Incidence and Presenting Characteristics of Angiosarcoma in the US, 2001-2020

Importance

Angiosarcoma is an aggressive vascular malignant neoplasm presenting either as a primary or secondary cancer, often arising after radiotherapy or in the context of preexisting lymphedema. Comprehensive data describing its incidence and presentation patterns are needed.

Objective

To describe the incidence, presenting characteristics, and change over time of angiosarcoma in the US.

Design, Setting, and Participants

This retrospective cross-sectional study used data from the US Cancer Statistics (USCS) National Program of Cancer Registries-Surveillance, Epidemiology, and End Results Combined Database, which captures more than 99% of newly diagnosed cancers in the US. The study included all 19 289 patients in the US with a new diagnosis of angiosarcoma between 2001 and 2020 captured in the USCS database. Statistical analysis was performed from June to September 2023.

Main Outcomes and Measures

Incidence of angiosarcoma, demographics of patients with angiosarcoma, and extent of disease at presentation.

Results

The study included 19 289 patients (median age, 71 years [IQR, 59-80 years]; 10 506 women [54.5%]) with a new diagnosis of angiosarcoma. The US incidence of angiosarcoma doubled between 2001 (657 cases) and 2019 (1312 cases), reflecting both an increase in the adjusted incidence rate of 1.6% per year (P = .001), to 3.3 cases per 1 000 000 person-years (95% CI, 3.1-3.5 cases per 1 000 000 person-years), and an increase in the population at risk. In 2020, the reported incidence rate (3.0 cases per 1 000 000 person-years) and cases of angiosarcoma (n = 1159) were modestly lower than in 2019. Overall, 72.3% of cases of angiosarcoma (n = 13 955) were cutaneous, subcutaneous, or breast angiosarcomas; 24.4% were visceral (n = 4701); and 3.3% were located in unknown or rare primary sites (n = 633). Secondary breast and chest wall angiosarcomas among women represented the largest contribution to increasing incidence. Among breast angiosarcomas, 99.2% (2684 of 2705) were in women and 71.9% (1944 of 2705) were secondary. A total of 80.4% of chest wall or thorax cases among women (1861 of 2316) were secondary vs 26.5% among men (112 of 422), and 63.9% of upper extremity cases among women (205 of 321) were secondary vs 26.8% (56 of 209) among men (P = .001). Rates of secondary angiosarcoma in the abdomen and lower extremities were similar between men and women. The incidence rate of visceral angiosarcoma was also found to be increasing (1.5% per year; P = .001).

Conclusions and Relevance

This cross-sectional study describes angiosarcoma presentation patterns and incidence rates in the US over a 20-year period and shows that the number of cases in men and women increased, with the greatest increase among women with secondary angiosarcoma of the chest, breast, and upper extremity. These data increase awareness of a rare but highly morbid disease and highlight the need for improved early detection of angiosarcoma among patients at high risk, such as women with a history of breast cancer.

Secondary Breast Angiosarcoma After a Primary Diagnosis of Breast Cancer: A Retrospective Analysis of the Surveillance, Epidemiology, and End Results (SEER) Database

OBJECTIVES

Angiosarcoma is a rare complication of breast-conserving therapy. This study evaluated the change in incidence between 1992 and 2016 of secondary breast angiosarcoma (SBA) in patients with a history of breast cancer and the impact of management strategies for the original breast carcinoma on angiosarcoma treatment.

METHODS

Breast cancer and angiosarcoma cases were abstracted from the Surveillance, Epidemiology, and End Result (SEER) database. SBAs were defined as angiosarcomas located in the breast occurring after a prior breast cancer diagnosis. Primary breast angiosarcomas (PBAs) were defined as an angiosarcoma diagnosis listed as "one primary only." Incidence rates were estimated using a proportion of the US total population. Survival was analyzed by the Kaplan-Meier method, and Cox proportional hazard models were used to assess the association of clinicopathologic characteristics on overall survival.

RESULTS

Between 1992 and 2016, 193 cases of SBA were reported in the SEER dataset in patients with a prior history of breast cancer. The incidence of breast angiosarcoma in patients with a prior diagnosis of breast cancer increased 3-fold from about 10 cases per 100,000 person-years to about 30 cases per 100,000 person-years over this same period ( P =0.0037). For treatment of SBA (n=193), almost all (95%) had surgery. Nine percent received radiation (compared with 35% of patients with PBA, P <0.001) and 23% received chemotherapy (vs. 45% for PBA, P =0.11).

CONCLUSIONS

We demonstrate an increasing incidence of SBA over the study period. These data can help inform shared decision-making for optimal management of locoregional breast cancer and raise awareness of secondary angiosarcoma.

Toll-Like Receptor 4 Agonist Injection With Concurrent Radiotherapy in Patients With Metastatic Soft Tissue Sarcoma: A Phase 1 Nonrandomized Controlled Trial

Importance

Metastatic soft tissue sarcomas (STSs) have limited systemic therapy options, and immunomodulation has not yet meaningfully improved outcomes. Intratumoral (IT) injection of the toll-like receptor 4 (TLR4) agonist glycopyranosyl lipid A in stable-emulsion formulation (GLA-SE) has been studied as immunotherapy in other contexts.

Objective

To evaluate the safety, efficacy, and immunomodulatory effects of IT GLA-SE with concurrent radiotherapy in patients with metastatic STS with injectable lesions.

Design, Setting, and Participants

This phase 1 nonrandomized controlled trial of patients with STS was performed at a single academic sarcoma specialty center from November 17, 2014, to March 16, 2016. Data analysis was performed from August 2016 to September 2022.

Interventions

Two doses of IT GLA-SE (5 μg and 10 μg for 8 weekly doses) were tested for safety in combination with concurrent radiotherapy of the injected lesion.

Main Outcomes and Measures

Primary end points were safety and tolerability. Secondary and exploratory end points included local response rates as well as measurement of antitumor immunity with immunohistochemistry and T-cell receptor (TCR) sequencing of tumor-infiltrating and circulating lymphocytes.

Results

Twelve patients (median [range] age, 65 [34-78] years; 8 [67%] female) were treated across the 2 dose cohorts. Intratumoral GLA-SE was well tolerated, with only 1 patient (8%) experiencing a grade 2 adverse event. All patients achieved local control of the injected lesion after 8 doses, with 1 patient having complete regression (mean regression, -25%; range, -100% to 4%). In patients with durable local response, there were detectable increases in tumor-infiltrating lymphocytes. In 1 patient (target lesion -39% at 259 days of follow-up), TCR sequencing revealed expansion of preexisting and de novo clonotypes, with convergence of numerous rearrangements coding for the same binding sequence (suggestive of clonal convergence to antitumor targets). Single-cell sequencing identified these same expanded TCR clones in peripheral blood after treatment; these T cells had markedly enhanced Tbet expression, suggesting TH1 phenotype.

Conclusions and Relevance

In this nonrandomized controlled trial, IT GLA-SE with concurrent radiotherapy was well tolerated and provided more durable local control than radiotherapy alone. Patients with durable local response demonstrated enhanced IT T-cell clonal expansion, with matched expansion of these clonotypes in the circulation. Additional studies evaluating synergism of IT GLA-SE and radiotherapy with systemic immune modulation are warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT02180698.

Incidence, demographics, and survival of malignant hemangioendothelioma in the United States

BACKGROUND

Malignant hemangioendothelioma is an endothelial cancer with heterogeneous clinical behavior that can range from indolent to aggressive, of which the majority are epithelioid (EHE). Its incidence and demographics have not been previously well defined in a large cohort.

METHODS

This retrospective analysis used the US Cancer Statistics National Program of Cancer Registries - Surveillance Epidemiology End Results (SEER) combined database to identify patients in the US newly diagnosed with hemangioendothelioma between the years of 2001 and 2017 (n = 1986). Survival analyses were performed on a subset of patients within the SEER-18 database with survival information available (n = 417). Outcomes included incidence, demographics of patients newly diagnosed with hemangioendothelioma, extent of disease at presentation, and overall survival.

RESULTS

The incidence of hemangioendothelioma in the US is 0.4 cases per million person-years. Although cases rose to 122 newly diagnosed in the year 2017 (90 EHE, 32 other hemangioendothelioma), incidence rates were stable. Skin and connective tissues were the most common presenting sites (33.4%), followed by liver (24.5%), lung (17.6%), and bone (12.5%). Median age at diagnosis was 55 years; 27.2% of patients were pediatric, adolescent, or young adult (<40 years). At presentation, 36.4% of patients had localized disease; 21.6% presented with regional and 41.7% with distant metastases. Observed survival at 3 years was 79.7%, 70.7%, and 46.0% for patients presenting with local, regional, and distant disease and most deaths occurred within the first 2 years.

CONCLUSIONS

Malignant hemangioendothelioma is ultra-rare but meaningfully impacts affected patients. These data may provide benchmarks for comparison of new approaches to hemangioendothelioma therapy and highlight poor survival outcomes.

Bolus versus Continuous Intravenous Delivery of Doxorubicin in Soft-Tissue Sarcomas: Post Hoc Analysis of a Prospective Randomized Trial (SARC021/TH CR-406)

PURPOSE

Continuous intravenous infusion (CIV) of doxorubicin (DOX) versus bolus (BOL) may minimize dose-dependent DOX cardiomyopathy, but it is unclear whether this advantage is evident as employed in typical soft-tissue sarcoma (STS) treatment. The impact of administration mode on adverse events (AE) and efficacy were compared using data from a randomized trial of DOX-based therapy (SARC021/TH CR-406).

EXPERIMENTAL DESIGN

In this post hoc analysis, CIV versus BOL was at discretion of the treating physician. Likelihood of AEs, and objective responses were assessed by adjusted logistic regression. Progression-free (PFS) and overall survival (OS) were compared using Kaplan-Meier, log-rank test, and adjusted Cox regression.

RESULTS

DOX was administered by BOL to 556 and by CIV to 84 patients. Proportions experiencing hematologic, non-hematologic, or cardiac AEs did not differ by administration mode. Hematologic AEs were associated with age, performance status, and cumulative DOX. Non-hematologic AEs were associated with age, performance status, and cumulative evofosfamide. Cardiac AEs were only associated with cumulative DOX; there was no interaction between DOX dose and delivery mode. PFS and OS were similar (median PFS 6.14 months BOL vs. 6.11 months CIV, P = 0.47; median OS 18.4 months BOL vs. 21.4 months CIV, P = 0.62). PFS, OS, and objective responses were not associated with delivery mode.

CONCLUSIONS

CIV was not associated with superior outcomes over BOL within DOX dosing limits of SARC021. Cardiac AEs were associated with increasing cumulative DOX dose. While not randomized with respect to DOX delivery mode, the results indicate that continued investigation of AE mitigation strategies is warranted.

Inflammatory myofibroblastic tumor of the mesentery with a SQSTM1::ALK fusion responding to alectinib

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an ultra-rare soft tissue neoplasm associated with fusion proteins encompassing the anaplastic lymphoma kinase (ALK) protein fused to a variety of partner proteins. Data regarding response to ALK-targeting agents based on fusion partner is limited.

CASE

A 30-year-old female sought emergency care after onset of abdominal and lower back pain in 2019. Computed tomography (CT) demonstrated a cystic, mesenteric mass within the pelvis measuring up to 8.9 cm. Complete laparoscopic excision of the mass from the mesentery of the right colon and terminal ileum was performed. Pathologic assessment revealed IMT with a fusion between sequestosome 1 and ALK (SQSTM1::ALK), described in only two other cases of IMT. Four months after surgery, CT revealed multi-focal, unresectable disease recurrence. She was referred to the University of Washington/Fred Hutchinson Cancer Center and placed on therapy with alectinib, after which she experienced a partial response. Three years after IMT recurrence, disease remains under control.

CONCLUSION

This is the third reported case of IMT associated with the novel SQSTM1::ALK fusion protein, and the second treated with alectinib. Treatment with the ALK inhibitor alectinib appears to be active in this setting.

