Sunitinib in Patients With Breast Cancer With FGFR1 or FGFR2 Amplifications or Mutations: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a phase II basket trial evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancer and genomic alterations known to be drug targets. Results from cohorts of patients with metastatic breast cancer (BC) with FGFR1 and FGFR2 alterations treated with sunitinib are reported.

METHODS

Eligible patients had measurable disease, Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) or stable disease of at least 16 weeks duration (SD16+) according to RECIST v1.1. Secondary end points included OR, progression-free survival, overall survival, duration of response, duration of stable disease, and safety.

RESULTS

Forty patients with BC with FGFR1 (N = 30; amplification only n = 26, mutation only n = 1, both n = 3) or FGFR2 (N = 10; amplification only n = 2, mutation only n = 6, both n = 2) alterations were enrolled. Three patients in the FGFR1 cohort were not evaluable for efficacy; all patients in the FGFR2 cohort were evaluable. For the FGFR1 cohort, two patients with partial response and four with SD16+ were observed for DC and OR rates of 27% (90% CI, 13 to 100) and 7% (95% CI, 1 to 24), respectively. The null hypothesis of 15% DC rate was not rejected (P = .169). No patients achieved DC in the FGFR2 cohort (P = 1.00). Thirteen of the 40 total patients across both cohorts had at least one grade 3-4 adverse event or serious adverse event at least possibly related to sunitinib.

CONCLUSION

Sunitinib did not meet prespecified criteria to declare a signal of antitumor activity in patients with BC with either FGFR1 or FGFR2 alterations. Other treatments and clinical trials should be considered for these patient populations.

Pembrolizumab in Patients With Tumors With High Tumor Mutational Burden: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry (TAPUR) Study is a pragmatic basket trial evaluating antitumor activity of approved targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from cohorts of patients with high tumor mutational burden (HTMB, defined as ≥9 mutations per megabase) with advanced colorectal cancer (CRC) and other advanced cancers treated with pembrolizumab are reported.

METHODS

Eligible patients were 18 years and older with measurable tumors and a lack of standard treatment options, an Eastern Cooperative Oncology Group performance status of 0-1, and adequate organ function. The primary end point was disease control (DC), defined as complete or partial response or stable disease (SD) of at least 16-weeks duration. For the CRC cohort, Simon's two-stage design with a null DC rate of 15% versus 35% (power = 0.85; α = .10) was used. Low accruing histology-specific cohorts were collapsed into one histology-pooled (HP) cohort. For the HP cohort, the null hypothesis of a DC rate of 15% was rejected if the lower limit of a one-sided 90% CI was >15%. Secondary end points included objective response (OR), safety, progression-free survival, overall survival, duration of response, and duration of SD.

RESULTS

Seventy-seven patients with HTMB with CRC (n = 28) or advanced cancers (n = 49) were treated with pembrolizumab. For the CRC cohort, the DC rate was 31% (P = .04) and the OR rate was 11%. For the HP cohort, the DC rate was 45% (one-sided 90% CI, 35 to 100) and the OR rate was 26%. The null hypothesis of a 15% DC rate was rejected for both cohorts. Twelve of 77 patients experienced treatment-related grade 3 adverse events (AEs) or serious AEs, including two deaths.

CONCLUSION

Pembrolizumab demonstrated antitumor activity in pretreated patients with advanced cancers and HTMB.

Cobimetinib Plus Vemurafenib in Patients With Solid Tumors With BRAF Mutations: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a phase II basket study evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers with genomic alterations known to be drug targets. The results in a cohort of patients with solid tumors with BRAF mutations treated with cobimetinib plus vemurafenib are reported.

METHODS

Eligible patients had measurable disease (RECIST v.1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. The primary end point was disease control (DC), defined as complete response (CR) or partial response (PR) or stable disease of at least 16-weeks duration (SD16+). Low-accruing histology-specific cohorts with BRAF mutations treated with cobimetinib plus vemurafenib were collapsed into a single histology-pooled cohort for this analysis. The results were evaluated on the basis of a one-sided exact binomial test with a null DC rate of 15% versus 35% (power, .82; α, .10). The secondary end points were objective response (OR), progression-free survival, overall survival, duration of response, duration of stable disease, and safety.

RESULTS

Thirty-one patients with solid tumors with BRAF mutations were enrolled. Twenty-eight patients were evaluable for efficacy. Patients had tumors with BRAF V600E (n = 26), K601E (n = 2), or other (n = 3) mutations. Two patients with CR (breast and ovarian cancers; V600E), 14 with PR (13 V600E, one N581I), and three with SD16+ (two V600E, one T599_V600insT) were observed with a DC rate of 68% (P < .0001; one-sided 90% CI, 54 to 100) and an OR rate of 57% (95% CI, 37 to 76). Nineteen patients experienced ≥one drug-related grade 3-5 adverse event or serious adverse event including one death attributed to treatment-related kidney injury.

CONCLUSION

Cobimetinib plus vemurafenib showed antitumor activity in patients with advanced solid tumors with BRAF V600E mutations; additional study is warranted to confirm the antitumor activity in tumors with non-V600E BRAF mutations.

Pertuzumab Plus Trastuzumab in Patients With Lung Cancer With ERBB2 Mutation or Amplification: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a pragmatic basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from a cohort of patients with lung cancer and ERBB2 mutation or amplification treated with pertuzumab plus trastuzumab (P + T) are reported.

METHODS

Eligible patients had advanced lung cancer of any histology, no standard treatment options, measurable disease (RECIST v1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and tumors with ERBB2 mutation or amplification. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) per RECIST v. 1.1 or stable disease (SD) of at least 16 weeks duration (SD16+). Secondary end points included safety, duration of response, duration of SD, progression-free survival, and overall survival.

RESULTS

Twenty-eight patients with lung cancer (27 non-small-cell, 1 small-cell) and ERBB2 mutation (n = 15), ERBB2 amplification (n = 12), or both (n = 1) were enrolled from November 2016 to July 2020. All patients were evaluable for efficacy and toxicity. Three patients with partial response (two ERBB2 mutation; one both mutation and amplification) and seven patients with SD16+ (five ERBB2 mutation; two amplification) were observed for a DC rate of 37% (95% CI, 21 to 50; P = .005) and OR rate of 11% (95% CI, 2 to 28). Five patients had one or more grade 3 or 4 adverse or serious adverse events at least possibly related to P + T.

CONCLUSION

Combination P + T showed evidence of antitumor activity in heavily pretreated patients with non-small-cell lung cancer and ERBB2 mutation or amplification, particularly those with ERBB2 exon 20 insertion mutations.

Pertuzumab Plus Trastuzumab in Patients With Endometrial Cancer With ERBB2/3 Amplification, Overexpression, or Mutation: Results From the TAPUR Study

PURPOSE

The TAPUR Study is a pragmatic basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from a cohort of patients with endometrial cancer (EC) with ERBB2 or ERBB3 (ERBB2/3) amplification, overexpression, or mutation treated with pertuzumab plus trastuzumab (P + T) are reported.

METHODS

Eligible patients had advanced EC, no standard treatment options, measurable disease (RECIST v1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and tumors with ERBB2/3 amplification, overexpression, or mutation. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) or stable disease (SD) of at least 16 weeks (SD16+) duration. Secondary end points include safety, duration of response, duration of SD, progression-free survival (PFS), and overall survival (OS).

RESULTS

Twenty-eight patients were enrolled from March 2017 to November 2019; all patients were evaluable for efficacy and toxicity. Seventeen patients had tumors with ERBB2/3 amplification and/or overexpression, eight with both ERBB2 amplification and ERBB2/3 mutations, and three with only ERBB2 mutations. Ten patients had DC (two partial response and eight SD16+); all 10 had ERBB2 amplification, and 6 of the 10 patients with DC had >1 ERBB2/3 alteration. DC and OR rates were 37% (95% CI, 21 to 50) and 7% (95% CI, 1 to 24), respectively; the median PFS and median OS were 16 weeks (95% CI, 10-28) and 61 weeks (95% CI, 24-105), respectively. One patient experienced a grade 3 serious adverse event (muscle weakness) at least possibly related to P + T.

CONCLUSION

P + T has antitumor activity in heavily pretreated patients with EC with ERBB2 amplification and warrants additional study.

Pertuzumab plus trastuzumab (P+T) in patients (pts) with biliary tract cancer (BTC) with ERBB2/3 amplification (amp), overexpression (oe), or mutation (mut): Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) study

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Background: TAPUR is a phase II basket study evaluating antitumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of pts with BTC with ERBB2/3 amp, oe, or mut treated with P+T are reported. Methods: Eligible pts had advanced BTC, no standard treatment (tx) options, measurable disease, ECOG Performance Status (PS) 0-2, and adequate organ function. Genomic testing was done in CLIA-certified, CAP-accredited labs. Dosing of P was 840 mg IV over 60 minutes (m), then 420 mg IV over 30-60 m Q3 weeks (wks); T was 8 mg/kg IV over 90 m, then 6 mg/kg IV over 30-60 m Q3 wks until disease progression. Primary end point was disease control (DC), defined as complete (CR) or partial (PR) response per RECIST v. 1.1, or stable disease (SD) at 16+ wks (SD16+). Simon 2-stage design tested the null DC rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 has DC, 18 more pts are enrolled; otherwise, cohort is closed for futility. If ≥7 of 28 pts has DC, the null DC rate is rejected. Secondary end points were progression-free survival (PFS), overall survival (OS), duration of response (DOR), duration of SD and safety. DOR is defined as time from pt’s first documented objective response (OR) to progressive disease (PD). Duration of SD is defined as time from start of tx to PD. Results: 29 pts with BTC (15 gallbladder (GB), 11 biliary duct (BD), 3 ampulla of Vater) and ERBB2/3 amp, oe, or mut were enrolled from Feb 2017 to Jan 2022. Median (med) age was 66 years (yrs) (range, 34-83 yrs). 66% of pts were female; 52% were White, 21% were Black/African American, 10% were Asian/Asian American; 83% were not Hispanic or Latino. 83% of pts had ECOG PS 0-1 and 48% had ≥3 prior systemic regimens. 1 pt was not evaluable and excluded from efficacy analysis. The table shows efficacy outcomes. 1 pt had CR (GB; ERBB2 amp; DOR: 71.1 wks), 8 pts had PR (6 GB/2 BD; 5 ERBB2 amp; 2 ERBB2 mut; 1 ERBB3 mut/ ERBB2 amp; med DOR: 30.4 wks (4.4 to 68.9 wks)) and 2 pts had SD16+. 4 pts with a KRAS mut did not achieve OR or SD16+. 4 pts had a Grade 3 drug-related adverse or serious adverse event (SAE): anemia, diarrhea, infusion related reaction (SAE), and fatigue. Conclusions: P+T demonstrated antitumor activity in pts with advanced BTC with ERBB2/3 alterations. These data, along with results previously reported by other studies, support continued study of P+T in pts with ERBB2 amplified BTC tumors. Clinical trial information: NCT02693535 . [Table: see text]

Cobimetinib Plus Vemurafenib in Patients With Colorectal Cancer With BRAF Mutations: Results From the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

PURPOSE

TAPUR is a phase II basket trial evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancer and genomic alterations known to be drug targets. The results of a cohort of patients with colorectal cancer (CRC) with BRAF mutations treated with cobimetinib (C) plus vemurafenib (V) are reported.

