Open-label, phase II, multicenter study of lasofoxifene plus abemaciclib for treating women with metastatic ER+/HER2- breast cancer and an ESR1 mutation after disease progression on prior therapies: ELAINE 2

BACKGROUND

Acquired ESR1 mutations in estrogen receptor-positive (ER+) metastatic breast cancer (mBC) drive treatment resistance and tumor progression; new treatment strategies are needed. Lasofoxifene, a next-generation, oral, endocrine therapy and tissue-specific ER antagonist, provided preclinical antitumor activity, alone or combined with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) in ESR1-mutated mBC.

PATIENTS AND METHODS

In the open-label, phase II, ELAINE 2 trial (NCT04432454), women with ESR1-mutated, ER+/human epidermal growth factor receptor 2-negative (HER2-) mBC who progressed on prior therapies (including CDK4/6i) received lasofoxifene 5 mg/day and abemaciclib 150 mg b.i.d until disease progression/toxicity. The primary endpoint was safety/tolerability. Secondary endpoints included progression-free survival (PFS), clinical benefit rate (CBR), and objective response rate (ORR).

RESULTS

Twenty-nine women (median age 60 years) participated; all but one were previously treated with a CDK4/6i (median duration 2 years). The lasofoxifene-abemaciclib combination was well tolerated with primarily grade 1/2 treatment-emergent adverse events (TEAEs), most commonly diarrhea, nausea, fatigue, and vomiting. One patient (with no prior CDK4/6i) discontinued treatment due to grade 2 diarrhea. No deaths occurred during the study. Median PFS was 56.0 weeks [95% confidence interval (CI) 31.9 weeks-not estimable; ∼13 months]; PFS rates at 6, 12, and 18 months were 76.1%, 56.1%, and 38.8%, respectively. CBR at 24 weeks was 65.5% (95% CI 47.3% to 80.1%). In 18 patients with measurable lesions, ORR was 55.6% (95% CI 33.7% to 75.4%). ESR1-mutant circulating tumor DNA (ctDNA) allele fraction decreased from baseline to week 4 in 21/26 (80.8%) patients.

CONCLUSIONS

Lasofoxifene plus abemaciclib had an acceptable safety profile, was well tolerated, and exhibited meaningful antitumor activity in women with ESR1-mutated, ER+/HER2- mBC after disease progression on prior CDK4/6i. Observed decreases in ESR1-mutant ctDNA with lasofoxifene concordant with clinical response suggest target engagement. If the ELAINE 2 findings are confirmed in the initiated, phase III, ELAINE 3 trial, these data could be practice-changing and help address a critical unmet need.

Operational Metrics for the ELAINE 2 Study Combining a Traditional Approach With a Just-in-TIME Model

PURPOSE

There are numerous barriers to enrollment in oncology biomarker-driven studies.

METHODS

The ELAINE 2 study (ClinicalTrials.gov identifier: NCT04432454) is an open-label phase 2 study of lasofoxifene combined with abemaciclib in patients with advanced or metastatic estrogen receptor-positive/human epidermal growth factor receptor 2-negative breast cancer with an ESR1 mutation. ELAINE 2 opened clinical sites by using a Traditional approach, which activated a site before patient identification, and the Tempus TIME Trial network, which opened a site only after identifying an eligible patient. This manuscript presents the operational metrics comparing the Traditional and TIME Trial site data.

RESULTS

The study enrolled patients over 34 weeks and 16 sites (six Traditional and 10 TIME Trial) participated. Duration for full clinical trial agreement execution for Traditional sites and TIME Trial sites averaged 200.5 (range, 142-257) and 7.6 days (range, 2-14), respectively. Institutional review board approval time for Traditional sites and TIME Trial sites was 27.5 (range, 12-71) and 3.0 days (range, 1-12), respectively. Duration from study activation to first consent was 33.3 (range, 18-58) and 8.8 days (range, 1-35) for Traditional and TIME Trial sites, respectively. The first patient on study was at a TIME Trial site 115 days before a Traditional site and the first seven patients enrolled were at TIME Trial sites. Traditional sites consented 23 and enrolled 16 patients, while TIME Trial sites consented 16 and enrolled 13. The trial enrolled 29 patients in 8.5 months with the anticipated enrollment duration being 12-18 months.

CONCLUSION

The TIME Trial network opened earlier and enrolled the first study patients. These results demonstrate that the Just-in-TIME model, along with a Traditional model, can improve enrollment in biomarker-driven studies.

