Phase IB study to evaluate the safety of selinexor in combination with multiple standard chemotherapy agents in patients with advanced malignancies

TPS2603

Background: Selinexor is a first-in-class, slowly reversible, Selective Inhibitor of Nuclear Export (SINE) compound that specifically blocks XPO1. Inhibition of XPO1 results in nuclear localization, accumulation, and reactivation of tumor suppressor proteins, therefore selectively inducing apoptosis in cancer cells, while largely sparing normal cells. This unique property of XPO1 inhibition has been deployed as a novel therapeutic strategy with success in several solid tumors and hematologic malignancy clinical trials. Preclinical studies have shown that SINE compounds behave synergistically to enhance cancer cell death with combined with different therapeutic agents. This Phase I trial is based on such preclinical evidence. The primary objective of the study is to establish the safety and tolerability of selinexor when given in combination with thirteen standard chemotherapy regimens. The secondary objectives are to determine disease control and progression-free survival of patients receiving selinexor administered with standard chemotherapy treatments in specific tumor subsets. Methods: Adult patients ≥ 18 years of age are eligible if they have histologically confirmed neoplasms (excluding hematological malignancies and brain tumors) that are refractory to established therapy known to provide clinical benefit for their condition. Patients are required to have either measurable disease (RECIST 1.1) or evaluable disease, and an ECOG performance status of 0-1. Enrollment is ongoing for dose escalation with the plan for dose expansion as follows: Clinical trial information: NCT02419495. [Table: see text]

First-in-human trial of multikinase VEGF inhibitor regorafenib and anti-EGFR antibody cetuximab in advanced cancer patients

BACKGROUND

The combination of multikinase VEGF inhibitor regorafenib and anti-EGFR antibody cetuximab overcomes intrinsic and acquired resistance in both EGFR-sensitive and EGFR-resistant preclinical models of colorectal cancer (CRC).

METHODS

Utilizing a standard 3+3 design, a phase I study was designed to determine safety, maximum tolerated dose (MTD), and dose-limiting toxicities (DLTs) of the regorafenib plus cetuximab combination among patients with advanced cancer including CRC. Comprehensive genomic profiling was performed on the exceptional responder.

RESULTS

Among the 27 patients enrolled the median age was 54 years. None of 19 patients treated at dose level 1 (cetuximab i.v. 200 mg/m2 followed by 150 mg/m2 weekly + regorafenib 80 mg daily) experienced a DLT, and 2 of 5 patients treated at dose level 2 (cetuximab i.v. 200 mg/m2 followed by 150 mg/m2 weekly + regorafenib 120 mg daily) experienced a DLT (grade 3 thrombocytopenia [n = 1] and grade 3 intra-abdominal bleed [n = 1]). Most common adverse events were grade 1 or 2 rash (20 patients). Of 24 evaluable patients, 11 (46%) patients had clinical benefit (stable disease > 6 cycles or partial response [PR]) (CRC n = 8, one patient each with head and neck cancer, carcinoma of unknown primary, and glioblastoma). A CRC patient, who progressed on anti-EGFR and regorafenib, achieved a PR (46% decrease per RECIST v1.1) lasting 15 months. Genomic profiling of an exceptional responder with response for over 27 cycles revealed hypermutated genotype with microsatellite instability (MSI).

CONCLUSION

Regorafenib 80 mg daily plus cetuximab 200 mg/m2 loading dose, followed by 150 mg/m2 every week is the MTD/recommended phase II dose. The combination demonstrated early signals of activity in wild-type CRC, including 1 exceptional responder with MSI high.

TRIAL REGISTRATION

clinicaltrials.gov NCT02095054FUNDING. The University of Texas MD Anderson Cancer Center is supported by the NIH Cancer Center Support Grant CA016672. This work was supported in part by the Cancer Prevention Research Institute of Texas grant RP110584 and National Center for Advancing Translational Sciences grant UL1 TR000371 (Center for Clinical and Translational Sciences).

Targeting the PI3K/AKT/mTOR Pathway for the Treatment of Mesenchymal Triple-Negative Breast Cancer: Evidence From a Phase 1 Trial of mTOR Inhibition in Combination With Liposomal Doxorubicin and Bevacizumab

Importance

Triple-negative breast cancer (TNBC) classified by transcriptional profiling as the mesenchymal subtype frequently harbors aberrations in the phosphoinositide 3-kinase (PI3K) pathway, raising the possibility of targeting this pathway to enhance chemotherapy response. Up to 30% of mesenchymal TNBC can be classified histologically as metaplastic breast cancer, a chemorefractory group of tumors with a mixture of epithelial and mesenchymal components identifiable by light microscopy. While assays to identify mesenchymal TNBC are under development, metaplastic breast cancer serves as a clinically identifiable surrogate to evaluate potential regimens for mesenchymal TNBC.

