Clinical Benefit Response Rate Research Articles

Camonsertib in DNA damage response-deficient advanced solid tumors: phase 1 trial results

Predictive biomarkers of response are essential to effectively guide targeted cancer treatment. Ataxia telangiectasia and Rad3-related kinase inhibitors (ATRi) have been shown to be synthetic lethal with loss of function (LOF) of ataxia telangiectasia-mutated (ATM) kinase, and preclinical studies have identified ATRi-sensitizing alterations in other DNA damage response (DDR) genes. Here we report the results from module 1 of an ongoing phase 1 trial of the ATRi camonsertib (RP-3500) in 120 patients with advanced solid tumors harboring LOF alterations in DDR genes, predicted by chemogenomic CRISPR screens to sensitize tumors to ATRi. Primary objectives were to determine safety and propose a recommended phase 2 dose (RP2D). Secondary objectives were to assess preliminary anti-tumor activity, to characterize camonsertib pharmacokinetics and relationship with pharmacodynamic biomarkers and to evaluate methods for detecting ATRi-sensitizing biomarkers. Camonsertib was well tolerated; anemia was the most common drug-related toxicity (32% grade 3). Preliminary RP2D was 160 mg weekly on days 1–3. Overall clinical response, clinical benefit and molecular response rates across tumor and molecular subtypes in patients who received biologically effective doses of camonsertib (>100 mg d−1) were 13% (13/99), 43% (43/99) and 43% (27/63), respectively. Clinical benefit was highest in ovarian cancer, in tumors with biallelic LOF alterations and in patients with molecular responses. ClinicalTrials.gov registration: NCT04497116.

Abstract CT006: First-in-class, first-in-human phase 1 trial of VT3989, an inhibitor of yes-associated protein (YAP)/transcriptional enhancer activator domain (TEAD), in patients (pts) with advanced solid tumors enriched for malignant mesothelioma and other tumors with neurofibromatosis 2 (NF2) mutations

Abstract Background: Inactivation of the Hippo pathway is a common finding in MM and other cancers, leading to constitutive YAP activation, but has thus far been undruggable. NF2 encodes Merlin that activates Hippo kinase resulting in inactivation of YAP, which is the major effector of Hippo signaling. NF2-deficient tumors, often due to inactivating NF2 mutations (NF2m), are dependent on YAP for growth. VT3989 is an oral, highly potent and selective inhibitor of TEAD palmitoylation, which blocks YAP function and has shown promising preclinical activity. Materials and Methods: This FIH trial used a 3 + 3 dose escalation design and evaluated VT3989 from 25 to 200 mg QD continuously and 50 to 200 mg intermittently. Pts with refractory solid tumors, ECOG PS 0-1, serum albumin > 2.5, urinary protein creatinine ratio ≤ 0.5 mg/mg and albumin creatinine ratio ≤ 100 mg/g were enrolled. Objectives were to determine the safety, tolerability and recommended Phase 2 dose (RP2D) of VT3989; to evaluate antitumor activity, pharmacokinetics (PK) and correlate NF2m and other alterations in tumor and ctDNA with response. Results: 67 pts have been enrolled. Median age 63.5y (21-83y), ECOG PS 0:1 13:54 pts. Median prior therapies 3 (range 0-8). Tumor types: 42 MM (29 pleural and 13 non-pleural) and 25 solid tumors including 9 meningioma and 4 sarcoma pts. 34 pts had NF2m (29 somatic and 5 germline). All MM pts had progressed on prior platinum/pemetrexed; all but 2 had prior immune checkpoint inhibitors. VT3989 is safe and well tolerated with no dose limiting toxicities. No MTD was defined up to 200 mg QD. The most common AEs are proteinuria, albuminuria and peripheral edema, mainly observed with the continuous schedule. There were 7 possibly related G3 AEs (fatigue, ALT, AST, dehydration, dyspnea, hypotension and peripheral edema) and 1 G4 cardiomyopathy. No pt developed decreased renal function or nephrotic syndrome. VT3989 has a 12-15 day half-life, dose proportional PK and reaches steady state within 2 weeks. Seven pts (6 refractory MM and 1 NF2m sarcoma) achieved RECIST v1.1 partial responses (PRs) with 4 confirmed, 3 unconfirmed (1 pending). 3 PRs in MM pts are ongoing up to 18+ months. The clinical benefit response rate (PR + SD > 8 weeks, per protocol) in MM pts is 57%. Of the 6 MM pts (1 pericardial, 1 pleural/peritoneal and 4 peritoneal) with PR, 2 have NF2m, 3 are wildtype, and 1 is unknown. Conclusions: VT3989 is safe and well tolerated with durable RECIST v1.1 antitumor responses in pts with advanced MM and NF2m cancers, providing the first early clinical proof-of-concept for effectively drugging the Hippo-YAP-TEAD pathway. RP2D optimization including further schedule evaluation and expansion are ongoing in pts with MM and NF2m tumors. Citation Format: Timothy A. Yap, David J. Kwiatkowski, Jayesh Desai, Ibiayi Dagogo-Jack, Michael Millward, Hedy L. Kindler, Anthony W. Tolcher, Sophia Frentzas, Archie W. Thurston, Len Post, F Andrew Dorr. First-in-class, first-in-human phase 1 trial of VT3989, an inhibitor of yes-associated protein (YAP)/transcriptional enhancer activator domain (TEAD), in patients (pts) with advanced solid tumors enriched for malignant mesothelioma and other tumors with neurofibromatosis 2 (NF2) mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT006.

Efficacy and safety of camrelizumab plus apatinib in previously treated patients with advanced non-small cell lung cancer harboring EGFR or ALK genetic aberration.