Operational metrics for the ELAINE II study combining a traditional approach with a just-in-time model

1504

Background: Trial recruitment that requires specific actionable mutations based on next-generation sequencing (NGS) is challenging. Barriers can include competing studies, physician study awareness, site proximity, mutation incidence, among other concerns. Methods: This study (NCT04432454) opened clinical sites using two methods during the COVID-19 pandemic. The “Traditional” approach included site selection, IRB and contract approval, and trial activation prior to a patient being identified for enrollment. The second approach used the Tempus “TIME” Trials network that would only open a site after identifying a patient with a mutation of interest and eligible for the trial. Results: The first patient enrolled was on 10/12/20 and the last patient was on 6/24/21. A total of 16 sites (6 Traditional and 10 TIME) participated. All Traditional sites, and none of the TIME sites, were affiliated with major academic institutions. Duration for full CTA execution for Traditional sites averaged 200.5 days (range 142 to 257) and for TIME sites averaged 7.6 days (range 2 to 14). IRB approval time average for Traditional sites was 27.5 days (range 12 to 71) and TIME sites was 3.0 days (range 1 to 12 days). Days from site selection to activation letter for Traditional sites was on average 250.0 days (range 187 to 281) and for TIME sites was 131.6 days (range 22 to 248). Time from study activation to first consent was 33.3 days (range 18 to 58) for Traditional sites and 8.8 days (range 1 to 35) for TIME sites. The first patient on-study was at a TIME site 115 days prior to a Traditional site and the first 7 patients enrolled were at TIME sites. Traditional sites consented 23 and enrolled 16 patients while the TIME sites consented 16 and enrolled 13. The trial enrolled all 29 patients in 8 months with the anticipated enrollment duration being 12 to 18 months. Conclusions: Although the Traditional and TIME programs had different operational models, they both contributed a significant number of patients and reduced the projected enrollment timeline. TIME sites enrolled the initial patients. These results demonstrate that the “Just-in-Time model,” in conjunction with a Traditional model, can reduce projected overall time to enrollment in biomarker-driven studies. [Table: see text]

A phase II study (TACTI-002) in first-line metastatic non–small cell lung carcinoma investigating eftilagimod alpha (soluble LAG-3 protein) and pembrolizumab: Updated results from a PD-L1 unselected population

9003

Background: Eftilagimod alpha (E) is a soluble LAG-3 protein binding to a subset of MHC class II molecules to mediate antigen presenting cell (APC)/CD8 T-cell activation. Stimulation of the APCs and subsequent T cell recruitment with E may lead to stronger anti-tumor responses than observed with pembrolizumab (P) alone. We hereby report results of the extended first-line non-small cell lung carcinoma (NSCLC) cohort of the TACTI-002 (“Two ACTive Immunotherapies”) phase II trial. Methods: Pts with untreated metastatic NSCLC, unselected for PD-L1 expression were recruited. Objective response rate (ORR) by iRECIST was the primary endpoint (EP) and secondary EPs include ORR by RECIST 1.1, tolerability, disease control rate (DCR), progression free survival (PFS), overall survival (OS) and exploratory biomarker. Pts received 30 mg E SC q2w for 8 cycles (1 cycle= 3 weeks) and then q3w for up to 1 year with P (200 mg IV q3w for up to 2 years). Imaging was done every 8 weeks. PD-L1 was assessed centrally. This has been approved by relevant CAs, ECs, and IRBs. Results: From Mar 2019 to Nov 2021 114 pts were enrolled. Median age was 67 years (44-85) and 74% were male. ECOG PS was 0 and 1 in 37% and 63% of pts, respectively. Pts presented squamous (35%) or non-squamous (62%) NSCLC with 88% of pts at stage IV at the time of study entry. All PD-L1 subgroups were represented (Table). Pts received median 6.0 (range 1–35) P and 7.0 (1-22) E administrations. 19 (17%) pts discontinued treatment due to adverse events (AEs). The most common (≥15%) AEs were dyspnea (33%), asthenia (30%), decreased appetite (22%), cough (20%), anemia (20%), fatigue (19%), pruritus (18%), constipation (17%) and diarrhea (15%). At data cut-off (Jan 2022), 75 pts with a minimum follow-up of 6 months were evaluated for efficacy. ORR (iRECIST) was 37.3% in the ITT and 41.8%% in the evaluable pts assessed by local read. DCR 73.3% was reported. Response rate for squamous and non-squamous pathology were 33.3 % and 40.3 %, respectively. Results according to RECIST 1.1 were comparable. Responses were observed in all PD-L1 subgroups (Table). 24/28 (86%) responses were already confirmed while median duration of response was not yet reached (5 events). Conclusions: E + P is safe and shows encouraging antitumor activity in first-line metastatic NSCLC patients unselected for PD-L1, warranting further investigation. Clinical trial information: NCT03625323. [Table: see text]

TACTI-003: A randomized phase IIb study of eftilagimod alpha (soluble LAG-3 protein) and pembrolizumab as first-line treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma

TPS6099

Background: Eftilagimod alpha (efti) is a soluble LAG-3 protein targeting a subset of MHC class II molecules that mediate antigen presenting cell (APC) and CD8 T-cell activation. Data from a non-randomized, phase II trial of efti plus pembrolizumab (TACTI-002) showed encouraging antitumor activity and manageable safety when given as second-line treatment of patients with recurrent or metastatic head and neck squamous-cell carcinoma (RM-HNSCC). TACTI-003 (NCT04811027) is a multicenter, open label, randomized phase IIb trial to investigate efti plus pembrolizumab in the first-line setting for RM-HNSCC. Methods: A total of 154 patients (pts) are currently being recruited into two cohorts (A+B). In cohort A, pts with tumors that are CPS≥1 will be randomly assigned 1:1 to receive either efti (30 mg subcutaneously Q2W for initial 6 months, thereafter Q3W) plus pembrolizumab (400 mg intravenously Q6W) for up to two years or pembrolizumab alone. Randomization will be stratified by CPS (1-19 vs. ≥ 20) and ECOG PS (0 vs. 1). Pts with tumors that are CPS < 1 will receive efti plus pembrolizumab (cohort B). Imaging will be performed every 9 weeks. The primary endpoint (EP) is objective response rate (ORR) by RECIST1.1. Secondary EPs include overall survival, ORR according to iRECIST, time to and duration of response, disease control rate, progression-free survival, occurrence of anti-efti -specific antibodies, safety, and quality of life. Exploratory endpoints comprise biomarkers. The study has been approved by relevant competent authorities, ethic committees and IRBs. Clinical trial information: NCT04811027.

A phase 1b, open-label, single-arm study of cofetuzumab pelidotin (a PTK7-targeting antibody-drug conjugate) in patients with PTK7-expressing, recurrent non-small cell lung cancer (NSCLC)

TPS3142

Background: Protein tyrosine kinase 7 (PTK7) is a highly conserved receptor tyrosine kinase involved in the Wnt signaling pathway and is overexpressed in multiple cancer types, including non-small cell lung cancer (NSCLC). Cofetuzumab pelidotin (ABBV-647) is an anti-PTK7 antibody-drug conjugate comprising the hu6MO24 monoclonal antibody, a cleavable cysteine-reactive linker, and Aur0101 (an auristatin microtubule inhibitor). It has shown promising preclinical anti-tumor effects (Damelin et al. Sci Transl Med 2017;9[372]:eaag2611) and clinical activity with a manageable safety profile in a Phase 1 study in patients with advanced solid tumors, with promising anti-tumor activity noted in NSCLC (Sachdev et al. DOI: 10.1200/JCO.2018.36.15_suppl.5565). Methods: This open-label, single-arm, multicenter Phase 1b study (NCT04189614) will assess the anti-tumor activity and safety of cofetuzumab pelidotin in approximately 40 patients with PTK7-expressing, recurrent NSCLC. The primary objective is to assess the objective response rate of cofetuzumab pelidotin according to Response Evaluation Criteria in Solid Tumors version 1.1. Secondary objectives include the duration of response, progression-free survival, overall survival, and safety and tolerability. Pharmacokinetic and biomarker samples will also be collected throughout for analysis. Patients must be aged ≥18 years with an Eastern Cooperative Oncology Group performance status of 0–1 and have recurrent histologically confirmed NSCLC with PTK7-expressing tumor (using a validated immunohistochemistry assay). Patients must have progressed after treatment with a platinum-based chemotherapy doublet and an immune checkpoint inhibitor (for tumors without targetable genetic alterations), or a platinum-based chemotherapy doublet and targeted agent(s) (for tumors with targetable genetic alterations). Patients must also have received ≤2 prior lines of systemic therapy (≤3 prior lines for tumors treated with targeted agent[s] for genetic alterations), including no more than 1 line of systemic chemotherapy. Cofetuzumab pelidotin (2.8 mg/kg) is administered intravenously every 3 weeks until the patient experiences disease progression, intolerable toxicity, or other study treatment discontinuation criteria are met. The study commenced on February 13, 2020 and enrollment is ongoing. Clinical trial information: NCT04189614.

Leveraging machine learning technology to efficiently identify and match patients for precision oncology clinical trials