METHODS

Eligible patients had advanced CRC, no standard treatment options, measurable disease (RECIST), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, tumors with BRAF V600E/D/K/R mutations, and no MAP2K1/2, MEK1/2, or NRAS mutations. C was taken 60 mg orally once daily for 21 days followed by seven days off, and V was taken 960 mg orally twice daily. Simon's two-stage design was used with a primary study end point of objective response or stable disease of at least 16 weeks duration. Secondary end points were progression-free survival, overall survival, and safety.

RESULTS

Thirty patients were enrolled from August 2016 to August 2018; all had CRC with a BRAF V600E mutation except one patient with a BRAF K601E mutation. Three patients were not evaluable for efficacy. Eight patients with partial responses and six patients with stable disease of at least 16 weeks duration were observed for disease control and objective response rates of 52% (95% CI, 35 to 65) and 30% (95% CI, 14 to 50), respectively. The null hypothesis of 15% disease control rate was rejected ( P < .0001). Thirteen patients had at least one grade 3 adverse event or serious adverse event at least possibly related to C + V: anemia, decreased lymphocytes, dyspnea, diarrhea, elevated liver enzymes, fatigue, hypercalcemia, hypophosphatemia, rash, photosensitivity, and upper gastrointestinal hemorrhage.

CONCLUSION

The combination of C + V has antitumor activity in heavily pretreated patients with CRC with BRAF mutations.

Pertuzumab Plus Trastuzumab in Patients With Colorectal Cancer With ERBB2 Amplification or ERBB2/3 Mutations: Results From the TAPUR Study

PURPOSE

The TAPUR Study is a pragmatic phase II basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers harboring potentially actionable genomic alterations. Data from two cohorts of patients with colorectal cancer (CRC) with either ERBB2 amplifications or ERBB2 or ERBB3 (ERBB2/3) mutations treated with pertuzumab plus trastuzumab (P + T) are reported.

METHODS

Eligible patients with measurable CRC were selected for treatment with P + T according to protocol-specified genomic matching rules. Patients had no remaining standard treatment options, Eastern Cooperative Oncology Group performance status 0-2, and adequate organ function. Simon's two-stage design was used with a primary study end point of disease control (DC; objective response [OR] or stable disease of at least 16 weeks duration [SD16+]). Secondary end points include safety, response duration, progression-free survival (PFS), and overall survival (OS).

RESULTS

Thirty-eight patients with CRC with ERBB2 amplification (N = 28) or ERBB2/ 3 mutations (N = 10) were treated with P + T. For the ERBB2 amplification cohort, DC and OR were observed in 54% and 25% of patients, respectively; the median PFS and median OS (95% CIs) were 17.2 (11.1 to 27.4) weeks and 60.0 (32.1 to 102.3) weeks, respectively. For the ERBB2/ 3 mutation cohort, DC and OR were observed in 10% and 0% of patients, respectively; the median PFS and median OS were 9.6 (5.1 to 16.0) weeks and 28.8 (7.6 to 146.3) weeks, respectively. Four of 38 patients experienced grade 3 adverse events or serious adverse events including anemia, infusion reaction, diarrhea, left ventricular systolic dysfunction, and decreased lymphocyte count.

CONCLUSION

Although P + T treatment does not appear to have antitumor activity in CRC with ERBB2/3 mutations, this combination has antitumor activity in patients with CRC with ERBB2 amplification and warrants further study.

Abstract CT110: Olaparib (O) in patients (pts) with solid tumors with ATM mutation or deletion: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with specific genomic alterations. Results in a cohort of pts with solid tumors with ATM mutation (mut) or deletion (del) treated with O are reported.

Methods: Eligible pts had solid tumors, no standard treatment (tx) options, measurable disease, ECOG Performance Status (PS) 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts received O tablets (300mg) or capsules (400mg) orally twice daily until disease progression. Low accruing histology-specific cohorts with the same genomic alteration were collapsed into one histology-pooled cohort for this analysis. Primary endpoint was disease control (DC) (complete (CR) or partial (PR) response or stable disease at 16+ wks (SD16+)) (RECIST v1.1). For histology-specific cohorts a Simon 2-stage design with a null DC rate of 15% vs. 35% (power = 0.85; α = 0.10) requires 28 pts with futility stopping after 10 pts. For histology-pooled cohorts with sample size &gt; 28, if the lower limit of a one-sided 90% CI is &gt;15%, the null hypothesis of a DC rate of 15% is rejected. 2-sided 95% CIs were used for other efficacy endpoint estimates. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety.

Results: 39 pts with solid tumors (17 histologies) with ATM mut (n=36) or del (n=3) were enrolled from 6/2016 to 1/2019. 3 pts were unevaluable for efficacy. Table 1 shows demographics and outcomes. 1 CR (prostate), 2 PR (unknown primary) and 6 SD16+ were observed in pts with ATM mut for a DC rate of 25% (90% CI: 16%, 100%) and an OR rate of 8% (95% CI: 2%, 23%). The null DC rate was rejected. 9 pts had ≥1 Grade 3 tx-related adverse or serious adverse event related to O.

Conclusions: Monotherapy O showed evidence of anti-tumor activity in pts with various solid tumors with ATM mut.

Table 1. Demographics and Baseline Characteristics (N=39); Efficacy Outcomes (N=36); Toxicity Outcomes (N=39) Median (Med) age, years (range) 65 (35, 77) Female, % 46 ECOG PS, % 0 33 1 59 2 8 Prior systemic regimens, % 0 3 1 8 2 15 ≥3 74 DC rate, % (OR or SD 16+) (1-sided 90% CI) 25 (16, 100) OR rate, % (95% CI) 8 (2, 23) Med PFS, wks (95% CI) 8.4 (8.0, 15.9) Med OS, wks (95% CI) 40.4 (30.3, 50.7) Med duration OR (range), wks 18.9 (4.3, 24.4) Med duration SD16+ (range), wks 27.3 (19.4, 31.0) Number of pts1 with treatment-related adverse or serious adverse events (all Grade 3) AE2 9 SAE3 4 1Patients may have experienced one or more events2anemia, anorexia, dehydration, fatigue, hypokalemia, nausea 3colitis, dizziness, lung infection, proteinuria, urinary tract infection/obstruction

Citation Format: Kathryn F. Mileham, Michael Rothe, Pam K. Mangat, Elizabeth Garrett-Mayer, Eddy S. Yang, Olatunji B. Alese, Angela Jain, Herbert L. Duvivier, Phillip Palmbos, Eugene R. Ahn, Jeanny B. Aragon-Ching, Kathleen W. Beekman, Deepti Behl, Funda Meric-Bernstam, Rodolfo Gutierrez, Amy Sanford, Ramya Thota, Michael Zakem, Song Zhao, Raegan O'Lone, Gina N. Grantham, Susan Halabi, Richard L. Schilsky. Olaparib (O) in patients (pts) with solid tumors with ATM mutation or deletion: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT110.

Cobimetinib plus vemurafenib (C+V) in patients (Pts) with solid tumors with BRAF V600E/d/k/R mutation: Results from the targeted agent and profiling utilization registry (TAPUR) study

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Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of pts with solid tumors with BRAF V600E/D/K/R mutation (mut) treated with C+V are reported. Methods: Eligible pts had advanced solid tumors, no standard treatment (tx) options, measurable disease, ECOG performance status (PS) 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts matched to C+V had various solid tumors with BRAF V600E/D/K/R mut, or other BRAF mut if approved by the Molecular Tumor Board, and no MAP2K1/2, MEK1/2, NRAS mut. Recommended dosing was C, 60 mg orally daily for 21 days, 7 days off and V, 960 mg orally every 12 hours. Primary endpoint was disease control (DC), defined as complete (CR) or partial (PR) response or stable disease at 16+ wks (SD 16+) (RECIST v1.1). Low accruing histology-specific cohorts with the same genomic target and tx were collapsed into a single histology-pooled cohort for this analysis. For histology-pooled cohorts with sample size of 28, the results are evaluated based on a one-sided exact binomial test with a null DC rate of 15% vs. 35% (power = 0.84; α = 0.10) and one-sided 90% confidence interval (CI). Other efficacy endpoint estimates are presented with two-sided 95% CIs. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety. Results: 31 pts with solid tumors (13 histologies; 6/31 ovarian cancer) with BRAF muts were enrolled from Dec 2016 to Jan 2021 and collapsed into one histology pooled cohort for analysis. 3 pts were not evaluable due to lack of post-baseline tumor evaluation and excluded from efficacy analyses. Demographics and outcomes are summarized in the Table. Pts had tumors with BRAF V600E mut (N = 26), G469V mut (N = 1), K601E mut (N = 2), N581I (N = 1) and T599_V600insT (N = 1). 2 CR (breast and ovarian cancer; V600E), 14 PR (13 V600E, 1 N581I), and 3 SD16+ (2 V600E, 1 T599_V600insT) were observed for a DC rate of 68% (90% CI: 54%, 100%) and an objective response (OR) rate of 57% (95% CI: 37%, 76%). CR durations were 5.1 (ovarian cancer) and 108.9 wks (breast cancer) and median duration of PR was 20.5 wks (range: 8.0, 176.0). 19 pts experienced ≥1 Grade 1-5 AE/SAE at least possibly related to tx including 1 death attributed to tx-related kidney injury. Conclusions: C+V demonstrated evidence of anti-tumor activity in pts with advanced solid tumors with BRAF V600E and other muts . Clinical trial information: NCT02693535. [Table: see text]

First-in-human dose escalation and expansion study of MT-6402, a novel engineered toxin body (ETB) targeting PD-L1, in patients with PD-L1 expressing relapsed/refractory advanced solid tumors: Interim data

2521

Background: MT-6402 is a unique and potent PD-L1-targeted engineered toxin body (ETB) capable of directly killing PD-L1 expressing tumor and immune cells by internalization of a fused Shiga-like toxin A subunit (SLTA) resulting in permanent SLTA-mediated ribosomal inactivation. The targeting of PD-L1 expressing tumor cells may directly drive tumor regression whereas targeting of PD-L1 expressing immune cells may release immunosuppression and drive immune recognition of the tumor. MT-6402 also delivers an HLA-A*02 restricted cytomegalovirus (CMV) class I antigen into PD-L1 expressing cells (antigen seeding) that can be recognized by existing CMV-specific cytotoxic T cells. Methods: A first-in-human dose escalation and expansion study in patients with PD-L1-expressing advanced solid tumors was initiated in 2021. As of 1 Jan 2022, 6 patients received at least one dose of MT-6402, 4 of whom were eligible for Dose Limiting Toxicity (DLT) assessment in Cohort 1. Results: A significant reduction in CD14+ monocytes starting in cycle 2 was observed in patients on therapy after each MT-6402 administration, indicating an HLA-independent PD effect consistent with preclinical observations. 5 of 6 patients had a marked decrease in Monocytic Myeloid Derived Suppressor Cells (MDSC). The reduction in MDSC and monocytes in the periphery overlapped with increased CCL2 levels, a chemokine that directs movement of myeloid cells. One patient with osseous metastases from non-small cell lung cancer (NSCLC) who is HLA-A*02 and CMV+ showed complete CMV-specific T-cell extravasation at day 8 and serum cytokine signatures consistent with antigen dependent responses and T cell mobilization. This patient had reduced tracer uptake of metastatic bone lesions with 3/4 lesions resolving completely. A second HLA A*02 CMV+ patient followed a similar trend towards loss of peripheral CMV-specific T cells with a concurrent increase in total CD8 T cells. The CD8 T cells from these 2 patients had elevated T-bet expression from baseline, indicating antigen specific TCR stimulation and expansion. The activated immune response was also accompanied by increased IP-10 and IL-2 cytokine signatures in the serum. Consistent with these findings, one of these two patients had transient (1-12 h) grade 2 infusion related reaction and the other had transient (1-12 h) grade 2 cytokine release syndrome, both on Day 15. These results describe a novel approach to checkpoint modulation by MT-6402, that adds antigen seeding to PD-L1 directing mechanisms. MT-6402 was well tolerated and no DLT was observed in Cohort 1 (16 µg /kg, QW in 4-week cycles). Conclusions: Dose escalation is ongoing. The results hold promise for development of MT-6402 for solid tumors, including in the R/R setting. Data for additional patients will be presented at the meeting. Clinical trial information: NCT04795713.