BackgroundCamrelizumab plus apatinib shows encouraging antitumor activity and acceptable toxicity in chemotherapy-pretreated patients with advanced non-small cell lung cancer (NSCLC); however, clinical benefits from this combination regimen in NSCLC patients with EGFR mutations or ALK rearrangements (EGFR+/ALK+) have not been reported. We assessed the efficacy and safety of this combined regimen in pretreated patients with advanced NSCLC and defined EGFR/ALK status (EGFR+/ALK+) in a phase 1b/2 trial.MethodsPreviously treated patients with advanced EGFR+/ALK+ NSCLC were enrolled and given camrelizumab 200 mg intravenously every 2 weeks plus apatinib at the recommended dose of 250 mg orally once daily. Patients harboring sensitive EGFR mutations or ALK fusion genes had received at least one EGFR/ALK TKI and a platinum-based chemotherapy regimen before the enrollment. The primary endpoint was objective response rate (ORR).ResultsAll 43 enrolled patients comprised the efficacy and safety analysis population. The confirmed ORR was 18.6% (95% CI: 8.4–33.4%) and the clinical benefit response rate was 27.9% (95% CI: 15.3–43.7%). Median progression-free survival (PFS) was 2.8 months (95% CI: 1.9–5.5 months) and median overall survival was not reached (95% CI: 7.3 months–not reached), with a median follow-up period of 15.7 months (range, 0.5–24.4 months). The most common grade ≥3 treatment-related adverse events (TRAEs) were hypertension (16.3%), proteinuria (11.6%) and palmar-plantar erythrodysaesthesia syndrome (9.3%). No unexpected adverse events were recorded.ConclusionsCamrelizumab plus apatinib showed moderate antitumor activity and acceptable safety profile in previously treated patients with advanced NSCLC and EGFR or ALK genetic aberrations, which warranted further validation.Trial RegistrationClinicalTrials.gov identifier: NCT03083041. Registered March 17, 2017.

Safety and efficacy of nivolumab plus recombinant human endostatin in previously treated advanced non-small-cell lung cancer.

BackgroundEvidence of the efficacy of immune checkpoint inhibitors (ICIs) plus antiangiogenic drugs in previously treated patients with advanced non-small-cell lung cancer (NSCLC) is still insufficient, so we investigated the safety and efficacy of nivolumab plus recombinant human (rh)-endostatin in such patients.MethodsPatients without epithelial growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) targetable mutations in advanced NSCLC who did not respond to previous treatment were enrolled. Eligible patients received nivolumab (3 mg/kg, i.v. drip, day 1) every 2 weeks and rh-endostatin (210 mg, continuous i.v. infusion for 168 h) every 4 weeks until disease progression or discontinuation. The primary endpoint was the objective response rate (ORR). The secondary endpoints included disease control rate (DCR), duration of response (DOR), clinical benefit response rate (CBR), progression-free survival (PFS), overall survival (OS) and safety.ResultsA total of 34 patients received a median of 4 cycles of therapy. In all, 14 patients achieved confirmed partial response (PR) with an ORR of 41.2% [14/34; 95% confidence interval (CI): 23.7–58.6%], DCR of 64.7% (22/34; 95% CI: 47.8–81.6%), CBR of 44.1% (95% CI: 26.5–61.7%), and a DOR of 6.9 (95% CI: 4.4–9.4) months. Median follow-up was 12.2 (range, 2.3–18.1) months. Median PFS (mPFS) was 6.8 (95% CI: 1.1–12.1) months, median OS (mOS) was 17.1 (95% CI: 6.6–27.6) months, and 12-month survival rate of 64.4% (95% CI: 46.2–82.6%). In all, 18 (18/34, 52.9%) patients experienced at least one treatment-related adverse event (TRAE), and Grade 3 TRAEs occurred in 4 (4/34, 11.8%) of them.ConclusionsThis study is first to assess nivolumab plus rh-endostatin in previously treated patients with advanced NSCLC. In view of its favorable efficacy and safety profile, this combination represents a promising treatment regimen in this patient population.

DNA methylation inhibition in myeloma: Experience from a phase 1b study of low-dose continuous azacitidine in combination with lenalidomide and low-dose dexamethasone in relapsed or refractory multiple myeloma

The DNA methyltransferase inhibitor azacytidine (aza) may reactivate pathways associated with plasma cell differentiation, cell cycle control, apoptosis, and immune recognition and thereby restore sensitivity to lenalidomide (len) and dexamethasone (dex) in relapsed and/or refractory multiple myeloma (RRMM). We aimed to develop an aza regimen that reaches epigenetically active levels 8 times in 28 days with less bone marrow toxicity than the myeloid malignancy standard of 7 consecutive doses to enable safe combination with len. Aza was escalated from 30 mg/m2 once a week up to a predefined maximum of 50 mg/m2 twice a week in combination with GFR-adjusted len (≥ 60 mL/min: 25 mg, 3059 mL/min: 10 mg) day 1 to 21 every 28 days and dex 40 mg once a week followed by a limited expansion study to a total N of 23 at the highest tolerated dose. Fifty-one patients (pts) with RRMM were screened, 42 were treated and 41 were evaluable for response based on at least 1 response assessment or progression after treatment start. The median number of prior lines of therapy was 5 (1-11) and 81% (34) were refractory to len and/or pomalidomide (pom). Two DLTs occurred in different cohorts, 1 neutropenic fever in 1/6 pts on the aza 40 mg/m2 twice a week GFR ≥ 60 mL/min cohort and 1 GGT elevation in 1/6 pts on the aza 50 mg/m2 GFR 30-59 mL/min cohort. An MTD was not reached and aza 50 mg/m2 SC twice a week was chosen for the expansion study. At least possibly related Grade 3/4 AEs occurred in 28 pts (67%) with the following in > 1 pt: neutropenia (N = 16, 38%), anemia (N = 6, 14%), lymphopenia (N = 5, 12%), thrombocytopenia (N = 4, 10%), leukopenia (N = 4, 10%), febrile neutropenia (N = 4, 10%), fatigue (N = 3, 7%), fever (N = 2, 5%), and infection (N = 2, 5%). At a median follow up time for alive pts of 60.2 months (range: 36.1-82.5 months), the overall response rate (≥ partial response) and clinical benefit response rate (≥ minor response) was 22 and 32%, respectively, with 4 very good partial responses (10%), 5 partial responses (12%), and 4 minor responses (10%). The median PFS was 3.1 months (95% confidence interval [CI]: 2.1-5.1 months), median TTP 2.7 months (95% CI: 2.1-7.5 months), and median OS 18.6 months (95% CI: 12.9-33.0 months). Achieving at least minor response and reaching TTP > 6 months was associated with approximately 35% lower median plasma levels of the enzyme that inactivates aza, plasma cytidine deaminase (CDA, P< .0001). Two of the len refractory pts achieved longer disease control than with any prior regimen and 1 responded immediately after progression on len, bortezomib, and prednisone. Analyses of the methylation state of over 480,000 CpG sites in purified myeloma cells at screening were possible in 11 pts and on day 28 in 8 of them. As in other studies, the majority of differentially methylated CpGs compared to normal plasma cells were hypomethylated in myeloma. Treatment decreased the number of CpGs that were differentially methylated in normal plasma cells by > 0.5% in 6 and by > 5% in 3 of the 8 pts, most pronounced in 2 pts with clinically convincing aza contribution who achieved a reduction in overall differentially methylated CpGs by 23 and 68%, respectively, associated with increased expression of immunoglobulin genes. The study demonstrated tolerability of twice a week SC aza at 50 mg/m2 with len and dex in RRMM and suggested aza may help overcome the len/pom refractory state, possibly by activating differentiation pathways. Relatively low response rates and association of clinical benefit with low plasma levels of the aza inactivating enzyme CDA suggest the aza regimen will need to be optimized further and pt selection may be required to maximize benefit.