Phase 2, multicenter, open-label basket trial of nab-sirolimus for patients with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 genes (PRECISION I)

TPS597

Background: Albumin-bound ( nab)-sirolimus, a novel mTOR inhibitor (mTORi) that utilizes nanoparticle technology to preferentially target tumors, is approved in the US for the treatment of adults with malignant PEComa. In an exploratory analysis of the AMPECT registrational trial of nab-sirolimus in advanced malignant PEComa (NCT02494570), 8/9 (89%) and 1/5 (20%) patients with TSC1 and TSC2 inactivating alterations, respectively, had confirmed response (Wagner, J Clin Oncol. 2021). Importantly, both TSC1 and TSC2 alterations have been observed in patients with various gastrointestinal cancers (Table). Overall, most treatment-related adverse events (TRAEs) in AMPECT were grade 1/2 and manageable for long-term treatment; no grade ≥4 TRAEs occurred. Methods: PRECISION I (NCT05103358) is a phase 2, open-label, multi-institutional basket trial evaluating efficacy and safety of nab-sirolimus in patients with alterations in TSC1 (Arm A) and TSC2 (Arm B). Patients ≥12 years old with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 (confirmed by central review of next-generation sequencing reports) who have progressed on standard therapies and are mTORi-naïve are eligible. nab-Sirolimus 100 mg/m2 will be administered weekly as an intravenous infusion over 30 minutes on Days 1 and 8 of each 21-day cycle. The primary endpoint is overall response rate determined by independent review using RECIST v1.1; other endpoints include duration of response, disease control rate, time to response progression-free survival by independent radiographic review, overall survival, patient-reported quality of life, and safety. Enrollment is ongoing. The most frequent tumor types expected in this tissue-agnostic trial are bladder, hepatobiliary, endometrial, soft tissue sarcoma, ovarian, and esophagogastric based on the prevalence of TSC1 or TSC2 alterations (Table). Clinical trial information: NCT05103358 . [Table: see text]

Phase 2, multicenter, open-label basket trial of nab-sirolimus for patients with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 genes (PRECISION I)

TPS818

Background: Albumin-bound ( nab)-sirolimus, a novel mTOR inhibitor (mTORi) that utilizes nanoparticle technology to preferentially target tumors, is approved in the US for the treatment of adults with malignant PEComa. In an exploratory analysis of the AMPECT registrational trial of nab-sirolimus in advanced malignant PEComa (NCT02494570), 8/9 (89%) and 1/5 (20%) patients with TSC1 and TSC2 inactivating alterations, respectively, had confirmed response (Wagner, J Clin Oncol. 2021). Importantly, both TSC1 and TSC2 alterations have been observed in patients with various gastrointestinal cancers (Table). Overall, most treatment-related adverse events (TRAEs) in AMPECT were grade 1/2 and manageable for long-term treatment; no grade ≥4 TRAEs occurred. Methods: PRECISION I (NCT05103358) is a phase 2, open-label, multi-institutional basket trial evaluating efficacy and safety of nab-sirolimus in patients with alterations in TSC1 (Arm A) and TSC2 (Arm B). Patients ≥12 years old with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 (confirmed by central review of next generation sequencing reports) who have progressed on standard therapies and are mTORi-naïve are eligible. nab-Sirolimus 100 mg/m2 will be administered weekly as an intravenous infusion over 30 minutes on Days 1 and 8 of each 21-day cycle. The primary endpoint is overall response rate determined by independent review using RECIST v1.1; other endpoints include duration of response, disease control rate, time to response, progression-free survival by independent radiographic review, overall survival, patient-reported quality of life, and safety. Enrollment is ongoing. The most frequent tumor types expected in this tissue-agnostic trial are bladder, hepatobiliary, endometrial, soft tissue sarcoma, ovarian, and esophagogastric based on the prevalence of TSC1 or TSC2 alterations (Table). Clinical trial information: NCT05103358 . [Table: see text]

Intracranial Solitary Fibrous Tumor/Hemangiopericytoma Treated with Microsurgical Resection: Retrospective Cohort Analysis of a Single-Center Experience

Objective

To provide benchmarks for further studies of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) of the central nervous system (CNS), we investigated the association of baseline demographic, clinico-pathologic, and treatment factors with outcomes in those treated at our center.

Methods

We conducted a retrospective, cohort analysis of patients treated for SFT/HPC at the University of Washington 1990–2020. Kaplan-Meier and univariable Cox analyses assessed relationships between baseline variables and local or global CNS recurrence, extraneural recurrence, progression-free survival (PFS) and overall survival (OS).

Results

Among 34 eligible patients, median duration of follow-up was 79 months (range 13–318 months). Local and global CNS recurrence occurred at a median of 81 m (95% CI 48–151) and 81 m (95% CI 47–112), respectively. Extraneural metastases occurred at a median 248 m (95% CI 180-Not Reached) and only in grade 3 tumors. Median PFS and OS were 76 months (95% CI: 47–109 months) and 210 months (95% CI 131–306 months), respectively. Univariable Cox analyses showed that age at diagnosis was associated with local (p = 0.01) and global CNS relapse (p = 0.01), and PFS (p = 0.03). Gross total resection was associated with decreased local or global CNS relapse (p = 0.02) and improved PFS (p = 0.03); peri-operative radiation was associated with decreased local CNS relapse (p = 0.02).

Conclusion

Following microsurgical resection of SFT/HPC, CNS relapse is common and associated with age, extent of resection, and adjuvant radiation. Extraneural relapse occurs in some patients. Delayed time-to-initial relapse justifies prolonged surveillance, but optimal approaches have not been defined.

Cardiac events among patients with sarcoma treated with doxorubicin by method of infusion: A real-world database study

BACKGROUND

Administration of doxorubicin by continuous intravenous (CIV) infusion, versus bolus (BOL) administration, has been proposed to mitigate the risk of cardiac events. This study used real-world data to explore the association between mode of doxorubicin administration and duration of treatment, time-to-treatment failure (TTF), and cardiac events.

METHODS

Occurrence of cardiac events after initiation of BOL versus CIV doxorubicin for sarcoma in the International Business Machines MarketScan claims database were compared. Duration of doxorubicin treatment, TTF, and time-to-first-cardiac event (TCE) were evaluated using Kaplan-Meier method and unadjusted and adjusted Cox regression models.

RESULTS

A total of 196 patients were included in the BOL group and 399 in the CIV group. In unadjusted analyses, there were significant differences between BOL versus CIV for duration of doxorubicin treatment (median 1.4 vs. 2.1 months, p = .002), TTF (median 8.8 vs. 5.6 months, p = .002), and TCE (medians not reached, p = .03). Adjusting for baseline covariates, only TTF remained significant (hazard ratio: 0.71, 95% confidence interval 0.59-0.86, p = .0004), favoring BOL.

CONCLUSIONS

While the risk of cardiac complications was higher with BOL in unadjusted analysis, the risk was no longer present in the adjusted analysis. While we cannot draw causal inferences due to the retrospective, nonrandomized study design, these data suggest that replacing BOL with prolonged CIV administration has not been effective as a strategy to mitigate cardiac events, given community standards of oncologic practice.

nab-Sirolimus for patients with advanced malignant PEComa with or without prior mTOR inhibitors: Biomarker results from AMPECT and an expanded access program

11574

Background: Malignant perivascular epithelioid cell tumor (PEComa) is a rare and aggressive sarcoma. nab-Sirolimus is an albumin-bound intravenous (IV) mTOR inhibitor (mTORi) approved for the treatment of adult patients with locally advanced unresectable or metastatic malignant PEComa. The AMPECT trial (NCT02494570) was the first prospective study in advanced malignant PEComa. In exploratory biomarker analyses, TSC1 or TSC2 alterations were associated with response. We report data from the final analysis of AMPECT patients, who were naïve to mTORi, and in patients with malignant PEComa with prior mTORi exposure treated with nab-sirolimus in an expanded access program (EAP) (NCT03817515). Methods: In AMPECT, patients with malignant PEComa naïve to mTORi received nab-sirolimus (100 mg/m2 IV days 1 and 8 of every 21-day cycle) until progression or unacceptable toxicity. The primary endpoint was ORR by independent radiology review. Other endpoints included duration of response (DOR) and disease control rate (DCR), defined as complete response (CR), partial response (PR), or stable disease (SD) at ≥12 weeks. In the EAP, patients with malignant PEComa and prior mTORi exposure received the same dose of nab-sirolimus as in AMPECT. Responses and DCR were evaluated post hoc via electronic medical record review. Genetic profiling, including TSC1 or TSC2 status, was assessed in both protocols, but no specific mutation criteria were required for enrollment. Results: Data include 47 total efficacy-evaluable patients, 31 in AMPECT and 16 with malignant PEComa and prior mTORi exposure treated in the EAP from July 2019–July 2021. Prior mTORi on the EAP included sirolimus, everolimus, temsirolimus, or sapanisertib; 12 patients had exposure to 1 prior mTORi and 4 to ≥2 prior mTORi, and 50% had had progressive disease as best response on mTORi. In AMPECT, ORR was 39% (12/31 patients), and DCR was 71%. Median DOR was not reached after 3 years of follow-up. On the EAP, 4/16 patients (25%) achieved PR (DOR range: 1.3+–25.2+ months, 3 ongoing), and 8/16 (50%) had SD as best response; the DCR was 63% (10/16). Of patients with known TSC1 or TSC2 inactivating alterations in the combined datasets (n = 23), 57% had a response (AMPECT, 64%; EAP, 44%). There were no Grade 4 or 5 treatment-related adverse events on either protocol Conclusions: nab-Sirolimus provided durable responses in mTORi-naïve patients with malignant PEComa and clinical benefit in an expanded access protocol for patients with malignant PEComa with prior mTORi therapy. Although AMPECT and the EAP cannot be directly compared, response rates showed similar trends regardless of prior mTORi exposure and in patients with TSC1 or TSC2 alterations. Based on the emerging biomarker results, a tissue-agnostic study in patients with TSC1 and TSC2 alterations has been initiated (NCT05103358). Clinical trial information: NCT02494570, NCT03817515.

Results of a phase I dose escalation and expansion study of tegavivint (BC2059), a first-in-class TBL1 inhibitor for patients with progressive, unresectable desmoid tumor

11523

Background: Desmoid tumors are known to have increased nuclear β-catenin levels. Tegavivint selectively disrupts the interaction of β-catenin and TBL1/ TBLR1, resulting in specific degradation of nuclear β-catenin. The primary objectives of this study were to determine the maximum tolerated dose (MTD), safety, and preliminary efficacy of tegavivint in patients (pts) with desmoid tumors. Methods: This study ( NCT03459469) utilized an accelerated dose escalation schema for the first two dose levels followed by a 3+3 design to determine the MTD/recommended phase 2 dose (RP2D) of tegavivint, followed by a dose expansion phase. The study included adult pts with sporadic desmoid tumors that were progressive (20% increase in tumor volume, recurrent in one year from surgery, or symptomatic), unresectable, and measurable via WHO criteria. Tegavivint was administered IV weekly (three weeks on, one week off) up to two years. Results: 24 pts were enrolled. Dose escalation enrolled 17 pts in six dose levels from 0.5 - 5 mg/kg. In dose expansion, 7 additional pts were enrolled. Dose expansion cohort also included 6 pts in dose escalation that were escalated to RP2D and 3 pts treated at RP2D in dose escalation (n = 16 total). Median age was 43 years (18-66). Median time from diagnosis was 3.1 years with median of one prior systemic treatment (range 0-6). Median time on study was 9.4 months; 3 pts remain on study at data cut-off. No dose-limiting toxicities were observed; MTD was not determined. RP2D was declared at 5 mg/kg based on pharmacologically relevant plasma concentrations and preliminary efficacy. Trough plasma concentrations (Cmin) exceeded in vitro IC50 efficacy estimates at 4 mg/kg and 5 mg/kg. Median half-life was 38 hours supporting once weekly administration. Treatment-related adverse events (TRAEs) occurring in ≥20% of pts included fatigue (71%), headache (38%), nausea (33%), constipation (21%), decreased appetite (21%), and dysgeusia (21%), mostly Grade 1-2. Grade 3 TRAEs of hypophosphatemia, stomatitis, increased ALT, diarrhea, and headache occurred in 5 separate pts. There were no grade 4-5 adverse events (AEs). One serious AE of Grade 2 extravasation occurred. Objective response rate (ORR) of 17% across all dose levels and 25% at RP2D (WHO and RECIST criteria) were observed. Median duration of response was 8.1 months (range 6 to 11.8 months) with all responses ongoing. The 9-month progression free survival rate was 76% (95% CI: 54 - 90%) among all pts and 79% (95% CI: 51 – 93%) among those treated at RP2D. Patient reported outcomes and correlative science will be included in the presentation. Conclusions: Tegavivint is well tolerated with mostly Grade 1/2 AEs and no serious toxicity associated with WNT inhibition. The ORR of 25% at the RP2D warrants continued development of tegavivint in desmoid tumors. Clinical trial information: NCT03459469.