Objective

To assess safety and efficacy of mammalian target of rapamycin (mTOR) inhibition in combination with liposomal doxorubicin and bevacizumab in patients with advanced metaplastic TNBC.

Design, Setting, and Participants

Phase 1 study with dose escalation and dose expansion at the University of Texas MD Anderson Cancer Center of patients with advanced metaplastic TNBC. Patients were enrolled from April 16, 2009, to November 4, 2014, and followed for outcomes with a cutoff date of November 1, 2015, for data analysis.

Interventions

Liposomal doxorubicin, bevacizumab, and the mTOR inhibitors temsirolimus or everolimus using 21-day cycles.

Main Outcomes and Measures

Safety and response. When available, archived tissue was evaluated for aberrations in the PI3K pathway.

Results

Fifty-two women with metaplastic TNBC (median age, 58 years; range, 37-79 years) were treated with liposomal doxorubicin, bevacizumab, and temsirolimus (DAT) (N = 39) or liposomal doxorubicin, bevacizumab, and everolimus (DAE) (N = 13). The objective response rate was 21% (complete response = 4 [8%]; partial response = 7 [13%]) and 10 (19%) patients had stable disease for at least 6 months, for a clinical benefit rate of 40%. Tissue was available for testing in 43 patients, and 32 (74%) had a PI3K pathway aberration. Presence of PI3K pathway aberration was associated with a significant improvement in objective response rate (31% vs 0%; P = .04) but not clinical benefit rate (44% vs 45%; P > .99).

Conclusions and Relevance

Using metaplastic TNBC as a surrogate for mesenchymal TNBC, DAT and DAE had notable activity in mesenchymal TNBC. Objective response was limited to patients with PI3K pathway aberration. A randomized trial should be performed to test DAT and DAE for metaplastic TNBC, as well as nonmetaplastic, mesenchymal TNBC, especially when PI3K pathway aberrations are identified.

Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry

Purpose In addition to prospective trials for non-small-cell lung cancers (NSCLCs) that are driven by less common genomic alterations, registries provide complementary information on patient response to targeted therapies. Here, we present the results of an international registry of patients with RET-rearranged NSCLCs, providing the largest data set, to our knowledge, on outcomes of RET-directed therapy thus far. Methods A global, multicenter network of thoracic oncologists identified patients with pathologically confirmed NSCLC that harbored a RET rearrangement. Molecular profiling was performed locally by reverse transcriptase polymerase chain reaction, fluorescence in situ hybridization, or next-generation sequencing. Anonymized data-clinical, pathologic, and molecular features-were collected centrally and analyzed by an independent statistician. Best response to RET tyrosine kinase inhibition administered outside of a clinical trial was determined by RECIST v1.1. Results By April 2016, 165 patients with RET-rearranged NSCLC from 29 centers across Europe, Asia, and the United States were accrued. Median age was 61 years (range, 29 to 89 years). The majority of patients were never smokers (63%) with lung adenocarcinomas (98%) and advanced disease (91%). The most frequent rearrangement was KIF5B-RET (72%). Of those patients, 53 received one or more RET tyrosine kinase inhibitors in sequence: cabozantinib (21 patients), vandetanib (11 patients), sunitinib (10 patients), sorafenib (two patients), alectinib (two patients), lenvatinib (two patients), nintedanib (two patients), ponatinib (two patients), and regorafenib (one patient). The rate of any complete or partial response to cabozantinib, vandetanib, and sunitinib was 37%, 18%, and 22%, respectively. Further responses were observed with lenvantinib and nintedanib. Median progression-free survival was 2.3 months (95% CI, 1.6 to 5.0 months), and median overall survival was 6.8 months (95% CI, 3.9 to 14.3 months). Conclusion Available multikinase inhibitors had limited activity in patients with RET-rearranged NSCLC in this retrospective study. Further investigation of the biology of RET-rearranged lung cancers and identification of new targeted therapeutics will be required to improve outcomes for these patients.