Bortezomib, Vorinostat, and Dexamethasone Combination Therapy in Relapsed Myeloma: Results of the Phase 2 MUK four Trial

IntroductionOutcomes continue to improve in relapsed myeloma as more effective treatment options emerge. We report a multicenter single-arm phase 2 trial evaluating toxicity and efficacy of the histone deacetylase (HDAC) inhibitor vorinostat in combination with bortezomib and dexamethasone. Patients and MethodsSixteen patients who had received a median of 1 prior treatment line received bortezomib subcutaneously 1.3 mg/m2 days 1, 4, 8, and 11; dexamethasone 20 mg orally days 1-2, 4-5, 8-9, and 11-12; vorinostat 400 mg orally days 1-4, 8-11, and 15-18 of a 21-day cycle. After receipt of a minimum of 3 cycles of therapy, participants received maintenance vorinostat (400 mg days 1-4 and 15-18 of a 28-day cycle). ResultsOverall response was 81.3%: complete response occurred in 4 of 16, very good partial response in 2 of 16, and partial response 7 of 16. Clinical benefit response rate was 100%; median progression-free survival was 11.9 months. A total of 75% patients experienced a dose reduction or stopped treatment as a result of intolerability. ConclusionAlthough toxicity and dose reductions were observed, this study demonstrates that the combination of vorinostat, bortezomib, and dexamethasone is effective in relapsed myeloma with good response rates, suggesting there is an ongoing rationale for further optimization of HDAC inhibitor–based combinations in the treatment of myeloma to improve tolerability and enhance efficacy.

Comprehensive Genomic Profiling Identifies Novel Genetic Predictors of Response to Anti-PD-(L)1 Therapies in Non-Small Cell Lung Cancer.

Immune checkpoint inhibitors (ICI) have revolutionized cancer management. However, molecular determinants of response to ICIs remain incompletely understood. We performed genomic profiling of 78 patients with non-small cell lung cancer (NSCLC) who underwent anti-PD-(L)1 therapies by both whole-exome and targeted next-generation sequencing (a 422-cancer-gene panel) to explore the predictive biomarkers of ICI response. Tumor mutation burden (TMB), and specific somatic mutations and copy-number alterations (CNA) were evaluated for their associations with immunotherapy response. We confirmed that high TMB was associated with improved clinical outcomes, and TMB quantified by gene panel strongly correlated with WES results (Spearman's ρ = 0.81). Compared with wild-type, patients with FAT1 mutations had higher durable clinical benefit (DCB, 71.4% vs. 22.7%, P = 0.01) and objective response rates (ORR, 57.1% vs. 15.2%, P = 0.02). On the other hand, patients with activating mutations in EGFR/ERBB2 had reduced median progression-free survival (mPFS) compared with others [51.0 vs. 70.5 days, P = 0.0037, HR, 2.47; 95% confidence interval (CI), 1.32-4.62]. In addition, copy-number loss in specific chromosome 3p segments containing the tumor-suppressor ITGA9 and several chemokine receptor pathway genes, were highly predictive of poor clinical outcome (survival rates at 6 months, 0% vs. 31%, P = 0.012, HR, 2.08; 95% CI, 1.09-4.00). Our findings were further validated in two independently published datasets comprising multiple cancer types. We identified novel genomic biomarkers that were predictive of response to anti-PD-(L)1 therapies. Our findings suggest that comprehensive profiling of TMB and the aforementioned molecular markers could result in greater predictive power of response to ICI therapies in NSCLC.

Assessing treatment benefits with CDK4/6i+ET for hormone receptor-positive advanced breast cancer: A network meta-analysis.

e12543 Background: Previously, the treatment of hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer (aBC) has relied solely on endocrine therapy (ET). Unfortunately, almost all tumors developed resistance to ET. Although cyclin-dependent kinase inhibitors (CDKi)+ET clearly improve several clinical outcomes, many relevant questions remain unanswered: is there a benefit in (i) overall survival (OS) (ii) progression-free survival (PFS), and (iii) which CDKi is the best. Methods: A systematic review was performed to identify trials that compared CDKi+ET versus ET alone for HR+/HER2-aBC. Pooled meta-estimates were generated to assess CDKi+ET OS benefit and PFS benefit. Bayesian network meta-analysis was performed to compare each CDKi in terms of PFS, clinical benefit rate (CBR), response rate (RR) and toxicity. Results: 2,523 studies were screened and 8 studies satisfied the inclusion criteria. There was a trend for OS benefit with CDKi+ET compared to ET alone with 97% posterior probability that CDKi+ET is better than ET alone and HR 0.81 (95% CrI 0.66-1.00). CDKi+ET also showed &gt; 99% probability of better than ET alone in both first and second-line settings in terms of PFS, RR, and CBR with PFS HR 0.56 (0.47-0.66) first line, 0.49 (0.39-0.60) second-line; RR OR 1.61 (1.29-1.97) first-line, 2.58 (1.71-3.80) second-line; CBR OR 1.75 (1.38-2.25) first-line, 2.38 (1.65-3.37) second-line. Ribociclib and abemaciclib showed weak-moderate evidence of better PFS and RR compared to palbociclib (64% to 81% posterior probability of superiority). There was no evidence of differences between ribociclib and abemaciclib. Palbociclib achieved better CBR compared to ribociclib and abemaciclib, although this difference may be related to the poor performance of placebo arm in studies that used palbociclib. In terms of safety, abemaciclib caused less neutropenia, but more diarrhea than ribociclib and palbociclib. Deep vein thrombosis was less frequent with ribociclib. Conclusions: CDKi+ET was 97% superior in terms of OS and &gt; 99% superior in terms of PFS, RR, and CBR compared to ET alone. Further studies are necessary in order to find the best agent and the best sequencing of CDKi for HR+/HER2- aBC treatment.

