A phase 2 study of a brachyury-targeting vaccine in combination with radiation therapy for the treatment of advanced chordoma.

BACKGROUND: This was a single-arm, phase 2 clinical trial of Bavarian Nordic (BN)-Brachyury vaccine plus radiotherapy (RT) designed to determine the objective response rate (ORR), progression-free survival (PFS), and safety of the combination in chordoma. METHODS: A total of 29 adult patients with advanced chordoma were treated with two subcutaneous priming vaccine doses of modified vaccinia Ankara-Bavarian Nordic (MVA-BN)-Brachyury and one vaccine dose of fowlpox virus (FPV)-Brachyury before RT. After RT, booster vaccinations were given with FPV-Brachyury every 4 weeks for 4 doses, then every 12 weeks (week 110). A minimum RT dose of >8 Gy in one fraction for each target was required. Response was evaluated by modified Response Evaluation Criteria in Solid Tumors 1.1 (mRECIST), where only radiated lesions were considered targets, and by standard RECIST 1.1 in a subset of patients. RESULTS: Two of 26 evaluable patients experienced durable partial response (PR) (ORR of 7.7%; 90% confidence interval [CI], 2.6-20.8]) by mRECIST 1.1. A total of 21 patients (80.8%; 90% CI, 65.4-90.3) had stable disease, and three patients (11.5%; 90% CI, 4.7-25.6) had progressive disease as best response per mRECIST 1.1. Median PFS was not reached during the study. CONCLUSIONS: This trial confirms the safety of BN-Brachyury and RT. Although the study did not meet the predefined study goal of four responses in 29 patients, we did observe two PRs and a PFS of greater than 2 years. For a vaccine-based study in chordoma, an ultra-rare disease where response rates are low, a randomized study or novel trial designs may be required to confirm activity.

Phase 1 trial of navitoclax and sorafenib in patients with relapsed or refractory solid tumors with hepatocellular carcinoma expansion cohort.

Navitoclax (ABT-263) is an oral BCL2 homology-3 mimetic that binds with high affinity to pro-survival BCL2 proteins, resulting in apoptosis. Sorafenib, an oral multi kinase inhibitor also promotes apoptosis and inhibits tumor angiogenesis. The efficacy of either agent alone is limited; however, preclinical studies demonstrate synergy with the combination of navitoclax and sorafenib. In this phase 1 study, we evaluated the combination of navitoclax and sorafenib in a dose escalation cohort of patients with refractory solid tumors, with an expansion cohort in hepatocellular carcinoma (HCC). Maximum tolerated dose (MTD) was determined using the continual reassessment method. Navitoclax and sorafenib were administered continuously on days 1 through 21 of 21-day cycles. Ten patients were enrolled in the dose escalation cohort and 15 HCC patients were enrolled in the expansion cohort. Two dose levels were tested, and the MTD was navitoclax 150 mg daily plus sorafenib 400 mg twice daily. Among all patients, the most common grade 3 toxicity was thrombocytopenia (5 patients, 20%): there were no grade 4 or 5 toxicities. Patients received a median of 2 cycles (range 1-36 cycles) and all patients were off study treatment at data cut off. Six patients in the expansion cohort had stable disease, and there were no partial or complete responses. Drug-drug interaction between navitoclax and sorafenib was not observed. The combination of navitoclax and sorafenib did not increase induction of apoptosis compared with navitoclax alone. Navitoclax plus sorafenib is tolerable but showed limited efficacy in the HCC expansion cohort. These findings do not support further development of this combination for the treatment of advanced HCC. This phase I trial was conducted under ClinicalTrials.gov registry number NCT01364051.

Long-term experience with intraoperative electron radiation therapy boost in extremity sarcoma.

BACKGROUND: In patients with extremity soft tissue sarcoma (eSTS), we describe outcomes of preoperative external beam radiation therapy (EBRT), limb-sparing surgery (LSS), and intraoperative electron radiation therapy (IOERT). METHODS: One hundred and eighteen patients with eSTS treated between October 17, 2002 and July 28, 2021 were identified. EBRT was delivered preoperatively followed by LSS and IOERT. RESULTS: The median follow-up was 24.9 months. The presentation was primary in 102 (94%) patients and recurrent in 6 (6%) patients. Tumor location was lower extremity in 82 (76%) patients and upper extremity in 26 (24%) patients. Stage distribution was as follows: 3 (3%) IA, 24 (22%) IB, 31 (29%) II, 24 (22%) IIIA, and 25 (23%) IIIB. Final surgical margins were negative in 96 (89%) patients. The 5-year local control, failure-free survival, and overall survival were 94%, 75%, and 64%, respectively. Univariate analysis identified age >50, lower extremity, and higher grade as significant negative prognostic factors for overall survival. Grade 3 fracture or osteoradionecrosis requiring surgical fixation, neuropathy, and lymphedema occurred in 7 (6%), 1 (1%), and 0 patients, respectively. CONCLUSIONS: This study represents one of the largest series using preoperative EBRT, LSS, and IOERT for eSTS, with high local control and a low rate of late severe toxicity.