Mutation enrichment next-generation sequencing for quantitative detection of KRAS mutations in urine cell-free DNA from patients with advanced colorectal and other cancers

602

Background: Molecular testing of cell-free (cf) DNA from urine is a completely non-invasive approach for detection of actionable mutations in cancer. Methods: A quantitative mutation enrichment next-generation sequencing (NGS) urine cell-free (cf) DNA KRASG12/G13mutation test was developed and results compared to clinical testing of archival tumor tissue and research testing of plasma cfDNA from patients with advanced colorectal (n=56, 79%) and other advanced cancers (n=15, 21%). Results: The analytical sensitivity of the KRASG12/G13 cfDNA test was 0.002%-0.006% mutant copies in wild-type background. In 71 patients, the agreement between urine cfDNA and tumor was 73% (sensitivity 63%; specificity 96%); the agreement increased to 89% for patients with recommended 90-110mL of urine. In 33 patients with available plasma samples, the agreement with tumor was 94% (sensitivity 92%; specificity 100%). In patients treated with systemic therapy there was lower number of KRASG12/G13 copies in urine and plasma cfDNA on therapy compared to baseline and progression ( P<0.003). Decrease in urine and plasma cfDNA KRASG12/G13 copies on therapy compared to no change/increase was associated with longer median time to treatment failure ( P<0.05). Conclusions: Mutation enrichment NGS detection of KRASG12/G13 mutations in urine cfDNA has good concordance with archival tumor tissue. Changes in urine cfDNA correspond with time to treatment failure.

Survival of patients with metastatic leiomyosarcoma: the MD Anderson Clinical Center for targeted therapy experience

Advanced stage leiomyosarcoma (LMS) is incurable with current systemic antitumor therapies. Therefore, there is clinical interest in exploring novel therapeutic regimens to treat LMS. We reviewed the medical records of 75 consecutive patients with histologically confirmed metastatic LMS, who had been referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center. To lay the foundation for potential phase I trials for the treatment of advanced LMS, we analyzed tumor response and survival outcome data. The frequent hotspot gene aberrations that we observed were the TP53 mutation (65%) and RB1 loss/mutation (45%) detected by Sequenom or next-generation sequencing. Among patients treated with gene aberration-related phase I trial therapy, the median progression-free survival was 5.8 months and the median overall survival was 15.9 months, significantly better than in patients without therapy (1.9 months, P = 0.001; and 8.7 months, P = 0.013, respectively). Independent risk factors that predicted shorter overall survival included hemoglobin <10 g/dL, body mass index <30 kg/m2 , serum albumin <3.5 g/dL, and neutrophil above upper limit of normal. The median survivals were 19.9, 7.6, and 0.9 months for patients with 0, 1 or 2, and ≥3 of the above risk factors, respectively (P < 0.001). A prognostic scoring system that included four independent risk factors might predict survival in patients with metastatic LMS who were treated in a phase I trial. Gene aberration-related therapies led to significantly better clinical benefits, supporting that further exploration with novel mechanism-driven therapeutic regimens is warranted.

Treatment with methylnaltrexone is associated with increased survival in patients with advanced cancer

BACKGROUND

Methylnaltrexone (MNTX), a peripherally acting μ-opioid receptor (MOR) antagonist, is FDA-approved for treatment of opioid-induced constipation (OIC). Preclinical data suggest that MOR activation can play a role in cancer progression and can be a target for anticancer therapy.

PATIENTS AND METHODS

Pooled data from advanced end-stage cancer patients with OIC, despite laxatives, treated in two randomized (phase III and IV), placebo-controlled trials with MNTX were analyzed for overall survival (OS) in an unplanned post hoc analysis. MNTX or placebo was given subcutaneously during the double-blinded phase, which was followed by the open-label phase, allowing MNTX treatment irrespective of initial randomization.

RESULTS

In two randomized, controlled trials, 229 cancer patients were randomized to MNTX (117, 51%) or placebo (112, 49%). Distribution of patients' characteristics and major tumor types did not significantly differ between arms. Treatment with MNTX compared with placebo [76 days, 95% confidence interval (CI) 43-109 versus 56 days, 95% CI 43-69; P = 0.033] and response (laxation) to treatment compared with no response (118 days, 95% CI 59-177 versus 55 days, 95% CI 40-70; P < 0.001) had a longer median OS, despite 56 (50%) of 112 patients ultimately crossing over from placebo to MNTX. Multivariable analysis demonstrated that response to therapy [hazard ratio (HR) 0.47, 95% CI 0.29-0.76; P = 0.002) and albumin ≥3.5 (HR 0.46, 95% CI 0.30-0.69; P < 0.001) were independent prognostic factors for increased OS. Of interest, there was no difference in OS between MNTX and placebo in 134 patients with advanced illness other than cancer treated in these randomized studies (P = 0.88).