Is a clinical biomarker predictive of outcomes with immune checkpoint inhibitor (ICI) therapy in a phase I patient population.

e14136 Background: NLR is reported to be a prognostic marker in multiple malignancies and has reported potential predictive value with ICI. We evaluated NLR as a predictor of response and time to treatment failure (TTF) in a phase I patient population treated with ICI. Methods: Regulatory approval was obtained. A retrospective chart review of patients treated on phase I trials with ICI based therapy at Karmanos Cancer Institute, was conducted. Data were collected on demographics, performance status, tumor type, response rate, TTF and NLR pre and post therapy. Associations with clinical benefit (response rate and stable disease) and TTF were conducted by univariable logistic and Cox regression analyses. Results: 100 pts; 52 female and 48 male were evaluated. Median age was 62 years (range 22-84 years). 11 were African American (AA) and all patients were pretreated with standard therapy and had progressed prior to enrollment. Median pretherapy NLR was 3.31 (range 0.91-25.5). 26 patients showed clinical benefit with ICI based therapy; 6 partial responses and 20 with stable disease. Univariable Cox analysis for baseline continuous NLR associated with TTF showed a significant relation between NLR and TTF (p = 0.023). Univariable logistic and Cox analyses for dichotomized baseline NLR with optimal cut-off values, resulted in low NLR favoring higher chance of clinical benefit (Odds ratio = 0.169 95% CI 0.028,1.013, p = 0.043) and longer TTF (Hazard ratio = 1.841, 95% CI 1.188,2.854 p = 0.006). Conclusions: Pretherapy NLR was a statistically significant predictor of clinical benefit with ICI therapy in a phase I patient population. NLR is an easily applicable clinical predictive biomarker that may help guide clinical trial choice, especially in a patient population with limited life expectancy.

A phase II study of ENMD-2076 in advanced soft tissue sarcoma (STS)

ENMD-2076, an aurora-A kinase inhibitor with anti-angiogenic properties, has shown activity in solid and hematologic malignancies. We investigated oral ENMD-2076 in an open-label, single-arm phase II study using 275 mg daily on a 28-day cycle in patients with advanced soft-tissue sarcomas (STS) receiving ≤1 line of prior therapy. Primary endpoint was 6-month progression-free survival (PFS) with ≤15% indicating no interest, and ≥40% indicating further interest in ENMD-2076. Secondary/exploratory endpoints included clinical benefit (CBR ≥6-months) and objective response (ORR) rates, PFS, OS, safety, and whole-exome sequencing (WES) for potentially associated biomarkers. Overall, 23/25 (92%) patients receiving ENMD-2076 were efficacy evaluable with median follow-up of 14 months (range 2.2–39.5). Common subtypes were leiomyosarcoma (n = 10), undifferentiated pleomorphic sarcoma (n = 3), angiosarcoma (n = 3), and alveolar soft-part sarcoma (n = 3). The 6-month PFS was 20.8% (95% CI:3.2–38.4) with a CBR of 17% (95% CI:1.55–33.23) and ORR of 9% (95% CI:3.08–20.46). Median PFS was 2.5 months (95% CI:2.20–4.47) and OS was 14.1 months (95% CI:6.07–20.07). The most common high-grade treatment-related adverse event was hypertension (60%). WES identified PTPRB mutations in 3/4 patients (p = 0.018) benefiting from ENMD-2076. Although this study failed to meet its primary endpoint, occasional responses and prolonged stable disease was noted. ENMD-2076 evaluation in PTPRB mutated tumors and/or angiosarcoma is warranted.

Use of depth of response to predict progression-free survival in relapsed or refractory multiple myeloma: Evaluation of results from 102 clinical trials.

Progression-free survival (PFS) is the standard endpoint for demonstration of clinical effectiveness of novel therapies in relapsed or refractory multiple myeloma (RRMM). However, the long evaluation times for PFS limits its usefulness in the development of new therapies. Therefore, the objective of this analysis was to determine the relationship between response rates and median PFS in RRMM. A database was systematically developed from 268 identified RRMM trials reported from 1999 to 2016. Evaluated covariates for the relationship between response rates and PFS included age, sex, drug class(es), and number of drug classes. One-hundred two (102) trials involving 136 cohorts were included in the meta-analysis, representing 13322 patients in total. Regression analysis using response rates and median PFS indicated that the correlation between very good partial response (VGPR) or better and median PFS was higher (R2 =0.63) than the separately analyzed correlations between clinical benefit, overall response, or complete response rate and median PFS (R2 =0.47 - 0.52). Subsequent covariate analysis revealed that treatment with an immunomodulatory imide drug (IMiD) further improved the relationship (R2 =0.69), with a longer median PFS at a given VGPR or better rate when at least 1 drug treatment was an IMiD. Number of drug classes was not found to alter this relationship. In conclusion, VGPR or better rate can be used to predict the median PFS, with adjustment for the additional PFS provided by an IMiD.

