Phase II Trial of nab-Sirolimus in Patients With Advanced Malignant Perivascular Epithelioid Cell Tumors (AMPECT): Long-Term Efficacy and Safety Update

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.nab-Sirolimus is approved in the United States for the treatment of metastatic or locally advanced malignant perivascular epithelioid cell tumor (PEComa) on the basis of the primary analysis results of the phase II Advanced Malignant Perivascular Epithelioid Cell Tumors (AMPECT) trial (ClinicalTrials.gov identifier: NCT02494570). Results from the primary analysis were previously published; however, the median duration of response (mDOR) had not been reached at that time. Here, 3 years after the primary analysis, we report final efficacy and safety data (data cutoff: April 29, 2022). At study completion, the confirmed overall response rate (by independent radiologist review using RECIST v1.1) was 38.7% (95% CI, 21.8 to 57.8), with an additional converted confirmed complete response (n = 2). Median progression-free survival remained the same at 10.6 months (95% CI, 5.5 to 41.2). The mDOR was reached at 39.7 months (95% CI, 6.5 to not reached [NR]), and the median overall survival at completion was 53.1 months (95% CI, 22.2 to NR). The most common treatment-related adverse events (TRAEs) were stomatitis (82.4%) and fatigue and rash (each 61.8%). No new or unexpected adverse events occurred, and no grade ≥4 TRAEs were reported. These results highlight the long-term clinical benefit of nab-sirolimus in patients with advanced malignant PEComa, with a DOR of >3 years.

Surgery and stereotactic radiosurgery for spinal leiomyosarcoma: a single-institution retrospective series and systematic review

OBJECTIVE

Leiomyosarcoma (LMS) is a rare, aggressive soft-tissue sarcoma that seldom spreads to the bone. The spine can be either the site of LMS osseous metastases or the primary tumor site. The optimal treatment option for spinal LMS is still unclear. The authors present a cohort of patients with spinal LMS treated with either upfront surgery or upfront CyberKnife stereotactic radiosurgery (SRS).

METHODS

The authors retrospectively studied the clinical and radiological outcomes of 17 patients with spinal LMS treated at their institution between 2004 and 2020. Either surgery or SRS was used as the upfront treatment. The clinical and radiological outcomes were assessed. A systematic review of the literature was also conducted.

RESULTS

Of the 17 patients (20 spinal lesions), 12 (70.6%) were female. The median patient age was 61 years (range 41-80 years). Ten patients had upfront surgery for their spinal lesions, and 7 had upfront CyberKnife radiosurgery. The median follow-up was 11 months (range 0.3-130 months). The median overall survival (OS) for the entire cohort was 13 months (range 0.3-97 months). In subgroup analysis, the median OS was lower for the surgical group (13 months, range 0.3-50 months), while the median OS for the SRS group was 15 months (range 5-97 months) (p = 0.5). Forty percent (n = 4) of those treated with surgery presented with local recurrence at a median of 6.7 months (range 0.3-36 months), while only 14% (n = 1) of those treated with CyberKnife radiosurgery had local recurrence after 5 months. Local tumor control (LTC) rates at the 6-, 12-, and 18-month follow-ups were 72%, 58%, and 43%, respectively, for the SRS group and 40%, 30%, and 20%, respectively, for the surgery group (p < 0.05). The literature review included 35 papers with 70 patients harboring spinal LMS; only 2 patients were treated with SRS. The literature review confirms the clinical and radiological outcomes of the surgical group, while data on SRS are anecdotal.

CONCLUSIONS

The authors present the largest series in the literature of spinal LMS and the first on SRS for spinal LMS. This study shows that LTC is statistically significantly better in patients receiving upfront SRS instead of surgery. The OS does not appear different between the two groups.

MR-guided focused ultrasound therapy of extra-abdominal desmoid tumors: a multicenter retrospective study of 105 patients

OBJECTIVE

To assess the safety and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for the treatment extra-abdominal desmoids.

METHODS

A total of 105 patients with desmoid fibromatosis (79 females, 26 males; 35 ± 14 years) were treated with MRgFUS between 2011 and 2021 in three centers. Total and viable tumors were evaluated per patient at last follow-up after treatment. Response and progression-free survival (PFS) were assessed with (modified) response evaluation criteria in solid tumors (RECIST v.1.1 and mRECIST). Change in Numerical Rating Scale (NRS) pain and 36-item Short Form Health Survey (SF-36) scores were compared. Treatment-related adverse events were recorded.

RESULTS

The median initial tumor volume was 114 mL (IQR 314 mL). After MRgFUS, median total and viable tumor volume decreased to 51 mL (95% CI: 30-71 mL, n = 101, p < 0.0001) and 29 mL (95% CI: 17-57 mL, n = 88, p < 0.0001), respectively, at last follow-up (median: 15 months, 95% CI: 11-20 months). Based on total tumor measurements (RECIST), 86% (95% CI: 75-93%) had at least stable disease or better at last follow-up, but 50% (95% CI: 38-62%) of remaining viable nodules (mRECIST) progressed within the tumor. Median PFS was reached at 17 and 13 months for total and viable tumors, respectively. NRS decreased from 6 (IQR 3) to 3 (IQR 4) (p < 0.001). SF-36 scores improved (physical health (41 (IQR 15) to 46 (IQR 12); p = 0.05, and mental health (49 (IQR 17) to 53 (IQR 9); p = 0.02)). Complications occurred in 36%, most commonly 1st/2nd degree skin burns.

CONCLUSION

MRgFUS reduced tumor volume, reduced pain, and improved quality of life in this series of 105 patients with extra-abdominal desmoid fibromatosis.

CLINICAL RELEVANCE STATEMENT

Imaging-guided ablation is being increasingly used as an alternative to surgery, radiation, and medical therapy for the treatment of desmoid fibromatosis. MR-guided high-intensity focused ultrasound is an incisionless ablation technique that can be used to reduce tumor burden effectively and safely.

KEY POINTS

• Desmoid fibromatosis was treated with MR-guided high-intensity focused ultrasound in 105 patients. • MR-guided focused ultrasound ablation reduced tumor volume and pain and improved quality of life. • MR-guided focused ultrasound is a treatment option for patients with extra-abdominal desmoid tumors.

A rare non-gadolinium enhancing sarcoma brain metastasis with microenvironment dominated by tumor-associated macrophages

Brain metastases occur in 1% of sarcoma cases and are associated with a median overall survival of 6 months. We report a rare case of a brain metastasis with unique radiologic and histopathologic features in a patient with low grade fibromyxoid sarcoma (LGFMS) previously treated with immune checkpoint inhibitor (ICI) therapy. The lone metastasis progressed in the midbrain tegmentum over 15 months as a non-enhancing, T2-hyperintense lesion with peripheral diffusion restriction, mimicking a demyelinating lesion. Histopathology of the lesion at autopsy revealed a rich infiltrate of tumor-associated macrophages (TAMs) with highest density at the leading edge of the metastasis, whereas there was a paucity of lymphocytes, suggestive of an immunologically cold environment. Given the important immunosuppressive and tumor-promoting functions of TAMs in gliomas and carcinoma/melanoma brain metastases, this unusual case provides an interesting example of a dense TAM infiltrate in a much rarer sarcoma brain metastasis.

Management Strategies and Outcomes in Primary Liver Angiosarcoma

OBJECTIVES

Primary hepatic angiosarcoma is a rare tumor of the liver that originates from endothelial and fibroblastic tissue, with poor prognosis and lack of standardized treatment. We retrospectively analyzed the clinical characteristics and treatment outcomes of 23 patients with primary liver angiosarcoma treated at an academic sarcoma center.

METHODS

We screened all patients with primary liver angiosarcoma treated at Stanford between 2000 and 2022. Data was collected from EPIC electronic medical records and included patient demographics, tumor characteristics, treatment modalities, and patient outcomes. Statistical analysis was completed using Python 3.0, while survival curves were generated using the Kaplan-Meier method and Lifelines Packages.

RESULTS

There were nearly equal numbers of males (11) and females (12) in our study, with most patients aged 70 to 79 at diagnosis. The median overall survival (OS) was 6 months (range 0.07 to 222.6 mo). The 2- and 5-year OS were both 38.6%. 71% of patients received systemic treatment with chemotherapy, while 29% received immunotherapy. Local treatment with surgery or radioembolization was performed in 14% of patients. Three patients in our study displayed particularly improved OS and received various treatments, which ranged from hepatic resection to ipilimumab/nivolumab.

CONCLUSION

Our study demonstrated that primary liver angiosarcoma has poor outcomes despite treatment. Surgical resection with negative margins is the only curative modality. However, most patients present with advanced disease and are not surgical candidates. Further research is needed to identify more effective systemic therapy options for this devastating disease.

A Retrospective Multi-Institutional Cohort Analysis of Clinical Characteristics and Outcomes in Dedifferentiated Chondrosarcoma

BACKGROUND

Dedifferentiated chondrosarcoma (DDCS) is a rare subset of chondrosarcoma. It is an aggressive neoplasm characterized by a high rate of recurrent and metastatic disease with overall poor outcomes. Systemic therapy is often used to treat DDCS; however, the optimal regimen and timing are not well defined, with current guidelines recommending following osteosarcoma protocols.

METHODS

We conducted a multi-institutional retrospective analysis of clinical characteristics and outcomes of patients with DDCS. Between 1 January 2004 and 1 January 2022, the databases from five academic sarcoma centers were reviewed. Patient and tumor factors, including age, sex, tumor size, site, location, the treatments rendered, and survival outcomes, were collected.

RESULTS

Seventy-four patients were identified and included in the analysis. Most patients presented with localized disease. Surgical resection was the mainstay of therapy. Chemotherapy was used predominantly in the metastatic setting. Partial responses were low (n = 4; 9%) and occurred upon treatment with doxorubicin with cisplatin or ifosfamide and single-agent pembrolizumab. For all other regimens, stable disease was the best response. Prolonged stable disease occurred with the use of pazopanib and immune checkpoint inhibitors.

