments effect, the data showed a potential impact of high Teff signature, and high CD8 and PD-L1 expressions on T-DM1 and less on HT. The potential opposite association of low Teff signature and low PD-L1 expression with improved benefit in the T-DM1+P arm was unexpected and needs further investigation.

Table 1: Prognostic biomarker effect on PFSBiomarker by categories (&gt;Median vs ≤Median)HR (95% CI) ITT n=671HR (95% CI) HT n=220HR (95% CI) T-DM1 n=227HR (95% CI) T-DM1+P n=224Teff sign0.89 (0.73-1.09)0.97 (0.68-1.38)0.64 (0.45-0.91)1.09 (0.75-1.58)Th1 cytokine sign0.91 (0.74-1.11)0.92 (0.64-1.31)0.78 (0.55-1.11)0.96 (0.67-1.36)Checkpoint inhibitor sign0.95 (0.78-1.15)0.91 (0.64-1.29)0.90 (0.64-1.26)1.02 (0.71-1.47)PD-L10.80 (0.66-0.98)0.79 (0.55-1.13)0.62 (0.44-0.87)1.07 (0.74-1.55)CD80.91 (0.75-1.11)1.10 (0.77-1.57)0.66 (0.46-0.93)0.98 (0.68-1.41)

Citation Format: Edith A Perez, Sanne Lysbet de Haas, Carlos H Barrios, Wolfgang Eiermann, Masakazu Toi, Young-Hyuck Im, Pier Franco Conte, Miguel Martin, Tadeusz Pienkowski, Xavier B Pivot, Howard A Burris III, Chiara Lambertini, Silke Hoersch, Monika Patre, Paul Anthony Ellis. Association of immune gene expression with outcome in the MARIANNE phase 3 clinical trial in HER2-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD5-11.

Association of an RNA signature (RS) with emergence of ICOS hi CD4 T cells and efficacy outcomes for the ICOS agonist vopratelimab (vopra) and nivolumab (nivo) in patients (pts) on the ICONIC trial

14

Background: ICOS is a costimulatory molecule upregulated on activated T cells. Vopra is an investigational ICOS agonist antibody that results in activation and proliferation of primed CD4 T effector cells. Vopra was assessed in heavily pretreated patients with advanced solid tumors as monotherapy (mono) or in combination with nivolumab (nivo) in the Phase 1/2 ICONIC trial (NCT02904226). Emergence of a distinct ICOS high (hi) population of peripheral CD4 T effector cells, not seen with PD-1 inhibitors alone, was associated with improved ORR, PFS and OS with vopra mono and combo therapy (AACR 2019). Baseline tumor and blood biomarkers were assessed for ability to predict ICOS hi CD4 T cell emergence and clinical outcomes. Methods: Fresh pre-treatment tumor biopsies were assessed by RS, a gene signature describing immune cell infiltration, and other biomarkers, including PD-L1 TPS by IHC. Pts were classified as RS1 and RS2 based on medium and high cutoffs. Associations between potential predictive biomarkers, ICOS hi CD4 T cell emergence and clinical outcomes were evaluated. Results: Baseline RS is significantly higher in patients with emergence of ICOS hi CD4 T cells. High RS was associated with increased emergence of ICOS hi CD4 T cells, accompanied by improved RECIST response, PFS, and OS. In contrast, no association was noted with PD-L1 IHC. Clinical trial information: NCT02904226. Conclusions: In this retrospective subset analysis, the RS score, but not PD-L1, in baseline tumor biopsies was predictive of emergence of an ICOS hi CD4 T cell population and improved RECIST response, PFS, and OS in patients treated with vopra alone and in combination with nivo. Clinical evaluation of vopra and investigational PD-1 inhibitor JTX-4014 in cancer patients with RS selection is planned. [Table: see text]

Abstract PR03: A phase 1 trial of AG-270 in patients with advanced solid tumors or lymphoma with homozygous MTAP deletion