Neoadjuvant Therapy Induces a Potent Immune Response to Sarcoma, Dominated by Myeloid and B Cells

PURPOSE

To characterize changes in the soft-tissue sarcoma (STS) tumor immune microenvironment induced by standard neoadjuvant therapy with the goal of informing neoadjuvant immunotherapy trial design.

EXPERIMENTAL DESIGN

Paired pre- and postneoadjuvant therapy specimens were retrospectively identified for 32 patients with STSs and analyzed by three modalities: multiplexed IHC, NanoString, and RNA sequencing with ImmunoPrism analysis.

RESULTS

All 32 patients, representing a variety of STS histologic subtypes, received neoadjuvant radiotherapy and 21 (66%) received chemotherapy prior to radiotherapy. The most prevalent immune cells in the tumor before neoadjuvant therapy were myeloid cells (45% of all immune cells) and B cells (37%), with T (13%) and natural killer (NK) cells (5%) also present. Neoadjuvant therapy significantly increased the total immune cells infiltrating the tumors across all histologic subtypes for patients receiving neoadjuvant radiotherapy with or without chemotherapy. An increase in the percentage of monocytes and macrophages, particularly M2 macrophages, B cells, and CD4+ T cells was observed postneoadjuvant therapy. Upregulation of genes and cytokines associated with antigen presentation was also observed, and a favorable pathologic response (≥90% necrosis postneoadjuvant therapy) was associated with an increase in monocytic infiltrate. Upregulation of the T-cell checkpoint TIM3 and downregulation of OX40 were observed posttreatment.

CONCLUSIONS

Standard neoadjuvant therapy induces both immunostimulatory and immunosuppressive effects within a complex sarcoma microenvironment dominated by myeloid and B cells. This work informs ongoing efforts to incorporate immune checkpoint inhibitors and novel immunotherapies into the neoadjuvant setting for STSs.

Is Chemotherapy Associated with Improved Overall Survival in Patients with Dedifferentiated Chondrosarcoma? A SEER Database Analysis

BACKGROUND

Dedifferentiated chondrosarcoma is a chondrosarcoma subtype associated with high rates of recurrence and a poor prognosis. Others have proposed treatment of dedifferentiated chondrosarcoma using osteosarcoma protocols, including perioperative chemotherapy. However, the rarity of this condition poses difficulties in undertaking single- institution studies of sufficient sample size.

QUESTION/PURPOSE

Is perioperative chemotherapy associated with improved overall survival in patients with dedifferentiated chondrosarcoma?

METHODS

We queried the Surveillance, Epidemiology, and End Results (SEER) 1973 to 2016 database for patients with a diagnosis of dedifferentiated chondrosarcoma (n = 308). As dedifferentiated chondrosarcoma was only classified as a distinct entity in SEER starting in 2000, only patients treated in 2000 and later were included. We excluded from our analyses those patients with distant disease at diagnosis, a primary site of disease other than bone or joints, and those who did not receive cancer-directed surgery. These criteria yielded 185 dedifferentiated chondrosarcoma patients for inclusion. We used Kaplan-Meier analyses and Cox proportional hazards models to assess the association of clinical, demographic, and treatment characteristics on overall survival (OS).

RESULTS

After controlling for confounding variables, including age, sex, tumor size, stage, grade, location, and radiation treatment status, and after adjusting for missing data, no overall survival benefit was associated with receipt of chemotherapy in patients with dedifferentiated chondrosarcoma (hazard ratio 0.75 [95% confidence interval 0.49 to 1.12]; p = 0.16).

CONCLUSION

Chemotherapy treatment of dedifferentiated chondrosarcoma was not associated with improved OS. These results must be viewed cautiously, given the limited granularity of information on chemotherapy treatment, the concerns regarding chemotherapy misclassification in SEER data, and the small sample of patients with dedifferentiated chondrosarcoma, all of which limit the power to detect a difference. Our findings are nevertheless consistent with those of prior reports in which no benefit of chemotherapy could be detected. Lack of clear benefit from perioperative chemotherapy in dedifferentiated chondrosarcoma argues that it should be used only after careful consideration, and ideally in the context of a clinical trial.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Efficacy and Safety of TRC105 Plus Pazopanib vs Pazopanib Alone for Treatment of Patients With Advanced Angiosarcoma: A Randomized Clinical Trial

Question

Does the combination of pazopanib plus carotuximab improve progression-free survival compared with pazopanib alone in patients with advanced angiosarcoma?

Findings

This phase 3 randomized clinical trial of 123 patients found no significant difference in median progression-free survival between patients receiving pazopanib plus carotuximab compared with pazopanib alone.

Meaning

The study’s findings indicate that the combination of pazopanib plus carotuximab is not superior to pazopanib alone in treating patients with advanced angiosarcoma.

Importance

Angiosarcoma is a rare sarcoma subtype with a poor outcome. Carotuximab plus pazopanib produced a median progression-free survival (PFS) of 7.8 months in pazopanib-naive patients with chemotherapy-refractory angiosarcoma in a phase 1/2 trial.

Objective

To determine whether carotuximab plus pazopanib improves PFS compared with pazopanib alone in patients with advanced angiosarcoma.

Design, Setting, and Participants

The TAPPAS Trial: An Adaptive Enrichment Phase 3 Trial of TRC105 and Pazopanib vs Pazopanib Alone in Patients With Advanced Angiosarcoma was a multinational, multicenter, open-label, parallel-group, phase 3 randomized clinical trial of 123 patients 18 years or older with advanced angiosarcoma that was conducted between February 16, 2017, and April 12, 2019, at 31 sites in the US and the European Union. Patients were randomized 1:1 to receive pazopanib alone or carotuximab plus pazopanib. The trial incorporated an adaptive enrichment design. Inclusion criteria were no more than 2 prior lines of systemic therapy and an Eastern Cooperative Oncology Group performance status of 0 or 1. The efficacy analysis used the intent-to-treat population; the safety analysis included all patients who received a dose of either study drug.

Exposures

Oral pazopanib, 800 mg/d, or intravenous carotuximab, 10 mg/kg, administered weekly, plus oral pazopanib, 800 mg/d, with dose modification allowed per patient tolerance or until disease progression.

Main Outcomes and Measures

The primary end point was PFS, assessed by blinded independent radiographic and cutaneous photographic review per Response Evaluation Criteria in Solid Tumors (RECIST) guidelines, version 1.1. Secondary end points included the objective response rate and overall survival. An interim analysis to determine the final sample size was conducted after enrollment of 123 patients. PFS in the group receiving pazopanib alone was compared with PFS in the group receiving carotuximab plus pazopanib using the log rank test.

Results

Of 114 patients with evaluable data (53 in the pazopanib arm and 61 in the carotuximab plus pazopanib arm), 69 (61%) were female and the median age was 68 years (range, 24-82 years); 57 (50%) had cutaneous disease and 32 (28%) had had no prior treatment. The primary end point (PFS) was not reached (hazard ratio [HR], 0.98; 95% CI, 0.52-1.84; P = .95), with a median of 4.3 months (95% CI, 2.9 months to not reached) for pazopanib and 4.2 months (95% CI, 2.8-8.3 months) for the combination arm. The most common all-grade adverse events in the single-agent pazopanib arm vs the combination arm were fatigue (29 patients [55%] vs 37 [61%]), headache (12 patients [23%] vs 39 [64%]), diarrhea (27 patients [51%] vs 35 [57%]), nausea (26 patients [49%] vs 29 [48%]), vomiting (12 patients [23%] vs 23 [38%]), anemia (5 patients [9%] vs 27 [44%]), epistaxis (2 patients [4%] vs 34 [56%]), and hypertension (29 patients [55%] vs 22 [36%]).

Conclusions and Relevance

In this phase 3 randomized clinical trial, carotuximab plus pazopanib did not improve PFS compared with pazopanib alone in patients with advanced angiosarcoma.

Trial Registration

ClinicalTrials.gov Identifier: NCT02979899

A Phase 1/2 Trial Combining Avelumab and Trabectedin for Advanced Liposarcoma and Leiomyosarcoma

PURPOSE

Leiomyosarcoma (LMS) and liposarcoma (LPS) frequently express PD-L1 but are generally resistant to PD-1/PD-L1 inhibition (ICI). Trabectedin is FDA-approved for LMS and LPS. This study aimed to evaluate the safety and efficacy of trabectedin with anti-PD-L1 antibody avelumab in patients with advanced LMS and LPS.

PATIENTS AND METHODS

A single-arm, open-label, Phase 1/2 study tested avelumab with trabectedin for advanced LMS and LPS. The phase I portion evaluated safety and feasibility of trabectedin (1, 1.2 and 1.5 mg/m2) with avelumab at standard dosing. Primary endpoint of the phase II portion was objective response rate (ORR) by RECIST 1.1. Correlative studies included T-cell receptor sequencing (TCRseq), multiplex immunohistochemistry, and tumor gene expression.

RESULTS

33 patients were evaluable; 24 with LMS (6 uterine and 18 non-uterine) and 11 with LPS. In Phase 1, dose limiting toxicities (DLTs) were observed in 2 of 6 patients at both trabectedin 1.2 and 1.5 mg/m2. The recommended Phase 2 dose (RP2D) was 1.0 mg/m2 trabectedin and 800 mg avelumab. Of 23 patients evaluable at RP2D, three (13%) had partial response (PR), ten (43%) had stable disease (SD) as best response. 6-month PFS was 52%; median PFS was 8.3 months. Patients with PR had higher Simpson Clonality score on TCRseq from peripheral blood mononuclear cells (PBMC) versus those with SD (0.182 vs 0.067, p = 0.02) or PD (0.182 vs 0.064, p = 0.01).

CONCLUSIONS

Although the trial did not meet the primary ORR endpoint, PFS compared favorably to prior studies of trabectedin warranting further investigation.

Fédération Nationale Des Centres de Lutte Contre Le Cancer (FNCLCC) Grading, Margin Status and Tumor Location Associate With Survival Outcomes in Malignant Peripheral Nerve Sheath Tumors

BACKGROUND

Histologic grading using the Fédération Nationale des Centres de Lutte Contre Le Cancer (FNCLCC) system is not universally accepted as applicable to malignant peripheral nerve sheath tumor (MPNST), as its prognostic value is not well established.

METHODS

We retrospectively evaluated 99 cases of MPNST to investigate any association between the outcomes overall survival (OS) and progression-free survival (PFS), and predictor variables FNCLCC grade, clinical setting, tumor location, and tumor size at diagnosis using multivariable Cox proportional hazard analysis.

RESULTS

Univariable and multivariable analysis demonstrate a statistically significant association between FNCLCC grade and both OS and PFS when comparing tumors by histologic grade. Of note, no deaths were observed in patients with grade 1 MPNST. Other variables associated with unfavorable outcomes include fragmented resection and primary site, with tumors in the extremities having favorable OS, but not PFS, when compared with those in truncal locations. Tumors in the head and neck had favorable PFS, but not OS, compared with those in the trunk. No statistically significant differences in OS or PFS were observed when comparing patient age and sex, tumor size at diagnosis, clinical setting (primary vs. type-1 neurofibromatosis vs. radiation associated) or history of neoadjuvant therapy. Interobserver agreement for FNCLCC grading of these tumors was considered good (S*=0.77, 95% confidence interval: 0.71-0.84).

CONCLUSIONS

Association between FNCLCC grading and survival outcomes in MPNST suggests potential value to routinely grading these neoplasms. However, the subjectivity of the grading system, particularly when assigning a tumor differentiation score, may pose a challenge, especially in low and intermediate grade lesions.