CONCLUSION

This unplanned post hoc analysis of two randomized trials demonstrates that treatment with MNTX and, even more so, response to MNTX are associated with increased OS, which supports the preclinical hypothesis that MOR can play a role in cancer progression. Targeting MOR with MNTX warrants further investigation in cancer therapy.

CLINICAL TRIALS NUMBER

NCT00401362, NCT00672477.

BRAF mutation testing with a rapid, fully integrated molecular diagnostics system

Fast and accurate diagnostic systems are needed for further implementation of precision therapy of BRAF-mutant and other cancers. The novel Idylla^TMBRAF Mutation Test has high sensitivity and shorter turnaround times compared to other methods. We used Idylla to detect BRAF V600 mutations in archived formalin-fixed paraffin-embedded (FFPE) tumor samples and compared these results with those obtained using the cobas 4800 BRAF V600 Mutation Test or MiSeq deep sequencing system and with those obtained by a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory employing polymerase chain reaction–based sequencing, mass spectrometric detection, or next-generation sequencing. In one set of 60 FFPE tumor samples (15 with BRAF mutations per Idylla), the Idylla and cobas results had an agreement of 97%. Idylla detected BRAF V600 mutations in two additional samples. The Idylla and MiSeq results had 100% concordance. In a separate set of 100 FFPE tumor samples (64 with BRAF mutation per Idylla), the Idylla and CLIA-certified laboratory results demonstrated an agreement of 96% even though the tests were not performed simultaneously and different FFPE blocks had to be used for 9 cases. The Idylla^TMBRAF Mutation Test produced results quickly (sample to results time was about 90 minutes with about 2 minutes of hands on time) and the closed nature of the cartridge eliminates the risk of PCR contamination. In conclusion, our observations demonstrate that the Idylla test is rapid and has high concordance with other routinely used but more complex BRAF mutation–detecting tests.

Abstract 493: Quantity of KRAS mutations in cell-free DNA is associated with survival of patients with advanced cancers

Background: Cell-free (cf) DNA from plasma offers an easily obtainable material for KRAS mutation analysis for diagnostics and monitoring. There is emerging evidence that the percentage of mutant cfDNA in the wild-type background (mutant allele fraction, MAF) and/or absolute quantity of mutant cfDNA can be associated with survival of patients with advanced cancers.

Methods: Plasma-derived cfDNA from patients with progressing advanced cancers was purified and 16 ng of DNA was tested with a KRAS multiplex assay to distinguish the wild-type allele from 7 of the most common mutations in the G12 and G13 hotspot of exon 2 using the QX200 Droplet Digital PCR™ platform (Bio-Rad). Results were compared to mutation analysis of archival primary or metastatic tumor tissue obtained at different points of clinical care from a CLIA-certified laboratory and clinical outcomes including survival.

Results: Of the 117 patients (colorectal cancer, 71; non-small cell lung cancer, 12; melanoma, 10; pancreatic cancer, 5; ovarian cancer, 5; appendiceal cancer, 5; other cancers, 9), KRAS mutations were detected in 85 (73%) archival FFPE tumor samples and 85 (73%) plasma cfDNA samples. The two methods had overall agreement in 109 patients (93%; kappa, 0.83, standard error, 0.06; 95% confidence interval [CI], 0.71-0.94), sensitivity of 95% (95% CI, 0.88-0.99), specificity of 88% (95% CI, 0.71-0.96), even though median time from tissue to blood sampling was 18.5 months (1.1-134.4 months). A higher MAF (&gt;7%) of KRAS in cfDNA as determined by 5% trimmed mean value was associated with shorter survival compared to lower (&lt;7%) MAF (5.4 vs. 7.6 months; P = 0.001), which was confirmed on multivariate analysis. A total of 20 patients with KRAS mutations in cfDNA had longitudinal testing of cfDNA from at least two time points obtained before and on experimental therapy. In these patients, changes in MAF demonstrated a trend towards positive correlation with changes in measurement of target tumor lesions on imaging per RECIST (r = 0.42, P = 0.07).

Conclusions: A higher percentage of KRAS mutation in plasma cfDNA is an independent predictive factor for shorter survival in patients with advanced cancers.

Citation Format: Kiran Madwani, Helen J. Huang, Dawne N. Shelton, Siqing Fu, Apostolia M. Tsimberidou, Sarina A. Piha-Paul, Aung Naing, David S. Hong, Daniel D. Karp, Debra L. Andrews, Goran Cabrilo, E. Scott Kopetz, Rajyalakshmi Luthra, Bryan K. Kee, Cathy Eng, Van K. Morris, George A. Karlin-Neumann, Funda Meric-Bernstam, Filip Janku. Quantity of KRAS mutations in cell-free DNA is associated with survival of patients with advanced cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 493.

