Spunt, Sheri L.

AbstractBackgroundEmbryonal sarcoma of the liver (ESL) is a rare mesenchymal tumor most common in childhood; the optimal treatment approach is uncertain. The clinical features and outcomes of patients with ESL enrolled in a Children’s Oncology Group (COG) clinical trial that evaluated a risk‐based strategy for treating soft tissue sarcomas in patients aged <30 years were evaluated.MethodsThis subset analysis included patients with ESL enrolled in COG study ARST0332. Central review of records, pathology, and imaging confirmed the diagnosis, presenting features, and surgery extent and complications. All patients received dose‐intensive ifosfamide/doxorubicin chemotherapy, with cycle timing dependent on surgery and radiotherapy. Tumor resection occurred before study entry or after four cycles of chemotherapy; radiotherapy for residual tumor was optional.ResultsThirty‐nine eligible/evaluable patients with ESL were analyzed. All tumors were >10 cm in diameter; four were metastatic. Tumor resection was performed upfront in 23 and delayed in 16. Positive surgical margins (n = 6) and intraoperative tumor rupture (n = 6) occurred only in upfront resections. Eight patients received radiotherapy. Estimated 5‐year event‐free and overall survival were 79% (95% confidence interval [CI], 65%–93%) and 95% (95% CI, 87%–100%), respectively. Positive margins increased the local recurrence risk. One of 13 patients with documented hemorrhagic ascites and/or tumor rupture developed extrahepatic intra‐abdominal tumor recurrence.ConclusionsThe treatment strategy used in ARST0332 achieved favorable outcomes for patients with ESL despite a substantial proportion having high‐risk disease features. Deferring tumor resection until after neoadjuvant chemotherapy may decrease the risk of intraoperative tumor rupture and improve the likelihood of adequate surgical margins.

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. ARST1321 was a phase II study designed to compare the near complete pathologic response rate after preoperative chemoradiation with/without pazopanib in children and adults with intermediate-/high-risk chemotherapy-sensitive body wall/extremity non-Rhabdomyosarcoma Soft Tissue Sarcoma (ClinicalTrials.gov identifier: NCT02180867 ). Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary aim of the study, the outcome data for this cohort were analyzed. Eight-five eligible patients were randomly assigned to receive (regimen A) or not receive (regimen B) pazopanib in combination with ifosfamide and doxorubicin + preoperative radiotherapy followed by primary resection at week 13 and then further chemotherapy at week 25. As of December 31, 2021, at a median survivor follow-up of 3.3 years (range, 0.1-5.8 years), the 3-year event-free survival for all patients in the intent-to-treat analysis was 52.5% (95% CI, 34.8 to 70.2) for regimen A and 50.6% (95% CI, 32 to 69.2) for regimen B ( P = .8677, log-rank test); the 3-year overall survival was 75.7% (95% CI, 59.7 to 91.7) for regimen A and 65.4% (95% CI, 48.1 to 82.7) for regimen B ( P = .1919, log-rank test). Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib, outcomes were not statistically significantly different between the two regimens.

AbstractBackground and ObjectivesThe impact upon wound healing of targeted molecular therapies, when incorporated into neoadjuvant therapy of soft tissue sarcoma, is largely unknown. Here, we describe wound complications following addition of pazopanib, a tyrosine kinase inhibitor (TKI), to neoadjuvant radiotherapy (RT) +/− chemotherapy for soft tissue sarcoma.MethodsWound complications were evaluated on dose‐finding and randomized arms of ARST1321, a phase II/III study incorporating neoadjuvant RT, +/− pazopanib, +/− ifosfamide/doxorubicin (ID) for sarcoma therapy.ResultsOf 85 evaluable patients, 35 (41%) experienced postoperative wound complications. Most (57%) were grade III. Randomization to pazopanib + RT + ID carried a 50% wound complication rate (17/34, with 47% grade III), compared to 22% (5/23) with ID + RT alone. In nonchemotherapy study arms, pazopanib + RT resulted in a 59% wound complication rate versus 25% for those receiving RT alone. Grade III wound complications occurred among 26% (15/58) of all patients receiving pazopanib. Wound complications occurred a median of 35 days postoperatively. Some occurred following diagnostic biopsies and at remote surgical sites.ConclusionThe addition of pazopanib to neoadjuvant chemotherapy and RT resulted in a higher wound complication rate following therapy of soft tissue sarcoma. The rate of grade III complications remained comparable to that reported in contemporary literature.