An Open-Label, Randomized, Multi-Center Study Comparing the Sequence of High Dose Aldesleukin (Interleukin-2) and Ipilimumab (Yervoy) in Patients with Metastatic Melanoma

Combination immunotherapy with sequential administration may enhance metastatic melanoma (MM) patients with long-term disease control. High Dose Aldesleukin/Recombinant Interleukin-2 (HD rIL-2) and ipilimumab (IPI) offer complementary mechanisms against MM. This phase IV study assessed the sequenced use of HD rIL-2 and IPI in MM patients. Eligible Stage IV MM patients were randomized to treatment with either two courses of HD rIL-2(600,000 IU/kg) followed by four doses of IPI 3 mg/kg or vice-versa. The primary objective was to compare one-year overall survival (OS) with historical control (46%, Hodi et al., NEJM 2010). Secondary objectives were 1-year progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs) profile. Evaluable Population (EP) included patients who received at least 50% of planned treatment with each drug. Thirteen and 16 patients were randomized to receive HD rIL-2 first, and IPI first, respectively. One-year OS rate was 75% for intention to treat population. Eighteen patients were included in EP, 8 in HD rIL-2, 10 in IPI first arm. In EP, 1-year OS, PFS and ORR rates were 87%, 68%, and 50%, respectively. The frequency of AEs was similar in both arms with 13 patients experiencing Grade 3 or higher AEs, 3 resulting in the end of study participation. There was one HD rIL-2-related death, from cerebral hemorrhage due to thrombocytopenia. In this study with small sample size, HD rIL-2 and IPI were safe to administer sequentially in MM patients and showed more than additive effects. 1-year OS was superior to that of IPI alone from historical studies.

CD4+ T cell and M2 macrophage infiltration predict dedifferentiated liposarcoma patient outcomes

Background

Dedifferentiated liposarcoma (DDLPS) is one of the most common soft tissue sarcoma subtypes and is devastating in the advanced/metastatic stage. Despite the observation of clinical responses to PD-1 inhibitors, little is known about the immune microenvironment in relation to patient prognosis.

Methods

We performed a retrospective study of 61 patients with DDLPS. We completed deep sequencing of the T-cell receptor (TCR) β-chain and RNA sequencing for predictive modeling, evaluating both immune markers and tumor escape genes. Hierarchical clustering and recursive partitioning were employed to elucidate relationships of cellular infiltrates within the tumor microenvironment, while an immune score for single markers was created as a predictive tool.

Results

Although many DDLPS samples had low TCR clonality, high TCR clonality combined with low T-cell fraction predicted lower 3-year overall survival (p=0.05). Higher levels of CD14+ monocytes (p=0.02) inversely correlated with 3-year recurrence-free survival (RFS), while CD4+ T-cell infiltration (p=0.05) was associated with a higher RFS. Genes associated with longer RFS included PD-1 (p=0.003), ICOS (p=0.006), BTLA (p=0.033), and CTLA4 (p=0.02). In a composite immune score, CD4+ T cells had the strongest positive predictive value, while CD14+ monocytes and M2 macrophages had the strongest negative predictive values.

Conclusions

Immune cell infiltration predicts clinical outcome in DDLPS, with CD4+ cells associated with better outcomes; CD14+ cells and M2 macrophages are associated with worse outcomes. Future checkpoint inhibitor studies in DDLPS should incorporate immunosequencing and gene expression profiling techniques that can generate immune landscape profiles.

Sustained response to pembrolizumab in recurrent perivascular epithelioid cell tumor with elevated expression of programmed death ligand: a case report

Background

Perivascular epithelioid cell tumors are defined by the World Health Organization as “a collection of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells.” Whereas localized perivascular epithelioid cell tumor is typically benign and treated successfully with surgical resection, prognosis for patients with advanced or metastatic perivascular epithelioid cell tumor is unfavorable, and there is no standard curative treatment.

Case presentation

We report a Caucasian case of metastatic perivascular epithelioid cell tumor previously treated with chemotherapy and surgery with elevated surface expression of programmed cell death ligand 1. Based on this result, treatment via immune checkpoint inhibition with the monoclonal antibody pembrolizumab was pursued. After 21 cycles, the patient sustained a complete response. Therapy was stopped after the 40th cycle, and she was moved to surveillance. She remained disease free 19 months off treatment.

Conclusions

This case report of a patient with perivascular epithelioid cell tumor treated successfully with programmed cell death protein-1 targeted therapy suggests that programmed cell death ligand-1 levels should be measured in patients with perivascular epithelioid cell tumor and immunotherapy considered for recurrent or metastatic patients. Future phase II/III studies in this disease should focus on sequencing of surgery and immunotherapy with a design of curative intent.

A phase III study (APROMISS) of AL3818 (Catequentinib, Anlotinib) hydrochloride monotherapy in subjects with metastatic or advanced synovial sarcoma

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Background: AL3818 (Catequentinib, Anlotinib) is a novel, orally administered, small molecule tyrosine kinase inhibitor. The primary objective of this Phase 3 study is to evaluate the efficacy of AL3818 monotherapy in patients (pts) with synovial sarcoma (SS) comparing with dacarbazine in randomization setting. Methods: Patients with a diagnosis of synovial sarcoma requiring second line or further line treatment were eligible for enrollment. The regimen was a 21-day cycle with oral AL3818 administered on 14 days on and 7 days off. This phase 3 trial is randomized in 2:1 ratio of AL3818 comparing to dacarbazine with option of crossover after PD of dacarbazine treatment. Progression free survival (PFS) with Log Rank test is the primary endpoint and this trial for SS is currently completed enrolled in US and Italy. Results: Total 79 pts initiated treatment and are evaluable, 52 received AL3818 as treatment arm (T), and 27 received dacarbazine (D) as control arm (C). Arms T/C median ages were 40.5/42.0 years (range: 18-70+) and 20/16 (38.5%/59.3%) were male. Overall, PFS was 2.89 months (95% CI: 2.73 – 6.87) for AL3818 and 1.64 (95% CI: 1.45 – 2.70) for D. The PFS of study met the primary endpoint with a p-value of 0.0015 and a HR of 0.449 (95% CI: 0.270– 0.744). At the month 4, 6, and 12, the percentages of progression free patients for AL3818 were 48.1%, 42.3% and 26.9%; and for D were 14.85%, 11.1% and 3.7%. For grade 3 treatment-related adverse events, 12(23.1%) of pts experienced for AL3818 and 7(25.9%) of pts experienced for D. The most common AL3818 related grade 3 AEs were diarrhea (5.8%) and hypertension (3.8%). Conclusions: This phase III trial demonstrates improved disease control and superior progression free survival for AL3818 vs dacarbazine in advanced SS. In addition, the study further confirms the acceptable benefit-risk profile of AL3818 from the prior randomized Phase 2b soft tissue sarcoma study (NCT02449343). AL3818 is a meaningful treatment option for pts with advanced SS. Clinical trial information: NCT 03016819 Clinical trial information: NCT03016819.

IL-15 mediated expansion of rare durable memory T cells following adoptive cellular therapy

Background

Synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are ideal solid tumors for the development of adoptive cellular therapy (ACT) targeting NY-ESO-1, as a high frequency of tumors homogeneously express this cancer-testes antigen. Data from early phase clinical trials have shown antitumor activity after the adoptive transfer of NY-ESO-1–specific T cells. In these studies, persistence of NY-ESO-1 specific T cells is highly correlated with response to ACT, but patients often continue to have detectable transferred cells in their peripheral blood following progression.

Method

We performed a phase I clinical trial evaluating the safety of NY-ESO-1–specific endogenous T cells (ETC) following cyclophosphamide conditioning. Peripheral blood mononuclear cells (PBMCs) from treated patients were evaluated by flow cytometry and gene expression analysis as well as through ex vivo culture assays with and without IL-15.

Results

Four patients were treated in a cohort using ETC targeting NY-ESO-1 following cyclophosphamide conditioning. Treatment was well tolerated without significant toxicity, but all patients ultimately had disease progression. In two of four patients, we obtained post-treatment tumor tissue and in both, NY-ESO-1 antigen was retained despite clear detectable persisting NY-ESO-1–specific T cells in the peripheral blood. Despite a memory phenotype, these persisting cells lacked markers of proliferation or activation. However, in ex vivo culture assays, they could be induced to proliferate and kill tumor using IL-15. These results were also seen in PBMCs from two patients who received gene-engineered T-cell receptor–based products at other centers.

Conclusions

ETC targeting NY-ESO-1 with single-agent cyclophosphamide alone conditioning was well tolerated in patients with SS and those with MRCL. IL-15 can induce proliferation and activity in persisting NY-ESO-1–specific T cells even in patients with disease progression following ACT. These results support future work evaluating whether IL-15 could be incorporated into ACT trials post-infusion or at the time of progression.

Outcomes of Patients with Sarcoma and COVID-19 Infection: A Single Institution Cohort Analysis

Outcomes for patients (pts) with sarcoma and COVID-19 are unknown. This is a single institution retrospective study of adults with sarcoma and COVID-19. Ten pts [median age 60 (range 24-69)] were identified. Five were hospitalized; two died from COVID-19 complications; another died from sarcoma. Time between last systemic treatment dose and COVID-19 diagnosis was 6-41 days in pts who died. 5 underwent prior radiation (RT); time between RT and COVID-19 diagnosis was 20-62 days for pts who died. All three pts with WBC differential data (two died) were lymphopenic. Efforts to capture outcomes for a larger cohort are urgently needed.

Abstract PS13-38: Cardiotoxicity among patients with breast cancer treated with doxorubicin: A real-world database study

Background While novel targeted agents are increasingly used to care for patients with breast cancer, doxorubicin (DOX) continues to play a role in management of patients, particularly those with aggressive disease. Dose-dependent cardiomyopathy is a challenge in its use. Strategies have been proposed to mitigate this, including administration by continuous intravenous (CIV) infusion as an alternative to bolus (BOL) administration. This study used real world data to explore the impact of DOX administration mode on cardiotoxicity, duration of DOX and time to treatment failure (TTF). Methods IBM MarketScan claims were used to identify patients age ≥ 18 who received at least 2 DOX administrations (excluding liposomal DOX) after cancer diagnosis. Patients with history of cardiac events were excluded. Cardiac events based on a range of International Classification of Disease (ICD) codes were compared for BOL versus CIV overall, by tumor site and by regimen during three follow-up periods, early (within 1 year), middle (&gt;1 to 5 years) and late (&gt;5 years), from DOX initiation using Fisher’s exact test. Duration of DOX and TTF, defined as time from initiation of DOX to subsequent systemic therapy, hospice or death, were evaluated using Kaplan-Meier method and unadjusted Cox proportional hazards models. Results: A total of 38,924 patients with breast cancer met eligibility criteria (13,186 with confirmed metastatic disease). The most common regimen used was DOX plus cyclophosphamide (n=31,815, 81.7%). Most patients had codes for both modes on the same claim date and could not be definitely assigned to BOL or CIV infusion groups; however, 917 and 5,433 patients had exclusive BOL and CIV codes, respectively. Among patients receiving DOX monotherapy (n=687), 361 and 100 had exclusive BOL and CIV codes, respectively. For patients with exclusive infusion type codes, the mean duration of DOX treatment was not significantly different for BOL vs CIV (58.9 vs 56.2 days, p=0.33 overall; 74.4 vs 74.8 days for monotherapy, p=0.97). Overall, cardiac events for BOL vs CIV were 5.1% vs 4.7% (p=0.55) during the early period, 3.1% vs 5.0%, (p=0.01) during the middle period, and 0.4% vs 1.0% (p=0.10) in the late period. There were no differences in cardiac events for BOL vs CIV among those treated with DOX monotherapy (p=0.90, 0.56 and 0.52 for the early, middle, and late period, respectively). TTF was shorter for BOL vs CIV (262.3 vs 366.0 days, p&lt;0.001). However, when evaluating TTF, there was a significant relationship between cardiotoxicities and longer TTF (hazard ratio, HR=0.85, 95% confidence interval, CI: 0.81-0.88, p&lt;0.001). This relationship was statistically significant for the early, middle and late periods, respectively (all p&lt;0.001). Conclusions: These data suggest that cardiac events may occur at a similar rate for BOL and CIV. This study is limited by the retrospective nature of this study and the ability to determine causality; the use of strict coding rules to correctly assign patients to BOL vs CIV groups maintained scientific integrity and a large sample size but did result in the loss of eligible patients. Future research, including adjusted analyses, are needed to further investigate the relationship between mode of infusion and clinical outcomes.

