Circulating tumor DNA analysis of the phase III VOYAGER trial: KIT mutational landscape and outcomes in patients with advanced gastrointestinal stromal tumor treated with avapritinib or regorafenib.

BACKGROUND: The current treatment paradigm of imatinib-resistant metastatic gastrointestinal stromal tumor (GIST) does not incorporate KIT/PDGFRA genotypes in therapeutic drug sequencing, except for PDGFRA exon 18-mutant GIST that is indicated for avapritinib treatment. Here, circulating tumor DNA (ctDNA) sequencing was used to analyze plasma samples prospectively collected in the phase III VOYAGER trial to understand how the KIT/PDGFRA mutational landscape contributes to tyrosine kinase inhibitor (TKI) resistance and to determine its clinical validity and utility. PATIENTS AND METHODS: VOYAGER (N = 476) compared avapritinib with regorafenib in patients with KIT/PDGFRA-mutant GIST previously treated with imatinib and one or two additional TKIs (NCT03465722). KIT/PDGFRA ctDNA mutation profiling of plasma samples at baseline and end of treatment was assessed with 74-gene Guardant360® CDx. Molecular subgroups were determined and correlated with outcomes. RESULTS: A total of 386/476 patients with KIT/PDGFRA-mutant tumors underwent baseline (pre-trial treatment) ctDNA analysis; 196 received avapritinib and 190 received regorafenib. KIT and PDGFRA mutations were detected in 75.1% and 5.4%, respectively. KIT resistance mutations were found in the activation loop (A-loop; 80.4%) and ATP-binding pocket (ATP-BP; 40.8%); 23.4% had both. An average of 2.6 KIT mutations were detected per patient; 17.2% showed 4-14 different KIT resistance mutations. Of all pathogenic KIT variants, 28.0% were novel, including alterations in exons/codons previously unreported. PDGFRA mutations showed similar patterns. ctDNA-detected KIT ATP-BP mutations negatively prognosticated avapritinib activity, with a median progression-free survival (mPFS) of 1.9 versus 5.6 months for regorafenib. mPFS for regorafenib did not vary regardless of the presence or absence of ATP-BP/A-loop mutants and was greater than mPFS with avapritinib in this population. Secondary KIT ATP-BP pocket mutation variants, particularly V654A, were enriched upon disease progression with avapritinib. CONCLUSIONS: ctDNA sequencing efficiently detects KIT/PDGFRA mutations and prognosticates outcomes in patients with TKI-resistant GIST treated with avapritinib. ctDNA analysis can be used to monitor disease progression and provide more personalized treatment.

Percutaneous cryoablation for desmoid fibromatosis: initial experience at a UK centre.

AIM: To report the first UK experience of cryoablation in desmoid fibromatosis (DF) with particular focus on technique, safety, and efficacy. MATERIALS AND METHODS: Patients were selected at multidisciplinary tumour board meetings at a specialist cancer hospital. Radiation dose, procedure duration, and number of cryoprobes were compared for small versus large tumours (>10 cm long axis). Response at magnetic resonance imaging (MRI) was evaluated using different criteria, and percentage agreement with clinical response as assessed in oncology clinic calculated. RESULTS: Thirteen procedures were performed in 10 patients (eight women, median age 51 years, IQR 42-69 years) between February 2019 and August 2021. Procedures for large tumours had higher radiation dose (2,012 ± 1,012 versus 1,076 ± 519 mGy·cm, p=0.048) used more cryoprobes (13 ± 7 versus 4 ± 2, p=0.009), and were more likely to have residual unablated tumour (38 ± 37% versus 7.5 ± 10%, p=0.045). Adverse events were minor apart from one transient radial nerve palsy. Eight of 10 patients had symptomatic benefit at clinical follow-up (median 353 days, IQR 86-796 days), and three started systemic therapy mean 393 days later. All patients who had complete ablation demonstrated symptomatic response, with no instances of repeat treatment, recurrence, or need for systemic therapy during the study period. All progression occurred outside ablation zones. CONCLUSION: Cryoablation for symptomatic DF is a reproducible technique with low, transient toxicity, where one or two treatments can achieve a meaningful response. Where possible, the ablation ice ball should fully cover DF tumours.

Diagnosis and management of tropomyosin receptor kinase (TRK) fusion sarcomas: expert recommendations from the World Sarcoma Network.

Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions.

Efficacy and tolerability of trabectedin in elderly patients with sarcoma: subgroup analysis from a phase III, randomized controlled study of trabectedin or dacarbazine in patients with advanced liposarcoma or leiomyosarcoma.