e13588

Background: Pre-screening for clinical trials is becoming more challenging as inclusion/exclusion criteria becomes increasingly complex. Oncology precision medicine provides an exciting opportunity to simplify this process and quickly match patients with trials by leveraging machine learning technology. The Tempus TIME Trial site network matches patients to relevant, open, and recruiting clinical trials, personalized to each patient’s clinical and molecular biology. Methods: Tempus screens patients at sites within the TIME Trial Network to find high-fidelity matches to clinical trials. The patient records include documentation submitted alongside NGS orders as well as electronic medical records (EMR) ingested through EMR Integrations. While Tempus-sequenced patients were automatically matched to trials using a Tempus-built matching application, EMR records were run through a natural language processing (NLP) data abstraction model to identify patients with an actionable gene of interest. Structured data were analyzed to filter to patients that lack a deceased date and have an encounter date within a predefined time period. Tempus abstractors manually validated the resulting unstructured records to ensure each patient was matched to a TIME Trial at a site capable of running the trial. For all high-level patient matches, a Tempus Clinical Navigator manually evaluated other clinical criteria to confirm trial matches and communicated with the site about trial options. Results: Patient matching was accelerated by implementing NLP gene and report detection (which isolated 17% of records) and manual screening. As a result, Tempus facilitated screening of over 190,000 patients efficiently using proprietary NLP technology to match 332 patients to 21 unique interventional clinical trials since program launch. Tempus continues to optimize its NLP models to increase high-fidelity trial matching at scale. Conclusions: The TIME Trial Network is an evolving, dynamic program that efficiently matches patients with clinical trial sites using both EMR and Tempus sequencing data. Here, we show how machine learning technology can be utilized to efficiently identify and recruit patients to clinical trials, thereby personalizing trial enrollment for each patient.[Table: see text]

Ph I/II study of oral selective AXL inhibitor bemcentinib (BGB324) in combination with erlotinib in patients with advanced EGFRm NSCLC: End of trial update

9110

Background: AXL, a receptor tyrosine kinase, is over-expressed in many cancers, and has been identified as a marker of poor prognosis in NSCLC. AXL overexpression is implicated in development of resistance to EGFR inhibitors including erlotinib (Erl) and osimertinib. AXL inhibition by bemcentinib (Bem), a first-in-class, oral, selective and potent AXL kinase inhibitor, abrogates resistance to EGFR inhibitors in vivo. Bem is currently under evaluation as a monotherapy and in combination with EGFRi, CPIs and chemotherapy across several PhII trials. Methods: Phase I of this study was designed to confirm safety/tolerability of Bem in NSCLC pts as monotherapy and in combination with Erl in pts previously progressing on Erl (arm A). In Phase II, pts who had progressed on an approved EGFRi (arm B) or who were responding/stable on Erl in the 1L setting (arm C) were treated with Bem 200mg and Erl 150mg od to evaluate the safety and activity of the combination, assessing reversal or prevention of resistance to EGFR inhibition in these 2 groups, respectively. Plasma protein biomarker levels were sequentially measured using the DiscoveryMap v3.3 panel (Myriad RBM). Results: As of 7 Oct 2020, all arms have completed recruitment. Median exposure to Bem was 63d (mean: 200d, range: 2d-1175d). Treatment was generally well-tolerated. Common TRAEs (>20% pts) were diarrhea (70%; G3 20%), nausea (50%; G3 0%), QTc prolongation (35%; G3 3%), vomiting (35%; G3 0%), and fatigue (25%; G3 5%). 1 unrelated G4, 0 G5 reported. In the run-in arm (5 female, median age 61 yrs [57-76]), 2/8 pts achieved SD for ̃1 yr, including 19% tumor shrinkage in 1 pt. In arm A (5 female, median age 58 yrs [38-67]), 1/8 pts (68 F) achieved tumor shrinkage of 38%, with treatment duration of 2 yrs until progression. A further 5 pts reported SD. In arm B, 11 pts (7 female, median age 63 yrs [49-78]) had received a median of 1 (0 - 4) prior lines of chemotherapy and a median of 2 prior lines of EGFRi. One achieved a PR (51M) and one a SD (62F) on the combination (CBR of 18%); durations on treatment were 1 yr, and 6 mos, respectively. Neither had EGFR T790M. mPFS was 1.4 mos. In arm C, 13 pts (10 female, median age 66 yrs [32-80]) were enrolled. 11/13 pts were evaluable for efficacy. 1 PR (58M) was reported with 47% tumor shrinkage, duration of treatment was 315d. 9 other pts achieved SD (CBR of 91%), including 4 (3 F/1 M, age range 64-71yrs) who continued on trial for 772+ to 1008+ d. mPFS is currently 12.2 mos. Protein biomarkers predictive of pt benefit upon Bem treatment are being explored. Conclusions: Bem with Erl combination is feasible and tolerable in NSCLC pts, with benefit was seen in a subset of pts who either progressed on an EGFRi or were receiving Erl concurrently in remission in the first line. Further studies of Bem + EGFRi are warranted to explore the potential benefits of this combination. Clinical trial information: NCT02424617.