Evolving role of entrectinib in treatment of NTRK-positive tumors.

Targeted therapy has shown to be a very effective treatment in tumors with specific genomic drivers. Trk has proven to be one such target. Efforts to target the Trk fusion with specific inhibitors have shown remarkable responses in a tumor agnostic fashion, with responses seen even in patients with intracranial metastasis. Entrectinib is a first-generation Trk inhibitor with impressive activity in early phase trials performed in patients with NTRK fusion positive solid tumors and ROS1 positive non-small-cell lung cancers with subsequent approval for those indications. Entrectinib was also found to be effective in treatment of brain metastasis and generally well tolerated.

Lay abstract Advances in medical science has allowed us to analyze genes within cancer cells and target abnormal genes more precisely. One such target is called NTRK, which carries genetic information and has been targeted using a medication called entrectinib. This medication is also very effective in patients with cancers that has spread to the brain. This medication can be used in any type of cancer if the cancer cells possess the abnormal DNA. Some of the side effects of entrectinib include weight gain, lightheadedness, throwing up, taste changes, swelling of legs, lack of energy and so on. Based on the benefit of entrectinib seen in clinical trials the medication was approved by the US FDA for treatment of any type of cancer with the NTRK problem. We hope that this new approach to cancer treatment will result in patients having greater benefit and live longer.

First-Line Therapy for Metastatic Soft Tissue Sarcoma.

OPINION STATEMENT: Soft tissue sarcomas are rare cancers with an expected incidence of about 14,000 new cases in 2018, and account for less than 1% of all cancers. It includes in excess of 75 heterogeneous subtypes with varying biology, molecular aberrations, and variable response to treatment. Because of the rarity of these tumors and the many different subtypes, there is no large-scale data to guide treatment, and hence the need for a multidisciplinary individualized approach to treatment, preferably at a high-volume tertiary referral center. For localized disease, surgery with or without radiation is the preferred treatment. In metastatic disease, the longest track record is with use of anthracyclines, either alone or in combination with ifosfamide, but the median overall survival even with combination was just over a year. There have been recent advances in understanding the heterogeneity of these tumors and the need for an individualized approach. With that new knowledge, recent approvals of trabectedin, eribulin, and pazopanib have been limited to some select histologic subtypes with improved outcomes. More recently, immunotherapy has been tested in select histotypes of sarcoma with encouraging activity and has led to further evaluation in combination with immunotherapeutic agents, as well as with chemotherapy and radiation treatments. Here, in this article, we summarize the data of the currently approved therapies in metastatic soft tissue sarcoma, with the principal focus on first-line therapies. We also review the recent encouraging data with PDGFR-targeted antibody (olaratumab) with doxorubicin which showed an impressive improvement in overall survival in phase II study. Molecular characterization of sarcoma subtypes will likely improve understanding of these very diverse tumors and improve target characterization. The ongoing efforts in better understanding these rare tumors hold the key to make a difference in the outcome of these patients.

Aldoxorubicin therapy for the treatment of patients with advanced soft tissue sarcoma.

Soft tissue sarcomas are a group of rare tumors of mesenchymal origin, and account for less than 1% of all cancers. The most commonly used drug for the treatment of soft tissue sarcoma is anthracycline chemotherapeutic agent, doxorubicin. The major limitation for doxorubicin is cardiotoxicity. Hence, to overcome this limitation and to increase efficacy, aldoxorubicin was developed, which has demonstrated activity in soft tissue sarcomas without much cardiotoxicity. In this review article, we discuss mechanism of action, pharmacokinetics, preclinical studies, clinical trial data and safety profile of aldoxorubicin and its potential applicability in the future of sarcoma treatment.

Eribulin therapy for the treatment of patients with advanced soft tissue sarcoma.

Eribulin is a structurally simplified, synthetic macrocyclic ketone analog of halichondrin B, which is a natural, polyether macrolide derived from marine sponges. Eribulin exerts its cytotoxicity by its unique microtubule dynamics inhibitory action. Eribulin was approved in 2010 by the US FDA as a third-line therapy for metastatic breast cancer patients previously treated with an anthracycline and a taxane. In 2016, it was approved for treatment of metastatic liposarcoma for patients who have progressed with anthracycline treatment. In this article, we review the pharmacokinetics, mechanism of action of eribulin with focus on preclinical and clinical data in sarcoma and also the role of miRNAs in soft tissue sarcomas.