Background: Homozygous deletion of MTAP, the gene encoding the metabolic enzyme methylthioadenosine phosphorylase, occurs in ~15% of human malignancies. Tumor cells with this deletion are selectively vulnerable to decreases in the methyl donor S-adenosylmethionine (SAM). AG-270 is a first-in-class, oral, potent, reversible inhibitor of methionine adenosyltransferase 2A (MAT2A), the key enzyme responsible for SAM synthesis. We report preliminary results from an ongoing, first-in-human, phase 1 trial of AG-270 (ClinicalTrials.gov Identifier: NCT03435250). Aims: The primary objective of this study is to determine the maximum tolerated dose (MTD) of AG-270. Secondary objectives include safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and efficacy. Methods: Eligibility requires homozygous deletion of cyclin dependent kinase inhibitor 2A (CDKN2A) in the patient’s tumor (as MTAP is usually co-deleted with CDKN2A), or loss of MTAP by IHC. Patients receive AG-270 daily in 28-day cycles, with intensive PK/PD sampling after the first dose and after 2 weeks of treatment. Paired tumor biopsies are collected at baseline and at the end of cycle 1. Disease evaluation is performed every 2 cycles. Results: As of 20 May 2019, 39 patients had been treated with AG-270: 50 mg once daily (QD; n=3), 100 mg QD (n=7), 150 mg QD (n=6), 200 mg QD (n=11), 400 mg QD (n=6), or 200 mg twice daily (BID; n=6). AG-270 was well absorbed. Plasma concentrations increased in a dose-proportional manner except at 400 mg QD, where exposure was lower than anticipated. The geometric mean area under the curve from 0-24 h at steady state (AUC0-24,ss) in the QD cohorts ranged from 33200 to 199085 ng*h/mL, and the geometric mean AUC0-24,ss in the 200 mg BID cohort was 254616 ng*h/mL. The median half-life of AG-270 ranged from 16.1 to 38.4 h. Decreases in plasma [SAM] were exposure-dependent. After 2 weeks of dosing, maximal reductions in plasma [SAM] ranged from 51% to 71% across the tested cohorts. Analysis of 9 paired tumor biopsies by IHC showed decreases in levels of symmetrically di-methylated arginine (SDMA) residues, consistent with MAT2A inhibition; the average H-score reduction compared to baseline was 36.4% [-98.8%, +21.4%]. Asymptomatic, exposure-dependent increases in unconjugated bilirubin were observed starting at 100 mg QD, consistent with the known potential of AG-270 to inhibit UGT1A1. Three patients (at 100 mg QD, 150 mg QD, and 200 mg BID) developed grade 2 and 3 diffuse erythematous rashes during the second week of dosing that resolved within 1 week of stopping treatment. Exposure-dependent, reversible decreases in platelet counts were first observed at 200 mg QD and were grade 3 and 4 in severity at 200 mg BID. Two patients treated at 200 mg BID developed reversible but dose-limiting grade 3 and 4 increases in liver enzymes. The MTD of AG-270 is 200 mg QD. An unconfirmed partial response has been observed in a patient with a high-grade neuroendocrine carcinoma of the lung. Seven patients have achieved radiographically confirmed stable disease of 2.0 to 9.9 months’ duration. Conclusions: AG-270 causes reductions in plasma [SAM] and in tumor SDMA levels at well-tolerated doses. This trial will next evaluate the combination of AG-270 with taxane-based chemotherapy, given preclinical data demonstrating enhanced antitumor activity with AG-270 and taxanes in MTAP-deleted cancer models.

Citation Format: Rebecca S Heist, Mrinal M Gounder, Sophie Postel-Vinay, Frederick Wilson, Elena Garralda, Khanh Do, Geoffrey I Shapiro, Patricia Martin-Romano, Gerburg Wulf, Michael Cooper, Caroline Almon, Salah Nabhan, Varsha Iyer, Yanwei Zhang, Kevin Marks, Elia Aguado-Fraile, Frank Basile, Keith Flaherty, Howard A Burris. A phase 1 trial of AG-270 in patients with advanced solid tumors or lymphoma with homozygous MTAP deletion [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr PR03. doi:10.1158/1535-7163.TARG-19-PR03

Patient Navigation in Cancer: The Business Case to Support Clinical Needs

PURPOSE

Patient navigation (PN) is an increasingly recognized element of high-quality, patient-centered cancer care, yet PN in many cancer programs is absent or limited, often because of concerns of extra cost without tangible financial benefits.

METHODS

Five real-world examples of PN programs are used to demonstrate that in the pure fee-for-service and the alternative payment model worlds of reimbursement, strong cases can be made to support the benefits of PN.

RESULTS

In three large programs, PN resulted in increased patient retention and increased physician loyalty within the cancer programs, leading to increased revenue. In addition, in two programs, PN was associated with a reduction in unnecessary resource utilization, such as emergency department visits and hospitalizations. PN also reduces burdens on oncology providers, potentially reducing burnout, errors, and costly staff turnover.

CONCLUSION

PN has resulted in improved patient outcomes and patient satisfaction and has important financial benefits for cancer programs in the fee-for-service and the alternative payment model worlds, lending support for more robust staffing of PN programs.