Abstract 2273: Targeting the PI3K/AKT/mTOR pathway for the treatment of metaplastic breast cancer: Does location of PIK3CA mutation or histology affect response

Background: Metaplastic breast cancers (MpBCs) are a chemo-refractory group of tumors that contain a component of squamous and/or mesenchymal differentiation identifiable by light microscopy. MpBCs contain a high frequency of aberrations in the PI3K/AKT/mTOR pathway, making this pathway a potential target for therapy.

Methods: Patients with advanced MpBC (N = 52) were treated with liposomal doxorubicin (D), bevacizumab (A) and the mTOR inhibitors temsirolimus (T) or everolimus (E). D and A were administered IV on day 1 with T (IV on days 1, 8 and 15) or E (continuous daily oral administration) using 21 day cycles. All tumors were evaluated to assess histology of metaplasia (spindle, mixed spindle vs non-spindle cell). Response was assessed every 6 weeks using RECIST. When available, archived tissue was evaluated for aberrations in the PI3K pathway using standard assays.

Results: Fifty-two MpBC patients were treated with DAT (N = 39) or DAE (N = 13). Median age was 58 (range 37-79); median number of prior regimens for metastatic disease was 1 (range 0-5). The objective response rate (ORR) was 21% [complete response (CR) = 4 (8%); partial response (PR) = 7 (13%)] and 10 (19%) pts had stable disease (SD)≥6 months for a clinical benefit rate (CBR) of 40%. Tissue was available in 43 pts and 32 (74%) had a PI3K pathway activating aberrations. PI3K pathway aberration was associated with a significant improvement in ORR (31 vs 0%; P = 0.04) but not CBR (44 vs 45%; P = 1.00) or progression-free survival (median 5 vs 3 months; P = 0.35). The most frequent PI3K pathway aberration was mutation in PIK3CA, occurring in 19 patients. Outcomes were similar if mutations of PIK3CA were located in the helical or kinase domain (ORR 25% vs 27%; P = 1.00 and CBR 38% vs 47%; P = 1.00, respectively). Spindle cell was the most frequent metaplastic histology seen, occurring in 18 tumors and mixed with other metaplastic histologies including squamous, chondroid and osseous in 14 additional tumors, while 20 tumors had non-spindle cell morphologies. The incidence of PI3K pathway aberration was similar across histologies (61% in spindle vs 67% in mixed spindle vs 60% in non-spindle cell). Tumors with mixed histology had lower ORR, CBR and PFS, but this was not statistically significant, likely due to small numbers in each cohort: ORR 22% in spindle vs 7% in mixed spindle vs 30% in non-spindle cell, P = 0.27; CBR 50% in spindle vs 21% in mixed spindle vs 40% in non-spindle cell, P = 0.25; and PFS median 4 months in spindle vs 2 months in mixed spindle vs 5 months in non-spindle cell, P = 0.68.

Conclusions: Response to mTOR inhibition is enhanced in MpBCs with PI3K pathway aberrations. However, specific aberrations in PIK3CA do not lead to differential response to mTOR inhibition. PI3K pathway aberrations and response to mTOR inhibition are seen across all histologies of MpBC, and the response is not enhanced in particular histologies.

Citation Format: Reva K. Basho, Michael Gilcrease, Rashmi K. Murthy, Thorunn Helgason, Daniel J. Booser, Daniel D. Karp, Funda Meric-Bernstam, Kenneth R. Hess, Shelley M. Herbrich, Vicente Valero, Constance Albarracin, Jennifer Litton, Mariana Chavez-MacGregor, Nuhad K. Ibrahim, James L. Murray, Kimberly B. Koenig, David Hong, Vivek Subbiah, Razelle Kurzrock, Filip Janku, Stacy Moulder. Targeting the PI3K/AKT/mTOR pathway for the treatment of metaplastic breast cancer: Does location of PIK3CA mutation or histology affect response. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2273.

Abstract 3146: Circulating tumor DNA assay performance for detection and monitoring of KRAS mutations in urine from patients with advanced cancers

Introduction: Non-invasive urinary ctDNA-based liquid biopsy approach can be used to detect and track cancer driver mutations for rapid diagnosis and disease monitoring. Using highly sensitivity ctDNA mutation detection platform, we examined the detection of KRAS G12/13 mutations in urine obtained from advanced cancer patients, assessed urine sample requirements, and compared the results with matched tumor tissue in patients with advanced cancers.