Abstract P5-21-25: Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2

Abstract BACKGROUND: Previous findings from the PALOMA-2 study (N=666) demonstrated the efficacy and safety of PAL+LET as first-line ABC therapy versus placebo (PBO)+LET (Finn et al, NEJM. 2016). This analysis evaluated the efficacy and safety of PAL+LET by geographic region (North America [NA], Europe [EU], and Asia Pacific [AP]; data cutoff: Feb 26, 2016). METHODS: Women with ER+/HER2– ABC who had not received prior systemic treatment in the advanced setting were randomized 2:1 to PAL (125 mg/d oral [3 wks on, 1 wk off])+LET (2.5 mg once daily) or PBO+LET. RESULTS: This analysis included 267 patients from NA, 307 from EU, and 92 from AP. At baseline, demographics and disease characteristics generally were similar between regions. In the overall population (Table 1), PAL+LET demonstrated improvements versus PBO+LET in progression-free survival (PFS), objective response rate (ORR), and clinical benefit response rate (CBR). Similarly, PFS was longer and ORR and CBR were higher with PAL+LET versus PBO+LET in NA, EU, and AP subgroups (Table 1). All-grade treatment-emergent adverse events (AEs) (PAL+LET/PBO+LET) occurred in 99%/99% of patients in NA, 98%/92% in EU, and 100%/96% in AP. In the PAL+LET arm, neutropenia (all-grade/grade ≥3) was the most common AE in all regions. The incidence of neutropenia was numerically higher in AP (91%/84%) compared with NA (73%/65%) and EU (81%/62%). Grade 3 or 4 febrile neutropenia occurred in 4 (2%) NA patients, 4 (2%) EU patients, and no AP patients in the PAL+LET arm and in no patients in any of the regions in the PBO+LET arm. CONCLUSIONS: PAL+LET showed improvement versus PBO+LET in PFS, ORR, and CBR in patients with ER+/HER2- ABC in NA, EU, and AP, with comparable magnitude of benefit between regions. With PAL+LET, neutropenia was the most commonly reported AE in all regions, with a numerically higher incidence reported in AP versus NA or EU; the safety profile was similar to previously reported results in the overall population. Funding: Pfizer (NCT01740427) section, copy and paste the following tag, including brackets, where you would like your table to appear Table 1. PFS, ORR, and CBR Median PFSPFS HRORR,* %CBR,* % (95% CI), mo(95% CI)(95% CI)(95% CI)Overall Population PAL+LET24.8 (22.1-NE)0.58 (0.46-0.72); P&amp;lt;0.00155.3 (49.9-60.7)84.3 (80.0-88.0)PBO+LET14.5 (12.9-17.1) 44.4 (36.9-52.2)70.8 (63.3-77.5)NA PAL+LET24.2 (17.5-NE)0.61 (0.43-0.85)54.3 (45.3-63.2)80.3 (72.3-86.8)PBO+LET13.8 (10.3-22.1) 50.6 (39.1-62.1)67.1 (55.6-77.3)EU PAL+LET24.8 (22.1-NE)0.57 (0.41-0.80)55.6 (47.6-63.5)87.5 (81.4-92.2)PBO+LET16.5 (11.3-19.6) 38.2 (26.7-50.8)73.5 (61.4-83.5)AP PAL+LET22.2 (19.4-25.7)0.49 (0.27-0.87)56.9 (42.2-70.7)84.3 (71.4-93.0)PBO+LET13.9 (7.4-22.0) 41.7 (22.1-63.4)75.0 (53.3-90.2)HR=hazard ratio; NE=not estimable; OR=objective response.*Confirmed OR in patients with measurable disease. . Citation Format: Gelmon KA, Castrellon A, Joy AA, Walshe JM, Ettl J, Mukai H, Park IH, Lu DR, Mori A, Bananis E, Diéras V, Finn RS. Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-25.

The prognostic impact of neutrophil to lymphocyte ratio in patients with recurrent or metastatic esophageal squamous cell carcinoma receiving immune checkpoint inhibitors.

69 Background: The study explored the prognostic impacts of clinical parameters including neutrophil to lymphocyte ratio (NLR) in recurrent/metastatic esophageal squamous cell carcinoma (R/M ESCC) patients receiving anti-programmed cell death protein-1 (PD-1)/PD ligand 1 (PD-L1)-based therapy. Methods: Thirty-eight patients were enrolled. Tumor response evaluation was made according to Response Evaluation Criteria in Solid Tumours 1.1, and the clinical benefit response (CBR) was defined as complete response, partial response or stable disease at least 6 months. Clinical factors were analyzed for their impacts on patients' overall survival (OS) and progression-free survival (PFS). Formalin-fixed, paraffin-embedded tissues from 8 patients were analyzed by NanoString nCounter Human PanCancer Immune Profiling (NanoString Technologies, Seattle, WA, US). Results: Twenty-six recurrent and 12 de novo metastatic ESCC patients were enrolled. The response rate is 11.8%, and the CBR rate was 21.1%. The median PFS and OS are 2.7 and 5.5 months, respectively. The CBR group has lower blood white blood cells (WBC) ( P = 0.029), monocytes (p = 0.003), and NLR (p = 0.005). In univariate analysis, WBC, neutrophils, and NLR were statistically associated with PFS; performance status (PS), disease extent, albumin, WBC, neutrophils, and NLR were statistically associated with OS. In multivariate analysis, NLR (p = 0.007) was statistically associated with PFS; PS (p = 0.029) and NLR (p = 0.050) were statistically associated with OS. On examining the immune-related genes in ESCC tissues’ microenvironment, the ratios of mast cells, neutrophils, and macrophages relative to tumor-infiltrating lymphocytes (TILs) have significantly lower in the CBR group than in the non-CBR group. Conclusions: High NLR was associated with inferior prognosis in R/M ESCC patients receiving anti-PD-1/PD-L1-based therapy. The increased ratio of neutrophil to TILs in the ESCC tumor microenvironment of non-CBR patients may suggest a mechanistic role of neutrophils in affecting the efficacy of anti-PD-1/PD-L1 therapy. (Supported by the grant of MOST 105-2314-B-002 -186 -MY3)

Palbociclib: A Review in HR-Positive, HER2-Negative, Advanced or Metastatic Breast Cancer.