CONCLUSIONS

DDCS has poor outcomes and conventional chemotherapy has limited benefit. Future studies should focus on defining the possible role of molecularly targeted therapies and immunotherapy in the treatment of DDCS.

Pexidartinib Provides Modest Pain Relief in Patients With Tenosynovial Giant Cell Tumor: Results From ENLIVEN

BACKGROUND

The double-blind, randomized, placebo-controlled phase 3 study of orally administered PLX3397 in patients with pigmented villonodular synovitis or giant cell tumor of the tendon sheath (ENLIVEN) showed that pexidartinib provides a robust objective tumor response in adults with tenosynovial giant cell tumors (TGCT) not amenable to improvement with surgery. Based on these results, in 2019, pexidartinib received accelerated approval in the United States in this population as a breakthrough therapy under an orphan drug designation. However, the ability of pexidartinib to relieve pain in ENLIVEN was not fully detailed, and the relationship between pain relief and objective tumor response was not described.

QUESTIONS/PURPOSES

(1) What level of pain relief was achieved by pexidartinib treatment in ENLIVEN? (2) How was pain relief related to objective tumor responses? (3) How durable was pain relief?

METHODS

The current study included planned primary and exploratory assessments of patient-assessed worst pain at the site of the tumor in the ENLIVEN trial. ENLIVEN was a phase 3 randomized, placebo-controlled clinical trial in which adults with TGCT not amenable to improvement with surgery received pexidartinib or placebo for 24 weeks, after which eligible patients could receive open-label pexidartinib. Of 174 patients assessed for eligibility, 121 were randomized (50% [60] to placebo, 50% [61] to pexidartinib), and 120 were given either placebo or pexidartinib (59 received placebo and 61 received pexidartinib) and were included in an intent-to-treat analysis. Fifty-nine percent (71 of 120) of the overall treated population was female, and 88% (106 of 120) were White. Mean age was 45 ± 13 years. Tumors were mostly in the lower extremities (92% [110 of 120]), most commonly in the knee (61% [73 of 120]) and ankle (18% [21 of 120]). As a secondary outcome, patients scored worst pain at the site of the tumor in the past 24 hours on an 11-point numeric rating scale (NRS). The primary definition of a pain response was a decrease of at least 30% in the weekly mean worst-pain NRS score and increase of less than 30% in narcotic analgesic use between baseline and week 25. Planned exploratory assessments of pain included the frequency of a pain response using alternative thresholds, including a decrease in worst-pain NRS score of 50% or more and a decrease of at least 2 points (minimum clinically important difference [MCID]), the magnitude of pain reduction between baseline and week 25, correlation between worst-pain NRS score and tumor shrinkage by RECIST 1.1 criteria, and the durability of the pain response during the open-label extension. Pain responses during the randomized portion of the trial were compared according to intention-to-treat analysis, with a one-sided threshold of p < 0.025 to reduce the risk of false-positive results. Pain assessment was complete for 59% (35 of 59) of patients in the placebo group and 54% (33 of 61) of patients in the pexidartinib group. Demographic and disease characteristics did not differ between the two treatment groups.

RESULTS

A difference in the primary assessment of a pain response was not detected between pexidartinib and placebo (response percentage 31% [19 of 61] [95% CI 21% to 44%] versus 15% [9 of 59] [95% CI 8% to 27%]; one-sided p = 0.03). In the exploratory analyses, pexidartinib provided a modest improvement in pain (response percentage 26% [16 of 61] [95% CI 17% to 38%] versus 10% [6 of 59] [95% CI 5% to 20%]; one-sided p = 0.02 using the 50% threshold and 31% [19 of 61] [95% CI 21% to 44%] versus 14% [8 of 59] [95% CI 7% to 25%]; one-sided p = 0.02 using the MCID threshold). The least-squares mean change in the weekly mean worst-pain NRS score between baseline and week 25 was larger in patients treated with pexidartinib than placebo (-2.5 [95% CI -3.0 to -1.9] versus -0.3 [95% CI -0.9 to 0.3]; p < 0.001), although the mean difference between the two groups (-2.2 [95% CI -3.0 to -1.4]) was just over the MCID. Improvement in the weekly mean worst-pain NRS score correlated with the reduction in tumor size (r = 0.44; p < 0.001) and tumor volume score (r = 0.61; p < 0.001). For patients in the open-label extension, the change in the worst-pain NRS score from baseline was similar to the change at the end of the randomized portion and just above the MCID (mean -2.7 ± 2.2 after 25 weeks and -3.3 ± 1.7 after 50 weeks of receiving pexidartinib).

CONCLUSION

Based on the current study, a modest reduction in pain, just larger than the MCID, may be an added benefit of pexidartinib in these patients, although the findings are insufficient to justify the routine use of pexidartinib for pain relief.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Long-term Outcomes of Diffuse or Recurrent Tenosynovial Giant Cell Tumor Treated with Postoperative External Beam Radiation Therapy

PURPOSE

Tenosynovial giant cell tumor (TGCT) is a rare proliferative disorder of synovial membrane that previously was known as pigmented villonodular synovitis. Primary treatment involves surgical resection; however, complete removal of all disease involvement is difficult to achieve. Radiation may be useful to reduce the risk of recurrence. We report and update our institutional experience treating diffuse and recurrent TGCT with postsurgical external beam radiation therapy.

METHODS AND MATERIALS

We performed a retrospective chart review of 30 patients with TGCT from 2003 to 2019 treated with radiation therapy. Each patient was evaluated for demographics, radiation treatment parameters, surgical management, complications, and outcome.

RESULTS

With mean follow-up of 82 months (range, 3-211), 24 patients (80%) who underwent surgery followed by radiation therapy did not experience any further relapse, and all 30 patients achieved local control (100%) with additional salvage therapy after radiation therapy. The most common site of disease was the knee (n = 22, 73%), followed by the ankle (n = 5, 16%) and the hand (n = 3, 10%). Seven patients (24%) presented at time of initial diagnosis and 23 (76%) presented with recurrent disease after surgical resection, with an average of 2.6 surgical procedures before radiation therapy. After resection, 18 of 30 patients (67%) demonstrated residual TGCT by imaging. The median radiation therapy dose delivered was 36 Gy (range, 34-36 Gy) in 1.8 to 2.5 Gy/fractions for 4 weeks. In the assessment of posttreatment joint function, 26 sites (86%) exhibited excellent or good function, 2 (7%) fair, and 2 poor (7%) as determined by our scoring system. There were no cases of radiation-associated malignancy.

CONCLUSIONS

Among patients with diffuse or recurrent TGCT, postsurgical external beam radiation therapy provided excellent local control and good functional status, with minimal treatment-related complications. Postsurgical radiation therapy is a well-tolerated noninvasive treatment that should be considered after maximal cytoreductive resection to prevent disease progression and recurrence.

Abstract A038: Enrollment of pediatric and adolescent patients with MAGE-A4+ advanced synovial sarcoma into cohort 2 of SPEARHEAD-1: a phase 2 trial of afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4])

Background: Afami-cel is an autologous, specific peptide enhanced affinity receptor T-cell therapy genetically engineered to target MAGE-A4+ solid tumors in HLA-A*02+ patients. SPEARHEAD-1 (NCT04044768) is a Phase 2, two-cohort, single-arm, open-label trial evaluating afami-cel in patients with advanced/metastatic synovial sarcoma or myxoid/round cell liposarcoma (MRCLS) and is the largest trial in metastatic synovial sarcoma to date. Preliminary data from Cohort 1 in 47 heavily pre-treated patients aged 16–75 years from 22 centers in North America and Europe, showed an overall response rate (ORR) per independent review of 34.0% (14/39 [35.9%] in synovial sarcoma; 2/8 [25%] in MRCLS) and a favorable benefit–risk profile with mainly low-grade cytokine release syndrome and tolerable/reversible hematologic toxicities.1 The reported ORR in synovial sarcoma in Cohort 1 was higher than reported ORRs for current standard-of-care therapies, such as pazopanib and trabectedin, in the second-line metastatic setting.2 As synovial sarcoma is the most common malignant nonrhabdomyosarcoma soft-tissue sarcoma in children and adolescents with few treatment options, especially for recurrent disease, the trial opened a second cohort to allow enrollment of pediatric patients with MAGE-A4+ synovial sarcoma who experienced disease progression post first-line chemotherapy, and to better understand MAGE-A4 tumor expression in children. Methods: Cohort 2 of the SPEARHEAD-1 trial is enrolling patients with advanced synovial sarcoma who are at least 10 years old and weigh at least 40 kg. The planned enrollment is 45 patients, including up to 13 children, to enable a pooled analysis of ORR in &gt;90 patients across Cohorts 1 and 2. HLA and MAGE-A4+ screening in Cohort 2 is conducted at a central laboratory using the same method as Cohort 1; MAGE-A4 testing is done using a clinical trial assay. All patients enrolled in Cohort 2 undergo apheresis and their isolated T-cells are then transduced with the MAGE-A4c1032 TCR using a lentivirus vector, followed by ex vivo expansion. Prior to afami-cel infusion of 1–10 × 109 transduced T-cells, patients will receive lymphodepleting chemotherapy consisting of fludarabine (30 mg/m2/day for 4 days) and cyclophosphamide (600 mg/m2/day for 3 days). Disease will be assessed by independent review per RECIST v1.1 using computerized tomography or magnetic resonance imaging at weeks 4, 8, 12, 16, 24, and every 2 months thereafter until confirmed disease progression. Patients enter long-term follow-up for 15 years. 1. Van Tine BA, et al. Paper 30: CTOS 2021; Virtual 2. Carroll C, et al. Cancer Res 2021;81(13_Suppl): Abstract nr 2630.