Optimizing chair time in infusion centers using intravenous cetirizine premedication for the prevention of hypersensitivity infusion reactions

e13508

Background: Oncology infusion centers are increasingly focused on improving operational efficiencies and patient satisfaction, while maintaining quality care. One key component is optimizing chair time, which has been especially important for patient safety during the COVID-19 pandemic to reduce risk of transmission. Many infusions require antihistamine premedication to reduce the risk of hypersensitivity infusion reactions (IRs). The two IV options are IV diphenhydramine and IV cetirizine, which have a quicker onset than oral options and can be administered IV push. In treating acute urticaria, IV cetirizine was shown to be comparable to IV diphenhydramine, with fewer side effects, and it may be effective for preventing IRs with improved chair time. Methods: A randomized, double-blind phase 2 study evaluating premedication with single dose IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 34 patients receiving paclitaxel, rituximab, its biosimilar or obinutuzumab (first cycle, retreatment after 6 months or with persistent IRs). The primary objective was the incidence of IRs after premedication. Secondary endpoints included sedation due to antihistamines and time to readiness for discharge. Sedation was reported by patients on a scale of 0-4 (0 = none to 4 = extremely severe). No formal statistical analyses were planned given the exploratory nature of the study. Results: Adults primarily with cancer (n = 31 [91%]) were enrolled during the COVID-19 pandemic, from March 25 to November 23, 2020. The median age was 65 and 67 years in the IV cetirizine and diphenhydramine groups, respectively. The number of patients with IRs was 2/17 (11.8%) with IV cetirizine versus 3/17 (17.6%) with IV diphenhydramine. The mean sedation score in the IV cetirizine group compared to the IV diphenhydramine group was lower at all time points, including at discharge (0.1 vs 0.4, respectively). Mean time to discharge was 24 minutes less with IV cetirizine (4.3 hours [1.5]) versus IV diphenhydramine (4.7 hours [1.2]). This difference was greater (30 minutes less) in those ≥65 years of age (4.4 [1.3] vs 4.9 [1.0] hours). Regardless of whether patients received paclitaxel (n = 9) or an anti-CD20 (n = 25), patients had less chair time when premedicated with IV cetirizine. There were fewer treatment-related adverse events (AEs) with IV cetirizine (2 events) than with IV diphenhydramine (4 events). Conclusions: This was the first randomized, controlled trial evaluating IV antihistamine premedication for IRs and chair time. It was shown that IV cetirizine can prevent IRs, with less sedation, fewer related AEs and reduced chair time compared to IV diphenhydramine. This improves infusion center operations and patient experience. Clinical trial information: NCT04189588.

Results from a phase II study of eftilagimod alpha (soluble LAG-3 protein) and pembrolizumab in patients with PD-L1 unselected metastatic non-small cell lung carcinoma

9046

Background: Eftilagimod alpha (efti) is a soluble LAG-3 protein that binds to a subset of MHC class II molecules to mediate antigen presenting cell (APC) activation and CD8 T-cell activation. The stimulation of the dendritic cell network and subsequent T cell recruitment with efti may lead to stronger anti-tumor responses in combination than observed with pembrolizumab alone. We hereby report results of the 1st line non-small cell lung carcinoma (NSCLC) part of the phase II trial (NCT03625323). Methods: Patients (pts) with untreated, immunotherapy naïve, advanced NSCLC unselected for PD-L1 expression were recruited into part A. The study used a Simon's 2-stage design (17 pts planned for stage 1 and 19 pts for stage 2), with objective response rate (ORR) by iRECIST as the primary endpoint (EP). Secondary EPs include tolerability, disease control rate (DCR), progression free survival (PFS), overall survival (OS), PK, PD and immunogenicity. Efti is administered as 30 mg subcutaneous injection every 2 wks for 8 cycles and then every 3 wks for 9 cycles with pembrolizumab (200 mg intravenous infusion every 3 wks for up to 2 yrs). Imaging was performed every 8 weeks locally and with blinded independent central review (BICR) retrospectively. The study was approved by ethic committees and institutional review boards. Results: In total 36 pts were enrolled. At data cut-off (Jan 2021; median FU of 14 months), the median age was 69 yrs (range 53-84) and 69 % were male. The ECOG PS 0 and 1 was 42% and 58% respectively. Patients had squamous (42%) and non-squamous (58%) NSCLC and 95% presented with metastatic disease. All PD-L1 subgroups (TPS < 1 %, ≥ 1 % to ≤49 %; ≥50 %) were represented with 36% pts having ≥50% TPS. Pts received a median of 7.0 (range 1 – 31) pembrolizumab and 11.5 (range 1-22) efti administrations. Responses as per BICR and local read are shown in the table. ORR (local, iRECIST) by different PD-L1 subgroups was 27% for pts with TPS<1%, 39 % for TPS ≥1 %and 54% for ≥50 % TPS. Median PFS (n=36) was 8.2 months while median OS was not yet reached. The most common (> 20 %) treatment emergent adverse events (AEs) were asthenia (47 %), cough (36 %), decreased appetite (36 %), dyspnea (32 %), pruritus (31 %), fatigue (28 %), diarrhea (25 %), anemia (25 %), constipation (25 %) and back pain (22%). Two patients discontinued treatment due to adverse reactions (Grade 4 immune-mediated hepatitis, Grade 3 AST+ALT increase). Conclusions: Efti in combination with pembrolizumab is safe and shows encouraging antitumor activity in 1st line advanced NSCLC patients across all PD-L1 (TPS) levels. Clinical trial information: NCT03625323. [Table: see text]