Oral palbociclib (Ibrance®) is a first-in-class, highly selective inhibitor of cyclin-dependent kinases 4 and 6 (i.e. a CDK4/6 inhibitor). It is indicated for the treatment of women with HR-positive, HER2-negative advanced or metastatic breast cancer, in combination with an aromatase inhibitor as initial endocrine-based therapy, and in combination with fulvestrant (with or without a luteinizing hormone-releasing hormone agonist) in those previously treated with endocrine therapy. In clinical trials, palbociclib in combination with letrozole as initial endocrine-based therapy in postmenopausal women (PALOMA-1 and PALOMA-2), or in combination with fulvestrant in pre-, peri-, or postmenopausal women with disease progression after endocrine therapy (PALOMA-3), significantly prolonged progression-free survival (PFS) and improved clinical benefit response (CBR) rates. Neutropenia was the most commonly reported any-grade and grade≥3 adverse event. It was infrequently associated with febrile neutropenia (<2%) and generally manageable with a palbociclib dose delay, interruption or reduction, without the routine use of growth factors, and without affecting efficacy. In conclusion, oral palbociclib combination therapy is a valuable emerging option for use in patients with HR-positive, HER2-negative advanced or metastatic breast cancer.

First-line therapy for treatment-naive patients with advanced/metastatic renal cell carcinoma: a systematic review of published randomized controlled trials.

In the recent years, a number of targeted therapies have been approved for first-line treatment of patients with metastatic renal cell carcinoma. A systematic review was conducted to assess the clinical efficacy, safety and effect of all first-line treatments evaluated to date on health-related quality of life (HRQoL). A systematic search of Embase, Cochrane and MEDLINE databases was performed to identify randomized controlled trials (1980-2015) evaluating any targeted therapy/immunotherapy against placebo or any other targeted intervention/immunotherapy in treatment-naive patients with metastatic renal cell carcinoma. Conference proceedings from major cancer congresses (2007-2015) were handsearched. Sixteen randomized controlled trials were identified, mostly phase III. Overall, targeted therapies were associated with either improved [sunitinib, bevacizumab+interferon α (IFNα) and temsirolimus] or comparable (sorafenib) progression-free survival (PFS) versus IFNα monotherapy. Sunitinib demonstrated comparable PFS and overall survival to pazopanib, comparable PFS to sorafenib and shorter PFS compared with bevacizumab+IFNα (although no conclusions were made with regard to superiority/inferiority). Compared with sorafenib, tivozanib demonstrated a significantly longer PFS, and both tivozanib and axitinib demonstrated higher response rates. Nintedanib demonstrated comparable PFS and overall survival to sunitinib in a phase II trial. Temsirolimus, sunitinib and sorafenib treatment led to better HRQoL versus IFNα; pazopanib was associated with better HRQoL versus sunitinib. No direct meta-analyses or indirect treatment comparison analysis were undertaken because of noncomparability of the trials. In general, targeted therapies demonstrated favourable clinical efficacy and improved HRQoL compared with IFNα monotherapy. The newer therapies, tivozanib and axitinib (but not nintedanib), appeared to exhibit greater clinical benefit (response rate) than older tyrosine kinase inhibitors.

A randomized phase II non-comparative study of PF-04691502 and gedatolisib (PF-05212384) in patients with recurrent endometrial cancer

ObjectivePF-04691502 and gedatolisib (PF-05212384) are potent, dual PI3K/mTOR inhibitors. This phase II study (B1271004) was conducted in patients with recurrent endometrial cancer following platinum-containing chemotherapy. The primary endpoint was to assess clinical benefit response (complete or partial response, or stable disease for ≥16weeks) following treatment with PF-04691502 or gedatolisib. MethodsThe main study consisted of four independent arms based on a Simon two-stage design. Patients were assigned to putative PI3K-basal (PF-04691502 or gedatolisib) or PI3K-activated (PF-04691502 or gedatolisib) arms based on stathmin-low or stathmin-high tumor expression, respectively. Japanese patients were also enrolled in a separate lead-in cohort. ResultsIn stage 1 (main study), eighteen patients were randomized to PF-04691502 and 40 to gedatolisib. The two PF-04691502 arms were discontinued early due to unacceptable toxicity, including pneumonia and pneumonitis. The most common treatment-related adverse events associated with gedatolisib were nausea (53%), mucosal inflammation (50%), decreased appetite (40%), diarrhea (38%), fatigue (35%), and dysgeusia and vomiting (each 30%). Clinical benefit response rate was 53% (10/19) in the gedatolisib/stathmin-low arm and 26% (5/19) in the gedatolisib/stathmin-high arm. Safety profile and pharmacokinetic characteristics of both drugs in the Japanese lead-in cohort were comparable to the Western population. ConclusionsGedatolisib administered by weekly intravenous infusion demonstrated acceptable tolerability and moderate activity in patients with recurrent endometrial cancer. PF-04691502 daily oral dosing was not well tolerated. Clinical benefit response criteria for proceeding to stage 2 were only met in the gedatolisib/stathmin-low arm. Stathmin-high expression did not correlate with greater treatment efficacy.ClinicalTrials.gov registration ID: NCT01420081.

Abstract OT1-03-17: ABRAZO: An international phase 2 (2-stage, 2-cohort) study of the oral PARP inhibitor talazoparib (BMN 673) in BRCA mutation subjects with locally advanced and/or metastatic breast cancer