Atezolizumab (MPDL3280A) Monotherapy for Patients With Metastatic Urothelial Cancer: Long-term Outcomes From a Phase 1 Study

Importance

Atezolizumab (anti-programmed death ligand 1) has demonstrated safety and activity in advanced and metastatic urothelial carcinoma, but its long-term clinical profile remains unknown.

Objective

To report long-term clinical outcomes with atezolizumab therapy for patients with metastatic urothelial carcinoma.

Design, Setting, and Participants

Patients were enrolled in an expansion cohort of an ongoing, open-label, phase 1 study. Median follow-up was 37.8 months (range, >0.7 to 44.4 months). Enrollment occurred between March 2013 and August 2015 at US and European academic medical centers. Eligible patients had measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1, Eastern Cooperative Oncology Group performance status 0 to 1, and a representative tumor sample. Programmed death ligand 1 expression on immune cells was assessed (VENTANA SP142 assay).

Interventions

Atezolizumab was given intravenously every 3 weeks until unacceptable toxic effects, protocol nonadherence, or loss of clinical benefit.

Main Outcomes and Measures

Primary outcome was safety. Secondary outcomes included objective response rate, duration of response, and progression-free survival. Response and overall survival were assessed in key baseline subgroups.

Results

Ninety-five patients were evaluable (72 [76%] male; median age, 66 years [range, 36-89 years]). Forty-five (47%) received atezolizumab as third-line therapy or greater. Nine patients (9%) had a grade 3 to 4 treatment-related adverse event, mostly within the first treatment year; no serious related adverse events were observed thereafter. One patient (1%) discontinued treatment due to a related event. No treatment-related deaths occurred. Responses occurred in 26% (95% CI, 18%-36%) of patients. Median duration of response was 22.1 months (range, 2.8 to >41.0 months), and median progression-free survival was 2.7 months (95% CI, 1.4-4.3 months). Median overall survival was 10.1 months (95% CI, 7.3-17.0 months); 3-year OS rate was 27% (95% CI, 17%-36%). Response occurred in 40% (95% CI, 26%-55%; n = 40) and 11% (95% CI, 4%-25%; n = 44) of patients with programmed death ligand 1 expression of at least 5% tumor-infiltrating immune cells (IC2/3) or less than 5% (IC0/1), respectively. Median overall survival in patients with IC2/3 and IC0/1 was 14.6 months (95% CI, 9.0 months to not estimable) and 7.6 months (95% CI, 4.7 to 13.9 months), respectively.

Conclusions and Relevance

Atezolizumab remained well tolerated and provided durable clinical benefit to a heavily pretreated metastatic urothelial carcinoma population in this long-term study.

Trial Registration

clinicaltrials.gov Identifier: NCT01375842.

A Randomized, Double-Blinded, Phase II Trial of Carboplatin and Pemetrexed with or without Apatorsen (OGX-427) in Patients with Previously Untreated Stage IV Non-Squamous-Non-Small-Cell Lung Cancer: The SPRUCE Trial

BACKGROUND

This randomized, double-blinded, phase II trial evaluated the efficacy of carboplatin and pemetrexed plus either apatorsen, an antisense oligonucleotide targeting heat shock protein (Hsp) 27 mRNA, or placebo in patients with previously untreated metastatic nonsquamous non-small cell lung cancer (NSCLC).

METHODS

Patients were randomized 1:1 to Arm A (carboplatin/pemetrexed plus apatorsen) or Arm B (carboplatin/pemetrexed plus placebo). Treatment was administered in 21-day cycles, with restaging every two cycles, until progression or intolerable toxicity. Serum Hsp27 levels were analyzed at baseline and during treatment. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), objective response rate, and toxicity.

RESULTS

The trial enrolled 155 patients (median age 66 years; 44% Eastern Cooperative Oncology Group performance status 0). Toxicities were similar in the 2 treatment arms; cytopenias, nausea, vomiting, and fatigue were the most frequent treatment-related adverse events. Median PFS and OS were 6.0 and 10.8 months, respectively, for Arm A, and 4.9 and 11.8 months for Arm B (differences not statistically significant). Overall response rates were 27% for Arm A and 32% for Arm B. Sixteen patients (12%) had high serum levels of Hsp27 at baseline. In this small group, patients who received apatorsen had median PFS of 10.8 months, and those who received placebo had median PFS 4.8 months.

CONCLUSION

The addition of apatorsen to carboplatin and pemetrexed was well tolerated but did not improve outcomes in patients with metastatic nonsquamous NSCLC cancer in the first-line setting.