Citation Format: Colin Lunt, Sandra P. D’Angelo, Albiruni Ryan Abdul Razak, Michael J. Wagner, Brian A. Van Tine, Kristen Ganjoo, Jean-Yves Blay, Dejka M. Araujo, Mark Agulnik, John W. Glod, Erin Van Winkle, Erica Elefant, Swethajit Biswas, Dennis Williams, Axel Le Cesne. Enrollment of pediatric and adolescent patients with MAGE-A4+ advanced synovial sarcoma into cohort 2 of SPEARHEAD-1: a phase 2 trial of afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4]) [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A038.

Cutaneous Angiosarcoma of the Head and Neck-A Retrospective Analysis of 47 Patients

Simple Summary

Cutaneous angiosarcoma (CAS) is a rare sarcoma with dismal prognosis. To better characterize this disease and elucidate potential treatments that improve overall survival (OS), we conducted a retrospective study exploring clinical characteristics and treatment outcomes of 47 patients with CAS of the head and neck treated at a tertiary academic center. We found that CAS continues to have a poor prognosis with high rates of recurrence even with current treatment modalities. Surgery was highly effective in improving OS in patients with disease that could be resected with low morbidity. Chemotherapy, radiotherapy (RT), and immunotherapy did not significantly improve OS. Our findings shed light on the current landscape of clinical characteristics and treatment of CAS and could prompt further research exploring new treatment options and role of immunotherapy in the management of this difficult disease.

Abstract

Cutaneous angiosarcoma (CAS) is a rare and aggressive malignant tumor with blood vessel or lymphatic-type endothelial differentiation. It has a poor prognosis with lack of standardized treatment options. This study retrospectively evaluated the clinical characteristics and treatment outcomes of 47 patients with CAS of the head and neck treated at an academic sarcoma center. Patient data were collected from the electronic medical records. 62% of patients were male with the scalp being the most commonly affected area (64%). The majority of patients presented with localized disease (53%). Median overall survival (OS) was 3.4 years with an OS of 36% at 5 years. There was a statistically significant increase in OS for patients who underwent surgery compared to those who did not (5.4 vs. 2.8 years). In contrast, radiotherapy (RT) or chemotherapy did not significantly increase OS. 45% of patients had recurrence of disease during their treatment course with a median time to recurrence of 22.8 months. There was not a significant difference in OS for patients who underwent immunotherapy compared to those who underwent chemotherapy, although only a few patients received immunotherapy. We found that surgery was an effective treatment modality in patients with easily resectable disease, while RT, chemotherapy, and immunotherapy did not significantly improve OS.

Clinical Activity of Single-Agent Cabozantinib (XL184), a Multi-receptor Tyrosine Kinase Inhibitor, in Patients with Refractory Soft-Tissue Sarcomas

PURPOSE

Soft-tissue sarcomas (STS) are a rare, heterogeneous group of mesenchymal tumors. For decades the mainstay of treatment for advanced, unresectable STS has been palliative chemotherapy. High levels of activated MET receptor have been reported in various sarcoma cell lines, together with elevated vascular endothelial growth factor (VEGF) levels in patients with STS, suggesting that dual targeting of the VEGF and MET pathways with the multi-receptor tyrosine kinase inhibitor cabozantinib would result in clinical benefit in this population.

PATIENTS AND METHODS

We performed an open-label, multi-institution, single-arm phase II trial of single-agent cabozantinib in adult patients with advanced STS and progressive disease after at least 1 standard line of systemic therapy. Patients received 60 mg oral cabozantinib once daily in 28-day cycles, and dual primary endpoints of overall response rate and 6-month progression-free survival (PFS) were assessed. Changes in several circulating biomarkers were assessed as secondary endpoints.

RESULTS

Six (11.1%; 95% CI, 4.2%-22.6%) of the 54 evaluable patients enrolled experienced objective responses (all partial responses). Six-month PFS was 49.3% (95% CI, 36.2%-67.3%), with a median time on study of 4 cycles (range, 1-99). The most common grade 3/4 adverse events were hypertension (7.4%) and neutropenia (16.7%). Patients' levels of circulating hepatocyte growth factor (HGF), soluble MET, and VEGF-A generally increased after a cycle of therapy, while soluble VEGFR2 levels decreased, regardless of clinical outcome.

CONCLUSIONS

Cabozantinib single-agent antitumor activity was observed in patients with selected STS histologic subtypes (alveolar soft-part sarcoma, undifferentiated pleomorphic sarcoma, extraskeletal myxoid chondrosarcoma, and leiomyosarcoma) highlighting the biomolecular diversity of STS.

Detection of MDM2 amplification by shallow whole genome sequencing of cell-free DNA of patients with dedifferentiated liposarcoma

High-level amplification of MDM2 and other genes in the 12q13–15 locus is a hallmark genetic feature of well-differentiated and dedifferentiated liposarcomas (WDLPS and DDLPS, respectively). Detection of this genomic aberration in plasma cell-free DNA may be a clinically useful assay for non-invasive distinction between these liposarcomas and other retroperitoneal tumors in differential diagnosis, and might be useful for the early detection of disease recurrence. In this study, we performed shallow whole genome sequencing of cell-free DNA extracted from 10 plasma samples from 3 patients with DDLPS and 1 patient with WDLPS. In addition, we studied 31 plasma samples from 11 patients with other types of soft tissue tumors. We detected MDM2 amplification in cell-free DNA of 2 of 3 patients with DDLPS. By applying a genome-wide approach to the analysis of cell-free DNA, we also detected amplification of other genes that are known to be recurrently affected in DDLPS. Based on the analysis of one patient with DDLPS with longitudinal plasma samples available, we show that tracking MDM2 amplification in cell-free DNA may be potentially useful for evaluation of response to treatment. The patient with WDLPS and patients with other soft tissue tumors in differential diagnosis were negative for the MDM2 amplification in cell-free DNA. In summary, we demonstrate the feasibility of detecting amplification of MDM2 and other DDLPS-associated genes in plasma cell-free DNA using technology that is already routinely applied for other clinical indications. Our results may have clinical implications for improved diagnosis and surveillance of patients with retroperitoneal tumors.

nab-Sirolimus for Patients With Malignant Perivascular Epithelioid Cell Tumors

PURPOSE

Malignant perivascular epithelioid cell tumor (PEComa) is a rare aggressive sarcoma, with no approved treatment. To our knowledge, this phase II, single-arm, registration trial is the first prospective clinical trial in this disease, investigating the safety and efficacy of the mammalian target of rapamycin inhibitor nab-sirolimus (AMPECT, NCT02494570).

PATIENTS AND METHODS

Patients with malignant PEComa were treated with nab-sirolimus 100 mg/m2 intravenously once weekly for 2 weeks in 3-week cycles. The primary end point was objective response rate evaluated by independent radiology review. Key secondary end points included duration of response, progression-free survival, and safety. A key exploratory end point was tumor biomarker analysis.

RESULTS

Thirty-four patients were treated (safety evaluable), and 31 were evaluable for efficacy. The overall response rate was 39% (12 of 31; 95% CI, 22 to 58) with one complete and 11 partial responses, 52% (16 of 31) of patients had stable disease, and 10% (3 of 31) had progressive disease. Responses were of rapid onset (67% by week 6) and durable. Median duration of response was not reached after a median follow-up for response of 2.5 years, with 7 of 12 responders with treatment ongoing (range, 5.6-47.2+ months). Twenty-five of 31 patients had tumor mutation profiling: 8 of 9 (89%) patients with a TSC2 mutation achieved a confirmed response versus 2 of 16 (13%) without TSC2 mutation (P < .001). The median progression-free survival was 10.6 months (95% CI, 5.5 months to not reached), and the median overall survival was 40.8 months (95% CI, 22.2 months to not reached). Most treatment-related adverse events were grade 1 or 2 and were manageable for long-term treatment. No grade ≥ 4 treatment-related events occurred.

CONCLUSION

nab-Sirolimus is active in patients with malignant PEComa. The response rate, durability of response, disease control rate, and safety profile support that nab-sirolimus represents an important new treatment option for this disease.

Ripretinib intrapatient dose escalation after disease progression provides clinically meaningful outcomes in advanced gastrointestinal stromal tumour

PURPOSE

Ripretinib is a switch-control tyrosine kinase inhibitor that broadly inhibits KIT and platelet-derived growth factor receptor α kinase signalling. Ripretinib showed preliminary efficacy in patients with advanced gastrointestinal stromal tumour (GIST) in a phase I study across a range of doses. Results were confirmed in the phase III INVICTUS study, and ripretinib 150 mg once daily (QD) was subsequently approved as a ≥fourth-line therapy. Here, we report the phase I study results of intrapatient dose escalation (IPDE) in patients with GIST treated across second, third and later lines of therapy.

METHODS

Patients with advanced GIST who experienced disease progression (PD) at ripretinib 150 mg QD could dose escalate to 150 mg twice daily (BID). Progression-free survival (PFS) 1 was calculated from the date of the first dose of ripretinib 150 mg QD to PD (as per Response Evaluation Criteria in Solid Tumours 1.1); PFS2 was from the date of IPDE (150 mg BID) to PD or death. Treatment-emergent adverse events (TEAEs) were summarised by dosing periods and compared descriptively.

RESULTS

Of 142 patients with GIST receiving ripretinib 150 mg QD, 67 underwent IPDE. IPDE provided benefit across all lines of therapy; the median PFS2 was 5.6, 3.3 and 4.6 months for patients on second-, third- and ≥fourth-line therapy, respectively. A partial metabolic response after IPDE was demonstrated in 13 of 37 patients with available positron emission tomography scans. TEAEs reported at both doses were similar.

CONCLUSION

Ripretinib IPDE after PD provided continued clinical benefit in advanced GIST across second, third and later lines of therapy with a similar safety profile to that observed with the QD regimen.