Bridging the gap by providing access to oncology care to rural communities: A hybrid delivery model combining in-person visits with Telehealth

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Background: Americans who live in rural areas experience unique barriers to access healthcare such as limited transportation, shortages in oncology providers, limited access to advanced services which contribute to poor health outcomes. The current COVID-19 pandemic has provided a catalyst for rapid adoption of telehealth. A regional cancer center has established a novel rural health partnership program that utilizes a hybrid model of on-site visits and telehealth to increase access to advanced oncology care for patients in rural communities. Here we describe the collaboration and benefits of this model. Methods: The rural health hybrid delivery model utilizes a combination of in-person and telehealth visits to provide immediate access to the regional center’s oncology care team and specialized services such as advanced surgeries, radiation, precision medicine, and clinical trials. Speed to care was built into the model as a key feature, offering initial appointments within 3 business days from the time of the referral, wherein treatment plans are developed facilitating immediate start. The model is a collaborative partnership, ensuring a coordinated care process driven by the regional oncologists working in coordination with the local provider to meet the needs of the patient. The patient is able to decrease transportation time, cost, and obtain care closer to their support system by keeping the patient in their community for basic needs. For more complex requirements, on-site visits are coordinated. This allows access to the regional center’s specialty oncology care services not available locally, while keeping the patient engaged with their local provider, which increases service utilization and expands the patient base. Leveraging telehealth visits at the local hospital ensures access to adequate broadband and technology capabilities to facilitate continuity of patient care. Results: This model provides the patient with timely access to specialty cancer care in their local community. Partnerships with two rural health systems were implemented in July and November 2020. 14 patients are enrolled in the program to date with a 100% retention rate. The turnaround time from treatment plan to treatment is 6 business days. There was a total of 62 oncology telehealth appointments, reducing patient travel by 12,705 driving miles, 310 travel hours, saving $7,380 in travel costs and accommodation. Conclusions: Telehealth provides a bridge to the rural health access gap, and advances health equity by offering specialized care to patients in their local communities. Improving access to best practice treatment strategies for all cancer patients moves us closer to resolving disparities in outcomes. Applications of this hybrid model of care to other rural sites is a promising strategy to reduce rural-urban disparities in cancer care.

Evaluation of pathologic and genomic characteristics in female breast cancer patients

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Background: The genomic landscape of female breast cancer is rapidly evolving partially owing to advancements in next generation sequencing (NGS). Here we report the genomic characteristics of female breast cancer patients with locally recurrent inoperable and metastatic disease. Methods: IRB approval was obtained for a retrospective analysis of archived pathology on patients treated at Cancer Treatment Centers of America. Comprehensive genomic profiling of tumors was derived from Foundation One (F1) and Guardant 360 NGS. Clinical information was derived from retrospective chart review. Inclusions: adult females with breast cancer with stage IV metastatic disease or locally recurrent inoperable disease. Exclusions: Males, missing genomic and pathologic information. Results of clinical, pathologic, and genomic data were summarized. Results: 1788 patients met study criteria. Median age: 48 yrs., range 20-79 yrs. Race: Caucasian 1029/1788 (58%), African American 582/1788 (32%), Hispanic 77/1788 (4%), Asian 26/1788 (1%), other 73/1788 (4%). Receptor status: Hormone receptor ER(+) &/or PR(+) 950/1788 (53.1%); Triple negative 390/1788 (21.8%); HER2(+) 205/1788 (11.5%); missing/incomplete: 243/1788 (13.6%). Ki-67 status: High 548/705 (77.7%)/Low 57/705 (8.1%)/Intermediate (INT) 100/705 (14.2%). PD-L1 status: PD-L1(-) 346/544 (63.6%)/ PD-L1(+) 179/544 (32.9%)/PD-L1 (indeterminate or QNS) 19/544 (3.5%). NGS test total (1984 tests): F1 1023/1984 (52%), F1 CDx 703/1984 (35%), F1 Act 91/1984 (6%), F1 Liquid 82/1984 (6%), Guardant 360 85/1984 (4%). Biomarkers (1096 results): Microsatellite Instability (MSI) High 4/1096 (0.3%), MSI- Intermediate (INT) 2/1096 (0.1%), MS-stable 1017/1096 (93%), Cannot be determined (CBD) 73/1096 (7%). Tumor Mutation Burden (TMB) (842 results): TMB high 22/842 (3%), TMB INT 233/842 (28%), TMB low 513/842 (61%), CBD 74/842 (9%). Genomic abnormalities (% alterations per patient): TP53 999/1783 (56.03%), PIK3CA 610/1783 (34.21%), MYC 425/1783 (23.84%), CCND1 318/1783 (17.84%), FGF19 298/1783 (16.71%), FGF3 296/1783 (16.60%), FGF4 293/1783 (16.43%), ESR1 266/1783 (14.92%), FGFR1 276/1783 (15.48%), PTEN 239/1783 (13.40%), ZNF703 251/1783 (14.08%), ERBB2 218/1783 (12.23%), GATA3 178/1783 (9.98%), CDH1 165/1783 (9.25%), RAD21 157/1783 (8.81%). Pathway defects (expressed as total % of alterations): Alterations in FGF genes 10.64%, mTOR pathway 8.36%, HHR pathway 3.17%. Conclusions: Female breast cancer patients display a heterogeneous variety of complex genomic alterations. Mutations in FGF genes were most common. The single most common alteration was in TP53. Other common alterations include PIK3CA, MYC, CCND1, and ESR1.

Pembrolizumab in Patients With Metastatic Breast Cancer With High Tumor Mutational Burden: Results From the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

PURPOSE

The TAPUR Study is a phase II basket trial that aims to identify signals of antitumor activity of commercially available targeted agents in patients with advanced cancers harboring genomic alterations known to be drug targets. Results in a cohort of patients with metastatic breast cancer (mBC) with high tumor mutational burden (HTMB) treated with pembrolizumab are reported.

METHODS

Patients with advanced mBC received standard doses of either 2 mg/kg or 200 mg infusions of pembrolizumab every 3 weeks. Simon's two-stage design was used with a primary study end point of disease control (DC) defined as objective response or stable disease of at least 16 weeks duration. If two or more patients in stage I achieved DC, the cohort would enroll 18 additional patients in stage II. Secondary end points include progression-free survival (PFS), overall survival, and safety.

RESULTS

Twenty-eight patients were enrolled from October 2016 to July 2018. All patients' tumors had HTMB ranging from 9 to 37 mutations/megabase. DC and objective response were noted in 37% (95% CI, 21 to 50) and 21% of patients (95% CI, 8 to 41), respectively. Median PFS was 10.6 weeks (95% CI, 7.7 to 21.1); median overall survival was 30.6 weeks (95% CI, 18.3 to 103.3). No relationship was observed between PFS and tumor mutational burden. Five patients experienced ≥ 1 serious adverse event or grade 3 adverse event at least possibly related to pembrolizumab consistent with the product label.

CONCLUSION

Pembrolizumab monotherapy has antitumor activity in heavily pretreated patients with mBC characterized by HTMB. Our findings support the recent US Food and Drug Administration approval of pembrolizumab for treatment of patients with unresectable or metastatic solid tumors with HTMB without alternative treatment options.

Randomized, double-blind, placebo-controlled phase II study of istiratumab (MM-141) plus nab-paclitaxel and gemcitabine versus nab-paclitaxel and gemcitabine in front-line metastatic pancreatic cancer (CARRIE)

BACKGROUND

Preclinical data suggest that dual blockade of the insulin-like growth factor-1 receptor (IGF-1R) and HER3 pathways has superior activity to IGF-1R blockade alone in pancreatic ductal adenocarcinoma (PDAC). We tested whether istiratumab, an IGF-1R- and ErbB3-bispecific antibody, can enhance the efficacy of standard of care (SOC) chemotherapy in patients with metastatic PDAC selected for high IGF-1 serum levels.

PATIENTS AND METHODS

CARRIE was an international, randomized, double-blind, placebo-controlled phase II study for patients with previously untreated metastatic PDAC. In part 1, 10 patients were evaluated for pharmacokinetics and safety. In part 2, patients with high free serum IGF-1 levels were randomized 1 : 1 to receive either istiratumab [2.8 g intravenously (i.v.) every 2 weeks] or placebo combined with gemcitabine/nab-paclitaxel at approved dose schedule. The co-primary endpoints were progression-free survival (PFS) in patients with high IGF-1 levels and PFS in patients with both high serum IGF-1 levels and heregulin (HRG)+ tumors. Key secondary endpoints were overall survival (OS), objective response rate (ORR) by RECIST v.1.1, and adverse events (AEs) rate.

RESULTS

A total of 317 patients were screened, with 88 patients randomized in part 2 (experimental arm n = 43; control n = 45). In the high IGF-1 cohort, median PFS was 3.6 and 7.3 months in the experimental versus control arms, respectively [hazard ratio (HR) = 1.88, P = 0.027]. In the high IGF-1/HRG+ subgroup (n = 44), median PFS was 4.1 and 7.3 months, respectively (HR = 1.39, P = 0.42). Median OS and ORR for the overall population were similar between two arms. No significant difference in serious or grade ≥3 AEs was observed, although low-grade AEs leading to early discontinuation were higher in the experimental (39.5%) versus control arm (24.4%).

CONCLUSIONS

Istiratumab failed to improve the efficacy of SOC chemotherapy in this patient setting. High serum IGF-1 levels did not appear to be an adverse prognostic factor when compared with non-biomarker-selected historic controls.

CLINICAL TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov: NCT02399137; EUDRA CT: 2014-004572-34.

Palbociclib in Patients With Non–Small-Cell Lung Cancer With CDKN2A Alterations: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry (TAPUR) Study is a phase II pragmatic basket trial evaluating antitumor activity of commercially available targeted agents in patients with advanced cancer with genomic alterations known to be drug targets. Results in a cohort of patients with non–small-cell lung cancer (NSCLC) with CDKN2A alterations treated with palbociclib are reported.