A phase II, open-label study of tomivosertib (eFT508) added on to continued checkpoint inhibitor therapy in patients (pts) with insufficient response to single-agent treatment

3112

Background: Despite the broad activity of checkpoint inhibitors across tumor types, primary or secondary resistance after initial response represents a major challenge. Tomivosertib (T), a potent and highly selective inhibitor of the immunosuppressive kinases MNK-1 and 2, blocks expression of checkpoint proteins PD-1, PD-L1, and LAG-3 as well as immunosuppressive cytokines IL-6 and IL-8. In preclinical models, T was shown to trigger an anti-tumor immune response and enhance the activity of checkpoint inhibitors in a T-cell dependent manner. In prior clinical studies, T had an acceptable safety profile as a single agent and in combination with anti-PD-L1 agent avelumab. Methods: Patients experiencing insufficient response (progression or stable disease for 12 weeks or more) to any FDA-approved checkpoint inhibitor in any approved indication were eligible. T at 200 mg oral (PO) BID was added to the existing checkpoint inhibitor until disease progression or unacceptable toxicity was noted. Results: 39 pts (23 male, 16 female) were enrolled across seven cancer types. Median age was 68 (range 42-85). Median prior therapies were 2 (range 1-6). The most common cancers were lung (N = 17), urothelial (N = 6), renal (N = 5) and head and neck (N = 5). 36 pts continued on anti PD-1 antibody (Pembrolizumab and Nivolumab, 18 each) and 3 on anti PD-L-1 antibody (Durvalumab 2, Atezolizumab 1) . The most common grade 3/4 treatment related adverse events occurring in more than 1 pt were alanine aminotransferase increase (2), blood creatine phosphokinase increase (2) and maculo-papular rash (2). 7 patients discontinued treatment (18%) due to adverse events attributable to either drug. Three partial responses (PR) per RECIST 1.1 were observed in pts with previous progression on checkpoint inhibitor therapy, one each in NSCLC (1/17), gastric (1/1) and renal cancer (1/5). 7 NSCLC pts (41%) were progression free for ≥ 24 weeks. All NSCLC patients entered the study with progression by RECIST 1.1 on single agent checkpoint inhibitor prior to adding T. Conclusions: The addition of T to existing checkpoint therapy was well tolerated and manifested clinical activity including objective responses in pts with progression on existing checkpoint inhibitor. A Progression Free Survival rate at 24 weeks of 41% was noted in NSCLC patients. Additional studies evaluating the addition of T to checkpoint inhibitor therapy after progression on anti PD-1 or PD-L-1 therapy are planned. Clinical trial information: NCT03616834 .

Initial results from a phase II study (TACTI-002) in metastatic non-small cell lung or head and neck carcinoma patients receiving eftilagimod alpha (soluble LAG-3 protein) and pembrolizumab

3100

Background: Eftilagimod alpha (efti) is a soluble LAG-3 protein that binds to a subset of MHC class II molecules to mediate antigen presenting cell (APC) activation and then CD8 T-cell activation. The stimulation of the dendritic cell network and subsequent T cell recruitment with efti may lead to stronger anti-tumor responses than observed with pembrolizumab alone. We hereby report initial results of a phase II trial (NCT03625323). Methods: A predefined number of patients (pts) are recruited into this 3-cohort trial irrespective of PD-L1 expression; part A: 1st line, PD-X naïve NSCLC; part B: 2nd line, PD-X refractory NSCLC and part C: 2nd line PD-X naive HNSCC. The study has a Simon's 2-stage design, with objective response rate (ORR) as primary endpoint. Secondary endpoints include disease control rate, progression free and overall survival, PK, PD and immunogenicity. Additional pts (N2) will be recruited for each part if pre-specified thresholds for ORR are met. Up to 109 pts will be enrolled. Efti is administered as 30 mg subcutaneous injection every 2 wks for 8 cycles and then every 3 wks for 9 cycles with pembrolizumab (200 mg intravenous infusion every 3 wks for up to 2 yrs). The study was approved by ethic committees and institutional review boards. Results: Between 04 Mar 19 and 31 Jan 2020, 48 pts were enrolled and evaluated for safety and exposure. The median age was 66 yrs (range 48-84) and 73 % were male. The ECOG was 0 in 50 % and 1 in 50 % of pts, respectively. Pts received a median of 5 (7) and in total 311 (413) pembrolizumab (efti) administrations, respectively. Three pts (6.3 %) discontinued study treatment due to AEs. The most common ( > 10%) adverse events (AEs) being cough (31 %), asthenia (23 %), decreased appetite (19 %), fatigue (19 %), dyspnea (17 %), diarrhea (15 %) and constipation 13 %). From part A all pts (n = 17) were evaluated. Eight pts (47 %) had a partial response (iPR) and six (35 %) had stable disease according to iRECIST representing an ORR (DCR) of 47 % (82 %). irPRs were observed in all different PD-L1 groups ( < 1%; ≥ 1 % ≤49 %; ≥ 50 %). Ten (10; 59 %) pts are still on therapy (8+ months). In part C stage 1 15/18 pts are evaluable and six (40 %) had an iPR to date. Conclusions: Efti in combination with pembrolizumab is safe and shows encouraging antitumor activity in all comer PD-L1 1st line NSCLC and 2nd line HNSCC. Stage 2 has opened for both parts. Clinical trial information: NCT03625323 .