Pexidartinib improves physical functioning and stiffness in patients with tenosynovial giant cell tumor: results from the ENLIVEN randomized clinical trial

Background and purpose - The ENLIVEN trial showed that, after 25 weeks, pexidartinib statistically significantly reduced tumor size more than placebo in patients with symptomatic, advanced tenosynovial giant cell tumor (TGCT) for whom surgery was not recommended. Here, we detail the effect of pexidartinib on patient-reported physical function and stiffness in ENLIVEN.Patients and methods - This was a planned analysis of patient-reported outcome data from ENLIVEN, a double-blinded, randomized phase 3 trial of adults with symptomatic, advanced TGCT treated with pexidartinib or placebo. Physical function was assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS)-physical function (PF), and worst stiffness was assessed using a numerical rating scale (NRS). A mixed model for repeated measures was used to compare changes in PROMIS-PF and worst stiffness NRS scores from baseline to week 25 between treatment groups. Response rates for the PROMIS-PF and worst stiffness NRS at week 25 were calculated based on threshold estimates from reliable change index and anchor-based methods.Results - Between baseline and week 25, greater improvements in physical function and stiffness were experienced by patients receiving pexidartinib than patients receiving placebo (change in PROMIS-PF = 4.1 [95% confidence interval (CI) 1.8-6.3] vs. -0.9 [CI -3.0 to 1.2]; change in worst stiffness NRS = -2.5 [CI -3.0 to -1.9] vs. -0.3 [CI -0.9 to 0.3]). Patients receiving pexidartinib had higher response rates than patients receiving placebo for meaningful improvements in physical function and stiffness. Improvements were sustained after 50 weeks of pexidartinib treatment.Interpretation - Pexidartinib treatment provided sustained, meaningful improvements in physical function and stiffness for patients with symptomatic, advanced TGCT.

Skin angiography assisted mastectomy in secondary breast angiosarcoma: Complete clinical response after neoadjuvant immunotherapy

Radiation-induced breast angiosarcoma, or secondary angiosarcoma (SAS), is a rare entity with a high risk of metastatic recurrence. Herein, we describe the use of intraoperative fluorescence-based skin angiography to guide surgical resection following a novel immunotherapy-based regimen for SAS resulting in a complete pathological response.

Rapid Response of a BRCA2/TP53/PTEN-Deleted Metastatic Uterine Leiomyosarcoma to Olaparib: A Case Report

None

Patients with metastatic uterine leiomyosarcoma (uLMS) have poor prognosis due to limited treatment options, especially when disease progresses on doxorubicin and gemcitabine-docetaxel regimens. Here we report a patient whose metastatic uLMS contains a BRCA2 deep deletion as well as TP53 and PTEN deep deletion. The patient responded rapidly to olaparib, a poly (ADP-ribose) polymerase inhibitor, after progressing on gemcitabine-docetaxel, doxorubicin, and temozolomide regimens. This case report shall be helpful to the treatment of other patients with metastatic uLMS that harbors a BRCA2 mutation or deletion.

Long-Term Remission with Ipilimumab/Nivolumab in Two Patients with Different Soft Tissue Sarcoma Subtypes and No PD-L1 Expression

Checkpoint inhibitor therapy has been shown to improve outcomes in multiple solid malignancies; however, data are limited in soft tissue sarcoma. We present two cases of patients with advanced soft tissue sarcoma of different subtypes (dedifferentiated liposarcoma and myxofibrosarcoma) with zero percent PD-L1 expression by immunohistochemistry who were treated with ipilimumab and nivolumab followed by maintenance nivolumab. Both patients had failed multiple lines of systemic treatment and experienced long-term remission after starting ipilimumab and nivolumab. Genetic testing revealed that no genetic mutations were found in common between the two cases. One patient received concurrent cryoablation, which may have sensitized his tumor to immunotherapy. Checkpoint inhibitor therapy may improve outcomes in soft tissue sarcoma regardless of PD-L1 status, especially when combined with cryoablation. Studies are needed to evaluate whether treatment response varies by sarcoma subtype and what molecular markers can be used to guide patient selection.

Evaluation of Absolute Lymphocyte Count at Diagnosis and Mortality Among Patients With Localized Bone or Soft Tissue Sarcoma

IMPORTANCE

Host-related immune factors have been implicated in the development and progression of diverse malignant neoplasms. Identifying associations between immunologic laboratory parameters and overall survival may inform novel prognostic biomarkers and mechanisms of antitumor immunity in localized bone and soft tissue sarcoma.

OBJECTIVE

To assess whether lymphopenia at diagnosis is associated with overall survival among patients with localized bone and soft tissue sarcoma.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study analyzed patients from the Stanford Cancer Institute with localized bone and soft tissue sarcoma between September 1, 1998, and November 1, 2018. Patients were included if laboratory values were available within 60 days of diagnosis and, if applicable, prior to the initiation of chemotherapy and/or radiotherapy. Statistical analysis was performed from January 1, 2019, to November 1, 2020.

EXPOSURES

Absolute lymphocyte count within 60 days of diagnosis and antimicrobial exposure, defined by the number of antimicrobial agent prescriptions and the cumulative duration of antimicrobial administration within 60 days of diagnosis.

MAIN OUTCOMES AND MEASURES

The association between minimum absolute lymphocyte count at diagnosis and 5-year overall survival probability was characterized with the Kaplan-Meier method and multivariate Cox proportional hazards regression models. Multivariable logistic regressions were fitted to evaluate whether patients with lymphopenia were at greater risk of increased antimicrobial exposure.

RESULTS

Among 634 patients, the median age at diagnosis was 53.7 years (interquartile range, 37.5-66.8 years), and 290 patients (45.7%) were women, with a 5-year survival probability of 67.9%. There was a significant inverse association between lymphopenia at diagnosis and overall survival (hazard ratio [HR], 1.82; 95% CI, 1.39-1.40), resulting in a 13.5% 5-year survival probability difference compared with patients who did not have lymphopenia at diagnosis (60.2% vs 73.7% for those who never had lymphopenia). In addition, poorer survival was observed with higher-grade lymphopenia (grades 3 and 4: HR, 2.44; 95% CI, 1.68-3.55; grades 1 and 2: HR, 1.60; 95% CI, 1.18-2.18). In an exploratory analysis, patients with increased antibiotic exposure were more likely to have lymphopenia (odds ratio, 1.96; 95% CI, 1.26-3.07 for total number of antimicrobial agents; odds ratio, 1.70; 95% CI, 1.10-2.57 for antimicrobial duration) than antimicrobial-naive patients.

CONCLUSIONS AND RELEVANCE

This study suggests that an abnormally low absolute lymphocyte count at diagnosis is associated with higher mortality among patients with localized bone and soft tissue sarcoma; therefore, lymphopenia may serve as a reliable prognostic biomarker. Potential mechanisms associated with host immunity and overall survival include a suppressed antitumor response and increased infectious complications, which merit future investigation.

Switch Control Inhibition of KIT and PDGFRA in Patients With Advanced Gastrointestinal Stromal Tumor: A Phase I Study of Ripretinib

PURPOSE

In advanced gastrointestinal stromal tumor (GIST), there is an unmet need for therapies that target both primary and secondary mutations of pathogenic KIT/PDGFRA oncoproteins. Ripretinib is a novel switch-control kinase inhibitor designed to inhibit a wide range of KIT and PDGFRA mutations.

PATIENTS AND METHODS

This first-in-human, to our knowledge, phase I study of ripretinib (ClinicalTrials.gov identifier: NCT02571036) included a dose-escalation phase and subsequent expansion phase at the recommended phase II dose (RP2D). Eligible patients included those with advanced GIST, intolerant to or experienced progression on ≥ 1 line of systemic therapy, and other advanced malignancies. Safety, dose-limiting toxicities (DLTs), maximum-tolerated dose (MTD), and preliminary antitumor activity were evaluated.

RESULTS

At data cutoff (August 31, 2019), 258 patients (n = 184 GIST) were enrolled, with 68 patients in the dose-escalation phase. Three DLTs were reported: grade 3 lipase increase (n = 2; 100 mg and 200 mg twice a day) and grade 4 increased creatine phosphokinase (n = 1; 150 mg once daily). MTD was not reached (maximum dose evaluated, 200 mg twice a day); 150 mg once daily was established as the RP2D. The most frequent (> 30%) treatment-emergent adverse events in patients with GIST receiving ripretinib 150 mg once daily (n = 142) were alopecia (n = 88 [62.0%]), fatigue (n = 78 [54.9%]), myalgia (n = 69 [48.6%]), nausea (n = 65 [45.8%]), palmar-plantar erythrodysesthesia (n = 62 [43.7%]), constipation (n = 56 [39.4%]), decreased appetite (n = 48 [33.8%]), and diarrhea (n = 47 [33.1%]). Objective response rate (confirmed) of 11.3% (n = 16/142) ranging from 7.2% (n = 6/83; fourth line or greater) to 19.4% (n = 6/31; second line) and median progression-free survival ranging from 5.5 months (fourth line or greater) to 10.7 months (second line), on the basis of investigator assessment, were observed.

CONCLUSION

Ripretinib is a well-tolerated, novel inhibitor of KIT and PDGFRA mutant kinases with promising activity in patients with refractory advanced GIST.

Nivolumab plus ipilimumab for soft tissue sarcoma: a single institution retrospective review

Aim: To analyze the efficacy of checkpoint inhibitors in soft tissue sarcoma. Materials & methods: We retrospectively reviewed patients with advanced soft tissue sarcoma treated with ipilimumab and nivolumab. All patients who received at least one cycle were included. Results: One patient had a complete response and five had a partial response, for an objective response rate of 15%. Clinical benefit rate was 34% with a median duration of 12.0 months (range: 4.5 to 28.9+ months [mo]). Median overall survival was 12.0 months (95% CI: 4.5-23.7+ mo). Median progression-free survival was 2.7 months (95% CI: 2.3-4.5+ mo) by Response Evaluation Criteria in Solid Tumors 1.1 and 2.9 months (2.5-6.0+ mo) by immune-related Response Evaluation Criteria in Solid Tumors. Adverse events of any grade were seen in 58% of patients, the most common being fatigue (21%) and cough (10%), 5% of patients experienced a grade 3 adverse event (AE) (hyperglycemia) or grade 4 AE (myocarditis). Conclusion: Ipilimumab/nivolumab combination showed efficacy and was well tolerated in advanced soft tissue sarcoma.