METHODS

Eligible patients were ≥ 18 years old with advanced NSCLC, no remaining standard treatment options, measurable disease, Eastern Cooperative Oncology Group performance status of 0 to 2, and adequate organ function. Patients with NSCLC with CDKN2A alterations and no Rb mutations received palbociclib 125 mg orally once daily for 21 days, followed by 7 days off. Simon’s two-stage design was used with a primary study end point of objective response or stable disease (SD) of at least 16 weeks in duration. Secondary end points are progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Twenty-nine patients were enrolled from January 2017 to June 2018; two patients were not evaluable for response but were included in safety analyses. One patient with partial response and six patients with SD were observed, for a disease control rate of 31% (90% CI, 19% to 40%). Median PFS was 8.1 weeks (95% CI, 7.1 to 16.0 weeks), and median OS was 21.6 weeks (95% CI, 14.1 to 41.1 weeks). Eleven patients had at least 1 grade 3 or 4 adverse event (AE) or serious AE (SAE) possibly related to palbociclib (most common, cytopenias). Other AEs or SAEs possibly related to the treatment included anorexia, fatigue, febrile neutropenia, hypophosphatemia, sepsis, and vomiting.

CONCLUSION

Palbociclib monotherapy demonstrated evidence of modest antitumor activity in heavily pretreated patients with NSCLC with CDKN2A alterations. Additional investigation is necessary to confirm efficacy and utility of palbociclib in this population.

Olaparib (O) in patients (pts) with pancreatic cancer with BRCA1/2 inactivating mutations: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) study

4637

Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of pancreatic cancer pts with germline or somatic BRCA1/2 inactivating mutations treated with O are reported. Methods: Eligible pts had advanced pancreatic cancer, no standard treatment (tx) options available, measurable disease, ECOG Performance Status (PS) 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts received O tablets or capsules dosed at 300 mg (n=27) or 400 mg (n=3), respectively, orally twice daily until disease progression. Simon 2-stage design tested the null disease control (DC) (objective response (OR) or stable disease at 16+ weeks (wks) (SD16+) according to RECIST) rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have DC, 18 more pts are enrolled. If ≥7 of 28 pts have DC, the tx is worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS), and safety. Results: Thirty pts with BRCA1/2 inactivating mutations were enrolled from Nov 2016 to Aug 2019; 20 were previously treated with platinum based therapy. Two were not evaluable and excluded from efficacy analyses. Demographics and outcomes are summarized in Table. One partial response (PR) and 7 SD16+ were observed for DC and OR rates of 31% (90% CI: 18% - 40%) and 4% (95% CI: 0% - 18%), respectively. Seven pts had at least one grade 3 AE or SAE at least possibly related to O including anemia, diarrhea, fever, elevated liver enzymes, enterocolitis, increased bilirubin, and oral mucositis. Conclusions: Monotherapy O showed anti-tumor activity in heavily pre-treated pts with pancreatic cancer with germline (5/12 pts with OR or SD16+) or somatic (3/16 pts with OR or SD16+) BRCA1/2 inactivating mutations extending findings of recent studies of O in pts with advanced pancreatic cancer. Clinical trial information: NCT02693535 . [Table: see text]

Abstract P1-18-30: Neoadjuvant aromatase inhibitor and pertuzumab and trastuzumab (NEOADAPT) up to one year for HR+HER2+ breast cancer: Results from a prematurely closed de-escalation study

Background. Current standard of care for HR+HER2+ breast cancer &gt;1cm per NCCN guidelines is chemotherapy with either trastuzumab(T) or trastuzumab and pertuzumab(TP) with anti-HER2 therapy continued for 1 year and anti-hormonal therapy for 5-10 years. Patients with HR+HER2+ breast cancer benefit less from chemotherapy than those with HR-HER2+ breast cancer. Recent studies show that pCR rates with aromatase inhibitor and dual-HER2 blockade for 3-6 months duration range between 21%- 33% with the highest pCR seen with 6 months. No clinical trial to date has looked at targeted therapy without chemotherapy for HR+HER2+ breast cancer up to 1 year. Methods. NEOADAPT is an IRB-approved phase II prospective single cohort study for patients with stage I-II HR+HER2+ breast cancer. Eligible pts received neoadjuvant aromatase inhibitor (and GnRH analogue or oophorectomy for premenopausal patients) and TP with q3w exams and q3mo breast MRI. Treatment may continue up to 1 year if ongoing response or radiographic CR (rCR) was observed. Surgery was allowed as soon as 3 months after the first MRI showing rCR provided the follow up MRI did not show further improvement. Primary endpoint was pCR rate defined as absence of invasive disease in the breast and lymph nodes. A Fleming two stage design was implemented with stopping rules with the null hypothesis being that the pCR rate is &lt;20% versus the alternative hypothesis where the pCR rate is &gt;40%. Secondary objective included median duration of treatment and exploratory analysis of correlation with Mammaprint Blueprint(MB) testing. 9 patients were enrolled before the study was prematurely closed. 3 patients who refused chemotherapy when the study was closed and were treated with the NEOADAPT protocol and fit the same inclusion/exclusion criteria are also included in this report. Results. Median age 55 (41-67); BMI 26.0 (22.2-37.6); T 2.75cm (1.3-4.8). 7 were premenopausal. 7 had disease that was HER2+ by FISH ratio &gt;2.0 only (2+ IHC). All 12 patients had MB test done: 8 high risk luminal, 3 high risk HER2, and 1 low risk HER2. 5/12 patients achieved rCR, with median duration of treatment to achieve rCR in those 5 pts being 6 months (3-9). 11/12 patients have completed definitive surgery, with the outlier being a patient who refuses surgery. 4/11 patients achieved pCR all of whom received 12 months of targeted treatment before surgery. All 4 pCR patients had rCR before surgery. Of the other 3/7 pts who had rCR and not pCR, 2 had rCR at 3 months and both had surgery at 6 mo with 1.7cm and 1.5mm of residual disease seen and 1 had rCR at 6mo completed 1 yr of prescribed treatment but refused surgery. 2/12 patients were taken off study before surgery and switched to a standard of care chemotherapy regimen due to progression but remain in NED post-surgery to date. No patients to date have had local recurrence or metastatic disease. Discussion. These results from a prematurely closed study suggest as confirmed in other recent studies, that a chemotherapy-sparing endocrine and targeted neoadjuvant approach for HR+HER2+ breast cancer seems to be a feasible and reasonable option particularly for those desiring a clinically informed de-escalation to their treatment plan. Clinical trial: NCT02689921

Citation Format: Eugene R Ahn, Ricardo H Alvarez, Damien Hansra, Anjanette Sorensen, Jizhou Ai, Maurie Markman. Neoadjuvant aromatase inhibitor and pertuzumab and trastuzumab (NEOADAPT) up to one year for HR+HER2+ breast cancer: Results from a prematurely closed de-escalation study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-18-30.

Pembrolizumab (P) in patients (Pts) with colorectal cancer (CRC) with high tumor mutational burden (HTMB): Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

133

Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of CRC pts with HTMB treated with P are reported. Methods: Eligible pts had advanced CRC, no standard treatment (tx) options, measurable disease, ECOG PS 0-1, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts had HTMB, defined as ≥9 mutations/megabase (Muts/Mb) by a FoundationOne test (n=26) or other tests (n=2) approved by the Molecular Tumor Board. Pts with MSI-H tumors were ineligible. Dosing of P was 2 mg/kg (n=8) or 200 mg (n=20) IV over 30 mins, every 3 wks. Simon two-stage design was used to test a null rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have disease control (DC) (objective response (OR) or stable disease at 16+ wks according to RECIST (SD16+)), 18 more pts enrolled. If ≥7 of 28 pts have DC, the tx is worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Results: Twenty-eight pts enrolled from June 2017 to November 2018; 1 pt was ineligible and excluded. HTMB ranged from 9 to 54 Muts/Mb. Table (N=27) summarizes demographics and outcomes. Tumor MS status was reported stable for 25 pts, ambiguous for 1 pt, and not available for 1 pt. One PR (MS stable and 10 Muts/Mb) and 7 SD16+ were observed for DC and OR rates of 28% (90% CI, 16% to 45%) and 4% (95% CI, 0% to 19%), respectively. 2 pts each had grade 3 AEs at least possibly related to P including abdominal infection, anorexia, colitis, diarrhea, fatigue, nausea, and vomiting; 1 also had SAE of acute kidney injury. Conclusions: Monotherapy with P showed anti-tumor activity in heavily pre-treated CRC pts with HTMB . Additional study is warranted to confirm the efficacy of P in this population. Clinical trial information: NCT02693535.

[Table: see text]

Palbociclib in Patients With Pancreatic and Biliary Cancer With CDKN2A Alterations: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry (TAPUR) Study identifies signals of antitumor activity of commercially available targeted agents in patients with advanced cancers that harbor genomic alterations known as drug targets. In this article, data from two cohorts of patients with pancreatic and biliary cancers with CDKN2A loss or mutation treated with palbociclib are reported.

METHODS

Eligible patients age 12 years and older with advanced measurable or evaluable solid tumors are provided treatment according to protocol-specified genomic matching rules. The primary study end point is objective response or stable disease of at least 16 weeks duration. For each cohort, a Simon two-stage design was used with a futility evaluation after 10 patients. Secondary end points include safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

Between July 2016 and November 2017, 12 and 10 patients with pancreatic and biliary cancer, respectively, with CDKN2A loss or mutation were treated with palbociclib. Twenty evaluable patients (10 per cohort) were included in the analysis. No patients had objective response or stable disease at 16 weeks, and both cohorts were closed. Two patients, neither with response, were determined to be ineligible. All patients were evaluated for safety, PFS, and OS. A median PFS of 7.2 weeks (90% CI, 4.0 to 8.0 weeks) and median OS of 12.4 weeks (90% CI, 4.7 to 23.1 weeks) were observed in the pancreatic cohort. A median PFS of 7.3 weeks (90% CI, 3.9 to 7.9 weeks) and median OS of 11.1 weeks (90% CI, 5.1 to 14.0 weeks) were observed in the biliary cohort. No unexpected toxicities were observed.

CONCLUSION

Palbociclib monotherapy does not have clinical activity in patients with advanced pancreatic or biliary cancers with CDKN2A loss or mutation. Toxicity is similar to reported experience with palbociclib in other tumor types.