11504 Background: Pazopanib is a multi-targeted tyrosine kinase inhibitor (TKI) with activity in advanced soft tissue sarcoma. ARST1321 was a phase II study designed to compare the near complete pathologic response rate (≥ 90% necrosis) following preoperative chemoradiation +/- pazopanib in children and adults with intermediate/high risk chemotherapy-sensitive body wall/extremity NRSTS. Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary analysis of the study, we now report the outcome data for this cohort. Methods: ARST1321 was a jointly designed COG and NRG Oncology study open to enrollment July 2014-October 2018. Eligible adult (≥18 years) and pediatric (< 18 years) patients with newly-diagnosed unresected body wall/extremity NRSTS were enrolled into the Chemotherapy Cohort (> 5 cm, FNCLCC grade 2/3, protocol-designated chemotherapy-sensitive histology). Following a dose-finding phase, patients were randomized to receive (Regimen A) or not receive (Regimen B) pazopanib (< 18 years: 350 mg/m2/day; ≥ 18 years: 600 mg/day) in combination with ifosfamide (7.5 gm/m2/cycle) and doxorubicin (75 mg/m2/cycle) + 45 Gy preoperative RT followed by primary resection at week 13, then further chemotherapy to week 25. Results: Eighty-five eligible patients were enrolled in the Chemotherapy Cohort and randomized to receive or not receive pazopanib. Median age 22.1 years (range: 5.7-64.2 years); 30 patients < 18 years. Most common histologies were synovial sarcoma (n = 42) and undifferentiated pleomorphic sarcoma (n = 19). As of December 31, 2021, at a median survivor follow-up of 3.3 years (range: 0.1 – 5.8 years), the 3-year event-free survival (EFS) for all patients in the intent-to-treat analysis was 52.5% (95% CI: 34.8%-70.2%) for Regimen A and 50.6% (32%-69.2%) for Regimen B (p = 0.8677); 3-year overall survival (OS) was 75.7% (59.7%-91.7%) for Regimen A and 65.4% (48.1%-82.7%) for Regimen B (p = 0.1919). Conclusions: Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib to preoperative chemoradiation in children and adults with intermediate/high risk body wall/extremity NRSTS, outcomes were not statistically significantly different between the two regimens. Pathologic response could be a TKI-related phenomenon and may not be a good surrogate marker of outcome in future studies. Clinical trial information: NCT02180867.

Abstract Germline mutations in TP53 cause a rare high penetrance cancer syndrome, Li–Fraumeni syndrome (LFS). Here, we identified a rare TP53 tetramerization domain missense mutation, c.1000G&gt;C;p.G334R, in a family with multiple late-onset LFS-spectrum cancers. Twenty additional c.1000G&gt;C probands and one c.1000G&gt;A proband were identified, and available tumors showed biallelic somatic inactivation of TP53. The majority of families were of Ashkenazi Jewish descent, and the TP53 c.1000G&gt;C allele was found on a commonly inherited chromosome 17p13.1 haplotype. Transient transfection of the p.G334R allele conferred a mild defect in colony suppression assays. Lymphoblastoid cell lines from the index family in comparison with TP53 normal lines showed that although classical p53 target gene activation was maintained, a subset of p53 target genes (including PCLO, PLTP, PLXNB3, and LCN15) showed defective transactivation when treated with Nutlin-3a. Structural analysis demonstrated thermal instability of the G334R-mutant tetramer, and the G334R-mutant protein showed increased preponderance of mutant conformation. Clinical case review in comparison with classic LFS cohorts demonstrated similar rates of pediatric adrenocortical tumors and other LFS component cancers, but the latter at significantly later ages of onset. Our data show that TP53 c.1000G&gt;C;p.G334R is found predominantly in Ashkenazi Jewish individuals, causes a mild defect in p53 function, and leads to low penetrance LFS. Significance: TP53 c.1000C&gt;G;p.G334R is a pathogenic, Ashkenazi Jewish–predominant mutation associated with a familial multiple cancer syndrome in which carriers should undergo screening and preventive measures to reduce cancer risk.