Background: Treatment options for soft tissue sarcoma (STS) patients aged ≥65 years (elderly) can be limited by concerns regarding the increased risk of toxicity associated with standard systemic therapies. Trabectedin has demonstrated improved disease control in a phase III trial (ET743-SAR-3007) of patients with advanced liposarcoma or leiomyosarcoma after failure of anthracycline-based chemotherapy. Since previous retrospective analyses have suggested that trabectedin has similar safety and efficacy outcomes regardless of patient age, we carried out a subgroup analysis of the safety and efficacy observed in elderly patients enrolled in this trial. Patients and methods: Patients were randomized 2 : 1 to trabectedin (n = 384) or dacarbazine (n = 193) administered intravenously every-3-weeks. The primary end point was overall survival (OS); secondary end points were progression-free survival (PFS), time-to-progression, objective response rate (ORR), duration of response, symptom severity, and safety. A post hoc analysis was conducted in the elderly patient subgroup. Results: Among 131 (trabectedin = 94; dacarbazine = 37) elderly patients, disease characteristics were well-balanced and consistent with those of the total study population. Treatment exposure was longer in patients treated with trabectedin versus dacarbazine (median four versus two cycles, respectively), with a significantly higher proportion receiving prolonged therapy (≥6 cycles) in the trabectedin arm (43% versus 23%, respectively; P = 0.04). Elderly patients treated with trabectedin showed significantly improved PFS [4.9 versus 1.5 months, respectively; hazard ratio (HR)=0.40; P = 0.0002] but no statistically significant improvement in OS (15.1 versus 8.0 months, respectively; HR = 0.72; P = 0.18) or ORR (9% versus 3%, respectively; P = 0.43). The safety profile for elderly trabectedin-treated patients was comparable to that of the overall trabectedin-treated study population. Conclusions: This subgroup analysis of the elderly population of ET743-SAR-3007 suggests that elderly patients with STS and good performance status can expect clinical benefit from trabectedin similar to that observed in younger patients. Trial registration: www.clinicaltrials.gov, NCT01343277.

Characterization of Interfacial Structure in Polymer-Fullerene Bulk Heterojunctions via

We introduce a new application of solid state NMR measurements towards characterizing the donor-acceptor interfaces within bulk heterojunction (BHJ) films. Rotational echo double resonance (REDOR) is used to measure dipolar couplings between ^{13}C nuclei on the acceptor phenyl-C_{61}-butyric acid methyl ester (PCBM) fullerene cage, which is ≈18% isotopically enriched with ^{13}C, and beta hydrogens on the donor poly(3-hexyl thiophene) (P3HT) main chain, which are >95% isotopically enriched with ^{2}H. The ^{13}C-^{2}H dipolar couplings are used for constraining possible models of molecular packing in the amorphous mixed phase of a P3HT/PCBM BHJ. The films studied are highly mixed (>80%) and have a maximum length scale of composition nonuniformity of ≈6 nm in the mixed phase, as demonstrated by ^{1}H spin diffusion NMR and supported by TEM. The REDOR results show that despite the lack of phase separation at length scales greater than ≈6 nm, neat P3HT and PCBM clusters exist on ≈3 nm size scales, and, for the average PCBM molecule, the number of nearest neighbors P3HTs is two.

Irinotecan and temozolomide in recurrent Ewing sarcoma: an analysis in 51 adult and pediatric patients.

BACKGROUND: Data on temozolomide (TEM) and irinotecan (IRI) activity in recurrent Ewing sarcoma (EWS), especially in adult patients, are limited. METHODS: Patients receiving TEM 100 mg/m2/day oral, and IRI 40 mg/m2/day intravenous, days 1-5, every 21 days, were included in this multi-institutional retrospective study. Disease control rate (DCR) [overall response rate (ORR) [complete response (CR) + partial response (PR)] + stable disease (SD)], 6-months progression-free survival (6-mos PFS) and 1-year overall survival (OS) were assessed. RESULTS: The median age of the 51 patients was 21 years (range 3-65 years): 34 patients (66%) were adults (≥18 years of age), 24 (48%) had ECOG 1 and 35 (69%) were presented with multiple site recurrence. TEMIRI was used at first relapse/progression in 13 (25%) patients, while the remainder received TEMIRI for second or greater relapse/progression. Fourteen (27%) patients had received prior myeloablative therapy with busulfan and melphalan. We observed five (10%) CR, 12 (24%) PR and 19 (37%) SD, with a DCR of 71%. 6-mos PFS was 49% (95% CI 35-63) and it was significantly influenced by ECOG (6-mos PFS 64% [95% CI 45-83] for ECOG 0, 34% [95% CI 14-54] for ECOG ≥1; p = .006) and LDH (6-mos PFS 62% [95% CI 44-79] for normal LDH, 22% [95% CI 3-42] for high LDH; p = .02), with no difference according to line of treatment, age and metastatic pattern. One-year OS was 55% (95% CI 39-70), with RECIST response (p = .001) and ECOG (p = .0002) independently associated with outcome. Grade 3 and 4 toxicity included neutropenia in 12% of patients, thrombocytopenia in 4%, diarrhea in 4%. CONCLUSIONS: This series confirms the activity of TEMIRI in both adults and pediatric patients. This schedule offers a 71% DCR, independently of the line of chemotherapy. Predictive factors of response are ECOG and LDH.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group.