A multicenter, phase II study of soluble LAG-3 (Eftilagimod alpha) in combination with pembrolizumab (TACTI-002) in patients with advanced non-small cell lung cancer (NSCLC) or head and neck squamous cell carcinoma (HNSCC)

TPS2667

Background: Eftilagimod alpha (efti, IMP321) is a recombinant LAG-3Ig fusion protein that binds to MHC class II and mediates antigen-presenting cell (APC) activation followed by CD8 T-cell activation. Pembrolizumab binds to the PD-1 receptor, blocking both immune-suppressing ligands, PD-L1 and PD-L2, from interacting with PD-1 to help restore effector T-cell responses. The rationale to combine efti and pembrolizumab comes from their complementary mechanisms of action. Efti activates APCs and lead to an increase in activated T cells which effect potentially reduces the number of non-responders to pembrolizumab. Combining an APC activator like efti to pembrolizumab is therefore fundamentally different from many other trials combining two checkpoint inhibitors like an anti-LAG-3 mAb with an anti-PD-1 mAb. In a previous phase I study (NCT 02676869) in metastatic melanoma the combination was found to be safe and well tolerable with encouraging signs of clinical activity. Methods: In the course of this multicenter, open label, Phase II study, patients will be recruited for each of three indications: A: 1st line, PD-X (PD-1 or PD-L1) naïve non-small cell lung cancer (NSCLC); B: 2nd line, PD-X refractory NSCLC; C: 2nd line PD-X naive head and neck squamous cell carcinoma (HNSCC). The study is designed according to Simon's optimal two-stage design, with objective response rate acc to iRECIST as primary endpoint. Secondary endpoints include progression free survival and overall survival. In case there are more responses achieved than a predefined threshold (each part counted separately) in pts recruited in the initial stage (n = 58), additional pts (51) will be recruited in stage 2. Efti will be administered for a maximum of 18 cycles (1 cycle = 3 weeks) as 30 mg subcutaneous injection every 2 weeks for the first 8 and every 3 weeks for the 10 following cycles. Pembrolizumab (200 mg intravenous infusion every 3 weeks) is administered in parallel for up to 35 cycles. Patients are followed up for progression and survival. Clinical trial information: 03625323.

Abstract OT1-01-11: Randomized phase 3 study of a novel, long-acting G-CSF (eflapegrastim) versus pegfilgrastim in the management of chemotherapy-induced neutropenia in early-stage breast cancer patients receiving docetaxel and cyclophosphamide (TC) (ADVANCE study)

Background: Eflapegrastim is a distinct biologic that uses an innovative, proprietary long-acting protein/peptide discovery technology (LAPSCOVERY™). Eflapegrastim consists of a novel, modified recombinant human G-CSF conjugated to the Fc fragment of IgG4 via a polyethylene glycol linker to produce a new, longer-acting G-CSF with a potentially unique distribution to areas rich in Fc receptors including its site of action in the bone marrow. A successful dose-finding Phase 2 trial including a pegfilgrastim control arm established the dose for a Phase 3 non-inferiority trial.

Trial Design: This is a randomized, open-label, active-controlled, multinational, multicenter, Phase 3 study comparing the efficacy and safety of eflapegrastim to pegfilgrastim. Patients (n=580) will be randomized in a 1:1 ratio to receive either eflapegrastim (equivalent to 3.6 mg G-CSF) or pegfilgrastim (equivalent to 6.0 mg G-CSF) once per chemotherapy cycle (up to 4 cycles), approximately 24 hours after chemotherapy. The primary endpoint is to compare the efficacy of a single dose of eflapegrastim with pegfilgrastim in patients with ESBC receiving TC, as measured by the Duration of Severe Neutropenia (DSN) in Cycle 1. Key secondary objectives include Time to Absolute Neutrophil Count (ANC) Recovery in Cycle 1; Depth of ANC Nadir in Cycle 1; incidence of Febrile Neutropenia. Safety and pharmacokinetics will also be assessed.