Citation Format: Poorni Manohar, Hannah M Linden, Lisa M Hess, Tomoko Sugihara, Yajun E Zhu, Howard G Muntz, Lee D Cranmer. Cardiotoxicity among patients with breast cancer treated with doxorubicin: A real-world database study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-38.

Assessment of Doxorubicin and Pembrolizumab in Patients With Advanced Anthracycline-Naive Sarcoma: A Phase 1/2 Nonrandomized Clinical Trial

Question

Is the combination of doxorubicin and pembrolizumab an effective and feasible regimen for patients with advanced sarcoma?

Findings

In this nonrandomized phase 1/2 clinical trial of 37 patients with advanced sarcoma, the combination of doxorubicin and pembrolizumab was well tolerated. The objective response rate was 13% for phase 2 patients and 19% overall, with median progression-free survival of 8.1 months and median overall survival of 27.6 months.

Meaning

Doxorubicin in combination with pembrolizumab is a promising combination worthy of further study, especially in certain sarcoma subtypes, including undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma.

Importance

Anthracycline-based therapy is standard first-line treatment for most patients with advanced and metastatic sarcomas. Although multiple trials have attempted to show improved outcomes in patients with soft-tissue sarcoma over doxorubicin monotherapy, each has fallen short of demonstrating improved outcomes.

Objective

To evaluate the safety and efficacy of doxorubicin in combination with pembrolizumab in patients with advanced, anthracycline-naive sarcomas.

Design, Setting, and Participants

This nonrandomized clinical trial used a 2-stage phase 2 design and was performed at a single, academic sarcoma specialty center. Patients were adults with good performance status and end-organ function. Patients with all sarcoma subtypes were allowed to enroll with the exception of osteosarcoma, Ewing sarcoma, and alveolar and embryonal rhabdomyosarcoma.

Interventions

Two dose levels of doxorubicin (45 and 75 mg/m²) were tested for safety in combination with pembrolizumab.

Main Outcomes and Measures

Objective response rate (ORR) was the primary end point. Overall survival (OS) and progression-free survival (PFS) were secondary end points. Correlative studies included immunohistochemistry, gene expression, and serum cytokines.

Results

A total of 37 patients (22 men; 15 women) were treated in the combined phase 1/2 trial. The median (range) patient age was 58.4 (25-80) years. The most common histologic subtype was leiomyosarcoma (11 patients). Doxorubicin plus pembrolizumab was well tolerated without significant unexpected toxic effects. The ORR was 13% for phase 2 patients and 19% overall. Median PFS was 8.1 (95% CI, 7.6-10.8) months. Median OS was 27.6 (95% CI, 18.7-not reached) months at the time of this analysis. Two of 3 patients with undifferentiated pleomorphic sarcoma and 2 of 4 patients with dedifferentiated liposarcoma had durable partial responses. Tumor-infiltrating lymphocytes were present in 21% of evaluable tumors and associated with inferior PFS (log-rank P = .03). No dose-limiting toxic effects were observed.

Conclusions and Relevance

In this nonrandomized clinical trial, doxorubicin plus pembrolizumab was well tolerated. Although the primary end point for ORR was not reached, the PFS and OS observed compared favorably with prior published studies. Further studies are warranted, especially those focusing on undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma.

Trial Registration

ClinicalTrials.gov Identifier: NCT02888665

Long-term Outcomes for Extraskeletal Myxoid Chondrosarcoma: A SEER Database Analysis

BACKGROUND

Extraskeletal myxoid chondrosarcoma (EMCS) is a rare tumor that typically has an indolent course but high rate of recurrence. We queried the Surveillance, Epidemiology, and End Results (SEER) database to assess factors associated with metastasis, treatment, and survival.

METHODS

We queried the SEER 1973-2016 database for patients with myxoid chondrosarcoma (ICD-O-3: 9231/3). Kaplan-Meier analyses and Cox proportional hazard models assessed effects on overall survival (OS) of demographics and clinical characteristics. Logistic regression assessed associations between tumor location and distant disease. Primary analysis was a complete case analysis; multiple imputation (MI) was used in a sensitivity analysis.

RESULTS

Locoregional disease (LRD) was found in 373 (85%) of patients. In univariate analysis with LRD, surgery correlated with superior OS [HR = 0.27; 95% confidence interval (CI), 0.16-0.47]; chemotherapy and radiotherapy associated with inferior OS (HR = 1.90; 95% CI, 1.11-3.27 and HR = 1.45; 95% CI, 1.03-2.06, respectively). No treatment modality associated with OS in the adjusted, complete case model. In the adjusted sensitivity analysis, surgery associated with superior outcomes (HR = 0.36; 95% CI, 0.19-0.69). There was no OS difference by primary tumor site. 10-year OS with distant disease was 10% (95% CI, 2%-25%).

CONCLUSIONS

Surgery in LRD associated with improved OS in univariate analysis and adjusted models correcting for missing data. There was no OS benefit with chemotherapy or radiotherapy.

IMPACT

This represents the largest report of EMCS with long-term follow-up. Despite the reputedly indolent nature of EMCS, outcomes with metastatic disease are poor. We provide OS benchmarks and guidance for stratification in future prospective trials.

Cost-utility analysis of surveillance strategies for soft tissue sarcoma recurrence

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Background: Soft tissue sarcomas (STS) are uncommon malignancies with significant biological and clinical variation. After primary curative therapy, patients enter a program of surveillance for recurrence with periodic chest x-rays (CXR) or computed tomography (CT). We compared costs and health outcomes of CXR and CT at a range of frequencies and durations of follow-up. Methods: We used a Markov model to simulate a cohort of 10,000 STS patients through their surveillance experience for lung metastasis after completion of definitive treatment for stage II or III primary disease. Health states in the model were no evidence of disease, recurrence, and death. We assessed the method of chest imaging, duration of follow-up, and interval (every 3 months or 6 months) of surveillance in the first 3 years. Cost effectiveness was assessed for each screening modality and screening frequency. Recurrence probabilities, utilities, treatment costs, and other parameters were from previously published data. Outcomes were costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICER). Results: The initial evaluation comparing screening every 3 months for 3 years, every 6 months for years 4 and 5, and annually from years 6 to 10 resulted in 632,264 QALYs and $1,038,351,481 costs for CT, compared to 631,834 QALYs and $746,019,937 for CXR, resulting in an ICER of $679,322/QALY. In comparing screening intervals, less frequent screening intervals of every 6 months compared to every 3 months for the first three years using CT resulted in an ICER of $690,527/QALY and for CXR, the ICER was $271,423/QALY. In comparing screening duration between 6 years and 10 years of follow-up, strategies with longer follow-up resulted in slightly higher QALYs in each of the comparison scenarios, at a much higher cost. Conclusions: In our evaluation, more frequent screening the first 3 years and longer duration of surveillance resulted in higher QALYs in both screening modalities. However, in the comparisons the ICERs exceed common willingness to pay thresholds of $150,000/QALY gained; CXR is the more cost-effective imaging modality. Limitation of this model includes the simplification of disease progression and heterogeneity in STS.

Long-term follow-up for duration of response (DoR) after weekly nab-sirolimus in patients with advanced malignant perivascular epithelioid cell tumors (PEComa): Results from a registrational open-label phase II trial, AMPECT

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Background: Malignant PEComa is a rare, aggressive sarcoma, with no approved medical treatment. Cytotoxic chemotherapies have limited benefit for patients with advanced disease. The AMPECT trial measured the effects of nab-sirolimus (ABI-009) and is the first prospective study in advanced malignant PEComa. nab-Sirolimus is a nanoparticle albumin-bound mTOR inhibitor with significantly higher intratumoral drug levels, mTOR target suppression, and anti-tumor activity in animal models versus other mTOR inhibitors. This report presents long-term follow-up of DoR after the primary analysis. Methods: Patients (N=34) received nab-sirolimus (100mg/m2 IV, weekly, 2/3 weeks) until progression or unacceptable toxicity. Primary endpoint: ORR by IRR. Key secondary endpoints included DoR, PFS6, OS, and safety. Exploratory endpoints included correlation of tumor genotype and outcome. The sample size of 30 efficacy-evaluable patients was based on an estimated ORR of 30% and the lower bound of the 95%CI of ORR to exclude values less than 14.7%. The primary analysis was conducted when all patients were treated ≥6 months (May 22, 2019). This report updates the primary response analysis and DoR with an additional 8.5-month of follow-up. Results: As of Feb 06, 2020, of the 31 efficacy-evaluable patients, the confirmed ORR by IRR was 39% (12/31, 95%CI: 21.8, 57.8), with 1 complete response (CR) and 11 partial responses (PR), 52% stable disease (SD, 16/31, with 10/16 SD ≥12 weeks), and 10% progressive disease (3/31); the disease control rate (CR+PR+SD ≥12 weeks) was 71%. PFS6 was 71% (95%CI: 47.7, 85.1). The majority of responses (67%) were reached at the first post-baseline scan at week 6, with a median time to response of 1.4 months (95%CI: 1.3 to 2.8). The median DoR by IRR was not yet reached (range 5.6-38.7+ months; calculated median 22.2+ months) with 8/12 (67%) responders still on treatment for >1 year and 5/12 (42%) >2 years. Mutational analysis available for 25 patients identified that TSC2 loss-of-function mutations significantly correlated with response; 8/9 (89%) patients with TSC2 had a confirmed response. Conclusions: Responses of advanced malignant PEComa to nab-sirolimus were highly durable and occurred in 39% of patients based on independent review. The high disease control rate with manageable toxicities suggest that nab-sirolimus is effective and represents an important new treatment option for these patients. NCT02494570. Clinical trial information: NCT02494570 .

Impact of bolus versus continuous infusion of doxorubicin (DOX) on cardiotoxicity in patients with breast cancer (BC) and sarcomas: Analysis of real-world data

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Background: Doxorubicin continues to play a central role in management of breast cancer and sarcomas. Dose-dependent cardiomyopathy is a challenge in its use. Strategies have been proposed to mitigate this, including administration by continuous intravenous (CIV) infusion as an alternative to bolus (BOL) administration. This study used real world data to explore the impact of DOX administration mode on cardiotoxicity, duration of DOX and time to treatment failure (TTF). Methods: This study used IBM MarketScan claims to identify patients age ≥ 18 who received at least 2 DOX administrations after cancer diagnosis. Patients with history of cardiac events/toxicities were excluded. Cardiac events were compared for BOL versus CIV overall, by tumor site and by regimen during three follow-up periods, early (within 1 year), middle (>1 to 5 years) and late (>5 years), from DOX initiation using Fisher’s exact test. Duration of DOX and TTF, defined as time from initiation of DOX to subsequent systemic therapy, hospice or death, were evaluated using Kaplan-Meier method and unadjusted Cox proportional hazards models. Results: 62,597 patients were eligible, including 38,961 with BC and 1,772 with sarcoma. Most patients had codes for both modes; 1,941 and 7,094 patients had exclusive BOL and CIV codes, respectively. For these patients, mean duration of DOX was longer for BOL vs. CIV (83.9 vs. 65.4 days, p<0.001). Cardiac events for BOL vs. CIV were 6.5% vs. 5.6% (p=0.098) during the early period, 4% vs. 5.1% (p=0.046) middle period, and 0.5% vs. 0.9% (p=0.068) late period. This pattern was consistent for BC and sarcoma and among those who were pre-treated. There were no differences in cardiac events for BOL vs. CIV for the chemotherapy naïve or DOX monotherapy groups (all periods p>0.10) but statistically different for the breast during the middle period, sarcoma at any time, and pretreated subgroup middle period (all p<0.05). TTF favored CIV over BOL among patients with BC (p<0.0001) but BOL over CIV in sarcoma (p=0.002). TTF was not significantly different between BOL and CIV for BC monotherapy (p=0.067) but was significant for sarcoma monotherapy favoring BOL administration (hazard ratio 0.72, 95% confidence interval 0.54-0.95, p=0.02). Conclusions: These data suggest that cardiac events may occur at a similar rate irrespective of mode of DOX administration. Further analyses are needed to understand how these relationships are impacted by other potential risk covariates (eg, age, gender) and by protective factors (eg, dexrazoxane).