Methods: 41 patients with advanced solid cancer with KRAS mutations on archival tumor from CLIA laboratory testing were prospectively enrolled with informed consent (colorectal cancer, n = 29; non-small cell lung cancer, n = 6; pancreatic cancer, n = 2; ovarian cancer, n = 2; other, n = 2). Urine was collected before and during experimental therapies. Urinary DNA was isolated using a method that enriches for highly fragmented, systemically derived cell-free DNA. KRAS G12/13 analysis was performed using mutation enrichment PCR coupled with next generation sequencing (MiSeq). Analytical sensitivity of the KRAS G12/13 assay is 0.006% mutant alleles in the background of 60 ng wild-type (wt) DNA and 0.002% mutant alleles in 360 ng wt DNA. Clinical data was collected retrospectively from the electronic medical record.

Results: For 41 patients enrolled on a study, urine volumes in pretreatment samples ranged from 13 to 120 mL (median, 55 mL). Urinary DNA yields were 151 to 23059 ng (median, 1039 ng). Using tissue as the reference, the positive percent agreement (PPA) between urine and tumor KRAS G12/13 test results was 54% (22/41) for urine samples with all volumes (13-120 mL) and any DNA input amount (2-360 ng) and 92% (12/13) for urine samples with volumes ≥50 mL and DNA input amount ≥60 ng. For metastatic CRC patient cohort, the PPA between urine and tumor KRAS G12/13 test result was 60% (18/30) for urine samples with all volumes and any DNA input amount (20-120 mL, 2-360 ng) and 100% (10/10) for urine samples with volumes ≥50 mL and DNA input amount ≥60 ng. Feasibility of longitudinal monitoring KRAS G12/13 mutational burden in urine of patients treated with experimental therapies was demonstrated.

Conclusion: KRAS G12/13 mutational status can be assess in urinary DNA with highest PPA amongst patients with urine volume ≥50 mL and DNA input amount ≥60 ng (92%). KRAS mutation detection from urine should be considered as a viable approach, particularly when tumor tissue is not available.

Citation Format: Takeo Fujii, Cecile Rose T. Vibat, Daniel D. Karp, Sarina A. Piha-Paul, Vivek Subbiah, Apostolia M. Tsimberidou, Siquing Fu, David S. Hong, Helen J. Huang, Kiran Madwani, Debra L. Andrews, Saege Hancock, Aung Naing, Rajyalakshmi Luthra, Bryan K. Kee, Scott Kopetz, Mark G. Erlander, Vlada Melnikova, Funda Meric-Bernstam, Filip Janku. Circulating tumor DNA assay performance for detection and monitoring of KRAS mutations in urine from patients with advanced cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3146.

Innovative Strategies for Decreasing Blood Collection Wait Times for Patients in Early-Phase Cancer Clinical Trials

PURPOSE

Long wait times are a primary source of dissatisfaction among patients enrolled in early-phase clinical trials. We hypothesized that an automated patient check-in system with readily available display for increasing awareness of waiting intervals would improve patient flow and use of our rooms, with decreased turnover time and increased throughput.

METHODS

We recorded in-room wait times for patients seen in our clinic and observed the logistics involved in the blood collection process to delineate causes for delays. We then implemented a three-step strategy to alleviate the causes of these delays: (1) changing the collection of materials and the review of faxed orders, (2) improving our LabTracker automated database system that included wait time calculators and real-time information regarding patient status, and (3) streamlining lower complexity appointments.

RESULTS

After our intervention, we observed a 19% decrease in mean wait times and a 30% decrease in wait times among patients waiting the longest (95th percentile). We also observed an increase in staff productivity during this process. Modifications in LabTracker provided the biggest reduction in mean wait times (17%).

CONCLUSION

We observed a significant decrease in mean wait times after implementing our intervention. This decrease led to increased staff productivity and cost savings. Once wait times became a measurable metric, we were able to identify causes for delays and improve our operations, which can be performed in any patient care facility.