Purpose. Osteosarcoma is a rare cancer and a third of patients who have completed primary treatment will develop osteosarcoma recurrence. The Src pathway has been implicated in the metastatic behavior of osteosarcoma; about 95% of samples examined express Src or have evidence of downstream activation of this pathway. Saracatinib (AZD0530) is a potent and selective Src kinase inhibitor that was evaluated in adults in Phase 1 studies. The primary goal of this study was to determine if treatment with saracatinib could increase progression-free survival (PFS) for patients who have undergone complete resection of osteosarcoma lung metastases in a double-blinded, placebo-controlled trial. Patients and Methods. Subjects with recurrent osteosarcoma localized to lung and who had complete surgical removal of all lung nodules were randomized within six weeks after complete surgical resection. Saracatinib, or placebo, was administered at a dose of 175 mg orally, once daily, for up to thirteen 28-day cycles. Results. Thirty-seven subjects were included in the analyses; 18 subjects were randomized to receive saracatinib and 19 to receive placebo. Intent-to-treat analysis demonstrated a median PFS of 19.4 months in the saracatinib treatment group and 8.6 months in the placebo treatment group (p=0.47). Median OS was not reached in either arm. Conclusions. Although saracatinib was well tolerated in this patient population, there was no apparent impact of the drug in this double-blinded, placebo-controlled trial on OS, and Src inhibition alone may not be sufficient to suppress metastatic progression in osteosarcoma. There is a suggestion of potential clinical benefit as evidenced by longer PFS in patients randomized to saracatinib based on limited numbers of patients treated.

11070 Background: Pazopanib is a tyrosine kinase inhibitor approved globally for advanced soft tissue sarcomas. The dose finding phase of this cooperative group trial assessed the dose limiting toxicities (DLT) and the maximally tolerated dose (MTD) of adding pazopanib to neoadjuvant chemoradiation or radiation therapy in children and adults with unresected intermediate/high-risk trunk and extremity non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). Methods: ARST1321, a jointly designed intergroup study lead by Children's Oncology Group and NRG Oncology opened for enrollment in July 2014. Eligible adult and pediatric patients with newly diagnosed, unresected trunk/extremity NRSTS with plans for primary tumor resection were enrolled into either the Chemotherapy Cohort (those with chemosensitive NRSTS > 5 cm, grade 3, including all synovial sarcoma) or the Non-Chemotherapy Cohort (those with chemotherapy insensitive NRSTS of any size, grade 2/3, or any chemosensitive NRSTS for whom no chemotherapy was planned per discretion of patients and treatment teams). In the Chemotherapy Cohort, pazopanib was given with ifosfamide (7.5 grams/m2) and doxorubicin (75 mg/m2) plus 45 Gy preoperative RT starting after cycle 2. Primary tumor was resected at week 13, followed by chemotherapy and pazopanib to week 25. In the Non-Chemotherapy Cohort, pazopanib was given with 50 Gy preoperative RT, primary tumor was resected at week 10, and pazopanib continued to week 25. Feasibility was assessed through week 6 of therapy to determine pazopanib dose escalation/de-escalation based on DLT, total doses of pazopanib, and overall adverse event profile. Results: In the Chemotherapy Cohort, MTD was reached at Dose Level 1 (350 mg/m2 peds; 600 mg adults) with two DLTs (1 grade 3 ALT rise, 1 intolerability to therapy) in 10 patients. In the Non-Chemotherapy Cohort, 11 patients enrolled at Dose Level 1 (350 mg/m2 peds; 600 mg adults) without any observed DLTs and all received ≥75% of prescribed total pazopanib dose; MTD was reached at Dose Level 2 (450 mg/m2 peds; 800 mg adults) with 2 DLTs in ten patients enrolled (1 grade 3 dermatitis and 1 intolerability to therapy) and 9/10 receiving ≥75% of full dose. Conclusions: Pazopanib in combination with chemoradiation or radiation therapy alone was found to be safe in children and adults with NRSTS. Following this finding, ARST1321 opened in both arms using the newly determined pazopanib MTDs. Clinical trial information: NCT02180867.