Eligibility Criteria: This study is enrolling histologically confirmed ESBC patients who are: eligible to receive adjuvant or neoadjuvant TC chemotherapy; at least 18 years of age, with adequate hematologic, renal and hepatic function. Patients will be excluded if they have: active concurrent malignancy or life-threatening disease; a known sensitivity or previous reaction to E. coli derived products or any of the products to be administered during study participation; concurrent adjuvant cancer therapy; locally recurrent/metastatic or contralateral breast cancer; previous exposure to filgrastim, pegfilgrastim, or other G-CSF products in clinical development prior to the administration of study drug; bone marrow or hematopoietic stem cell transplant or radiation therapy prior to enrollment, or are pregnant or breast-feeding.

Statistical Methods: The goal of this study is to demonstrate non-inferiority. For the Primary Efficacy Analysis, the mean DSN in Cycle 1 will be compared between the eflapegrastim and pegfilgrastim treatment arms. A 2-sided 95% confidence interval (CI) of the difference between the mean DSN of the eflapegrastim arm and the mean DSN of the pegfilgrastim arm will be calculated using bootstrap resampling with treatment as the only stratification factor. For the Secondary Efficacy Analyses, the results will each be summarized by treatment arm and cycle. The two-sided 95% CI for the difference between the treatment arms will be calculated.

Target Accrual: Approximately 580 patients. Enrollment began January 2016.

Contact Information: Spectrum Pharmaceuticals. advance@sppirx.com.

Citation Format: Schwartzberg LS, Bharadwaj J, Peguero JA, Vacirca JL, Ibrahim EN, Bhat G, Choi MR, McGregor K, Agajanian R. Randomized phase 3 study of a novel, long-acting G-CSF (eflapegrastim) versus pegfilgrastim in the management of chemotherapy-induced neutropenia in early-stage breast cancer patients receiving docetaxel and cyclophosphamide (TC) (ADVANCE study) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-01-11.

Prevention of everolimus/exemestane (EVE/EXE) stomatitis in postmenopausal (PM) women with hormone receptor-positive (HR+) metastatic breast cancer (MBC) using a dexamethasone-based mouthwash (MW): Results of the SWISH trial

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Background: Stomatitis is a frequent adverse event (AE) associated with mTOR inhibition. In BOLERO-2 patients (pts) receiving EVE/EXE, all grade (Gr) stomatitis was 67%; 33% had Gr ≥ 2 and 8% Gr 3. Median time to ≥ Gr 2 onset was 15.5 days; incidence of new stomatitis (Gr ≥ 2) plateaued at 6 wks. In a meta-analysis, 89% of first stomatitis events occurred within 8 wks. Topical steroids are used to treat aphthous ulcers; anecdotal use as prophylaxis has been reported. Methods: Eligibility included PM women with HR+ MBC prescribed EVE/EXE. Treatment included EVE 10 mg and EXE 25 mg QD, with 10 mL of commercially available 0.5 mg/5 mL dexamethasone oral solution to swish x 2 min and spit QID for 8 wks starting day 1. Pts completed a daily adherence log, including an oral pain (range 0-10) and normalcy of diet score. The primary endpoint was to compare the incidence of Gr ≥ 2 stomatitis at 8 wks with BOLERO-2 results. Secondary endpoints included MW use by average times/day, EVE/EXE dose intensity, incidence of all Gr stomatitis and time to resolution to Gr ≤ 1. Results: 92 women were enrolled; 86 were evaluable for efficacy. Median age was 61 yrs (range 34-87); median dose intensity was 10 (range 3-10) and 25 mg (range 8-25) for EVE and EXE, respectively. 95% of pts used the MW 3-4 times/day (median MW use/day = 3.95, range 1.9-4). At 8 wks, the rate of ≥ Gr 2 stomatitis was 2.4% (2 pts) with a Gr 1 rate of 18.8%. A comparison of stomatitis incidence by grade between BOLERO-2 and SWISH is shown in the table. In the 75 patients with complete ECOG scores, 88% maintained/improved ECOG status. Mean pain scale score was < 1 at all visits; 88% of pts reported a normal diet at 8 wks. 13% discontinued EVE/EXE due to suspected related AEs (most common: rash, 2%; hyperglycemia, 2%; stomatitis, 2%; and pneumonitis, 1%). Conclusions: Prophylactic use of 0.5 mg/5 mL dexamethasone oral solution markedly decreases the incidence and severity of stomatitis in patients receiving EVE/EXE for MBC and should be considered a new standard of oral care in this setting. Clinical trial information: NCT02069093. [Table: see text]