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

Relationship between IHC4 score and response to neo-adjuvant chemotherapy in estrogen receptor-positive breast cancer.

AIMS: To determine whether IHC4 score assessed on pre-treatment core biopsies (i) predicts response to neo-adjuvant chemotherapy in ER-positive (ER+) breast cancer; (ii) provides more predictive information than Ki67 alone. METHODS: 113 patients with ER+ primary breast cancer treated with neo-adjuvant chemotherapy at the Royal Marsden Hospital between 2002 and 2010 were included in the study. Pathologic assessment of the excision specimen was made for residual disease. IHC4 was determined on pre-treatment core biopsies, blinded to clinical outcome, by immunohistochemistry using quantitative scoring of ER (H-score), PgR (%) and Ki67 (%). Determination of HER2 status was made by immunohistochemistry and fluorescent in situ hybridization for 2+ cases. IHC4 and Ki67 scores were tested for their association with pathological complete response (pCR) rate and residual cancer burden (RCB) score. RESULTS: 18 (16%) of the 113 patients and 8 (9%) of the 88 HER2-ve cases achieved pCR. Ki67 and IHC4 score were both positively associated with achievement of pCR (P < 10-7 and P < 10-9, respectively) and RCB0+1 (P < 10-5 and P < 10-9, respectively) following neo-adjuvant chemotherapy in all patients. Rates of pCR+RCB1 were 45 and 66% in the highest quartiles of Ki67 and IHC4 scores, respectively. In ER+HER2-ve cases, pCR+RCB1 rates were 35% and in the highest quartile of both Ki67 and IHC4. There were no pCRs in the lower half of IHC4 or Ki67 scores. CONCLUSIONS: IHC4 was strongly predictive of pCR or near pCR in ER+ breast cancers following neo-adjuvant chemotherapy. Ki67 was an important component of this predictive ability, but was not as predictive as IHC4.

Pazopanib in advanced vascular sarcomas: an EORTC Soft Tissue and Bone Sarcoma Group (STBSG) retrospective analysis.

BACKGROUND: Pazopanib is a multitargeted tyrosine kinase inhibitor approved for the treatment of patients with selective subtypes of advanced soft tissue sarcoma (STS) who have previously received standard chemotherapy including anthracyclines. Data on the efficacy in vascular sarcomas are limited. The main objective of this study was to investigate the activity of pazopanib in vascular sarcomas. PATIENTS AND METHODS: A retrospective study of patients with advanced vascular sarcomas, including angiosarcoma (AS), epithelioid hemangioendothelioma (HE) and intimal sarcoma (IS) treated with pazopanib in real life practice at EORTC centers as well as patients treated within the EORTC phase II and III clinical trials (62043/62072) was performed. Patient and tumor characteristics were collected. Response was assessed according to RECIST 1.1. and survival analysis was performed. RESULTS: Fifty-two patients were identified, 40 (76.9%), 10 (19.2%) and two (3.8%) with AS, HE and IS, respectively. The response rate was eight (20%), two (20%) and two (100%) in the AS, HE and IS subtypes, respectively. There was no significant difference in response rate between cutaneous and non-cutaneous AS and similarly between radiation-associated and non-radiation-associated AS. Median progression-free survival (PFS) and median overall survival (OS; from commencing pazopanib) were three months (95% CI 2.1-4.4) and 9.9 months (95% CI 6.5-11.3) in AS, respectively. CONCLUSION: The activity of pazopanib in AS is comparable to its reported activity in other STS subtypes. In this study, the activity of pazopanib was similar in cutaneous/non-cutaneous and in radiation/non-radiation-associated AS. In addition, pazopanib showed promising activity in HE and IS, worthy of further evaluation.