Evaluation of an NCCN guideline-based weight management pathway on weight loss in female breast cancer patients

301

Background: Obesity is a risk factor for many breast cancer (BC) subtypes & is associated w/ inferior BC outcomes. Here, we investigate the effect of a NCCN based intervention on weight loss (WL) in BC pts. Methods: Prospective study using WL guidelines adapted from NCCN Survivorship (V. 2.2017). Data collected: demographics, clinical, cardiovascular risk factors (CVD), weight, height, body fat%. Stats: 1 sample T-Test w/ 2 tail p-value & 95% CI used to calculate change in weight from baseline to 3 & 6 months (mo) using hypothetical mean of 0. Inclusions: Female BC pts, stage 0-III, OW (BMI > 25mg/m2) or OB (BMI > 30kg/m2). Exclusions: No BC, stage IV, not OW/OB, lost to follow up (f/u), non-compliance, death, or recurrent disease. Intervention: BMI assessed at baseline at initial visit where pt received 20 minute OB counseling by oncologist (ONC). Pts include NEW pts (treatment & surgery naïve) & F/U pts (pts finished definitive treatment in survivorship). ONC counseling included pt education on OB & cancer outcomes & CVD risk. Initially, pts referred to physical therapy (PT) for exercise program & dietician (DT) for nutrition counseling. Pts visit PT & DT q 3 mo. ONC counseling provided periodically during scheduled visits. Results: 70 pts enrolled 10/26/2017 – 10/8/2018. Median pt age = 56 yrs (37-87). Menopausal status: 25/70 (36%) pre menopause vs. 45/70 (64%) post menopause. Race: 29/70 Caucasian (41%), 41/70 (59%) African American, 0/70 (0%) other. Ethnicity: 2/70 (3%) Latin vs. 68/70 (97%) non-Latin. Avg. BMI = 34 kg/m2 (26-54). Avg. weight = 90 kg (61-143). Stage: 0 = 7/70 (10%) , I = 26/70 (37%), II = 21/70 (30%), III = 16/70 (23%). Receptors: 12/70 (17%) triple negative, 13/70 (19%) Her-2+, 49/70 (70%) ER/PR+. CVD risk factors & body fat% shown separately. Mean WL for the 70 pts (NEW + F/U, N = 70) = -0.7 kg @ 3 mo. (p = 0.08), 95%CI (-1.510- +0.101); mean WL = -0.7 kg @ 6 mo. (p = 0.16), 95%CI (-1.703-+0.295). Mean WL for NEW pts, (N = 52) lost -0.9 kg @ 3 mo. (p = 0.0467), 95%CI (-1.809- -0.014). New pts lost -0.7 kg @ 6 mo. (p = 0.21), 95% CI (-1.868 - +0.440). Conclusions: Implementation of the NCCN guidelines + ONC counseling as part of a WL program mitigates weight gain @ 3 & 6 mo in all OW & OB BC pts & induced significant weight loss in NEW pts @ 3 mo.

Palbociclib (P) in patients (pts) with non-small cell lung cancer (NSCLC) with CDKN2A alterations: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

9041

Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of NSCLC pts with CDKN2A loss or mutation treated with P are reported. Methods: Eligible pts had advanced NSCLC, no standard treatment options, measurable disease, ECOG PS 0-2 and adequate organ function. Genomic testing was performed using commercially available tests. Pts matched to P had NSCLC with CDKN2A loss or mutation and no RB mutations. A Simon two-stage design was used to test a null rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have disease control (DC) (objective response (OR) or stable disease at 16 weeks (wks) (SD16+)), an additional 18 pts are enrolled. If ≥7 of 28 pts have DC, the drug is considered worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Results: Twenty-nine pts were enrolled from January 2017 to June 2018; 1 pt was unevaluable for response but is included in safety analyses. Pts received P at 125 mg orally once daily for 21 days, followed by 7 days off. Demographics and outcomes are summarized in Table (N = 28). One PR and 6 SD16+ were observed for a DC rate of 29% (90% CI, 15% to 37%). 10 pts had at least one grade 3 or 4 AE or SAE at least possibly related to P with the most common being cytopenias. Other grade 3-4 AEs or SAEs at least possibly related to P included fatigue, anorexia, febrile neutropenia, myocardial infarction, sepsis, vomiting, and hypophosphatemia. Conclusions: Monotherapy with P demonstrated evidence of anti-tumor activity in heavily pre-treated NSCLC pts with CDKN2A loss or mutation . Additional study is warranted to confirm the efficacy of P in pts with NSCLC with CDKN2A loss or mutation. Clinical trial information: NCT02693535. [Table: see text]

Pembrolizumab (P) in patients (pts) with metastatic breast cancer (MBC) with high tumor mutational burden (HTMB): Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

1014

Background: TAPUR is a phase II basket study evaluating the anti-tumor activity of commercially available targeted agents in pts with advanced cancers with specific genomic alterations. P is an immune checkpoint inhibitor and HTMB is an emerging predictive biomarker for checkpoint inhibitor therapy. Results in a cohort of MBC pts with HTMB treated with P are reported. Methods: Eligible pts had advanced cancer, no standard treatment options, ECOG PS 0-1, measurable disease and acceptable organ function. Genomic testing was performed using commercially available tests selected by sites. Pts matched to P had HTMB defined as ≥9 mutations/megabase (Muts/Mb) by a FoundationOne test (n=20) or approved by the TAPUR Molecular Tumor Board for other tests (n=8). A Simon two-stage design was used to test a null rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have disease control (DC) (objective response (OR) or stable disease at 16 weeks (wks) (SD16+)), an additional 18 pts are enrolled. If ≥7 of 28 pts have DC, the drug is considered worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Results: Twenty-eight female MBC pts were enrolled from October 2016 to July 2018. Pts received P at 2 mg/kg (n=8) or 200 mg (n=20) IV over 30 minutes, every 3 wks. HTMB ranged from 9 to 37 Muts/Mb. Demographics and outcomes are summarized in Table (N=28). No relationship was observed between #Muts/Mb and PFS or OS. Two grade 3 AEs (weight loss and hypoalbuminemia) and 1 grade 2 SAE (urinary tract infection) were reported as at least possibly related to P. Conclusions: P demonstrated anti-tumor activity in heavily pre-treated MBC pts with HTMB . Additional study of P is warranted in MBC pts with HTMB. Clinical trial information: NCT02693535. [Table: see text]

Effects on histologic subgroup, race, and BMI in 2,110 breast cancer patient: Results from single institution in Georgia

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Background: Disparities in breast cancer (BC) care still clearly exist among Whites (W) and African-Americans (AA) racial groups. These disparities resulting in higher mortality among AA compared to W. The objective of this analysis was to estimate the prevalence of BC subtypes in a population-based sample of BC cases, collected in a Breast Cancer Database (BCD) and to examine correlations with demographic and clinicopathologic variables and patient survival. Methods: retrospective analysis of patients registered at BCD was performed. Pts with BC were analyzed for differences in survival based on histologic subgroup (HS), race and BMI. Median Kaplan Meyer estimate for potential follow-up was 13.1 months with 95% CI (10.6, 15.0). Univariate and multivariate analysis were used to identify factors associated with demographic and cancer biology variables. Results: A total of 2,110 patients were registered at BCD and were available for this analysis.The median age at diagnosis was 50.8 years with 95% CI of (50.2, 51.0). 50% were W and 46.6% were AA. HS were classified by immunohistochemistry CLIA central lab, ER+ 61.1%, HER2+ 21.8% and TNBC 17%.Fisher’s exact test showed statistically difference in HS distribution among the races (p < 0.0001); 25% and 11.7% TNBC, for AA and W, respectively. The mean BMI was 29.0 with 95% CI of (29.6, 30.2). BMI characteristics were obese 47.2%, overweight 28.6% and normal 22.2%. Fisher’s exact test showed statistically difference in BMI distribution among the races, 57% and 39% obesity, for AA and W, respectively (p < 0.0001). Log-rank test showed that 2-years OS is worse for TNBC (48%), than for ER+ (72%) and HER2+ (75%). In the multivariable model AA survival was statistically inferior than for W ( p= 0.0094). Cox proportional hazard model was constructed to assess the effect of age, BMI, race and HS (Table). Conclusions: This single institution analysis demonstrated a statistically differences between TNBC, AA, and abnormal BMI as poor prognostic factors in BC pts impacting OS. Further research should investigate how to improve care for AA women who are at higher risk for breast cancer mortality. [Table: see text]

Evaluation of pathologic and genomic characteristics in male breast cancer (MBC) patients

1098

Background: MBC is a rare entity comprising less than 1% of breast cancers [Siegel RL 2017]. Due to the low incidence of MBC, information about the genomic landscape of MBC is lacking. Here we describe detailed pathologic and genomic characteristics of MBC patients. Methods: IRB approval was obtained for a retrospective analysis of archived pathology on patients treated at Cancer Treatment Centers of America. Comprehensive genomic profiling of tumors was derived from Foundation One next generation sequencing. Clinical information was derived from retrospective chart review. Inclusions: adult males with breast cancer with stage IV metastatic disease. Exclusions: Females, stage 0-IIIC disease, missing genomic and pathology information. Results of clinical, pathology and genomic data were summarized. Results: 10 patients met study criteria. Median age: 56 yrs., range 39-61 yrs. Race: 5/10 (50%) Caucasian, 5/10 (50%) African American. Number of prior treatment regimens: mean = 2.6 (range 0-6). Intrinsic subgroup: hormone receptor (HR)+/ HER2- 7/10 (70%), HR+/ HER2+ 2/10 (20%), HR-/ HER2+ 1/10 (10%), triple negative breast cancer (TNBC) 0/10 (0%). Tumor histology: invasive ductal carcinoma 10/10 (100%). Histology grade: poorly differentiated (diff.) 4/10 (40%), moderate diff. 4/10 (40%), well diff. 1/10 (10%), unknown 1/10 (10%). Biopsy site: primary tumor 4/10 (40%), metastatic site 4/10 (40%), liquid biopsy 1/10 (10%). Most frequent genomic alterations: PIK3CA 5/9 (56%), CCND1 4/9 (44%), ZNF703 3/9 (33%), FGF4 3/10 (33%), GATA3 3/9 (33%) FGF 19 3/9 (33%), FGF3 3/9 (33%) Alterations in FGF seen 14/38 (36.8%) of total genomic alterations. Most frequent alterations by primary tumor: ZNF703 3/4 (75%), FGF3 2/4 (50%), FGFR1 2/4 (50%), CCND1 2/4 (50%), FGF19 2/4 (50%), FGF4 2/4 (50%); by metastatic site: PIK3CA 4/5 (80%), GATA 3 2/5 (40%), CCND1 2/5 (40%), FGF3 1/5 (20%), FGF19 1/5 (20%), FGF4 1/5 (20%). Genomic alteration by histologic subgroup; HR+ HER2- PIK3CA 3/6 (50%), CCND1 3/6 (50%), FGF4 3/6 (50%), ZNF703 3/6 (50%), FGF19 3/6 (50%), FGF3 3/6 (50%); HR+/ HER2+: PIK3CA 2/2 (100%), CCND1 1/2 (50%), GATA3 1/2 (50%), MLL3 1/2 (50%); TNBC: BRCA2 1/1 (100%), BARD1 1/1 (100%). Microsatellite status was stable in 6/6 (100%) of patients. Conclusions: MBC patients display a heterogeneous variety of complex genomic alterations. Mutations in FGF genes were most commonly observed. Other common alterations seen in this series include PIK3CA, CCND1, ZNF703, and GATA3. Furthermore, the genomic profile of primary tumor site differed from the genomic profile of the metastatic site.

Abstract P4-01-05: Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 equivocal breast cancer

Background:

Determination of ERBB2 (HER2) expression or amplification informs eligibility of HER2-targeted therapies. ASCO and NCCN guidelines recommend evaluation of HER2 status on primary invasive breast cancers and on a metastatic site if stage IV, where possible, as treatment is based on the status of the metastasis. Reassessment of HER2 status should also be considered in patients with disease recurrence as initially HER2-negative tumors may acquire HER2 amplification at progression. HER2 status can be complicated by equivocal results from in situ hybridization (ISH) and/or immunohistochemistry (IHC). Clarification requires reflex testing on the same tissue specimen or repeat testing on a new specimen, however some patients' tissue status remains equivocal. Furthermore, metastases to bone, lung, or brain may be difficult to re-biopsy or of low DNA quality. Rapid and non-invasive blood-based cell-free DNA (cfDNA) NGS may facilitate identification of HER2 targetable disease in advanced breast cancer.