BRAF Mutation Testing in Cell-Free DNA from the Plasma of Patients with Advanced Cancers Using a Rapid, Automated Molecular Diagnostics System

Cell-free (cf) DNA from plasma offers an easily obtainable material for BRAF mutation analysis for diagnostics and response monitoring. In this study, plasma-derived cfDNA samples from patients with progressing advanced cancers or malignant histiocytosis with known BRAF(V600) status from formalin-fixed paraffin-embedded (FFPE) tumors were tested using a prototype version of the Idylla BRAF Mutation Test, a fully integrated real-time PCR-based test with turnaround time about 90 minutes. Of 160 patients, BRAF(V600) mutations were detected in 62 (39%) archival FFPE tumor samples and 47 (29%) plasma cfDNA samples. The two methods had overall agreement in 141 patients [88%; κ, 0.74; SE, 0.06; 95% confidence interval (CI), 0.63-0.85]. Idylla had a sensitivity of 73% (95% CI, 0.60-0.83) and specificity of 98% (95% CI, 0.93-1.00). A higher percentage, but not concentration, of BRAF(V600) cfDNA in the wild-type background (>2% vs. ≤ 2%) was associated with shorter overall survival (OS; P = 0.005) and in patients with BRAF mutations in the tissue, who were receiving BRAF/MEK inhibitors, shorter time to treatment failure (TTF; P = 0.001). Longitudinal monitoring demonstrated that decreasing levels of BRAF(V600) cfDNA were associated with longer TTF (P = 0.045). In conclusion, testing for BRAF(V600) mutations in plasma cfDNA using the Idylla BRAF Mutation Test has acceptable concordance with standard testing of tumor tissue. A higher percentage of mutant BRAF(V600) in cfDNA corresponded with shorter OS and in patients receiving BRAF/MEK inhibitors also with shorter TTF. Mol Cancer Ther; 15(6); 1397-404. ©2016 AACR.

Abstract P3-14-02: Targeting the PI3K/AKT/mTOR pathway for the treatment of mesenchymal triple-negative breast cancer (TNBC): Evidence of efficacy and proof of concept from a phase I trial with dose expansion of mTOR inhibition in combination with liposomal doxorubicin and bevacizumab

Background: Approximately 30% of TNBCs are characterized by microarray as claudin-low, mesenchymal or mesenchymal stem cell-like and, unlike basal TNBCs, these tumors frequently harbor aberrations in the PI3K/AKT/mTOR axis, raising the possibility of targeting this axis to enhance chemotherapy response. Assays to clinically identify mesenchymal TNBCs are under development, but published results confirm that up to 30% are metaplastic breast cancers (MpBCs), a chemo-refractory group of tumors that contain a mixture of epithelial and mesenchymal components, making them identifiable by microscopy. As such, MpBCs serve as surrogates of response for potential regimens to treat mesenchymal TNBC.

Methods: Patients (pts) with advanced TNBC (N=64) were treated with liposomal doxorubicin (D), bevacizumab (A) and the mTOR inhibitors temsirolimus (T) or everolimus (E). D and A were administered IV on day 1 with T (IV on days 1, 8 and 15) or E (continuous daily oral administration) using 21 day cycles. Response was assessed every 6 weeks using RECIST. When available, archived tissue was evaluated for aberrations in the PI3K pathway using standard assays.

Results: Fifty-two MpBC pts were treated with DAT (N=39) or DAE (N=13). Median age was 58 (range 37-79); median # of prior regimens for metastatic disease was 1 (range 0-5). The objective response rate (ORR) was 21% [complete response (CR)=4 (8%); partial response (PR)=7 (13%)] and 10 (19%) pts had stable disease (SD)≥6 months for a clinical benefit rate (CBR) of 40%. Tissue was available for testing in 43 pts and 32 (74%) had a PI3K pathway activating aberration (Table 1).

Response According to PI3K Pathway AberrationPI3K Pathway AberrationN (%)CRPRSD≥6monthsCBRORRAny PI3K Pathway Aberration*32 (74)46444%31%PIK3CA Mutation19 (59)23447%26%p.H1047R12 (38)21350%25%p.E545K6 (19)02150%33%p.G1007R1 (3)010100%100%p.E545A1 (3)0000%0%p.H1047Y1 (3)0000%0%p.K111E1 (3)0000%0%p.E542K1 (3)0000%0%PIK3CA Amplification1 (3)010100%100%PTEN Mutation5 (16)0000%0%PTEN Loss5 (16)02040%40%AKT1 p.E17K Mutation2 (6)0000%0%AKT2 Amplification1 (3)100100%100%PIK3R1 Mutation2 (6)01050%50%NF2 Mutation1 (3)100100%100%No PI3K Pathway Aberration11 (26)00545%0%*Some tumors had &gt;1 aberration detected

PI3K pathway activation was associated with a significant improvement in ORR (31 vs 0%; P=0.043) but not CBR (44 vs 45%; P=1.000) or progression-free survival (median 5.1 vs 2.9 months; P=0.352). A pt with 5 year+ durable CR (on maintenance everolimus) had a mutation in NF2. To emphasize the importance of pt selection, it is notable that 12 pts with non-metaplastic TNBC were also treated with DAT, and only 1 pt had a response (CR/PR=1; SD≥6 months=0), for a CBR that was significantly worse than pts with MpBC (8 vs 40%; P=0.045).