Tenosynovial giant cell tumor of the suboccipital region - A rare, benign neoplasm in this location

Tenosynovial giant cell tumors (TGCTs) are benign neoplasms that arise from the synovium of tendon sheaths, bursae, and joints. We report a rare presentation of TGCT involving the suboccipital spine.

Abstract C077: Updated results of phase 1 study of ripretinib (DCC-2618), a broad-spectrum KIT and PDGFRA inhibitor, in patients with gastrointestinal stromal tumor (GIST) by line of therapy (NCT02571036)

Objective: Ripretinib (DCC-2618) is a kinase switch control inhibitor designed to broadly inhibit KIT and PDGFRA mutations. Based on clinical activity observed in heavily pretreated patients (pts) with GIST in a Phase 1 study (NCT02571036), ripretinib is under evaluation in two Phase 3 studies: INVICTUS (NCT03353753) in ≥4th-line pts and INTRIGUE (NCT03673501) in 2nd-line pts, each at the recommended dose of 150 mg once daily (QD). This abstract reports updated results from the escalation and expansion phases of the Phase 1 study for pts treated with ≥100 mg daily dose. Methods: The Phase 1 study includes a dose-escalation phase that tested oral ripretinib QD or twice daily (BID) in 28-day cycles, followed by an expansion phase with the recommended Phase 2 dose (RP2D) of 150 mg QD in 6 cohorts, including cohorts for pts with GIST based on prior regimens (2nd/ 3rd, 4th, and &gt;4th-line). Local Response Evaluation Criteria in Solid Tumors (RECIST) response assessments were performed every 2 cycles and pts who progressed per RECIST in the expansion cohorts were allowed to dose escalate to 150 mg BID. Results: At a cut-off date of March 01, 2019, 179 pts with GIST in the escalation and expansion phases (median follow-up of 10.4 months; range, 0.1–32.3) were enrolled at dose levels of ≥100 mg daily with KIT-driven (169 pts), PDGFRA-driven (9 pts), or wild-type-driven GIST (1 pt). Of 178 pts with GIST treated at the ≥100 mg daily dose (1 pt was not included in the intent-to-treat population as the pt only participated in the food effect portion of the study), there were 37 2nd-line pts, 31 3rd-line pts, 60 4th-line pts, and 50 &gt;4th-line pts. The objective response rate (ORR) by best response was 30% in 2nd-line pts (n=11; includes 3 unconfirmed responses), 23% in 3rd-line pts (n=7; includes 3 unconfirmed responses), and 11% in ≥4th-line pts (n=12; includes 4 unconfirmed responses); responses ≥4th-line include 15% in 4th-line pts (n=9; includes 4 unconfirmed responses) and 6% in &gt;4th-line pts (n=3; includes no unconfirmed responses). In 2nd-line pts, the disease control rate (DCR) was 31% (n=9) at 52 weeks. The median progression-free survival (mPFS) was 42 weeks in 2nd-line pts, 40 weeks in 3rd-line pts, and 24 weeks in ≥4th-line pts (includes 30 weeks in 4th-line pts and 16 weeks in &gt;4th-line pts). In 2nd-line pts, the median duration of response was 80 weeks and the median duration of treatment was 44 weeks. For any line, 13% of pts (n=24) experienced treatment-emergent adverse events (TEAEs) leading to study treatment discontinuation, 17% of pts (n=31) experienced TEAEs leading to dose reduction and 49% (n=88) had TEAEs leading to study drug interruption. Grade 3 or 4 TEAEs in &gt;5% of pts were lipase increased (18%; n=33), anemia (11%; n=20), hypertension (7%; n=13), and abdominal pain (6%; n=11). Conclusion: In this Phase 1 study, ripretinib demonstrated encouraging clinical benefit (as measured by mPFS, ORR [best response] and DCR) and was generally well-tolerated in pts with GIST treated in the 2nd-line or later. Preliminary data from this Phase 1 study further supports testing in the ongoing Phase 3 study in 2nd-line GIST.

Citation Format: Ping Chi, Filip Janku, Michael Heinrich, Kristen Ganjoo, Hans Gelderblom, Michael Gordon, Robin Jones, Albiruni Razak, Jonathan Trent, Margaret von Mehren, Simin Hu, Ying Su, Rodrigo Ruiz-Soto, Suzanne George. Updated results of phase 1 study of ripretinib (DCC-2618), a broad-spectrum KIT and PDGFRA inhibitor, in patients with gastrointestinal stromal tumor (GIST) by line of therapy (NCT02571036) [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C077. doi:10.1158/1535-7163.TARG-19-C077

Endometriosis Malignant Transformation Review: Rhabdomyosarcoma Arising From an Endometrioma

Background:

Endometriosis is a widely known benign disease, but 0.5%–1% of cases are associated with malignancy. It has been linked with ovarian neoplasms, particularly endometrioid and clear cell adenocarcinoma histology. Rhabdomyosarcomas are rarely associated with endometriosis.

Case:

A 35-year-old patient underwent surgical management of endometriomas to optimize infertility treatment. She later developed abdominal pain with rapid recurrence of ovarian masses. This prompted additional surgery with biopsies diagnosing ovarian rhabdomyosarcoma. Retroactive review of pathologic specimens from her prior surgery demonstrated the neoplasm originated from her prior endometrioma. Focal areas suggested possible underlying ovarian adenosarcoma with stromal overgrowth.

Discussion:

The incidence of rhabdomyosarcoma arising from endometriosis is exceedingly rare. The accuracy of diagnosing endometriosis and ruling out neoplasm requires coordinated efforts of a multidisciplinary team, involving radiologists, pathologists, oncologists, and gynecologic surgeons.

Detection of Circulating Tumor DNA in Patients With Uterine Leiomyomas

PURPOSE

The preoperative distinction between uterine leiomyoma (LM) and leiomyosarcoma (LMS) is difficult, which may result in dissemination of an unexpected malignancy during surgery for a presumed benign lesion. An assay based on circulating tumor DNA (ctDNA) could help in the preoperative distinction between LM and LMS. This study addresses the feasibility of applying the two most frequently used approaches for detection of ctDNA: profiling of copy number alterations (CNAs) and point mutations in the plasma of patients with LM.

PATIENTS AND METHODS

By shallow whole-genome sequencing, we prospectively examined whether LM-derived ctDNA could be detected in plasma specimens of 12 patients. Plasma levels of lactate dehydrogenase, a marker suggested for the distinction between LM and LMS by prior studies, were also determined. We also profiled 36 LM tumor specimens by exome sequencing to develop a panel for targeted detection of point mutations in ctDNA of patients with LM.

RESULTS

We identified tumor-derived CNAs in the plasma DNA of 50% (six of 12) of patients with LM. The lactate dehydrogenase levels did not allow for an accurate distinction between patients with LM and patients with LMS. We identified only two recurrently mutated genes in LM tumors (MED12 and ACLY).

CONCLUSION

Our results show that LMs do shed DNA into the circulation, which provides an opportunity for the development of ctDNA-based testing to distinguish LM from LMS. Although we could not design an LM-specific panel for ctDNA profiling, we propose that the detection of CNAs or point mutations in selected tumor suppressor genes in ctDNA may favor a diagnosis of LMS, since these genes are not affected in LM.

Pexidartinib versus placebo for advanced tenosynovial giant cell tumour (ENLIVEN): a randomised phase 3 trial

BACKGROUND

Tenosynovial giant cell tumour (TGCT), a rare, locally aggressive neoplasm, overexpresses colony-stimulating factor 1 (CSF1). Surgery is standard with no approved systemic therapy. We aimed to evaluate pexidartinib, a CSF1 receptor inhibitor, in patients with TGCT to provide them with a viable systemic treatment option, especially in cases that are not amenable to surgical resection.

METHODS

This phase 3 randomised trial had two parts. Part one was a double-blind study in which patients with symptomatic, advanced TGCT for whom surgery was not recommended were randomly assigned via an integrated web response system (1:1) to the pexidartinib or placebo group. Individuals in the pexidartinib group received a loading dose of 1000 mg pexidartinib per day orally (400 mg morning; 600 mg evening) for the first 2 weeks, followed by 800 mg per day (400 mg twice a day) for 22 weeks. Part two was an open-label study of pexidartinib for all patients. The primary endpoint, assessed in all intention-to-treat patients, was overall response at week 25, and was centrally reviewed by RECIST, version 1.1. Safety was analysed in all patients who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, number NCT02371369.

FINDINGS

Between May 11, 2015, and Sept 30, 2016, of 174 patients assessed for eligibility, 120 patients were randomly assigned to, and received, pexidartinib (n=61) or placebo (n=59). There were 11 dropouts in the placebo group and nine in the pexidartinib group. Emergence of mixed or cholestatic hepatotoxicity caused the data monitoring committee to stop enrolment six patients short of target. The proportion of patients who achieved overall response was higher for pexidartinib than placebo at week 25 by RECIST (24 [39%] of 61 vs none of 59; absolute difference 39% [95% CI 27-53]; p<0·0001). Serious adverse events occurred in eight (13%) of 61 patients in the pexidartinib group and one (2%) of 59 patients in the placebo group. Hair colour changes (67%), fatigue (54%), aspartate aminotransferase increase (39%), nausea (38%), alanine aminotransferase increase (28%), and dysgeusia (25%) were the most frequent pexidartinib-associated adverse events. Three patients given pexidartinib had aminotransferase elevations three or more times the upper limit of normal with total bilirubin and alkaline phosphatase two or more times the upper limit of normal indicative of mixed or cholestatic hepatotoxicity, one lasting 7 months and confirmed by biopsy.