Methods:

We assessed the frequency of ERBB2 amplification detectable by a blood-based cell-free DNA (cfDNA) assay among patients with metastatic breast cancer with equivocal HER2 results in tissue. cfDNA samples were ordered as part of routine clinical care using an assay validated for the detection of copy number amplification in ERBB2 (tests run between 03/2014-04/2017 by Guardant Health, Redwood City, CA). Submitted pathology reports were reviewed for HER2 status which was categorized as positive, negative, or equivocal based on the interpretation issued by the reading pathologist at the time the test was ordered. Patients were included if they had an equivocal result on IHC and/or ISH unless both assays were performed on the same specimen and one provided a definitive negative or positive HER2 result. Additionally, 4 patients with equivocal IHC or ISH results were excluded as biopsy of another tumor site revealed a positive HER2 result around the same time as the equivocal test. For the 349 patients with multiple cfDNA samples, the earliest pathology report was referenced.

Results:

Tissue HER2 status was available for 1,853 unique patients (98.8% female, median age at testing was 58y, range 26-91y). 141 patients (7.6%) had equivocal HER2 results in tissue; 99 by IHC alone, 14 by ISH alone, and 28 were equivocal by both assays. Among these, 126 patients (89.4%) had at least one sample with ctDNA detected. 12/126 (9.5%) had amplification of ERBB2 detected in at least one cfDNA sample. Samples were drawn a median of 267 days after tissue collection (range 4 days – 11.5 years). Frequency of ERBB2 amplification was similar regardless of time between tissue and blood collection but was higher among patients with ISH results alone (4/14, 36.4%) compared to those with IHC alone (6/89, 6.7%) or both assays (6/26, 7.6%; p=0.006).

Conclusion:

cfDNA testing identifies a significant number of patients with HER2-targetable advanced breast cancer whose tissue was HER2 equivocal. cfDNA testing may supplement tissue-based methods to help clarify HER2 status in metastatic disease as well as identify patients who may acquire HER2 amplification subsequent to their initial biopsy.

Citation Format: Rich TA, Raymond VM, Ahn ER, Banks KC, Brufsky A, Lee C, Lippman M, Pluard TJ, Schwab RB, Lanman RB. Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 equivocal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-05.

Abstract OT1-03-04: A phase II study of neoadjuvant aromatase inhibitor with pertuzumab and trastuzumab for patients with ER+HER2+ stage I-II breast cancer (NEOADAPT)

Background. Recent clinical trial results indicate that it is more appropriate than ever to conduct de-escalation clinical trials looking at less chemotherapy for patients with relatively early stage HER2+ breast cancer, particularly those with so called triple positive breast cancer (ER+PR+HER2+, or TPBC). TBCRC 006 showed that if hormone therapy is added to dual-HER2 blockade (lapatinib and trastuzumab) pathological complete response rate (pCR) can increase to 21% with another 22% having low residual disease (&lt;1cm) with only 12 weeks of neoadjuvant therapy. After CLEOPATRA showed unprecedented improvement in OS comparing docetaxel trastuzumab and pertuzumab versus docetaxel and trastuzumab (15.7 mo median OS difference), we designed NEOADAPT to test the hypothesis that a flexible duration of neoadjuvant treatment based on clinical and radiographic response with an aromatase inhibitor coupled with pertuzumab and trastuzumab would have a &gt;40% pCR rate. The potential impact of this trial is to provide more treatment options for women with early stage TPBC in a current environment when more than 40% of such patients are currently getting chemotherapy.

Trial Design. This single arm prospective cohort study is IRB approved and currently enrolling (NCT02689921). Intervention will be neoadjuvant aromatase inhibitor +/- LHRH agonist or oophorectomy if premenopausal with trastuzumab and pertuzumab in standard q 3-week dosing schedules. Duration of treatment will be determined by clinical exam, q 3mo dynamic breast MRI but no longer than 1 year maximum before surgery. Study ends upon definitive surgery. Duration of treatment will be 3 months after last radiographic CR seen on MRI barring progression or patient/physician choice.

Eligibility Criteria. Patients with stage I-II biopsy confirmed invasive breast cancer that is ER/PR+ and HER2+ by latest ASCO guidelines. Multifocal breast cancer is allowed on the provision that all lesions are biopsied and confirmed to also be TPBC and felt by the pathologist to be the same tumor. Age &gt;18 yrs, ECOG PS 0-2, LVEF &gt;50% at baseline. Rest of inclusion and exclusion criteria are typical for most studies in this setting.

Specific Aims. The primary endpoint is to document pCR rate. Secondary endpoints are to conduct an exploratory analysis of whether Mammaprint can identify patients who are more likely to obtain pCR or not and to describe sensitivity and specificity of breast MRI in predicting pCR.

Statistical Design. To identify a hypothesized pCR rate of &gt;40% with 80% power, 32 patients will be enrolled. The Fleming two stage design will be implemented with stopping rules with the first stage of interim analysis done when the first 15 evaluable patients have surgical results. Further details will be provided in poster.

Present accrual and target accrual. At time of abstract submission 5 of 32 patients have been enrolled and the study is currently available at 2 Cancer Treatment Centers of America sites, Midwestern and Southeastern Regional Medical Center. Plan is to open the study at all 5 CTCA sites before end of 2017.

Contact information for those specifically interested in this trial. Principal investigator Eugene Ahn MD eugene.ahn@ctca-hope.com.

Citation Format: Ahn ER, Alvarez R, Maurie M. A phase II study of neoadjuvant aromatase inhibitor with pertuzumab and trastuzumab for patients with ER+HER2+ stage I-II breast cancer (NEOADAPT) [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 OT1-03-04.

Elevated endothelial microparticle—monocyte complexes induced by multiple sclerosis plasma and the inhibitory effects of interferon-β1b on release of endothelial microparticles, formation and transendothelial migration of monocyte-endothelial microparticle complexes

Monocyte migration through the disrupted cerebral endothelial cell (EC) junctions plays an essential role in formation of multiple sclerosis (MS) demyelinating lesions. During pathogenesis of MS, activated ECs release endothelial microparticles (EMP), which possibly facilitate transendothelial migration (TEMIG) of monocytes. To assess functional roles of EMP in MS, specifically, their (i) interaction with monocytes, (ii) effect on monocyte TEMIG in an in vitro model of the brain microvascular endothelial cells (BMVEC), (iii) phenotypic profiles of EMP elicited by MS plasma and (iv) the effects of IFN-b1b on release of EMP and on TEMIG of monocytes (mono) and monocytes:EMP complexes (mono:EMP) through the BMVEC. The effect of IFN-b1b on the release of EMP and the TEMIG of mono and mono:EMP was assessed by preincubating BMVEC cultures of IFN-b1b prior to addition of plasma. Three EMP phenotypes, CD54, CD62E and CD31 were assayed. Plasma specimens from 20 patients with relapsing—remitting MS (11 in exacerbation, MS-E, and 9 in remission, ME-R) and 10 healthy controls were studied. Incubation of BMVEC with MS-E plasma yielded elevated levels of EMPCD54, EMP62E and EMPCD31 relative to MS-R and control plasmas. MS-E but not MS-R or control plasma also augmented TEMIG of monocytes, respectively. Mono:EMP complexes further augmented TEMIG relative to mono alone, but only in the presence of MS-E plasma; there was no significant effect with MS-R or control plasmas. The presence of IFN-b1b inhibited TEMIG of mono and mono:EMP by 20% and 30%, respectively. MS-E but not MS-R plasma elicited release of activation-derived EMP and enhanced TEMIG of mono and mono:EMP. IFN-b1b inhibited TEMIG and release of EMP, suggesting a role of EMP and a novel therapeutic mechanism for IFN-β1b in MS.

Life-Threatening Hypercoagulable State Following Splenectomy in ITP: Successful Management with Aggressive Antithrombotic Therapy and Danazol

A life-threatening hypercoagulable state (HCS) is reported that developed after splenectomy in idiopathic thrombocytopenic purpura (ITP). A 50-year-old active male was rejected for blood donation because of an incidental finding of low platelet counts, 40,000/uL. The diagnosis was ITP. Although asymptomatic, he underwent splenectomy because of poor response to steroids and intravenous (IV) gamma globulin. One month after splenectomy, he suffered pulmonary emboli without deep venous embolism (DVT), followed by bilateral DVT, threatening amputation of the legs. Emergency thrombolysis, insertion of stent, and IV heparin saved his legs. Extensive workup for HCS was negative. IV heparin was witheld for colonoscopy for possible gastrointestinal neoplasm, at which time DVT recurred, necessitating another thrombolysis and heparin infusion. He was discharged on enoxaparin, antiplatelet therapy, and danazol. Platelet hyperactivation, characterized by high platelet microparticles (PMP) and CD62P, was present throughout his course of active ITP, resolving when ITP went into remission with danazol therapy. ITP has remained in remission for 4 years after stopping enoxaparin and danazol. In vitro, his plasma in active ITP induced activation of normal platelets, generating PMP and inducing CD62p-positive platelets and platelet aggregates; his plasma from remission had no effect. This indicates the presence of a platelet activating factor, possibly anti-platelet antibodies. Splenectomy may have allowed procoagulant PMP to accumulate to high levels resulting in HCS. We advise awareness of thrombotic complications post-splenectomy in the subset of ITP patients who are largely asymptomatic and exhibit persisting platelet activation.

Survival of patients with de-novo metastatic breast cancer: analysis of data from a large breast cancer-specific private practice, a university-based cancer center and review of the literature

Approximately 6 % of patients with breast cancer are diagnosed with de-novo distant metastases. We set out to look at two cohorts of patients seen at breast cancer-specific practices, compare the results to other reports and larger databases, and see how advances in treatment have impacted overall survival (OS). The records from a large breast cancer oncology private practice and a second data set from the University of Miami/Sylvester Comprehensive Cancer Center (UM/SCCC) tumor database were, retrospectively, reviewed to identify patients with de-novo metastases. We included those patients identified to have metastatic disease within 3 months of diagnosis of a breast primary cancer. Patients diagnosed between 1996 and 2006 were chosen for our study population. The OS for the private practice was 41.0 months (46.0 for ER positive and 26.0 for ER negative) and 36.0 months for UM/SCCC (52 months for ER positive and 36 months for ER negative). ER negativity and CNS- or visceral-dominant disease were associated with a significantly worse prognosis within the private practice. Dominant site was associated with a significantly worse prognosis within the UM/SCCC database but with a trend also for ER negativity. Age and ethnicity did not contribute significantly to the survival of patients within either cohort. The median survival in both cohorts and most other reported series was larger than that seen in the surveillance, epidemiology, and end results program and the National Cancer Database. The median OS among patients with de-novo metastatic breast cancer treated within two breast-specific oncology practices was over 3 years, which appears better than larger, more inclusive databases and publications from earlier decades.

Defining the survival benchmark for breast cancer patients with systemic relapse

BACKGROUND

Our original paper, published in 1992, reported a median overall survival after first relapse in breast cancer of 26 months. The current retrospective review concentrates more specifically on patients with first systemic relapse, recognizing that subsets of patients with local recurrence are potentially curable.

METHODS

Records of 5,168 patients from a largely breast-cancer-specific oncology practice were reviewed to identify breast cancer patients with their first relapse between 1996 and 2006 after primary treatment. There were 189 patients diagnosed with metastatic disease within 2 months of being seen by our therapeutic team and 101 patients diagnosed with metastatic disease greater than 2 months. The patients were divided in order to account for lead-time bias than could potentially confound the analysis of the latter 101 patients.