Transitioning adriamycin ifosfamide mesna (AIM) chemotherapy in sarcoma patients to the outpatient setting: Evaluation of outpatient chemotherapy in an oncology care model setting

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Background: The combination of doxorubicin, ifosfamide and mesna (AIM) significantly improves outcomes among patients with advanced soft tissue sarcomas. The rising cost of inpatient care, alternative payment model changes and patient preferences has prompted institutions to consider shifting therapy to the outpatient setting. However, the safety and feasibility of outpatient AIM chemotherapy is not well established. The University of Arizona Cancer Center developed an Outpatient Program (OP) to facilitate administration of traditional inpatient chemotherapy regimens in the outpatient setting. We transitioned AIM based chemotherapy to the outpatient setting based on selective criteria and caregiver support. The transition to outpatient treatment could lead to large cost-savings implications under the oncology care model. Methods: The current retrospective analysis evaluated the safety and efficacy of outpatient AIM chemotherapy for sarcoma administered in the outpatient setting. An economic study evaluated AIM in the outpatient setting, address, cost of labs, chemotherapy and bed days saved from transitioning chemotherapy from the inpatient setting. Results: Twenty-one patients with soft-tissue sarcoma were treated with outpatient AIM, for a total of 83 cycles. The median age was 60 (27-73) with 6 females and 15 males being evaluated. The median number of cycles per patient was 3.9 (range, 1-6), an average of 4.68 days of infusion days per cycle. Notable side effects included three patients ifosfamide-induced neurologic syndrome and 2 with hematuria. Acute grade 3 and 4 hematological toxicities were observed in 16 and 15 of patients, respectively with 11 occurrences of febrile neutropenia in 9 patients. Of the 21 patients, 15 patients (71%) were hospitalized at least once and 9 patients (43%) were hospitalized due to neutropenic fever. Total bed days saved by transitioning AIM outpatient was 390, for a total hospital cost savings of $1,043,250. Current costs savings for laboratory, chemotherapy and patient assistance access is still being tabulated. Conclusions: The combination of ifosfamide and mesna as a continuous outpatient infusion is feasible and well-tolerated using proper selection of patient and caregiver evaluation. This new model of administration provides an opportunity to decrease cost of care, improve patient satisfaction and reduce utilization of healthcare resource for community and academic cancer center sites.

A randomized phase II study of gemcitabine (G) alone or with pazopanib (P) in refractory soft tissue sarcoma (STS)

11515

Background: Both G and P are active single-agents in the treatment of STS. We hypothesized that the anti-VEGF-R activity of P could augment the efficacy of G and conducted this study of G+P vs G+placebo (0). Methods: In this multi-center, double-blind study, eligibility included metastatic STS with receipt of 1–3 prior systemic regimens inclusive of an anthracycline. Patients (pts) were stratified by sarcoma subtype (liposarcoma (LPS) vs. other) and study site, then randomly assigned 1:1 to receive G 1000 mg/m2 IV over 30 minutes on days 1 and 8 every 21 days plus either P 800 mg PO or matching 0 daily. The primary endpoint was progression-free survival (PFS). Results: 54 pts were accrued from 2012–2019, Accrual was halted prior to the planned N of 80 due to withdrawal of funding. There were no differences in pt characteristics between the two arms including age (median = 60), sex (M/F 52/48%), histology (LPS 30%, leiomyosarcoma 26%, UPS 15%, synovial 11%, other 17%) and number of prior systemic therapies (median = 1). With a median follow-up of 19.1 months, PFS favored G+P and was significant using the Gehan-Wilcoxon test which favorably weighs earlier events (table). The response rate was 6.9% on the G+P arm and 8.0% on the G+0 arm; response rate was 22% for LPS treated with G+P. The most common grade ≥3 AEs (G+P v G+0) were: neutropenia (41% vs 40), hypertension (17% v 4), anemia (7% v 12). One patient died of hepatic failure on the G+P arm. Conclusions: This study demonstrated improved PFS with G+P as compared with G alone. Early termination limited statistical power. G+P is active in LPS, although P regulatory labeling currently limits use for LPS. Clinical trial information: NCT01532687 . [Table: see text]

Identification and quantitation of clinically relevant microbes in patient samples: Comparison of three k-mer based classifiers for speed, accuracy, and sensitivity

Infections are a serious health concern worldwide, particularly in vulnerable populations such as the immunocompromised, elderly, and young. Advances in metagenomic sequencing availability, speed, and decreased cost offer the opportunity to supplement or even replace culture-based identification of pathogens with DNA sequence-based diagnostics. Adopting metagenomic analysis for clinical use requires that all aspects of the workflow are optimized and tested, including data analysis and computational time and resources. We tested the accuracy, sensitivity, and resource requirements of three top metagenomic taxonomic classifiers that use fast k-mer based algorithms: Centrifuge, CLARK, and KrakenUniq. Binary mixtures of bacteria showed all three reliably identified organisms down to 1% relative abundance, while only the relative abundance estimates of Centrifuge and CLARK were accurate. All three classifiers identified the organisms present in their default databases from a mock bacterial community of 20 organisms, but only Centrifuge had no false positives. In addition, Centrifuge required far less computational resources and time for analysis. Centrifuge analysis of metagenomes obtained from samples of VAP, infected DFUs, and FN showed Centrifuge identified pathogenic bacteria and one virus that were corroborated by culture or a clinical PCR assay. Importantly, in both diabetic foot ulcer patients, metagenomic sequencing identified pathogens 4–6 weeks before culture. Finally, we show that Centrifuge results were minimally affected by elimination of time-consuming read quality control and host screening steps.

Currently, the gold standard for identifying pathogens that are causing infection is to attempt growth in culture followed by identification based on physical characteristics such as shape and metabolic profile. However, many organisms do not grow in culture or are overgrown by faster growing organisms that out-compete them. Another method to identify pathogens in infections is to sequence the DNA in the samples and use that DNA sequence to identify the pathogens present—a process called metagenomic sequencing. Analyzing clinical metagenomic data can be difficult given the amount of data generated, high levels of human DNA contamination and a lack of well-defined bioinformatics methods. In this study, three leading software tools were compared for identification and quantitation of microbes in metagenomic data. One tool, called Centrifuge, reliably identified microbes present at just 1% relative abundance while requiring less computer time and resources than the others to which it was compared. Moreover, we found that Centrifuge results changed minimally when time-consuming quality control and host-screening steps were eliminated. We also examined Centrifuge’s performance in real-word clinical data sets showing that Centrifuge identified the same pathogens as culture.

Center-Specific Modeling Predicts Cancer Trial Accrual More Accurately Than Investigators and Random Effects Modeling at 16 Cancer Centers

PURPOSE

Clinical trials often exceed their anticipated enrollment periods, and study sites often do not meet accrual goals. We previously reported the development and validation of a single-site accrual prediction model. Here, we describe the expansion of this methodology at 16 cancer centers (CCs) and compare an overall model versus site-specific models.

METHODS

This retrospective cohort study used data from treatment and supportive care intervention studies permanently closed to accrual between 2009 and 2015 at 16 United States-based CCs. Center and ClinicalTrials.gov data were used to generate both site-specific and random effects mixed models (random effect: institution). Accrual predictions were generated from each model and compared with the accrual prediction of the disease team (DT).

RESULTS

Sixteen institutions submitted 5,787 eligible trials (range, 93 to 697 trials per institution). Local accrual ranged from 363 to 6,716 participants; 1,053 studies (18%) accrued no participants. Actual average accrual was 8.5 participants (median, four participants). Site-specific models predicted accrual at 99% of actual and correctly predicted whether a study would accrue four or more participants 73% of the time versus DT prediction of 58%. Correlation at the category level was 30%; model sensitivity and specificity were 83% and 62%, respectively. The overall model predicted accrual 93% of actual and correctly predicted accrual of four or more participants 66% of the time, with a correlation at the category level of 28%.

CONCLUSION

Both regression models predicted clinical trial accrual at least as or more accurately than DT at all but one center. Site-specific models generally performed slightly better than the random effects model. This study confirms the previous finding that this method is an accurate and objective metric that can be easily implemented to improve clinical research resource allocation across multiple centers.

Systemic Interferon-γ Increases MHC Class I Expression and T-cell Infiltration in Cold Tumors: Results of a Phase 0 Clinical Trial

Interferon-γ (IFNγ) has been studied as a cancer treatment with limited evidence of clinical benefit. However, it could play a role in cancer immunotherapy combination treatments. Despite high expression of immunogenic cancer-testis antigens, synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) have a cold tumor microenvironment (TME), with few infiltrating T cells and low expression of major histocompatibility complex class I (MHC-I). We hypothesized that IFNγ treatment could drive inflammation in a cold TME, facilitating further immunotherapy. We conducted a phase 0 clinical trial treating 8 SS or MRCL patients with weekly systemic IFNγ. We performed pre- and posttreatment biopsies. IFNγ changed the SS and MRCL TME, inducing tumor-surface MHC-I expression and significant T-cell infiltration (P < 0.05). Gene-expression analysis suggested increased tumor antigen presentation and less exhausted phenotypes of the tumor-infiltrating T cells. Newly emergent antigen-specific humoral and/or T-cell responses were found in 3 of 7 evaluable patients. However, increased expression of PD-L1 was observed on tumor-infiltrating myeloid cells and in some cases tumor cells. These findings suggest that systemic IFNγ used to convert SS and MRCL into "hot" tumors will work in concert with anti-PD-1 therapy to provide patient benefit.

A phase I/II study of pembrolizumab (Pem) and doxorubicin (Dox) in treating patients with metastatic/unresectable sarcoma

11009

Background: Patients with advanced soft tissue sarcomas (STS) treated with single agent Dox have a median progression-free survival (PFS) of 4.6 months (mo) and response rate (RR) of 14%. Dox sensitizes tumors to Pem through calreticulin release and killing of immunosuppressive cells. Thus we hypothesize that combining Dox + Pem will improve patient outcomes. Methods: A phase I/II trial (NCT02888665) evaluating Dox+Pem was designed for Dox naïve STS and select bone sarcomas with a 1° endpoints of safety (CTCAE v4.03) and response rate (RR) by RECIST 1.1. Patients received one “priming” dose of Pem (200mg IV) prior to starting Dox+Pem Q3wks. Dox+Pem was continued for up to 6 cycles, followed by Pem monotherapy for up to 2 years or progression. The phase I portion used a 3+3 design with 2 Dox doses (45 & 75 mg/m2), followed by a Simon 2-stage expansion. A retrospective study of patients treated at our center on non-ifosfamide containing Dox trials (DoxT) was performed in order to compare our observed PFS with a comparable historic population. Results: Treatment was well tolerated; detailed safety data will be presented. No additional cardiac risk was observed. No DLTs were observed during phase I and 75mg/m2 was selected as the phase 2 Dox dose. The study met criteria for expansion to the 2nd stage. Though the planned enrollment was 41, the study closed after 37 as it was clear that the RR (22% , including phase I patients) would not meet the phase 2 RR target of 29%. However, 59% of patients had stable disease (disease control rate = 81%) with tumor regression in a majority of patients. The median PFS on Dox + Pem was 8.1 mo (95% CI: 6.3, 10.8). Patients treated with Dox + Pem had a significantly longer median PFS compared to the DoxT cohort (4.1 mo, 95%CI 3.0 – 6.6, p < 0.001). Conclusions: Dox+Pem is well-tolerated. While this study failed to meet its 1° RR endpoint, a highly significant improvement in PFS was observed compared with historical controls. This is consistent with findings in other cancers, such as head & neck, where improved clinical outcomes were observed without significant increase in RR by RECIST. A randomized trial of Dox +/- Pem should be carefully considered in light of recent negative trials in STS. Clinical trial information: NCT02888665.