INTERPRETATION

Pexidartinib is the first systemic therapy to show a robust tumour response in TGCT with improved patient symptoms and functional outcomes; mixed or cholestatic hepatotoxicity is an identified risk. Pexidartinib could be considered as a potential treatment for TGCT associated with severe morbidity or functional limitations in cases not amenable to improvement with surgery.

FUNDING

Daiichi Sankyo.

Abstract CT058: Ripretinib (DCC-2618) pharmacokinetics (PK) in a Phase I study in patients with gastrointestinal stromal tumors (GIST) and other advanced malignancies: A retrospective evaluation of the PK effects of proton pump inhibitors (PPIs)

Objectives: Ripretinib is a novel, oral kinase switch control inhibitor of KIT and PDGFRα. Encouraging clinical benefit from the phase 1 dose escalation and expansion study as measured by ORR, DCR and PFS in 2nd, 3rd, and &gt;4th line GIST patients with a favorable tolerability profile at doses &gt;100 mg/day has been previously reported (ESMO 2018, abstract #1603O). It has been reported that more than 40% of GIST patients use acid-reducing agents. PPIs are the most potent acid-reducing agents that may impair the absorption of kinase inhibitors 1,2. This retrospective analysis aims to explore whether ripretinib can be used regardless of concomitant PPI use.

Methods: The analysis assessed the impact of PPIs on the plasma concentration of ripretinib using PK data from the expansion cohort at the recommended Phase 2 dose of 150 mg QD. Plasma concentrations of ripretinib and its active metabolite DP-5439 obtained from patients who used or did not use PPIs were compared on Cycle 1 Day 1 (C1D1, n=106) and Day 15 (C1D15, n=102). Patients using PPIs were defined as those who continuously took PPIs for at least 4 days prior to C1D1 or C1D15. Patients who did not use PPIs were defined as those who did not take PPIs or any other acid-reducing agents during the study.

Results: PK profiles were consistent between patients using and not using PPIs (Table 1), indicating a low likelihood of a clinically significant drug interaction between PPIs and ripretinib.

Conclusions: This retrospective PK analysis provides supporting evidence that restriction of co-administration of PPIs with ripretinib may not be necessary. A dedicated drug interaction study is planned to provide a definitive assessment. References: 1. Smelick et al, Mol. Pharmaceutics 2013, 10, 4055−4062 2. Budha et al, Clin Pharmacol Ther. 2012, 92(2):203-13

Table 1.PK Exposure of Ripretinib and DP-5439 in Patients Using or not Using PPIsPK ConcentrationsRipretinib in ng/mL [mean (CV%)]DP-5439 in ng/mL [mean (CV%)]Ripretinib + DP-5439 in ng/mL [mean (CV%)]Using PPIsNot using PPIsUsing PPIsNot using PPIsUsing PPIsNot using PPIsC1D1 6 hr566 (58%) n=24670 (53%) n=82302 (64%) n=23297 (59%) n=82862 (54%) n=24975 (48%) n=82C1D15 pre-dose364 (79%) n= 24344 (63%) n=78960 (80%) n=24889 (86%) n=781350 (72%) n=241260 (75%) n=78C1D15 6 hr834 (51%) n=24871 (47%) n=731170 (69%) n=241060 (67%) n=732040 (53%) n=241960 (49%) n=73Notes: Table 1 is based on data from patients without a history of gastrectomy. A separate analysis in patients with gastrectomy will be published after sufficient data is obtained.

Citation Format: Filip Janku, Michael Heinrich, Ping Chi, Albiruni Abdul Razak, Margaret von Mehren, Michael Gordon, Kristen Ganjoo, Jonathan Trent, Robin L. Jones, Hans Gelderblom, Kelli Running, Jing Wang, Rodrigo Ruiz-Soto, Suzanne George. Ripretinib (DCC-2618) pharmacokinetics (PK) in a Phase I study in patients with gastrointestinal stromal tumors (GIST) and other advanced malignancies: A retrospective evaluation of the PK effects of proton pump inhibitors (PPIs) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT058.

Abstract CT029: Pharmacokinetic (PK), safety, and tolerability profile of DCC-2618 in a phase I trial supports 150mg QD selected for a pivotal phase III trial in gastrointestinal stromal tumor (GIST)

Background: DCC-2618, a pan-KIT and PDGFRα kinase switch control inhibitor, is being studied in a pivotal, randomized phase 3 trial, INVICTUS (NCT03353753), based on encouraging disease control observed in a phase 1 trial (NCT02571036) in heavily pretreated GIST patients (pts). In the phase 1 trial, escalating doses of DCC-2618 up to 400 mg per day did not result in a DLT or MTD dose level. The RP2D of 150 mg QD was selected based on PK, efficacy and safety observed across the dose escalation cohorts before enrolling pts into expansion cohorts.

Methods: Dose escalation in the phase 1 study is complete, and this study is now enrolling pts into 6 expansion cohorts, including 3 GIST cohorts. DCC-2618 was administered in 28-day cycles at daily oral doses of 20 to 200 mg BID or 100 to 250 mg QD in pts with advanced solid tumors, including GIST. The safety and tolerability of DCC-2618 will be reviewed as a function of exposure to study drug. We report PK results from all dose-escalation cohorts and the expansion phase. The impact of dose modifications including intra-patient dose escalation was assessed based on PK.

Results: As of Jan 18, 2018, a total of 168 patients had been treated including 141 GIST patients. The most common treatment-emergent adverse effects (TEAE; all grades, ≥10% of patients) for the overall population across all dose levels included fatigue, myalgia, lipase increase (↑), alopecia, constipation, decreased appetite, nausea, hand-foot-syndrome, anaemia, diarrhea, dyspnea, abdominal pain, weight decrease, arthralgia, and hypertension (HTN). The most common TEAEs for the RP2D of 150 mg QD, based on 106 pts, included fatigue, myalgia, lipase ↑, alopecia, constipation and hand-foot-syndrome. G3 or G4 TEAE, regardless of attribution, occurring in ≥2% pts across all dose levels included included lipase ↑, anemia and HTN. 7.2% of patients underwent dose reductions. All patients who could have received at least 1 cycle prior to Dec 1, 2017 were included for further analysis (127 total, 114 GIST). Among these 114 GIST patients, 83 (73%) remain active on treatment, and 27, 14, 9 and 6 patients have been on DCC-2618 for more than 6, 9, 12, or 15 mo, respectively (15 pts were treated beyond progression per RECIST; a total of 21 were allowed to dose escalate while on study). The median follow up is 3.7 months with a range from 1 to 20 months. Population PK modeling using data from 67 patients demonstrated that combined exposures of DCC-2618 and its active metabolite, DP-5439, increase dose-proportionally. Dosing with a high fat meal increased exposure only slightly. The impact of dose escalation on plasma exposure will be shown.

Conclusions: The PK, safety and tolerability data presented together with efficacy data from the phase 1 trial demonstrate a favorable profile and broad therapeutic window for DCC-2618 and support the selection of 150 mg QD as the RP2D for the ongoing pivotal phase 3 INVICTUS study of DCC-2618 in pts with &gt;4th-line GIST.

Citation Format: Filip Janku, Michael Heinrich, Albiruni Razak, Michael Gordon, Ping Chi, Kristen Ganjoo, Margaret von Mehren, Neeta Somaiah, Jongtae Lee, Keisuke Kuida, Rodrigo Ruiz Soto, Oliver Rosen, Suzanne George. Pharmacokinetic (PK), safety, and tolerability profile of DCC-2618 in a phase I trial supports 150mg QD selected for a pivotal phase III trial in gastrointestinal stromal tumor (GIST) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT029.

Abstract A05: Circulating tumor DNA levels correlate with response to treatment in LMS patients

Circulating tumor DNA (ctDNA) has significant potential for several clinical applications, including assessment of treatment response and monitoring of recurrent/residual disease. We performed a pilot study to explore the feasibility of ctDNA monitoring in patients with leiomyosarcoma (LMS).

We profiled matching plasma and FFPE tumor specimens from 9 LMS patients. We analyzed between 2 to 6 longitudinal plasma samples (median of 5) and between 1 to 7 tumor specimens (median of 2) per patient. ctDNA analysis was performed on plasma samples collected pre-/post-surgery, throughout chemo-/radiotherapy and during follow-up. We used two separate approaches in our study: 1) targeted deep sequencing of ctDNA, tumor DNA and germline DNA to detect single nucleotide variants and indels using Cancer Personalized Profiling by deep Sequencing with integrated digital error suppression (CAPP-Seq; with a median deduplicated depth of sequencing of 2,136x); 2) copy number variant analysis in ctDNA by genome representation profiling (GRP; median coverage across the whole genome 0.23x) and in the matched tumors by SNP arrays. One patient was excluded from the analysis due to inadequate sequencing coverage in tumor specimen.

For CAPP-Seq analysis, we designed a custom 184kb capture panel targeting 89 genes that are recurrently mutated in LMS. Using strict variant calling criteria (requiring that variants be present on each strand of the original DNA “duplex” molecule) our panel identified a median of one nonsynonymous coding/splicing variant per tumor. We detected the same variants in TP53, RB1 and ATRX genes in ctDNA of 6/8 patients (with a baseline sensitivity of 87.5% and overall specificity of 98.96% calculated using plasma from 24 healthy donors). These six patients presented with advanced disease at the time of the first blood collection and were progressing throughout multiple lines of therapy. Two patients who did not have any variants detectable by CAPP-Seq in plasma had localized disease at the time of the first blood collection and/or responded well to the therapy. We found that changes in ctDNA levels appear to correspond with the extent of disease and response to treatment. Specifically, ctDNA levels decreased in a subset of patients after surgery or at the time of temporary response to chemo- and/or radiotherapy. Congruently, increases in ctDNA levels correlated with progression in most of the patients. There was a high correlation between ctDNA levels detected by CAPP-Seq (quantified as mutant molecules/mL plasma) and GRP (quantified as percent of genome showing copy number aberrations) across all plasma samples (Pearson's r= 0.88, p &lt; 0.0001), but in a few samples ctDNA was detected by only one of the two assays.