Abstract Background: Cancer cells with deleterious mutations in breast cancer susceptibility genes 1 and 2 (BRCA1/2) are deficient in the DNA double-strand break repair mechanism, rendering them highly dependent on the single-strand break repair pathway, which is initiated by poly-(ADP-ribose) polymerase (PARP) [1-3]. In cells with deleterious BRCA1/2 mutations, PARP inhibition is synthetically lethal because of accumulation of irreparable DNA damage [1-3]. Talazoparib (BMN 673) exhibits a novel two-pronged approach in treating BRCA1/2-mutant tumors: 1) potent catalytic inhibition of the PARP enzyme; and 2) trapping of PARP at sites of DNA damage [4-7]. The capacity to trap PARP-DNA complexes varies widely across PARP inhibitors and is not correlated with catalytic inhibition potency [4-7]. In preclinical models, trapping PARP on DNA is more potent at inducing cancer cell death than enzymatic inhibition of PARP alone [4,7]. Talazoparib is the most potent clinical-stage PARP inhibitor tested to date with the highest efficacy at trapping PARP-DNA complexes [7]. Talazoparib has shown single-agent antitumor efficacy in several solid tumor types and was generally well tolerated in a phase 1/2 clinical study [8]. Methods: This 2-stage, 2-cohort, phase 2 international study (ABRAZO) evaluates the safety and efficacy of talazoparib in patients with a deleterious germline BRCA1 or BRCA2 mutation with locally advanced and/or metastatic breast cancer. Eligible subjects will be assigned to one of two cohorts based on prior chemotherapy for metastatic disease. Cohort 1 (n=70) includes patients with a complete response (CR) or partial response (PR) to platinum-containing regimens for metastatic disease. Cohort 2 (n=70) includes patients who have received &amp;gt;2 prior chemotherapy regimens in the metastatic setting but have not had prior platinum therapy for locally advanced or metastatic disease (prior adjuvant or neoadjuvant therapy with a platinum is allowed). The primary objective is objective response rate (ORR). Secondary objectives include clinical benefit response (CBR) rate, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Health-related quality of life (QoL) assessments are an exploratory objective. Eligible subjects will receive oral talazoparib (1 mg/day, 21-day cycles) until disease progression or unacceptable toxicity. This trial is currently enrolling patients from the United States and Europe (NCT02034916). This study is funded by BioMarin Pharmaceutical Inc.

Efficacy and Safety of Salvage Therapy Using Carfilzomib for Relapsed or Refractory Multiple Myeloma Patients: A Multicentre Retrospective Observational Study

Introduction: Carfilzomib has been established in previous years as a treatment for patients with relapsed and/or refractory multiple myeloma (RR-MM). A retrospective multicentre study to evaluate the clinical use of carfilzomib for RR-MM outside of a clinical trial setting was conducted by our group.Methods: All consecutive patients with RR-MM who received carfilzomib-containing salvage therapy outside of a clinical trial between March 2013 and April 2015 were included in this study. For the response and survival analyses, patients were included only if they received at least one full cycle of carfilzomib and response evaluation was available. Carfilzomib was used either as a single agent or in combinations with other drugs, according to the treating physician's choice. Per manufacturer's recommendations, carfilzomib was given by intravenous infusion over 10-30 minutes on days 1, 2,8,9,15,16 of 28-days cycle. The recommended dose of carfilzomib was 20 mg/m2 on days 1 and 2 in cycle 1, which was increased on subsequent administrations to 27 mg/m2 (the 20/27 mg/m2 schedule), provided that the previous dose was well tolerated. Doses, however, were modified according to the treating physician's discretion.Results: One-hundred and thirty-five patients were included. The median age at carfilzomib initiation was 67.9 years (range, 41-88). Male and female patients were equally balanced. Eastern Cooperative Oncology Group (ECOG) performance status 3 or 4 was evident in 14.8% of patients. All patients were previously exposed to bortezomib and 93% to lenalidomide as well. The median time from last treatment to carfilzomib was 5.5 months (range, 0.3-43). Patients had received a median of 3 lines of therapy prior to carfilzomib (range, 1-7). The median number of administrated cycles of carfilzomib was 4 (range, 0.3-22). The majority of patients (79.3%) received carfilzomib according to the 20/27 mg/m2 dose schedule. The remaining patients received carfilzomib either at a dose that did not exceed 20 mg/m2 (11.8%) or at maximal dose higher than 27 mg/m2 (8.9%, mostly as a 20/27/56 mg/m2 dose schedule). Carfilzomib was administrated as a single agent in 5.1% of patients or combined with a second agent in 43% of them. Additionally, 46.7% of patients received carfilzomib as part of a three-drug combination and 5.2% of patients as part of four-drug combination or more. In comparison to patients who received two-drug combination (or carfilzomib alone), patients who received three-drug (or more) combination were younger, with less prior treatment lines and higher baseline haemoglobin, albumin and eGFR (Table I). There was also pre-selection by lower frequency of ImIds resistance in the three-drug combination sub-group, but bortezomib resistance was similar between sub-groups. One hundred and twenty three patients (91.1% of patients) were evaluable for response and survival analysis. The overall response rate was 48.8%, with one patient (0.8%) achieving complete response (CR), 30 patients (24.4%) attaining very good partial response (VGPR) and 29 patients (23.6%) with partial response (PR). Additionally, 15 patients (12.2%) achieved minimal response (MR), reaching a clinical benefit response (CBR) rate of 61%. A multivariate analysis revealed three parameters negatively impact the likelihood of achieving response: bortezomib resistance (odds ratio 0.33, 95% CI 0.12-0.94, p=0.03); lenalidomide resistance (odds ratio 0.31, 95% CI 0.11-0.91, p=0.03), and albumin <3.5 g/dL (odds ratio 0.32, 95% CI 0.14-0.71 p=0.005). The median duration of response was 8.3 months, significantly higher in patients receiving three-drug combination and in patients presenting without extramedullary disease. The median progression free survival (PFS) and overall survival for the entire cohort were 4.9 months (95% CI 3.9-6.9) and 19.3 months (95% CI 9.4-not yet reached), respectively. Toxicity was manageable, although treatment-related death was seen in 5% of patients.Conclusion: In the setting of progressive multiple myeloma, carfilzomib in a combination regimens yields an effective results with a manageable toxicity. Drug resistance is an important factor in determining response quality to carfilzomib. DisclosuresRaanani:Ariad: Other: Advisory Board; Pfizer: Other: Advisory Board; BMS: Other: Advisory Board; Novartis: Other: Advisory Board, Research Funding.