IMPLICATIONS FOR PRACTICE

This randomized, double-blinded, phase II trial evaluated the efficacy of carboplatin and pemetrexed plus either apatorsen, an antisense oligonucleotide targeting heat shock protein 27 mRNA, or placebo in patients with previously untreated metastatic nonsquamous non-small cell lung cancer (NSCLC). The addition of apatorsen to carboplatin and pemetrexed was well tolerated but did not improve outcomes in patients with metastatic nonsquamous NSCLC cancer in the first-line setting.

WITHDRAWN: Cardio-Oncology: Stronger Together

This article has been removed from JACC where it was posted in error. It is an article for JACC: CardioOncology (10.1016/j.jaccao.2019.08.001) and will be included in the first issue. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Abstract CT189: Improved progression-free and overall survival (PFS/OS) in patients (pts) with emergence of JTX-2011 associated biomarker (ICOS high CD4 T cells) on the ICONIC trial

Background: ICOS is a costimulatory molecule upregulated on activated T cells. JTX-2011 is an ICOS agonist antibody intended to stimulate primed CD4 T effector cells. JTX-2011 was assessed in pts with advanced solid tumors as monotherapy (mono) and combination (combo) with nivolumab (nivo) in the Phase I/II ICONIC trial (NCT02904226). Peripheral T cell phenotyping in ICONIC demonstrated emergence of an ICOS high (hi) subset of CD4 T cells associated with tumor reductions in mono and combo pts. In ex vivo studies, soluble JTX-2011 stimulated a polyfunctional cytokine response only in ICOS hi cells.

Methods: Ad hoc flow cytometry phenotyping on PBMCs from a subset of pts with evaluable samples (n=50) was initiated retrospectively in early 2018 in ongoing pts, then prospectively on newly enrolled pts. Clinical characteristics and outcomes were analyzed, including unadjusted p-values for post-hoc statistical analyses. Phenotyping was also done on samples from pts treated with PD-1/L1 inhibitor (PD-1/L1i) mono collected outside of ICONIC.

Results: Emergence of ICOS hi CD4 T effector cells (all FoxP3-, subset Tbet+ Ki67+) was observed in all pts with ≥30% target lesion tumor reduction by investigator assessment on mono and combo therapy (n=7). Emergence was seen in pts with stable target lesions (n=11/23) including loss of these cells with disease progression. ICOS hi cells were not seen in ICONIC pts with target lesion increase ≥20% (n=14), or in pts treated with PD-1/L1i mono, including responders. Emergence of ICOS hi CD4 T cells correlated with improved PFS and OS (Table).

ICONIC Pt characteristicsICOS hi (N=18)ICOS low (N=32)≥3 prior therapies, n (%)13 (72.2)18 (56.3)Prior immunotherapy, n (%)6 (33.3)15 (46.9)Tumor type, n (%)Gastric n=9 (50), NSCLC n=3 (16.7), TNBC n=2 (11.1), Other n=4 (22.2)Gastric n=8 (25), NSCLC n=6 (18.8), TNBC n=4 (12.5), Other n=14 (43.8),Mono vs Combo, n (%)Mono n=2 (11.1), Combo n=16 (88.9)Mono n=11 (34.4), Combo n=21 (65.6)G3-4 treatment-related adverse events, n (%)1 (5.6)2 (6.3)Time on JTX-2011, median mths (range), p=0.00065.6 (1.45-18.4)1.41 (0.03-6.28)PFS, investigator and central imaging review, median mths, (investigator, p&lt;0.0001; central p=0.0011)6.22OS, median mths, p=0.0183(not yet reached)9

Conclusion: Emergence of a distinct ICOS hi population of peripheral CD4 T cells is associated with improved PFS and OS with JTX-2011 mono and combo therapy. Two JTX-2011 development paths are planned: (1) combo with agents that induce ICOS hi CD4 T cells; (2) use of potential putative biomarkers predictive of emergence of this T cell population and JTX-2011 response.

Citation Format: Timothy Anthony Yap, Justin F. Gainor, Margaret K. Callahan, Gerald S. Falchook, Russell Kent Pachynski, Patricia LoRusso, Shivaani Kummar, Geoffrey Thomas Gibney, Howard A. Burris, Scott S. Tykodi, Osama E. Rahma, Tanguy Seiwert, Kyriakos P. Papadopoulos, Ellen Hooper, Christopher J. Harvey, Amanda Hanson, Sean Lacey, Rachel McComb, Courtney Hart, Haley Laken, Ty McClure, Elizabeth Trehu. Improved progression-free and overall survival (PFS/OS) in patients (pts) with emergence of JTX-2011 associated biomarker (ICOS high CD4 T cells) on the ICONIC trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT189.