Our results suggest that serial analysis of ctDNA is a promising approach for evaluation of treatment response in LMS patients. Validation of these findings in a prospective study on a larger group of patients will be required to determine the use of this approach in a clinical setting.

References:

CAPP-Seq: PMIDs 24705333, 27018799

GRP: PMIDs 25585704, 26687610

Citation Format: Joanna Przybyl, Jacob J. Chabon, Lien Spans, Kristen Ganjoo, Sujay Vennam, Aaron M. Newman, Erna Forgó, Sushama Varma, Shirley Zhu, Maria Debiec-Rychter, Ash Alizadeh, Maximilian Diehn, Matt van de Rijn. Circulating tumor DNA levels correlate with response to treatment in LMS patients [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr A05.

Efficacy and safety of trabectedin or dacarbazine in patients with advanced uterine leiomyosarcoma after failure of anthracycline-based chemotherapy: Subgroup analysis of a phase 3, randomized clinical trial

OBJECTIVE

Trabectedin demonstrated significantly improved disease control in leiomyosarcoma and liposarcoma patients in a global phase 3 trial (NCT01343277). A post hoc analysis was conducted to assess the efficacy and safety of trabectedin or dacarbazine in women with uterine leiomyosarcoma (uLMS), the largest subgroup of enrolled patients (40%).

METHODS

Of 577 patients randomized 2:1 to receive trabectedin 1.5mg/m² by 24-hour IV infusion or dacarbazine 1g/m² by 20-120-minute IV infusion once every three weeks, 232 had uLMS (trabectedin: 144; dacarbazine: 88). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR: complete responses+partial responses+stable disease [SD] for at least 18weeks), duration of response (DOR), and safety.

RESULTS

PFS for trabectedin was 4.0months compared with 1.5months for dacarbazine (hazard ratio [HR]=0.57; 95% CI 0.41-0.81; P=0.0012). OS was similar (trabectedin 13.4months vs. dacarbazine 12.9months, HR=0.89; 95% CI 0.65-1.24; P=0.51) between groups. ORR was 11% with trabectedin vs. 9% with dacarbazine (P=0.82). CBR for trabectedin was 31% vs. 18% with dacarbazine (P=0.05); median DOR was 6.5months for trabectedin vs. 4.1months for dacarbazine (P=0.32). Grade 3/4 treatment-emergent adverse events observed in ≥10% of patients in the trabectedin group included transient aminotransferase (aspartate/alanine) elevations, anemia, leukopenia, and thrombocytopenia.

CONCLUSIONS

In this post hoc subset analysis of patients with uLMS who had received prior anthracycline therapy, trabectedin treatment resulted in significantly longer PFS versus dacarbazine, with an acceptable safety profile. There was no difference in OS.

Efficacy and Safety of Trabectedin or Dacarbazine for Metastatic Liposarcoma or Leiomyosarcoma After Failure of Conventional Chemotherapy: Results of a Phase III Randomized Multicenter Clinical Trial

PURPOSE

This multicenter study, to our knowledge, is the first phase III trial to compare trabectedin versus dacarbazine in patients with advanced liposarcoma or leiomyosarcoma after prior therapy with an anthracycline and at least one additional systemic regimen.

PATIENTS AND METHODS

Patients were randomly assigned in a 2:1 ratio to receive trabectedin or dacarbazine intravenously every 3 weeks. The primary end point was overall survival (OS), secondary end points were disease control-progression-free survival (PFS), time to progression, objective response rate, and duration of response-as well as safety and patient-reported symptom scoring.

RESULTS

A total of 518 patients were enrolled and randomly assigned to either trabectedin (n = 345) or dacarbazine (n = 173). In the final analysis of PFS, trabectedin administration resulted in a 45% reduction in the risk of disease progression or death compared with dacarbazine (median PFS for trabectedin v dacarbazine, 4.2 v 1.5 months; hazard ratio, 0.55; P < .001); benefits were observed across all preplanned subgroup analyses. The interim analysis of OS (64% censored) demonstrated a 13% reduction in risk of death in the trabectedin arm compared with dacarbazine (median OS for trabectedin v dacarbazine, 12.4 v 12.9 months; hazard ratio, 0.87; P = .37). The safety profiles were consistent with the well-characterized toxicities of both agents, and the most common grade 3 to 4 adverse effects were myelosuppression and transient elevation of transaminases in the trabectedin arm.

CONCLUSION

Trabectedin demonstrates superior disease control versus conventional dacarbazine in patients who have advanced liposarcoma and leiomyosarcoma after they experience failure of prior chemotherapy. Because disease control in advanced sarcomas is a clinically relevant end point, this study supports the activity of trabectedin for patients with these malignancies.

Clinically Relevant Molecular Subtypes in Leiomyosarcoma

PURPOSE

Leiomyosarcoma is a malignant neoplasm with smooth muscle differentiation. Little is known about its molecular heterogeneity and no targeted therapy currently exists for leiomyosarcoma. Recognition of different molecular subtypes is necessary to evaluate novel therapeutic options. In a previous study on 51 leiomyosarcomas, we identified three molecular subtypes in leiomyosarcoma. The current study was performed to determine whether the existence of these subtypes could be confirmed in independent cohorts.

EXPERIMENTAL DESIGN

Ninety-nine cases of leiomyosarcoma were expression profiled with 3'end RNA-Sequencing (3SEQ). Consensus clustering was conducted to determine the optimal number of subtypes.

RESULTS

We identified 3 leiomyosarcoma molecular subtypes and confirmed this finding by analyzing publically available data on 82 leiomyosarcoma from The Cancer Genome Atlas (TCGA). We identified two new formalin-fixed, paraffin-embedded tissue-compatible diagnostic immunohistochemical markers; LMOD1 for subtype I leiomyosarcoma and ARL4C for subtype II leiomyosarcoma. A leiomyosarcoma tissue microarray with known clinical outcome was used to show that subtype I leiomyosarcoma is associated with good outcome in extrauterine leiomyosarcoma while subtype II leiomyosarcoma is associated with poor prognosis in both uterine and extrauterine leiomyosarcoma. The leiomyosarcoma subtypes showed significant differences in expression levels for genes for which novel targeted therapies are being developed, suggesting that leiomyosarcoma subtypes may respond differentially to these targeted therapies.

CONCLUSIONS

We confirm the existence of 3 molecular subtypes in leiomyosarcoma using two independent datasets and show that the different molecular subtypes are associated with distinct clinical outcomes. The findings offer an opportunity for treating leiomyosarcoma in a subtype-specific targeted approach.

A phase 2 trial of R1507, a monoclonal antibody to the insulin-like growth factor-1 receptor (IGF-1R), in patients with recurrent or refractory rhabdomyosarcoma, osteosarcoma, synovial sarcoma, and other soft tissue sarcomas: results of a Sarcoma Alliance for Research Through Collaboration study

BACKGROUND

Insulin-like growth factor-1 receptor (IGF-1R) is implicated in the pathogenesis of rhabdomyosarcoma (RMS), osteosarcoma (OS), and synovial sarcoma (SS). The authors conducted a multi-institutional phase 2 trial of the monoclonal antibody R1507 in patients with various subtypes of recurrent or refractory sarcomas.

METHODS

Eligibility criteria included age ≥ 2 years and a diagnosis of recurrent or refractory RMS, OS, SS, and other soft tissue sarcomas. Patients received a weekly dose of 9 mg/kg R1507 intravenously. The primary endpoint was the best objective response rate using World Health Organization criteria. Tumor imaging was performed every 6 weeks × 4 and every 12 weeks thereafter.

RESULTS

From December 2007 through August 2009, 163 eligible patients from 33 institutions were enrolled. The median patient age was 31 years (range, 7-85 years). Histologic diagnoses included OS (n = 38), RMS (n = 36), SS (n = 23), and other sarcomas (n = 66). The overall objective response rate was 2.5% (95% confidence interval, 0.7%-6.2%). Partial responses were observed in 4 patients, including 2 patients with OS, 1 patient with RMS, and 1 patient with alveolar soft part sarcoma. Four additional patients (3 with RMS and 1 with myxoid liposarcoma) had a ≥ 50% decrease in tumor size that lasted for <4 weeks. The median progression-free survival was 5.7 weeks, and the median overall survival was 11 months. The most common grade 3/4 toxicities were metabolic (12%), hematologic (6%), gastrointestinal (4%), and general constitutional symptoms (8%).

CONCLUSIONS

R1507 is safe and well tolerated but has limited activity in patients with recurrent or refractory bone and soft tissue sarcomas. Additional studies to help identify the predictive factors associated with clinical benefit in selected histologies such as RMS appear to be warranted.

Bevacizumab and cyclosphosphamide, doxorubicin, vincristine and prednisone in combination for patients with peripheral T-cell or natural killer cell neoplasms: an Eastern Cooperative Oncology Group study (E2404)

Peripheral T-cell lymphoma (PTCL) and natural killer (NK) cell lymphoma have poor survival with conventional cytotoxic chemotherapy. Because angiogenesis plays an important role in the biology of PTCL, a fully humanized anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab (A), was studied in combination with standard cyclosphosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy (ACHOP) to evaluate its potential to improve outcome in these patients. Patients were treated with 6-8 cycles of ACHOP followed by eight doses of maintenance A (15 mg/kg every 21 days). Forty-six patients were enrolled on this phase 2 study from July 2006 through March 2009. Forty-four patients were evaluable for toxicity and 39 were evaluable for response, progression and survival. A total of 324 cycles (range: 2-16, median 7) were administered to 39 evaluable patients and only nine completed all planned treatment. The overall response rate was 90% with 19 (49%) complete response/complete response unconfirmed (CR/CRu) and 16 (41%) a partial response (PR). The 1-year progression-free survival (PFS) rate was 44% at a median follow-up of 3 years. The median PFS and overall survival (OS) rates were 7.7 and 22 months, respectively. Twenty-three patients died (21 from lymphoma, two while in remission). Grade 3 or 4 toxicities included febrile neutropenia (n = 8), anemia (n = 3), thrombocytopenia (n = 5), congestive heart failure (n = 4), venous thrombosis (n = 3), gastrointestinal hemorrhage/perforation (n = 2), infection (n = 8) and fatigue (n = 6). Despite a high overall response rate, the ACHOP regimen failed to result in durable remissions and was associated with significant toxicities. Studies of novel therapeutics are needed for this patient population, whose clinical outcome remains poor.