Phosphoproteomics in translational research: a sarcoma perspective.

Phosphoproteomics has been extensively used as a preclinical research tool to characterize the phosphorylated components of the cancer proteome. Advances in the field have yielded insights into new drug targets, mechanisms of disease progression and drug resistance, and biomarker discovery. However, application of this technology to clinical research has been challenging because of practical issues relating to specimen integrity and tumour heterogeneity. Beyond these limitations, phosphoproteomics has the potential to play a pivotal role in translational studies and contribute to advances in different tumour groups, including rare disease sites like sarcoma. In this review, we propose that deploying phosphoproteomic technologies in translational research may facilitate the identification of better defined predictive biomarkers for patient stratification, inform drug selection in umbrella trials and identify new combinations to overcome drug resistance. We provide an overview of current phosphoproteomic technologies, such as affinity-based assays and mass spectrometry-based approaches, and discuss their advantages and limitations. We use sarcoma as an example to illustrate the current challenges in evaluating targeted kinase therapies in clinical trials. We then highlight useful lessons from preclinical studies in sarcoma biology to demonstrate how phosphoproteomics may address some of these challenges. Finally, we conclude by offering a perspective and list the key measures required to translate and benchmark a largely preclinical technology into a useful tool for translational research.

Gemcitabine and docetaxel in relapsed and unresectable high-grade osteosarcoma and spindle cell sarcoma of bone.

BACKGROUND: Few new compounds are available for relapsed osteosarcoma. We retrospectively evaluated the activity of gemcitabine (G) plus docetaxel (D) in patients with relapsed high-grade osteosarcoma and high-grade spindle cell sarcoma of bone (HGS). METHODS: Patients receiving G 900 mg/m(2) d 1, 8; D 75 mg/m(2) d 8, every 21 days were eligible. Primary end-point: progression-free survival (PFS) at 4 months; secondary end-point: overall survival (OS) and response rate. RESULTS: Fifty-one patients were included, with a median age of 17 years (8-71), 26 (51%) were pediatric patients. GD line of treatment: 2nd in 14 patients, ≥3rd in 37. 25 (49%) patients had metastases limited to lungs, 26 (51%) multiple sites. HISTOLOGY: 40 (78%) osteosarcoma, 11 (22%) HGS. Eight (16%) patients achieved surgical complete response (sCR2) after GD. Four-month PFS rate was 46%, and significantly better for patients with ECOG 0 (ECOG 0: 54% vs ECOG 1: 43% vs ECOG 2: 0%; p = 0.003), for patients undergoing metastasectomy after GD (sCR2 75% vs no-sCR2 40 %, p = 0.02) and for osteosarcoma (osteosarcoma 56% vs HGS 18%; p = 0.05), with no differences according to age, line of treatment, and pattern of metastases. Forty-six cases had RECIST measurable disease: 6 (13%) patients had a partial response (PR), 20 (43%) had stable disease (SD) and 20 (43%) had progressive disease (PD). The 1-year OS was 30%: 67% for PR, 54% for SD and 20% for PD (p = 0.005). CONCLUSIONS: GD is an active treatment for relapsed high-grade osteosarcoma, especially for ECOG 0 patients, and should be included in the therapeutic armamentarium of metastatic osteosarcoma.

Residual proliferative cancer burden to predict long-term outcome following neoadjuvant chemotherapy.

BACKGROUND: The purpose of this study was (i) to test the hypothesis that combining Ki67 with residual cancer burden (RCB) following neoadjuvant chemotherapy, as the residual proliferative cancer burden (RPCB), provides significantly more prognostic information than either alone; (ii) to determine whether also integrating information on ER and grade improves prognostic power. PATIENTS AND METHODS: A total of 220 patients treated with neoadjuvant chemotherapy for primary breast cancer were included in the study. Analyses employed a Cox proportional hazard model. Prognostic indices (PIs) were created adding in Ki67, grade and ER to RCB. Leave-one-out cross-validation was used to reduce bias. The overall change in χ(2) of the best model for each index was used to compare the prognostic ability of the different indices. RESULTS: All PIs provided significant prognostic information for patients with residual disease following neoadjuvant chemotherapy. RPCB (χ(2) = 61.4) was significantly more prognostic than either RCB (χ(2) = 38.1) or Ki67 (χ(2) = 53.8) alone P < 0.001. A PI incorporating RCB, Ki67 grade and ER provided the most prognostic information overall and gave χ(2) = 73.8. CONCLUSIONS: This study provides proof of principle that the addition of post-treatment Ki67 to RCB improves the prediction of long-term outcome. Prediction may be further improved by addition of post-treatment grade and ER and warrants further investigation for estimating post-neoadjuvant risk of recurrence. These indices may have utility in stratifying patients for novel therapeutic interventions after neoadjuvant chemotherapy.