A single-center retrospective study of patients treated with trabectedin (TRB) with long-term follow up

11061

Background: TRB is FDA approved drug for the treatment of liposarcoma (Lipo) and leiomyosarcoma (LMS). The aim of this study was to evaluate potential biomarkers associated with prolonged benefit in patients treated with TRB at our center prior to 2016. Methods: We performed a retrospective search of UW/FHCRC CASIS database to identify patients treated with TRB prior to 2016. Demographic variables and clinical variables (such as histology and treatment) were retrieved. Statistics were performed with R 3.4.1 software. Pairwise Pearson’s correlation was calculated for the # of prior chemotherapy regimens with # of TRB cycles. The Kaplan-Meir method was used to evaluate overall survival (OS). Log-rank test was conducted to compare groups in terms of OS. Results: 145 sarcoma patients treated with TRB were identified with a mean follow up of 5 years (generally on NCT01427582 or NCT01343277). Patients averaged 1.9 prior chemotherapy regimens prior to TRB (range 0-7 regimens) and received an average of 5.6 TRB doses (range 1-25 doses). Subtypes are listed on table. The # of prior regimens was negatively correlated with the # of TRB cycles that patients received (pairwise correlation coefficient = -1.77; p=0.034), suggesting that multiple prior treatment lines either made TRB less tolerable or made sarcoma less sensitive to TRB. The median OS for this heavily treated metastatic population was 0.5 years. However, patients who were able to stay on TRB for more than 5 cycles had a significantly higher OS (p=0.001). While only 23% of patients who received less than 5 cycles of TRB were alive at 5 years (95% CI: 0.15, 0.32), 53% of those who received 5 or more cycles of (95% CI: 0.39, 0.65) were alive at 5 years. Conclusions: TRB may be more effective when administered as an earlier line of therapy. Patients who are able to stay on TRB for a longer duration had a significant improvement in OS. Detailed subset analysis will be presented as will initial findings of our biomarker work. These retrospective data warrant further evaluation. Clinical trial information: NCT01427582 or NCT01343277. [Table: see text]

Chemotherapy in the management of olfactory neuroblastoma/esthesioneuroblastoma: An analysis of the surveillance, epidemiology, and end results (SEER) 1973-2015 database

e17573

Background: Olfactory neuroblastoma (ON) is a malignant tumor of nasal cavity arising in sensory neuroectodermal olfactory cells. Chemotherapy (CT) has been proposed as an adjunct to primary local therapy. Here, we investigated the role of CT in primary ON treatment. Methods: SEER was searched for ON (ICD-3 9522). Inclusion criteria were (1) unique cases; (2) primary nasal cavity tumor; (3) staging information; and (4) ability to derive Kadish stage. Abstracted covariates included sex, age, tumor grade, nodal status, year of diagnosis, derived Kadish stage, and treatment (surgery, radiotherapy (RT), CT). Outcomes included disease-specific (DSS) and overall (OS) survival. In SEER, CT and RT are classified as Yes vs No/Unknown. Uni- and multi-variable Cox analyses assessed CT treatment on DSS and OS, controlling for covariates noted above. To account for proportional hazards violations, such variables were either stratified or time-varying. Multiple imputation addressed missing data. A p < 0.05 was designated for statistical significance. Analyses were conducted using Stata ver 12. Results: 797 ON cases were included. In univariable analysis, CT treatment (yes vs no/unknown) was associated with inferior DSS (HR 2.81, 95% CI 2.11 3.74, p < 0.001) and OS (HR 2.03, 95% CI 1.63 2.54, p < 0.001). In multivariable analyses, CT was again associated with inferior DSS (HR 1.74, 95% CI 1.21, 2.51, p = 0.003) and OS (HR 1.71, 95% CI 1.26, 2.32, p = 0.001). Limiting analysis to those with local/regional disease treated with local therapy (surgery and/or radiation), CT remained associated with inferior outcomes [DSS (HR 2.78, 95% CI 1.63, 4.74, p < 0.001) and OS (HR 2.17, 95% CI 1.45, 3.27, p < 0.001)]. Sensitivity analyses ruled out chemotherapy misclassification as an explanation for our results. Conclusions: Our analysis does not support the use of chemotherapy to improve either DSS or OS in primary ON treatment. We controlled for known ON prognostic factors available from SEER. Other prognostic and treatment selection factors could exist for which we did not control. Chemotherapy may also beneficially affect outcomes other than DSS or OS. While concerns have been expressed regarding CT treatment misclassification in SEER, our analyses did not identify such misclassification as an explanation.

ABI-009 (nab-sirolimus) in advanced malignant perivascular epithelioid cell tumors (PEComa): Preliminary efficacy, safety, and mutational status from AMPECT, an open label phase II registration trial

11005

Background: Malignant PEComa is a rare, aggressive sarcoma, with no approved treatment or prior clinical trials. Case reports suggest mTOR activation through mutations or deletions of TSC1 or TSC2 and activity of mTOR inhibitors in this disease. ABI-009 is an albumin-bound mTOR inhibitor with increased tumor uptake. The AMPECT trial is the first prospective study in malignant PEComa. Methods: Eligible patients (pts) with centrally confirmed PEComa receive ABI-009 (100 mg/m2 IV, wkly, 2/3 wks) until progression or unacceptable toxicity. Primary endpoint: ORR by independent review (IR), assessed every 6 wks (RECIST v1.1). Secondary endpoints: duration of response (DOR), PFS6, PFS, and safety. Exploratory endpoints (EE): investigator-assessed (IA) outcomes and mutational status. Sample size: 30 efficacy-evaluable pts based on target ORR of 30% (primary analysis planned when all pts treated ≥6 mo). Results: EE and safety are reported (IR pending). As of Feb 12, 2019, enrollment is complete; 34 pts treated, 31 evaluable for efficacy, 42% (13/31) pts ongoing Rx. IA ORR is 42% PR (13/31, 95% CI: 24.5, 60.9), 35% SD (11/31), and 23% PD (7/31); 69% of PRs were reached at 1st restaging (wk 6); 69% PRs are ongoing, with 5 pts >1yr and 2 pt >2 yrs on Rx (all ongoing). Other IA outcomes: median DOR is not reached; PFS6 is 66%; median PFS is 8.9 mo (95% CI: 5.5, -). The most common (>30%) nonhematologic treatment-related AEs (TRAEs) of any grade: mucositis (65%), fatigue (53%), nausea/weight loss (35% each), diarrhea (32%); the most common (>15%) hematologic TRAEs: anemia (44%) and thrombocytopenia (18%). Pneumonitis (15%) was G1/G2. The most common (>10%) G3 TRAEs: mucositis (18%), anemia (12%); No grade ≥4 TRAEs. TSC1 or TSC2 mutations occurred in 5 and 9 (no overlap) of 25 pts with known mutational status, respectively. PR was seen in 100% (9/9) pts with TSC2 mutation, 20% (1/5) pts with TSC1 mutation, and 9% (1/11) pts without mutation in TSC1 or TSC2, P < 0.0001 (2x3 Fisher exact test). PR was significantly higher in pts with TSC2 mutations vs pts without mutation in TSC1 or TSC2, P = 0.0001 (Fisher exact test). Disease control (PR+SD) was seen in 93% (13/14) pts with TSC1 or TSC2 mutations vs 55% (6/11) pts without mutation in TSC1 or TSC2, P = NS. Conclusions: Preliminary IA outcomes showed that ABI-009 treatment of PEComa resulted in substantial and durable responses with manageable toxicities. TSC2 mutations were associated with IA response. Clinical trial information: NCT02494570.

Spotlight on aldoxorubicin (INNO-206) and its potential in the treatment of soft tissue sarcomas: evidence to date

Anthracyclines, and doxorubicin in particular, remain a mainstay of sarcoma therapy. Despite modest activity and significant toxicities, no cytotoxic monotherapy has yet yielded superior overall survival over doxorubicin for therapy of advanced soft tissue sarcomas in a randomized trial. Similarly, combination regimens have also been unable to overcome doxorubicin in terms of overall survival. Strategies to ameliorate the most prominent side effect of doxorubicin, cardiotoxicity, are available, but their use in sarcoma patients has been limited. Aldoxorubicin is a prodrug consisting of doxorubicin with a covalent linker. It binds rapidly after intravenous infusion to cysteine-34 of human serum albumin. The drug-albumin conjugate is preferentially retained in tumor tissue, with uptake into tumoral cells. At physiologic pH, the complex is stable. Hydrolysis can occur under the acidic conditions of the endocytic lysosome, releasing doxorubicin. Doxorubicin then distributes to various cellular compartments, including Golgi, mitochondrion, and nucleus, with subsequent cytotoxic effects. Aldoxorubicin has demonstrated in vitro and in vivo activities in both cancer model systems and human xenografts. Preclinical models also support its decreased cardiac effects vs doxorubicin, although such promising results require formal comparison at efficacy equivalent doses of the two drugs. Phase I studies confirmed the tolerability of aldoxorubicin in humans. Clinical cardiotoxicity was not observed, but molecular and subclinical cardiac effects could be demonstrated. A Phase II study in treatment-naïve, advanced sarcoma patients demonstrated improved progression-free survival and response rate over doxorubicin, although no survival benefit was evident. A Phase III study of aldoxorubicin vs investigator's choice from a panel of chemotherapy regimens in the salvage setting was unable to demonstrate a benefit in progression-free or overall survival in the entire population. Progression-free survival in L-sarcomas (leiomyosarcomas and liposarcomas) was documented. While evidence of subclinical cardiac effects was seen in a small proportion of aldoxorubicin-treated patients, data from both the Phase II and III studies indicated a favorable cardiotoxicity profile vs doxorubicin. Despite the negative results from this Phase III study, the importance of anthracycline therapy in sarcoma management merits further investigation of the potential role of aldoxorubicin in this indication. Other avenues for progress include identification of sensitive histologies and biomarkers of activity, exploration of clinical niches without proven standard therapies, and exploration of alternate dosing strategies.

Economic Evaluation of Talimogene Laherparepvec Plus Ipilimumab Combination Therapy vs Ipilimumab Monotherapy in Patients With Advanced Unresectable Melanoma

Importance

A phase 2 trial comparing talimogene laherparepvec plus ipilimumab vs ipilimumab monotherapy in patients with advanced unresectable melanoma found no differential benefit in progression-free survival (PFS) but noted objective response rates (ORRs) of 38.8% (38 of 98 patients) vs 18.0% (18 of 100 patients), respectively.

Objective

To perform an economic evaluation of talimogene laherparepvec plus ipilimumab combination therapy vs ipilimumab monotherapy.

Design, Setting, and Participants

For PFS, cost-effectiveness and cost-utility analyses using a 2-state Markov model (PFS vs progression or death) was performed. For ORRs, cost-effectiveness analysis of the incremental cost of 1 additional patient achieving objective response was performed. In this setting based on a US payer perspective (2017 US dollars), participants were patients with advanced unresectable melanoma.

Main Outcomes and Measures

The PFS life-years and PFS quality-adjusted life-years were determined, and the associated incremental cost-effectiveness ratios (ICERs) and incremental cost-utility ratios (ICURs) were estimated. Also estimated was the ICER per 1 additional patient (out of 100 treated patients) achieving objective response. Base-case analyses were validated by sensitivity analyses.

Results

In PFS analyses, the cost of talimogene laherparepvec plus ipilimumab ($494 983) exceeded the cost of ipilimumab monotherapy ($132 950) by $362 033. The ICER was $2 129 606 per PFS life-years, and the ICUR was $2 262 706 per PFS quality-adjusted life-year gained. Probabilistic sensitivity analyses yielded an ICER of $1 481 208 per PFS life-year gained and an ICUR of $1 683 191 per PFS quality-adjusted life-year gained. In 1-way sensitivity analyses, the PFS hazard ratio and the utility of response were the most influential parameters. Talimogene laherparepvec plus ipilimumab has a 50% likelihood of being cost-effective at a willingness-to-pay threshold of $1 683 191 per PFS quality-adjusted life-year gained. In ORR analyses, talimogene laherparepvec plus ipilimumab ($474 904) vs ipilimumab alone ($132 810), a $342 094 difference, yielded an ICER of $1 629 019 per additional patient achieving objective response. In subgroup analyses by disease stage and BRAFV600E mutation status, ICERs ranged from $1 069 044 to $17 104 700 per 1 additional patient achieving objective response.

Conclusions and Relevance

The cost to gain 1 additional progression-free quality-adjusted life-year, 1 additional progression-free life-year, or to have 1 additional patient attain objective response is about $1.6 million. This amount may be beyond what payers typically are willing to pay. Combination therapy of talimogene laherparepvec plus ipilimumab does not offer an economically beneficial treatment option relative to ipilimumab monotherapy at the population level. This should not preclude treatment for individual patients for whom this regimen may be indicated.

Response to PD1 inhibition in conventional chondrosarcoma

Background

Chondrosarcoma is one of the most common malignant bone tumors in adults. Conventional chondrosarcoma represents around 85% of all chondrosarcomas and is notoriously difficult to treat with chemotherapy.