11002 Background: Pazopanib is a multi-targeted tyrosine kinase inhibitor with activity in advanced soft tissue sarcoma. ARST1321 is a phase II study designed to compare the near complete pathologic response rate (≥ 90% necrosis) of preoperative chemoradiation +/- pazopanib in children and adults with intermediate/high risk chemotherapy-sensitive NRSTS. Methods: ARST1321 is a jointly designed COG and NRG Oncology study opened to enrollment in July 2014. Eligible adult (≥18 years) and pediatric ( < 18 years) patients with unresected, newly diagnosed truncal/extremity NRSTS were enrolled into the Chemotherapy Cohort ( > 5 cm, grade 2/3, protocol-designated chemotherapy-sensitive histology). Following a dose-finding phase, patients were randomized to receive (Regimen A) or not receive (Regimen B) pazopanib ( < 18 years: 350 mg/m2/day; ≥ 18 years: 600 mg/day) in combination with ifosfamide (7.5 gm/m2/cycle) and doxorubicin (75 mg/m2/cycle) + 45 Gy preoperative RT followed by primary resection at week 13, then adjuvant chemotherapy. Results: As of June 30, 2018, 81 eligible patients were enrolled and randomized. Week 13 response is available for 42 patients (60% of expected information). The rate of ≥ 90% pathologic necrosis was 58.3% for Regimen A and 22.2% for Regimen B. Based on the significance level of 0.081 (for the second efficacy analysis with overall one-sided significance level of 0.20, power of 0.80, and O’Brien-Fleming-type cumulative error spending function), the 83.8% confidence interval for the difference was between 16.5% and 55.8%. At this predetermined interim analysis, the efficacy bound was crossed indicating that Regimen A is more efficacious than Regimen B. Given these findings, enrollment was stopped. Grade 3/4 toxicities were 73.8% for Regimen A and 29% for Regimen B with neutropenia, thrombocytopenia and febrile neutropenia being the most common toxicities. Conclusions: The rate of near complete pathologic response was significantly greater with the addition of pazopanib to preoperative chemoradiation in children and adults with intermediate/high risk NRSTS. The comparison of survival outcomes requires longer follow-up. Clinical trial information: NCT02180867.

TPS10591 Background: Osteosarcoma is a rare cancer and 33% of patients who have completed primary treatment will recur. The Src pathway has been implicated in the metastatic behavior of several tumors including osteosarcoma where 95% of samples express Src or have evidence of downstream activation of this pathway. Saracatinib (AZD0530) is a potent and selective Src kinase inhibitor. The recommended phase II dose in adults was found to be 175mg daily. The primary goal of this study is to determine if treatment with Saracatinib can increase progression free survival (PFS) for patients who have undergone complete resection of metastatic osteosarcoma nodules in the lung. Secondary goals are evaluation of overall survival, time to treatment failure, and evaluation of several biological correlatives. Methods: This is a multi-institutional, phase II.5, placebo-controlled study with an accrual goals of 88 randomized patients. Patients between 15 and 75 years, with histological confirmation of recurrent osteosarcoma, localized to the lung, who have potential for complete surgical resection, are eligible for enrollment. After complete resection, patients are randomized to treatment with saracatinib or placebo, of a daily oral dose of 175 mg, continuously for up to 1 year or until progression. Patients who recur in the lung while on-study and who are amenable to complete surgical resection will be un-blinded. Those patients who received placebo may have the option to undergo surgical resection. If fully resected, they will be offered therapy with saracatinib under the same treatment guidelines as above. As of January 2013, 38 patients have enrolled and 32 patients met the criteria to be randomized and began oral therapy with either saracatinib or placebo. An interim analysis is planned after 40 patients have been randomized. Clinical trial information: NCT00752206.

Abstract Background Previous studies of the prognostic importance of FOXO1 fusion status in patients with rhabdomyosarcoma (RMS) have had conflicting results. We re‐examined risk stratification by adding FOXO1 status to traditional clinical prognostic factors in children with localized or metastatic RMS. Methods Data from six COG clinical trials (D9602, D9802, D9803, ARST0331, ARTS0431, ARST0531; two studies each for low‐, intermediate‐ and high‐risk patients) accruing previously untreated patients with RMS from 1997 to 2013 yielded 1727 evaluable patients. Survival tree regression for event‐free survival (EFS) was conducted to recursively select prognostic factors for branching and split. Factors included were age, FOXO1, clinical group, histology, nodal status, number of metastatic sites, primary site, sex, tumor size, and presence of metastases in bone/bone marrow, soft tissue, effusions, lung, distant lymph nodes, and other sites. Definition and outcome of the proposed risk groups were compared to existing systems and cross‐validated results. Results The 5‐year EFS and overall survival (OS) for evaluable patients were 69% and 79%, respectively. Extent of disease (localized versus metastatic) was the first split (EFS 73% vs 30%; OS 84% vs. 42%). FOXO1 status (positive vs negative) was significant in the second split both for localized (EFS 52% vs 78%; OS 65% vs 88%) and metastatic disease (EFS 6% vs 46%; OS 19% vs 58%). Conclusions After metastatic status, FOXO1 status is the most important prognostic factor in patients with RMS and improves risk stratification of patients with localized RMS. Our findings support incorporation of FOXO1 status in risk stratified clinical trials.