Chest wall leiomyosarcoma after breast-conservative therapy for early-stage breast cancer in a young woman with Li-Fraumeni syndrome

Li-Fraumeni syndrome (LFS) is one of the most penetrant forms of familial cancer susceptibility syndromes, characterized by early age at tumor onset and a wide spectrum of malignant tumors. Identifying LFS in patients with cancer is clinically imperative because they have an increased sensitivity to ionizing radiation and are more likely to develop radiation-induced secondary malignancies. This case report describes a young woman whose initial presentation of LFS was early-onset breast cancer and whose treatment of this primary malignancy with breast conservation likely resulted in a secondary malignancy arising in her radiation field. As seen in this case, most breast cancers in patients with LFS exhibit a triple-positive phenotype (estrogen receptor-positive/progesterone receptor-positive/HER2-positive). Although this patient met classic LFS criteria based on age and personal and family history of cancer, the NCCN Clinical Practice Guidelines in Oncology for Genetic/Familial High-Risk Assessment: Breast and Ovarian Cancer endorse genetic screening for TP53 mutations in a subset of patients with early-onset breast cancer, even in the absence of a suggestive family history, because of the potential for de novo TP53 mutations.

Maintenance bevacizumab is associated with increased hemoglobin in patients with advanced, nonsquamous, non-small cell lung cancer

We retrospectively analyzed hematologic parameters in 22 patients with advanced, nonsquamous, NSCLC undergoing VEGF inhibition on a phase II clinical trial of bevacizumab, carboplatin, and gemcitabine. We also examined TTP in relation to hemoglobin changes. Median hemoglobin increased significantly from a 12.9 g/dL pretreatment to 13.8 g/dL (p =.01) after the second cycle of maintenance bevacizumab until the first off cycle measurement. There was no difference in TTP in patients who achieved a rise in hemoglobin compared with patients who did not (median 238 days vs. 268 days, p =.38.) Maintenance bevacizumab is associated with increased hemoglobin in advanced, nonsquamous, NSCLC patients.

Bendamustine is effective therapy in patients with rituximab-refractory, indolent B-cell non-Hodgkin lymphoma: results from a Multicenter Study

BACKGROUND

Bendamustine hydrochloride is a novel alkylating agent. In this multicenter study, the authors evaluated the efficacy and toxicity of single-agent bendamustine in patients with rituximab-refractory, indolent B-cell lymphoma.

METHODS

Eligible patients (N = 100, ages 31-84 years) received bendamustine at a dose of 120 mg/m(2) by intravenous infusion on Days 1 and 2 every 21 days for 6 to 8 cycles. Histologies included follicular (62%), small lymphocytic (21%), and marginal zone (16%) lymphomas. Patients had received a median of 2 previous regimens (range, 0-6 previous regimens), and 36%were refractory to their most recent chemotherapy regimen. Primary endpoints included overall response rate (ORR) and duration of response (DOR). Secondary endpoints were safety and progression-free survival (PFS).

RESULTS

An ORR of 75% (a 14% complete response rate, a 3% unconfirmed complete response rate, and a 58% partial response rate) was observed. The median DOR was 9.2 months, and median PFS was 9.3 months. Six deaths were considered to be possibly treatment related. Grade 3 or 4 (determined using National Cancer Institute Common Toxicity Criteria [version 3.0.19]. reversible hematologic toxicities included neutropenia (61%), thrombocytopenia (25%), and anemia (10%). The most frequent nonhematologic adverse events (any grade) included nausea (77%), infection (69%), fatigue (64%), diarrhea (42%), vomiting (40%), pyrexia (36%), constipation (31%), and anorexia (24%).

CONCLUSIONS

Single-agent bendamustine produced a high rate of objective responses with acceptable toxicity in patients with recurrent, rituximab-refractory indolent B-cell lymphoma.

Breast Angiosarcoma: Case Series and Expression of Vascular Endothelial Growth Factor

PURPOSE: Angiosarcoma of the breast is a rare, malignant tumor for which little is known regarding prognostic indicators and optimal therapeutic regimens. To address this issue, we performed a retrospective analysis of breast angiosarcoma cases seen at Stanford University along with immunohistochemical analysis for markers of angiogenesis. METHODS: Breast angiosarcoma cases seen between 1980 and 2008 were examined. Viable tissue blocks were analyzed for expression of vascular endothelial growth factor and its receptors. RESULTS: A total of 16 cases were identified. Data was collected regarding epidemiology, treatment, response rates, disease-free survival, and the use of various imaging modalities. Five tissue blocks remained viable for immunohistochemical analysis. Vascular endothelial growth factor-A was positively expressed in 3 of these samples. CONCLUSION: Angiosarcoma of the breast is an aggressive malignancy with a propensity for both local recurrence and distant metastases. Angiogenesis inhibition may represent a novel therapeutic modality in this rare, vascular malignancy.

A phase II first-line study of gemcitabine, carboplatin, and bevacizumab (GCB) in advanced (adv) stage non-squamous non-small cell lung cancer (NSCLC)

e19024

Background: B adds to 1st-line paclitaxel/carboplatin (PC) for pts with adv NSq-NSCLC. Gemcitabine/carboplatin (GC) has equivalent efficacy to PC with a different toxicity profile. This study was designed to evaluate toxicities (AEs) of GCB and to estimate survival. Methods: Patients (pts) with untreated adv NSq-NSCLC, with no evidence of CNS metastases were eligible. Pts received G 1000 mg/m2 on d1, 8; C AUC 5 d1; and B 15 mg/kg d1 q21d for up to 6 cycles. B was then continued q21d until disease progression or unacceptable toxicity. Chemo dose reductions were mandated for significant cytopenias. Imaging was every 2 cycles. Results: From 07/06 to 12/08, 48 pts enrolled (accrual complete): 23(48%) men, 19(40%) never smokers, median age 59yo (35–81). One pt died prior to receiving therapy and is not included in the analysis. Median cycle number is 6(0–37). To date, 35 pts (74%) completed ≥ 4 cycles of 3 drugs. Dose reductions occurred in 29(62%) of pts. G3/4 AEs included: neutropenia (47%/17%), thrombocytopenia (11%/15%), and anemia (6%/0%). No pts were hospitalized for neutropenic fever. G3/G4 non-hematologic AEs included dyspnea (6%/2%), bacterial pneumonia (4%/0) hypertension (4%/2%), 1G3 wound dehiscence, 1G4 MI, 1G3 transaminitis and hyperbilirubinemia, 1G3 proteinuria and 1G3 leucocyturia. 1 pt died from hemoptysis with untreated aspergillosis found post-mortem. Other bleeding included 1 case each with G3 epistaxis, hemorrhoidal bleeding and ecchymosis. Common G1/2 AEs included fatigue, hypertension, anemia, constipation, nausea, headaches, transaminitis and epistaxis. In 42 evaluable pts: we saw 7(17%) PRs, and 31(74%) SDs at 1st f/up. 44/47 pts were followed for a median of 10.5mo (3 recently enrolled pts with f/u < 20d - excluded). Median time to first event (progression/death/toxicity requiring discontinuation) was 6.4mo [95%CI 4.6–8.6mo]. 17/44 (38.6%) pts have died with median overall survival (mOS) not reached but preliminarily estimated at 16.7mo [95%CI 13.4mo-inf]. Estimated OS is 73% at 1yr and 32% at 2yrs. Conclusions: Treatment with GCB has an acceptable toxicity profile with promising mOS despite a low RR and frequent dose reductions in a population with a high proportion of non-smokers and women.

No significant financial relationships to disclose.

Non-Hodgkin lymphoma of the breast

BACKGROUND

Primary lymphoma of the breast has been reported to have a high local and central nervous system recurrence (CNS) rate, suggesting the need for consolidation radiotherapy and CNS prophylaxis. A retrospective study was done to evaluate the institutional experience in this patient population.

METHODS

In all, 37 patients with lymphoma involving the breast at initial diagnosis and managed at Stanford University from 1981-2005 were included. Diagnostic tissue biopsies were obtained either from the breast mass or an involved lymph node. Treatment and response data, patterns of recurrence, and outcomes were reviewed.

RESULTS

Diffuse large B cell lymphoma (DLBCL) was the most common histologic subtype seen in 18 of 37 (49%) patients. Follicular and marginal zone subtypes were seen in 38%. Most patients presented with an incidental breast mass in stage I(E) or II(E). Four (11%) patients presented with bilateral breast involvement, with only 1 patient presenting with CNS disease. DLBCL patients received doxorubicin-based chemotherapy, with 70% receiving involved field radiotherapy and a single patient receiving intrathecal therapy. No recurrences occurred in the involved breast and a single parenchymal CNS recurrence was recorded. Among the DLBCL patients, the 5-year progression-free survival (PFS) was 61%, with a median follow-up of 3.8 years (range, 5 months to 19 years) and the 5-year overall survival (OS) was estimated at 82%. Patients with indolent lymphoma had an estimated 5-year PFS of 76% and an OS of 92%.

CONCLUSIONS

DLBCL of the breast was successfully treated with doxorubicin-based chemotherapy alone or with involved field radiotherapy in an estimated 61% of patients at 5 years. A single CNS recurrence was observed in our series of patients, most of whom presented with limited disease.