Velcade, Vorinostat and Dexamethasone (V2 D) in Relapsed Myeloma: Results of the Phase 2 Muk Four Trial

Introduction: Bortezomib (Velcade) and dexamethasone is a standard combination for relapsed myeloma. Both in vitro data and initial clinical trials signalled the efficacy of the combination of intravenous bortezomib and the oral histone deacetylase inhibitor vorinostat. Although the randomised phase 3 VANTAGE 088 trial identified an improvement in progression free survival with the combination of bortezomib and vorinostat compared to bortezomib monotherapy in relapsed myeloma, 50% of patients in the vorinostat group had at least one dose reduction compared with 25% in the placebo group, with potential impact on clinical outcomes. Subcutaneous bortezomib has now become the standard route of administration because of lower rates of peripheral neuropathy. MUK four is a single arm phase 2 multi-centre UK trial to evaluate the toxicity profile and efficacy of an alternative dosing schedule of vorinostat in combination with subcutaneous bortezomib and oral dexamethasone. We report the final analysis of toxicity and response data.Methods: Patients with relapsed myeloma treated with 1-3 prior lines of therapy received up to 8 cycles of V2 D (bortezomib 1.3 mg/m2 subcutaneously days 1, 4, 8 and 11, vorinostat 400 mg orally days 1-4, 8-11 and 15-18 and dexamethasone 20 mg orally days 1, 2, 4, 5, 8, 9, 11 and 12 of a 21 day cycle). Following completion of a minimum of 3 cycles of V2 D, participants received maintenance vorinostat (400 mg days 1-4 and 15-18 of a 28 day cycle) until disease progression, intolerance or participant withdrawal. Responses were assessed using the modified IMWG response criteria and toxicities graded using CTCAE v4.0.Results: Between August 2013 and November 2014, 16 participants were recruited to MUK four. Median age was 69.5 years (range 50.0-78.0) and median lines of prior treatment was 1 (1-3). Prior treatment included thalidomide-based combinations in 13/16 (81.3%), bortezomib-based in 7/16 (43.8%) and lenalidomide-based in 2/16 (12.5%). 9/16 (56.3%) participants had received prior high dose melphalan ASCT. Median time from diagnosis was 38.6 months (9.3-120.4).At analysis in June 2015 8/16 (50%) participants continued on maintenance vorinostat. All 16 patients were evaluable for response within the first 8 cycles of V2 D. Overall response rate was 81.3% (13/16, 95% CI [55.4-96.0]) consisting of CR in 4/16 (25.0%), VGPR 2/16 (12.5%) and PR in 7/16 (43.8%). The remaining 3/16 (18.8%) achieved MR giving a clinical benefit response rate of 16/16 (100%).Participants received a median of 6 cycles of initial treatment with 6/16 (37.5%) receiving all 8 cycles. Treatment was discontinued in 4/8 (50%) because of disease progression, in 2/8 (25%) because of toxicity and in 2/8 (25%) for clinician discretion. Overall 12/16 (75%) participants experienced a dose reduction of either vorinostat or bortezomib or terminated treatment early as a result of toxicity. 11/16 (68.8%) reduced vorinostat and 10/16 (62.5%) reduced bortezomib. The most frequent grade 2 toxicities during the first 8 cycles were fatigue in 8/16 (50%), anaemia in 7/16 (43.8%), diarrhoea in 5/16 (31.3%), nausea in 4/16 (25.0%) and peripheral neuropathy in 4/16 (25.0%). The most frequent grade 3-4 toxicities encountered during the first 8 cycles were thrombocytopenia in 8/16 (50%), anaemia in 1/16 (6.3%), diarrhoea in 1/16 (6.3%) and fatigue in 1/16 (6.3%). During maintenance vorinostat only 1 participant experienced an adverse reaction above grade 2 (grade 3 neutropenia).Conclusion: Bortezomib, vorinostat and dexamethasone is a highly effective combination in relapsed myeloma with good response rates. Maintenance vorinostat is well tolerated. Although toxicity and dose reductions are observed with combination therapy, this study demonstrates that the combination of proteasome inhibitor, HDAC inhibitor and dexamethasone offers promise. Further data on PFS will be presented. DisclosuresJenner:Amgen: Honoraria; Takeda: Honoraria. Off Label Use: Vorinostat for treatment of myeloma. Pawlyn:Celgene: Honoraria, Other: Travel support; The Institute of Cancer Research: Employment. Williams:Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau. Davies:Array-Biopharma: Membership on an entity's Board of Directors or advisory committees; Takeda-Millennium: Membership on an entity's Board of Directors or advisory committees; University of Arkansas for Medical Sciences: Employment; Onyx-Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

Oral Ridaforolimus Plus Trastuzumab for Patients With HER2+ Trastuzumab-Refractory Metastatic Breast Cancer

BackgroundAlthough trastuzumab-containing therapies prolong survival in patients with metastatic breast cancer (MBC), most tumors develop trastuzumab resistance, potentially mediated by aberrant phosphatidylinositide 3-kinase (PI3K)/AKT signaling. Ridaforolimus (a mammalian target of rapamycin [mTOR] inhibitor) may overcome trastuzumab resistance by inhibiting PI3K signaling. MethodsA single-arm, phase IIb trial was conducted to evaluate the efficacy and safety of ridaforolimus-trastuzumab in human epidermal growth factor receptor 2–positive (HER2+) trastuzumab-refractory MBC (NCT00736970). Ridaforolimus was administered orally (40 mg daily) for 5 d/wk plus weekly trastuzumab. The primary end point was objective response (OR). ResultsThirty-four patients were enrolled (91% had received 1 or 2 previous trastuzumab-based therapies, whereas 9% had received 3 previous therapies). The most common reasons for discontinuation were disease progression (62%) and adverse events (AEs; 24%). Three patients died; 1 because of bowel perforation, which was possibly ridaforolimus related. Partial response was observed in 5 patients (15%). Median duration of response was 19.1 weeks (range, 15.9-80.1 weeks). Fourteen patients (41%) achieved stable disease (SD); 7 patients (21%) maintained SD for ≥ 24 weeks. The clinical benefit response (CBR) rate was 34.3%. Median progression-free survival (PFS) and overall survival (OS) were 5.4 months (range, 0-20.3 months; 95% confidence interval [CI], 2.0-7.4) and 17.7 months (range, 0-25.9 months; 95% CI, 8.8-20.8), respectively. PFS rate at 6 months was 37%. The most common treatment-related AEs were stomatitis (59%), diarrhea (27%), and rash (27%). ConclusionRidaforolimus-trastuzumab was well tolerated and demonstrated antitumor activity in trastuzumab-resistant HER2+ MBC.