Case presentation

We describe a 67-year-old man with metastatic conventional chondrosarcoma who was treated with nivolumab. Treatment was discontinued after restaging showed increased tumor burden, which later proved to be pseudoprogression. The patient restarted nivolumab and continues to have a near complete response.

Conclusion

Conventional chondrosarcoma may be sensitive to checkpoint inhibitors. Further, this case demonstrates clearly the phenomenon of pseudo-progression in this disease, a factor that must be considered in the design of clinical trials and clinical care. This case supports additional study of immunomodulatory agents in this deadly disease.

Propranolol for the treatment of vascular sarcomas

Vascular sarcomas are abnormal proliferations of endothelial cells. They range from benign hemangioma to aggressive angiosarcoma, and are characterized by dysregulated angiogenic signaling. Propranolol is a β-adrenergic receptor inhibitor that has demonstrated clinical efficacy in benign infantile hemangioma, and is now being used experimentally for more aggressive vascular sarcomas and other cancers. In this review, we discuss the use of propranolol in targeting these receptors in vascular tumors and other cancers.

Effect of intratumoral (IT) injection of the toll-like receptor 4 (TLR4) agonist G100 on a clinical response and CD4 T-cell response locally and systemically

71

Background: Soft tissue sarcomas (STS) are heterogeneous tumors which are morbid and lethal. G100 is under investigation in multiple clinical trials and contains a potent TLR4 agonist (oil-in-water emulsion of glucopyranosyl lipid A) that has been tested as vaccine adjuvant. We hypothesized IT G100 would induce robust local and potentially systemic anti-tumor immune response, leading to improved outcomes. Methods: 15 metastatic STS patients with superficial lesions were treated with weekly IT G100 for 8-12 wks; 12 patients received radiation (RT) for 2 wks to start, while 3 received IT G100 for 6 wks prior to RT. Biopsies and PBMC were collected pre and post treatment, and flow cytometry was performed on biopsies. TIL and PBMC were analyzed with TCR deep sequencing. PBMC were analyzed by single cell multiplex cytokine profiling. Results: No grade ≥ 3 toxicity was observed, and local tumor control was achieved in all evaluable tumors (14/14). Treated tumors tracked post-trial (mean 156 days) had persistent local control with 1 CR (7%), 1 PR (7%), and 11 SD (79%). In 3 patients with long term follow up, treated lesions remained controlled vs index lesions (-53% vs +31% at mean 235 days, p = 0.002). In all tumors after G100 alone, T cell infiltration increased. In P14, CD3 live cells in tumor rose from < 1% to 62%. PBMC clonality increased in 8/14 tested including P06, who had 4× increase in clonality and CR in the injected lesion; PBMC and TIL TCR overlap increased from 13.4% to 21.5%. P13 had a 2.3× rise in TIL clonality; the top clone (a CD4 T cell) expanded from 0.1% to 38% and expressed more TNFα than the rest (p < 0.0001). Single cell cytokine analysis of PBMC showed 7/13 (54%) increased in polyfunctionality (producing > 2 cytokines) in CD4 T cells; no consistent increase was seen in CD8 T cells. TNFα levels in pre-treatment monocytes correlated with PFS (R2= 0.5, p = 0.02). Conclusions: IT G100 is a viable agent for local control of metastatic STS lesions. With or without RT, G100 appears to cause CD4 T cell mediated local and systemic response. Combination of G100 with other immunomodulators could induce clinically significant systemic responses, as seen in follicular NHL treated with G100. Clinical trial information: NCT02180698.

Performance of a prognostic 31-gene expression profile in an independent cohort of 523 cutaneous melanoma patients

BACKGROUND

The heterogeneous behavior of patients with melanoma makes prognostication challenging. To address this, a gene expression profile (GEP) test to predict metastatic risk was previously developed. This study evaluates the GEP's prognostic accuracy in an independent cohort of cutaneous melanoma patients.

METHODS

This multi-center study analyzed primary melanoma tumors from 523 patients, using the GEP to classify patients as Class 1 (low risk) and Class 2 (high risk). Molecular classification was correlated to clinical outcome and assessed along with AJCC v7 staging criteria. Primary endpoints were recurrence-free (RFS) and distant metastasis-free (DMFS) survival.

RESULTS

The 5-year RFS rates for Class 1 and Class 2 were 88% and 52%, respectively, and DMFS rates were 93% versus 60%, respectively (P < 0.001). The GEP was a significant predictor of RFS and DMFS in univariate analysis (hazard ratio [HR] = 5.4 and 6.6, respectively, P < 0.001 for each), along with Breslow thickness, ulceration, mitotic rate, and sentinel lymph node (SLN) status (P < 0.001 for each). GEP, tumor thickness and SLN status were significant predictors of RFS and DMFS in a multivariate model that also included ulceration and mitotic rate (RFS HR = 2.1, 1.2, and 2.5, respectively, P < 0.001 for each; and DMFS HR = 2.7, 1.3 and 3.0, respectively, P < 0.01 for each).

CONCLUSIONS

The GEP test is an objective predictor of metastatic risk and provides additional independent prognostic information to traditional staging to help estimate an individual's risk for recurrence. The assay identified 70% of stage I and II patients who ultimately developed distant metastasis. Its role in consideration of patients for adjuvant therapy should be examined prospectively.

Final analysis of a randomised trial comparing pembrolizumab versus investigator-choice chemotherapy for ipilimumab-refractory advanced melanoma

AIM

To evaluate the protocol-specified final analysis of overall survival (OS) in the KEYNOTE-002 study (NCT01704287) of pembrolizumab versus chemotherapy in patients with ipilimumab-refractory, advanced melanoma.

METHODS

In this randomised, phase II study, eligible patients had advanced melanoma with documented progression after two or more ipilimumab doses, previous BRAF or MEK inhibitor or both, if BRAF^V600 mutant-positive. Patients were randomised to pembrolizumab 2 mg/kg or 10 mg/kg every 3 weeks or investigator-choice chemotherapy. Crossover to pembrolizumab was allowed following progression on chemotherapy. The protocol-specified final OS was performed in the intent-to-treat population. Survival was positive if p < 0.01 in one pembrolizumab arm.

RESULTS

A total of 180 patients were randomised to pembrolizumab 2 mg/kg, 181 to pembrolizumab 10 mg/kg and 179 to chemotherapy. At a median follow-up of 28 months (range 24.1-35.5), 368 patients died and 98 (55%) crossed over to pembrolizumab. Pembrolizumab 2 mg/kg (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.67-1.10, p = 0.117) and 10 mg/kg (0.74, 0.57-0.96, p = 0.011) resulted in a non-statistically significant improvement in OS versus chemotherapy; median OS was 13.4 (95% CI 11.0-16.4) and 14.7 (95% CI 11.3-19.5), respectively, versus 11.0 months (95% CI 8.9-13.8), with limited improvement after censoring for crossover. Two-year survival rates were 36% and 38%, versus 30%. Progression-free survival, objective response rate and duration of response improved with pembrolizumab versus chemotherapy, regardless of dose. Grade III-V treatment-related adverse events occurred in 24 (13.5%), 30 (16.8%) and 45 (26.3%) patients, respectively.

CONCLUSION

Improvement in OS with pembrolizumab was not statistically significant at either dose versus chemotherapy.

16S rRNA gene sequencing on a benchtop sequencer: accuracy for identification of clinically important bacteria

AIMS

Test the choice of 16S rRNA gene amplicon and data analysis method on the accuracy of identification of clinically important bacteria utilizing a benchtop sequencer.

METHODS AND RESULTS

Nine 16S rRNA amplicons were tested on an Ion Torrent PGM to identify 41 strains of clinical importance. The V1-V2 region identified 40 of 41 isolates to the species level. Three data analysis methods were tested, finding that the Ribosomal Database Project's SequenceMatch outperformed BLAST and the Ion Reporter Metagenomics analysis pipeline. Lastly, 16S rRNA gene sequencing mixtures of four species through a six log range of dilution showed species were identifiable even when present as 0·1% of the mixture.

CONCLUSIONS

Sequencing the V1-V2 16S rRNA gene region, made possible by the increased read length Ion Torrent PGM sequencer's 400 base pair chemistry, may be a better choice over other commonly used regions for identifying clinically important bacteria. In addition, the SequenceMatch algorithm, freely available from the Ribosomal Database Project, is a good choice for matching filtered reads to organisms. Lastly, 16S rRNA gene sequencing's sensitivity to the presence of a bacterial species at 0·1% of a mixture suggests it has sufficient sensitivity for samples in which important bacteria may be rare.

SIGNIFICANCE AND IMPACT OF THE STUDY

We have validated 16S rRNA gene sequencing on a benchtop sequencer including simple mixtures of organisms; however, our results highlight deficits for clinical application in place of current identification methods.

Phase 1 Study of Monotherapy with KHK2866, an Anti-Heparin-Binding Epidermal Growth Factor-Like Growth Factor Monoclonal Antibody, in Patients with Advanced Cancer

BACKGROUND

KHK2866 is a recombinant, humanized, non-fucosylated, monoclonal antibody directed at heparin-binding epidermal growth factor-like growth factor (HB-EGF).

OBJECTIVE

To determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, potential immunogenicity, and preliminary clinical efficacy of KHK2866 monotherapy in patients with advanced and refractory cancer in a first-in-human, phase 1 study.

MATERIALS AND METHODS

Using a standard 3 + 3 dose-escalation design, 20 patients received KHK2866 (0.3, 1, and 3 mg/kg) intravenously once weekly. Two additional patients received 0.1 mg/kg in a cohort which was subsequently added following protocol amendment.

RESULTS

The first three patients enrolled experienced grade 2 hypersensitivity (acute infusion reactions) after the first dose of KHK2866. After prophylactic treatment with an H1-blocker and corticosteroids in subsequently recruited patients, two grade 2 hypersensitivity reactions were observed in the remaining 19 patients. Grade 2/3 neurotoxicity appeared to be dose-limiting at 3 mg/kg in the original dose-escalation cohorts (n = 2), at 1 mg/kg in the MTD dose expansion cohort (n = 1), and at 0.1 mg/kg (n = 1). Neurotoxicity was manifested as complex partial seizure activity, aphasia, and confusion after first-dose administration. Pharmacokinetic exposure to KHK2866 increased proportionally to dose. Mean elimination half-life was 71.9-118 h over the dose range from 0.3 to 3 mg/kg. All KHK2866 doses decreased serum free HB-EGF levels, generally below the lower limit of quantification.

CONCLUSIONS

The study was terminated because of neuropsychiatric toxicity. The only predictive factor for neuropsychiatric toxicity was administration of KHK2866. These effects were reversible, but were not predictable. Their etiology is not presently understood. [Study registered at ClinicalTrials.gov #NCT0179291].

Development and Validation of a Clinical Trial Accrual Predictive Regression Model at a Single NCI-Designated Comprehensive Cancer Center

BACKGROUND

Clinical study sites often do not achieve anticipated accrual to clinical trials, wasting critical patient, material, and human resources. The expensive and extensive process to bring a drug to approval highlights the need to streamline clinical pipeline processes. We sought to create a predictive accrual model to be used when considering clinical trial activation at the level of the individual site.

MATERIALS AND METHODS

This retrospective cohort study used 7 years of registry data from treatment and supportive care interventional studies at a single academic cancer center to build a negative binomial regression model with local and protocol variables known prestudy. Actual, team-predicted, and model-predicted accrual and sensitivity/specificity were calculated.

RESULTS

To build the model, 207 trials were used. Investigational drug application, disease team, number of national sites, local Institutional Review Board use, total national accrual time, accrual completed, and national enrollment goal were independently and significantly associated with accrual. Predicted accrual was 94% of actual, maintaining predictive value at multiple cutoff values. Validation included 61 trials. The model correctly predicted whether a study would accrue at least 4 subjects 75% of the time. Correlation at the category level was 44.3%, and model sensitivity and specificity are 70% and 78%, respectively.

CONCLUSIONS

We identified and validated national and local key factors associated with accrual at our site. This methodology has not been previously validated broadly with the intent of trial feasibility. Model validation shows it to be an accurate and quick metric in anticipating accrual success that can be used for resource allocation.