Phase 1 dose escalation study of XMT-1536, a novel NaPi2b-targeting antibody-drug conjugate (ADC), in patients (pts) with solid tumors likely to express NaPi2b

3010

Background: XMT-1536 is a Dolaflexin ADC targeting the sodium-phosphate cotransporter NaPi2b, expressed in ovarian, non-squamous lung, papillary thyroid, endometrial, papillary renal and salivary duct cancers. Methods: In this ongoing Phase 1 study, pts with solid tumors likely to express NaPi2b, who progressed on standard therapy, are treated with intravenous XMT-1536 using a 3+3 design with a modified Fibonacci escalation. NaPi2b expression by IHC is being examined retrospectively in archived tumors. Primary objectives in dose escalation are safety and tolerability and determination of maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D). (ClinicalTrials.gov NCT03319628). Results: As of Jan. 28, 2019, 36 pts (22 ovarian, 7 endometrial, 4 NSCLC, 3 other) have received treatment with XMT-1536. Treatment was initially given every 3 weeks (q3w); 20 pts were treated in dose cohorts from 3 to 40 mg/m2. There was one DLT of reversible AST elevation at 40 mg/m2. The dosing interval was then changed to every 4 weeks (q4w), and dose escalation was restarted at 20 mg/m2. There was one DLT of reversible AST elevation at 30 mg/m2 on the q4w schedule. Further followup and dose escalation are ongoing. The most common (≥10% of patients) treatment-related adverse events (TRAEs) have been nausea, fatigue, headache, increased AST, anorexia, increased alkaline phosphatase, fever, increased GGT, myalgia, and vomiting. Grade 3 TRAEs were reversible AST increases in 3 patients and increased GGT, decreased lymphocytes, and systolic congestive heart failure in 1 patient each. Treatment-related serious AEs of fever and systolic congestive heart failure occurred in 1 patient each. Among patients dosed at 20 mg/m2 or higher who had restaging scans (n=20), there were 2 PR, in ovarian cancer pts at 30 mg/m2 q3w and 20 mg/m2 q4w, and 11 SD, with disease control maintained for up to 24 weeks. Patient-level results for NaPi2b expression will be presented. The systemic exposure of total payload showed approximately dose-proportional increase. Plasma concentration of free drug payload and its active metabolite were low. Conclusions: XMT-1536 has been well-tolerated up to the 30 mg/m2 dose level with early signs of anti-tumor activity. Dose escalation continues in pts with advanced solid tumors likely to express NaPi2b. Clinical trial information: NCT03319628.

XENERA-1: A phase II trial of xentuzumab (Xe) in combination with everolimus (Ev) and exemestane (Ex) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) and non-visceral involvement

TPS1103

Background: The mTOR inhibitor Ev, combined with Ex, is a mainstay in the treatment of post-menopausal women with advanced HR+/HER2- BC. However, the activity of Ev is limited by counter-regulatory feedback mechanisms in cancer cells, involving reactivation of insulin-like growth factor (IGF)/mTOR survival signaling. Combining Ev with the humanized IGF-1 and IGF-2 ligand-blocking antibody Xe abrogates this feedback, thus intensifying inhibition of tumor growth; this leads to a pronounced effect in patients with non-visceral (e.g., bone and lymph node) metastases. The phase II XENERA-1 trial evaluates the combination of Xe with Ev and Ex in post-menopausal women with HR+/HER2- BC. Methods: XENERA-1 (NCT03659136) is a double-blind, placebo-controlled, randomized study to assess the efficacy and safety of Xe in combination with Ev and Ex, in post-menopausal women with HR+/HER2- locally advanced/mBC and non-visceral disease. The population comprises post-menopausal mBC patients who have progressed on ≤1 previous line of a non-steroidal aromatase inhibitor, with or without a CDK 4/6 inhibitor, who may have received fulvestrant. Other inclusion criteria are: an Eastern Cooperative Oncology Group Performance Status of 0 or 1; adequate organ function; and non-visceral disease (absence of brain, liver, lung, peritoneal or pleural metastases). Patients are randomized (1:1) to receive Xe (1000 mg/week, iv) or placebo (weekly, iv), in combination with Ev (10 mg/day) and Ex (25 mg/day). Treatment will continue until disease progression, unacceptable toxicity or other reasons. The primary endpoint is progression-free survival according to RECIST 1.1 criteria, by independent review. Secondary endpoints are: overall survival; disease control; duration of disease control; objective response; and time to progression of pain/intensification of palliation. Safety and pharmacokinetic endpoints, and exploratory biomarkers will also be evaluated. The first patient was enrolled in January 2019; target enrollment is 80 patients in 12 countries. Clinical trial information: NCT03659136.