Conclusions: Using MpBC as a surrogate of response, DAT/DAE has significantly better activity in mesenchymal compared to non-selected TNBC. Response is enhanced in pts with PI3K pathway activation. DAT/DAE should be tested in non-metaplastic, mesenchymal TNBC once a diagnostic assay is available.

Citation Format: Basho RK, Gilcrease M, Murthy RK, Helgason T, Booser DJ, Karp DD, Meric-Bernstam F, Wheler JJ, Valero V, Albarracin C, Litton J, Chavez-MacGregor M, Ibrahim NK, Murray JL, Koenig KB, Hong D, Subbiah V, Kurzrock R, Janku F, Moulder S. Targeting the PI3K/AKT/mTOR pathway for the treatment of mesenchymal triple-negative breast cancer (TNBC): Evidence of efficacy and proof of concept from a phase I trial with dose expansion of mTOR inhibition in combination with liposomal doxorubicin and bevacizumab. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-14-02.

Abstract C50: Phase I dose escalation study of the oral multi-kinase VEGF inhibitor regorafenib and the anti-EGFR monoclonal antibody cetuximab in patients with advanced solid tumors including colorectal cancer

Background: The combination of multi-kinase VEGF inhibitor regorafenib and anti-EGFR monoclonal antibody cetuximab overcame intrinsic and acquired resistance in both EGFR-sensitive and EGFR-resistant preclinical models of colorectal cancer (CRC). (Clin Cancer Res; 21(13); 2975-83)

Methods: We designed a phase I study to determine the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), and dose-limiting toxicities (DLTs) of the oral multi-kinase inhibitor regorafenib and the anti-EGFR monoclonal antibody cetuximab in patients (pts) with advanced cancer including metastatic colorectal cancer. Tumor responses were assessed using RECIST v1.1.

Results: Twenty seven pts were enrolled between May 2014 and August 2015. 22 (81%) pts were evaluable for toxicity and response. 5 heavily pre-treated pts were not evaluable for DLTs because they discontinued the trial before the end of the DLT window, mainly because of disease progression. 21 pts were treated at dose level 1 (cetuximab IV 200 mg/m2 followed by 150 mg/m2 weekly + regorafenib 80 mg daily) and 6 pts at dose level 2. MTD was exceeded at dose level 2 (cetuximab IV 200 mg/m2 followed by 150 mg/m2 weekly + regorafenib 120 mg daily), with 2 DLTs observed, including G3 thrombocytopenia (n = 1) and G3 thrombocytopenia with intraperitoneal bleeding (n = 1). The most common adverse events observed in all patients across both dose levels tested included G1-2 rash, G1-2 hypomagnesaemia, G1 myalgia, G1 fatigue, G1 nausea/vomiting. In addition other AE's included G2 hand-foot syndrome (n = 5), and G2 hypertension (N = 2). One patient with KRAS wt CRC achieved a partial response (PR) (46% decrease) lasting 15 months who was previously resistant to cetuximab. Another KRAS wt CRC patient with a hyper-mutated genotype [Lynch syndrome (MSI High), both BRCA1 and 2 mutations, FGFR3 mutation] achieved stable disease (SD) for &gt; 10 months. 10 patients (37%) achieved SD&gt;4 months or PR that included renal cell carcinoma (n = 1), EGFR mutant glioblastoma multiforme (n = 1), squamous cell cancer (n = 1) and carcinoma of unknown primary (n = 1).

Conclusions: The combination of cetuximab and regorafenib was well tolerated at doses of cetuximab IV 200 mg/m2 followed by 150 mg/m2 weekly, with regorafenib 80 mg daily. Anticancer activity was observed in patients with wild type colorectal cancer.

Citation Format: Vivek Subbiah, David S. Hong, Behrang Amini, Sarina Piha-Paul, Joanna Grace Fernandez, Siquing Fu, Apostolia M. Tsimberidou, Aung Naing, Filip Janku, Daniel D. Karp, Michael Overman, Cathy Eng, Scott Kopetz, Funda Meric-Bernstam, Gerald S. Falchook. Phase I dose escalation study of the oral multi-kinase VEGF inhibitor regorafenib and the anti-EGFR monoclonal antibody cetuximab in patients with advanced solid tumors including colorectal cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C50.