RESULTS

Median survival for our primary study population of 189 patients was 33 months. As expected, the median survival from first systemic relapse (MSFSR) for the 101 patients excluded because of the potential for lead-time bias was better at 46 months. Factors influencing prognosis included estrogen receptor (ER) status, disease-free interval (DFI), and dominant site of metastasis. Compared with our original series, even with elimination of local-regional recurrences in our present series, the median survival from first relapse has improved by 7 months over the past two decades.

CONCLUSION

The new benchmark for MSFSR approaches 3 years.

Improved clinical outcomes associated with vitamin D supplementation during adjuvant chemotherapy in patients with HER2+ nonmetastatic breast cancer

BACKGROUND

Vitamin D (VD) supplementation has pleiotropic effects that extend beyond their impact on bone health, including the disruption of downstream VD receptor signaling and human epidermal growth factor receptor 2 (HER2) signaling through the ErbB2/AKT/ERK pathway. In the present study, we examined our institutional experience with patients having nonmetastatic HER2-positive (HER(+)) breast cancer and hypothesized that those patients who received VD supplementation during neoadjuvant chemotherapy would have improved long-term outcomes.

PATIENTS AND METHODS

We performed a retrospective review of all patients (n = 308) given trastuzumab-based chemotherapy between 2006 and 2012 at the University of Miami/Sylvester Comprehensive Cancer Center (UM/SCCC). We identified 2 groups of patients for comparison-those who received VD supplementation during neoadjuvant chemotherapy (n = 134) and those who did not (n = 112). Univariate and multivariate Cox proportional hazard regression models were fitted to overall survival (OS) and disease-free survival (DFS).

RESULTS

More than half of the patients received VD during neoadjuvant chemotherapy (54.5%), with 60% receiving a dose < 10,000 units/wk and 33.3% having a VD deficiency at the start of therapy. In our final multivariate model, VD use was associated with improved DFS (hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.15-0.88; P = .026], whereas larger tumor size was associated with worse DFS (HR, 3.52; 95% CI, 1.06-11.66; P = .04). There were no differences in OS based on any of the categories, including VD use, tumor size, number of metastatic lymph nodes, age at diagnosis, or lymphovascular invasion (LVI).

CONCLUSION

VD supplementation in patients with nonmetastatic HER2(+) breast cancer is associated with improved DFS.

Abstract P6-09-02: Improved clinical outcomes associated with vitamin D supplementation during adjuvant chemotherapy in patients with HER2+ non-metastatic breast cancer

Background

Vitamin D (VitD) supplementation decreases the risk of osteoporotic fractures in the elderly; however, its extraskeletal benefits, especially in the prevention and treatment of breast cancer, are less well-established. Many studies have shown an association of low VitD levels with higher cancer incidence, including breast cancer and poorer outcomes, but whether this association merely reflects a selection bias to healthier lifestyles, remains an area of controversy. We hypothesized that women with more aggressive HER2+ breast cancer would have improved clinical outcomes while on VitD supplements.

Methods

We performed a retrospective review of all patients (n = 300) given trastuzumab chemotherapy between 2006 and 2012 at UM/SCCC. We identified two groups of patients for comparison - those who received VitD supplementation (VD) during adjuvant chemotherapy (n = 130) or none (NVD) during adjuvant chemotherapy (n = 123). Patients who lacked sufficient records to clarify VitD supplement use, men, patients with de-novo-metastatic breast cancer, bilateral breast cancers, and patients without follow-up were excluded. Five-year disease-free survival (DFS) and overall survival (OS) were calculated. Univariate and multivariate analyses were performed using a Cox proportional hazards (CPH) model to evaluate the relationship between VD supplementation and death.

Results

The median age at diagnosis was 54 and 50 in the VD and NVD groups. In the VD group, the average VitD dose was 10,890 IU/wk, and the baseline and post-25-H VitD serum level was 35 and 41ng/ml, respectively. Descriptive analysis of the VD and NVD groups were as follows: postmenopausal (55.4%, 43.9%), tumor &lt;2cm (42.3%, 36.6%), no lymph node involvement (42.3%, 36.6%), LVI (46.4%, 33.3%), high nuclear grade (60%, 61.5%), HR+ (66.2%, 54.5%), African American race (4.6%, 9.8%), and BMI&gt;30 at end of chemotherapy (26.2%, 31.7%). At a median follow-up of 31 and 23 months, the estimated five-year DFS (69.4% vs. 44.7%, p = 0.009) and OS (97.5% vs. 85.6%, p = &lt;0.0001) were significantly superior in the VD group versus the NVD group. These differences remained significant after adjustment for age, ethnicity, menopausal state, tumor size, node positivity, LVI, high-grade tumor, HR+, and BMI&gt;30. Analysis showed an interaction between OS and ethnicity (African American = 0.008) and node positivity (p = 0.02) and near-significance for LVI (p = 0.07). Despite those confounding variables, VitD use remained significantly associated with improved OS (p = 0.003) and had a HR or 0.10 with a 95% CI of 0.02-0.45.

Conclusion

Our study suggests that Vitamin D supplementation in non-metastatic HER2 breast cancer patients is associated with improved DFS and OS, and the relationship remains significant after adjusting for potential confounding factors. It is unclear whether vitamin D supplementation might have pre-selected for HER2+ breast cancers with more favorable prognosis or synergized with anti-HER2 therapy. To our knowledge, this is the first study reporting improved outcomes associated with relatively high dose Vitamin D supplementation in the HER2+ breast cancer population. Further research is warranted to define the role of Vitamin D in breast cancer treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-09-02.

Antiphospholipid antibodies and platelet activation as risk factors for thrombosis in thrombocythaemia

INTRODUCTION

Risk factors for thrombosis (TB) in thrombocythaemia (TC) associated with myeloproliferative disorder (MPD) are not well defined.

METHODS

We measured antiphospholipid antibodies (APLA) in 35 patients with TC associated with MPD. Fourteen had TB and 21 did not. We assayed IgG and IgM APLA by ELISA for 6 antigens: beta2GP1, cardiolipin (CL), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylethanolamine (PE) and FVII/VIIa, together with markers of activation of platelets (CD62P) and endothelium [endothelial microparticles (EMP)].

RESULTS

At least one positive APLA was detected in 66% of TC patients overall. The incidence was significantly higher in the TB subgroup (92.8%) than non-TB (47.6%, p < 0.05). Multiple APLA (positive for more than one antigen) were also more frequent in TB, for both IgG and IgM, for all 6 antigens tested (p < 0.05). However, IgM APLA predominated, being about 2-fold more frequently positive than IgG for all 6 antigens. Platelet CD62P was significantly higher in the TB group (p < 0.05). EMP did not differ between TB and non-TB. The most frequent thrombotic complication was recurring ischemic cerebral vascular accidents (ICVA), leading to progressive cognitive impairment. Venous TB often developed at unusual sites. Recurring and reversible TB were common features in TC.

SUMMARY

This study suggests that APLA and platelet activation are risk factors for TB in TC. APLA are prevalent in TC, and IgM APLA predominated over IgG. Activation of platelets but not of endothelium may be consistent with the reversible and recurrent features of TB in TC.

Is the Improved Efficacy of Trastuzumab and Lapatinib Combination Worth the Added Toxicity? A Discussion of Current Evidence, Recommendations, and Ethical Issues Regarding Dual HER2-Targeted Therapy

Following FDA approval of trastuzumab in 1998 and lapatinib in 2007, several clinical studies have addressed the question of whether trastuzumab and lapatinib combination therapy is better than trastuzumab alone in the metastatic breast cancer and neoadjuvant setting. In this review, updated to September 2012, we focus on the relevant clinical trials that address this question and, based on the available data, reach conclusions regarding a rational and reasonably individualized approach to the management of HER2+ breast cancer. With the FDA approval of pertuzumab in June 2012 and the likely approval of T-DM1 approaching, several ethical issues overshadow the excitement oncologists have for these new treatment options. We discuss the potential evolution of highly active anti-HER2 therapy (HAAHT) as an optimal treatment paradigm for HER2+ breast cancer. Additionally, we review lessons learned from the evolution of HAART for HIV treatment.

Dual HER2-targeted approaches in HER2-positive breast cancer

Approximately 15-20% of all breast cancers are human epidermal growth factor receptor 2 (HER2) positive, with clinical studies having validated the HER2 receptor tyrosine kinase pathway as an important therapeutic target. Presently, two HER2-targeted therapies are approved by the Food and Drug Administration for treatment of HER2-positive breast cancer: the HER2-targeted humanized monoclonal antibody trastuzumab and the small-molecule tyrosine kinase inhibitor lapatinib. Despite use of these HER2-targeted agents, many patients still experience disease progression. For this reason, numerous new agents and therapeutic strategies are under investigation. Based on preclinical data suggesting synergistic effects from dual therapy targeting HER2, clinical trials that test the effects of combining anti-HER2 agents have been conducted and are ongoing. Here, we review recently presented data from several clinical trials, which indicate that the strategy of combining HER2 blockade therapies can offer greater clinical efficacy, with adverse effects of varying degrees. Specifically, we review new data reported at the 2010 San Antonio Breast Cancer Symposium (SABCS 2010), including the phase II NeoSphere and phase III NeoALTTO clinical trials, and data from three clinical trials reported at the 2011 American Society of Clinical Oncology (ASCO 2011) meeting. Together these trials elucidate the potential role of combining trastuzumab with lapatinib or pertuzumab. We also discuss additional ongoing studies that will help further define the role of dual HER2 blockade therapies and its impact on clinical practice.

Danazol therapy combined with intermittent application of chemotherapy induces lasting remission in myeloproliferative disorder (MPD): an alternative for the elderly with advanced MPD

There is no good alternative therapy available for elderly patients with advanced myeloproliferative disorders (MPD) who failed on conventional therapies and are not candidates for bone marrow transplant. We report here an effective therapy that induced exceptionally long-lasting remissions and improved quality of life. Eighteen elderly patients (mean age: 70·6 years) (16 myelofibrosis and 2 thrombocythemia) who had failed on conventional therapies were treated. Danazol was administered daily at 200-800 mg throughout the study. Chemotherapy was applied intermittently as needed to reduce spleen size and blood counts. Busulfan (2-4 mg/day) was used most often and 6-mercaptopurine (6-MP) (50-100 mg/day) and/or cytarabine (100-200 mg/m(2)) if the white blood cell (WBC) count rose rapidly. When MPD stabilized, chemotherapy was discontinued and dosage of danazol was reduced. Therapy was well tolerated. Overall, 61% of patients responded with unexpectedly long-lasting remissions and improved quality of life. Three (17%) had excellent (E) response, defined by normalization of blood counts and non-palpable spleen, while eight (44%) had good (G) response, defined by rise of Hct by ≥7% and ≥50% reduction of spleen. Mean duration of remission was 45 months (10-78 months) in E responders and 11 months in G responders (2-22 months). This regimen offers a safe and effective alternative for advanced MPD in the elderly.

Increased procoagulant cell-derived microparticles (C-MP) in splenectomized patients with ITP

BACKGROUND

Splenectomy is frequently employed for therapeutic and diagnostic purposes in various clinical disorders. However its long-term safety is not well elucidated. Although risk of infection by encapsulated organisms is widely recognized, less well-known are risks of thrombosis and cardiovascular disease.