Rapid-onset antidepressant action of ketamine: potential revolution in understanding and future pharmacologic treatment of depression.

WHAT IS KNOWN AND OBJECTIVE: The current pharmacotherapeutic treatment of major depressive disorder (MDD) generally takes weeks to be effective. As the molecular action of these drugs is immediate, the mechanistic basis for this lag is unclear. A drug that has a more rapid onset of action would be a major therapeutic advance and also be a useful comparator to provide valuable mechanistic insight into the disorder and its treatment. COMMENT: Recent evidence suggests that ketamine produces rapid-onset antidepressant action. Important questions are as follows: is it specific or coincidental to other effects; is there a dose-response relationship; and is the mechanism related to that of current antidepressants. NMDA receptor antagonism is unlikely the explanation for ketamine's antidepressant action. WHAT IS NEW AND CONCLUSION: It is not an exaggeration to state that the new findings, if validated, might produce a revolution in understanding and treating depressive disorders.

International Union of Basic and Clinical Pharmacology. LXXXIII: classification of prostanoid receptors, updating 15 years of progress.

It is now more than 15 years since the molecular structures of the major prostanoid receptors were elucidated. Since then, substantial progress has been achieved with respect to distribution and function, signal transduction mechanisms, and the design of agonists and antagonists (http://www.iuphar-db.org/DATABASE/FamilyIntroductionForward?familyId=58). This review systematically details these advances. More recent developments in prostanoid receptor research are included. The DP(2) receptor, also termed CRTH2, has little structural resemblance to DP(1) and other receptors described in the original prostanoid receptor classification. DP(2) receptors are more closely related to chemoattractant receptors. Prostanoid receptors have also been found to heterodimerize with other prostanoid receptor subtypes and nonprostanoids. This may extend signal transduction pathways and create new ligand recognition sites: prostacyclin/thromboxane A(2) heterodimeric receptors for 8-epi-prostaglandin E(2), wild-type/alternative (alt4) heterodimers for the prostaglandin FP receptor for bimatoprost and the prostamides. It is anticipated that the 15 years of research progress described herein will lead to novel therapeutic entities.

Current unmet needs in locally advanced (unresectable) or metastatic dedifferentiated liposarcoma, the relevance of progression-free survival as clinical endpoint, and expectations for future clinical trial design: an international Delphi consensus report.

BACKGROUND: Locally advanced (unresectable) or metastatic dedifferentiated liposarcoma (DDLPS) is a common presentation of liposarcoma. Despite established diagnostic and treatment guidelines for DDLPS, critical clinical gaps remain driven by diagnostic challenges, symptom burden and the lack of targeted, safe and effective treatments. The objective of this study was to gather expert opinions from Europe and the United States on the management, unmet needs and expectations for clinical trial design as well as the value of progression-free survival (PFS) in this disease. Other aims included raising awareness and educate key stakeholders across healthcare systems. MATERIALS AND METHODS: An international panel of 12 sarcoma key opinion leaders (KOLs) was recruited. The study consisted of two rounds of surveys with pre-defined statements. Experts scored each statement on a 9-point Likert scale. Consensus agreement was defined as ≥75% of experts scoring a statement with ≥7. Revised statements were discussed in a consensus meeting. RESULTS: Consensus was reached on 43 of 55 pre-defined statements across disease burden, treatment paradigm, unmet needs, value of PFS and its association with overall survival (OS), and cross-over trial design. Twelve statements were deprioritised or merged with other statements. There were no statements where experts disagreed. CONCLUSION: This study constitutes the first international Delphi panel on DDLPS. It aimed to explore KOL perception of the disease burden and unmet need in DDLPS, the value of PFS, and its potential translation to OS benefit, as well as the relevance of a cross-over trial design for DDLPS therapies. Results indicate an alignment across Europe and the United States regarding DDLPS management, unmet needs, and expectations for clinical trials. Raising awareness of critical clinical gaps in relation to DDLPS can contribute to improving patient outcomes and supporting the development of innovative treatments.