METHODS

We investigated levels of cell-derived microparticles (C-MP) in 23 splenectomized ITP (ITP-S) and 53 unsplenectomized ITP patients (ITP-nS). Assay of C-MP derived from platelets (PMP), leukocytes (LMP), red cells (RMP) and endothelial cells (EMP) were performed by flow cytometry. Coagulation parameters included PT, aPTT and activities of FVIII, IX and XI. Results of all measures were compared between the two groups, ITP-S vs ITP-nS.

RESULTS

Levels of all C-MP were higher in ITP-S than ITP-nS but only RMP and LMP reached statistical significance (p = 0.0035 and p < 0.0001, respectively). The aPTT was significantly shorter in ITP-S (p = 0.029). Interestingly, correlation analysis revealed that RMP, but not other C-MP, were associated with shortening of aPTT (p = 0.024) as well as with increased activities of factors VIII (p = 0.023), IX (p = 0.021) and XI (p = 0.0089).

CONCLUSIONS

RMP and LMP were significantly elevated in splenectomized compared to non-splenectomized ITP patients. This suggests that the spleen functions to clear procoagulant C-MP, and that elevation of C-MP might contribute to increased risk of thrombosis, progression of atherosclerosis and cardiovascular disease following splenectomy.

Interstitial lung disease (ILD) and severe ITP

INTRODUCTION

Platelets play an important role in inflammatory and immune responses. We report interstitial lung disease (ILD) developing during the acute phase of severe thrombocytopenia in 3 patients with severe refractory ITP.

METHODS AND RESULTS

We identified 3 cases with severe ITP who developed ILD in the course of refractory chronic ITP. The thrombocytopenia was severe in all cases. ILD was an incidental finding at the presentation and often misdiagnosed as lung infections. ILD was documented by lung biopsy in cases 1 and 2, supplemented by serial chest X-rays and/or CAT scan. As the ITP improved, ILD regressed in case 1, persisted in case 2, and progressed to advanced pulmonary fibrosis in case 3.

CONCLUSION

We report an association of ILD with severe refractory ITP. ILD was detected in acute phase of platelet destruction, suggesting that platelet destruction may have triggered inflammation in the lung, leading to ILD.

Platelet activation in Helicobacter pylori-associated idiopathic thrombocytopenic purpura: eradication reduces platelet activation but seldom improves platelet counts

INTRODUCTION

It has been suggested that Helicobacter pylori eradication often increases platelet counts in patients with chronic idiopathic thrombocytopenic purpura (ITP). In addition, H. pylori has been shown to induce platelet activation (CD62p or P-selectin expression) in previous studies. We assessed the response of platelet count and CD62p expression after eradication therapy in patients with ITP and H. pylori infection.

METHODS AND RESULTS

We prospectively studied 15 ITP patients diagnosed with H. pylori infection by serology and breath test. A follow-up breath test was used to document eradication. Two out of 15 patients showed improvement in platelet counts after 6 months, 1 of which may have had drug-induced thrombocytopenia. Overall, certain platelet response rate in our series was 6.7% (1/15). We found that platelet CD62p expression by flow cytometry was elevated in 10/15 (66.7%) H. pylori-infected patients, which is a statistically significant difference when compared with 3/33 (9.1%) control ITP patients seronegative for H. pylori (p = 0.002). In addition, eradication therapy decreased CD62p expression (p = 0.04). However, reduction in platelet activation was not associated with an increase in platelet counts (mean 72.4 x 10(9)/l before and 68.7 after therapy; p = 0.4).

CONCLUSION

In our series, platelet activation was common in ITP patients with H. pylori, and eradication therapy decreased platelet activation but seldom increased platelet counts. Increased platelet CD62p expression is a putative link between chronic infections and atherosclerosis, but further study is needed to clarify the implications of our observation.

Antiphospholipid antibodies (APLA) in immune thrombocytopenic purpura (ITP) and antiphospholipid syndrome (APS)

Antiphospholipid antibodies (APLA) are associated with anti-phospholipid syndrome (APS), a thrombotic disorder, but they are also frequently detected in immune thrombocytopenic purpura (ITP), a bleeding disorder. To investigate possible differences of APLA between these two disorders, we assayed IgG and IgM APLA by ELISA in 21 patients with ITP and 33 with APS. The APLA reacting against two protein target antigens, beta(2)-glycoprotein 1 (beta2GP1) and FVII/VIIa, and four phospholipids [cardiolipin (CL), phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE)] as well as lupus anticoagulant (LA) were analyzed. We made the following observations: (i) IgG and IgM antibodies to beta2GP1 and IgM antibodies to FVII/VIIa were more common in APS than ITP, P < 0.05, while IgG antibodies against the phospholipids (aCL, aPC, aPS, aPE) were more common in ITP than APS, P < 0.05; (ii) multiple APLA > or =3 antigens) were more frequent in APS than ITP, P < 0.05; (iii) LA was frequently associated with APS but was absent in ITP; (iv) APLA is quite common in ITP: two-thirds were positive for at least one APLA. In summary, APLA are prevalent in ITP but their profile differs from APS. In APS, antibodies were predominantly against beta2GP1 and 80% had positive LA, while in ITP the APLA reacted most often with the phospholipids without LA. The difference in APLA may result in opposite clinical manifestations in two disorders.

Endothelial microparticles induce formation of platelet aggregates via a von Willebrand factor/ristocetin dependent pathway, rendering them resistant to dissociation

Endothelial microparticles (EMP) released from activated or apoptotic endothelial cells (EC) are emerging as useful markers for detection of EC dysfunction. Our recent observation that EMP carry von Willebrand factor (vWf) led us to investigate their interaction with platelets. EMP were incubated with normal washed platelets in the presence or absence of ristocetin, then platelet aggregates were measured by flow cytometry. In the absence of ristocetin, negligible EMP conjugated with platelets (< 5%) but in the presence of ristocetin (1 mg mL(-1)), EMP induced up to 95% of platelets to aggregate. EMP-platelet interaction was 80% blocked by anti-CD42b, or by 0.1 microm filtration to remove EMP. Platelet aggregates induced by normal plasma or high molecular weight vWf (Humate-P) dissociated 50% within 15-25 min following 1:20 dilution. In contrast, aggregates formed with EMP persisted two- to threefold longer with the same treatment, indicating greater stability. A similar degree of prolongation of dissociation was observed using plasma from thrombotic thrombocytopenic purpura (TTP) patients compared with normal plasma. Addition of EMP to plasma from severe von Willebrand disease restored his ristocetin-induced platelet aggregation. Multimer analysis of vWf on EMP showed unusually large vWf (ULvWf). In summary, EMP carries ULvWf multimers, promote platelet aggregates, and increase the stability of the aggregates thus formed.

Long-term remission from life-threatening hypercoagulable state associated with lupus anticoagulant (LA) following rituximab therapy

Rituximab, a chimeric monoclonal CD20 antibody, is useful in the treatment of B-cell lymphomas and certain autoimmune diseases. We report a successful outcome of rituximab for life threatening hypercoagulable state associated with lupus anticoagulant (LA). A 30-year-old woman initially presented 10 years ago with DVT and positive serology for SLE and LA. While on Coumadin, she suffered from recurrent DVT in the legs and arms, pulmonary emboli, Budd-Chiari syndrome, mesenteric vein thrombosis, bone infarcts, recurrent strokes, and chronic ITP. All measures including plasmapheresis and monthly IV cyclophosphamide were of no benefit. She was recently admitted with spontaneous subdural hematoma with INR of 3.8. Upon discontinuation of anticoagulation for surgical drainage, she developed acute abdomen from thrombosis and recurrent DVT. Because she had failed prior standard measures, 4 weekly infusions of rituximab (375 mg/m2) were given following 2 rounds of plasmapheresis. Subsequently, she made a remarkable recovery over the next month and has been free of thrombosis on Coumadin for over 15 months. LA, IgM antibodies to cardiolipin, and B2GP1 were consistently positive. After rituximab therapy, LA became negative and IgM antibodies to cardiolipin decreased and ITP went into remission. Rituximab induced a lasting remission in a woman suffering from life-threatening hypercoagulable state associated with LA. Her clinical remission was associated with disappearance of LA.

Antiphospholipid antibodies in immune thrombocytopenic purpura tend to emerge in exacerbation and decline in remission

Although the presence of antiphospholipid antibodies (APLA) in immune thrombocytopenic purpura (ITP) has been reported, their clinical significance is not clear. The present study investigated APLA profiles in relation to the clinical stages of ITP. We studied APLA in 40 patients in three stages of ITP: exacerbation/relapse (n=7), stable (n=14) and remission (n=19). Both IgG and IgM APLA to six target antigens were measured by enzyme-linked immunosorbent assay: beta2-glycoprotein 1 (beta2GP1), cardiolipin, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine and factor VII/VIIa. The central finding was that APLA were common in ITP but differed significantly in disease stages, being highest in exacerbation (86% positive), intermediate in stable disease (57%) and lowest in remission (42%). In exacerbations, APLA were predominantly of IgG class, while in stable disease, IgM predominated. During remission, APLA often became undetectable. Both the frequency and titres of APLA were significantly higher during exacerbation than remission. An inverse correlation was found between platelet count and nearly all APLA (except beta2GP1). Sequential study of six patients revealed that APLA tended to emerge and rise with exacerbation, concurrently with new episodes of bleeding and became undetectable during remission. These findings raise the possibility that APLA may play a role in the exacerbation and remission of ITP or they may be a consequence of platelet destruction.

Differences of soluble CD40L in sera and plasma: Implications on CD40L assay as a marker of thrombotic risk

INTRODUCTION

Soluble CD40L (sCD40L) ELISA has emerged as a promising predictor of poor outcomes in acute coronary syndrome. Yet many blood processing techniques have been used with little consideration of their effect on the results.

METHODS

We measured sCD40L by ELISA in 10 patients with thrombocytopenia and 12 with normal or high platelet counts and 8 healthy controls using three sampling techniques: serum clotted on ice (serum-I) or at room temperature (serum-RT) and platelet poor plasma (PPP).

RESULTS

Serum-RT samples, compared to serum-I, gave significantly higher CD40L values (p=0.003), demonstrating that ex vivo sCD40L release by activated platelets is inhibited by cold temperature. Although serum-I and PPP were comparable in patients with normal platelet counts, serum-I gave significantly higher values than PPP in the thrombocytosis group (p=0.01), suggesting that cold inhibition is insufficient in the latter group. To estimate the fraction of sCD40L that was microparticle-bound CD40L (mp-CD40L), 16 samples underwent 0.1-microm filtration. 50.6% of sCD40L was mp-CD40L in serum-RT, whereas 21.3% and 29.9% were observed in serum-I and PPP, respectively. Lastly, plasma sCD40L was assayed in 46 patients with and 35 without thrombosis. Plasma sCD40L did not correlate with platelet count in non-thrombotic, non-inflammatory patients but did (p<0.01) in those with thrombosis.

CONCLUSIONS

Sample processing and temperature profoundly affect sCD40L assay. Serum-I and PPP minimize the release of sCD40L ex vivo and better represent sCD40L in vivo. However, PPP may be preferable particularly in patients with thrombocytosis. The existence of mp-CD40L highlights the importance of centrifuge conditions.