To treat or not to treat: a rare case of pseudo-thrombotic thrombocytopenic purpura in a Jehovah's Witness.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare microvascular occlusive disorder characterized by systemic intravascular aggregation of platelets, thrombocytopenia, and mechanical injury to red blood cells. We report a rare case of pernicious anemia presenting as TTP in a Jehovah's Witness. CASE REPORT: A 46-year-old Jehovah's Witness female presented with epigastric pain, vomiting, and diarrhea for 2 days and fatigue and paresthesias for 4 weeks. Initial laboratory evaluation showed severe anemia and thrombocytopenia with elevated total bilirubin and lactate dehydrogenase. Peripheral blood smear showed schistocytes, macroovalocytes, and hypersegmented neutrophils. TTP was suspected and plasmapheresis was offered. The patient refused it due to her religious beliefs. Due to the presence of macroovalocytes and hypersegmented neutrophils, vitamin B12 level was checked and found to be extremely low. Anti-intrinsic factor antibodies and anti-parietal cell antibodies were also positive; hence a diagnosis of pernicious anemia was established. Treatment with intramuscular vitamin B12 was initiated, which resulted in dramatic neurologic and hematologic improvement. DISCUSSION: Vitamin B12 deficiency can lead to elevated levels of homocysteine in the blood. Homocysteine can cause endothelial dysfunction, which can lead to formation of microvascular thrombi. Due to this phenomenon, vitamin B12 deficiency can rarely present with schistocytes and thrombocytopenia, which combined with other stigmata of vitamin B12 deficiency, can be misdiagnosed as TTP.

Case report: Metastatic refractory undifferentiated small round-cell sarcoma successfully treated with surufatinib and camrelizumab.

Background: Undifferentiated small round-cell sarcomas (uSRCSs) are a subgroup of sarcomas that are difficult to diagnose. Some uSRCSs have specific gene re-arrangements, but others do not. Currently, there is no specific treatments for advanced uSRCSs, and its treatment is largely based on general experience with sarcomas, which includes chemotherapy, targeted therapy, and immunotherapy. In this article, we report a patient with uSRCS who responded to treatment with anti-VEGF inhibitor surufatinib and anti-PD-1 inhibitor camrelizumab after progression on first-line chemotherapy, second-line anlotinib combined with immunotherapy, and third-line chemotherapy. Case description: In July 2020, a 37-year-old female patient was diagnosed with advanced uSRCS. Results for the Ewing sarcoma RNA binding protein 1 and Wilms tumor suppressor (EWSR1/WT1) fusion gene were negative. The patient was also negative with BCOR (BCL6 co-repressor) and CIC (capicua transcriptional repressor) fusion gene. The next-generation sequencing results revealed point mutations on Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Beta (PIK3CB), Transcription Factor Binding To IGHM Enhancer 3 (TFE3), Mucin 16 (MUC16), and AXL (Axl, also called UFO, ARK, and Tyro7, is part of a family of receptor tyrosine kinases). The patient received 4 cycles of the Ifosfamide and epirubicin hydrochloride regimen, and her best objective response was stable disease. On November 3, 2020, a computed tomography (CT) scan revealed progressive disease (PD). Two cycles of camrelizumab (a programmed death-1 inhibitor) plus anlotinib (an anti- vascular endothelial growth factor drug) were administered, but PD was again observed. Thus, a regimen of gemcitabine plus docetaxel was adopted. Unfortunately, the disease progressed once again after two cycles of the treatment. On February 4, 2021, the patient began to receive targeted therapy with surufatinib combined with camrelizumab. A CT scan showed that the tumor achieved a partial response. As of April 2023, the patient had a progression-free survival time of 26 months. Conclusions: Surufatinib in combination with camrelizumab could be effective in the treatment of advanced uSRCSs.

Cardiac Tumors: Review.

Cardiac tumors are rare and encompass a variety of presentations. Clinica symptoms are usually nonspecific, but they can present as obstructive, embolic, or constitutional symptoms. Treatment options and prognosis vary highly depending on the subtype, tumor size, and location. Surgical resection is usually the first-line therapy, except for cardiac lymphomas, and provides favorable long-term prognosis in most benign tumors. Cardiac sarcomas, however, are usually diagnosed in advanced stages, and the treatment relies on a multimodal approach with chemotherapy and radiotherapy. Metastatic cardiac tumors are usually related to advanced disease and carry an overall poor prognosis.

Real-world evidence on efficacy and toxicity of targeted therapy in older melanoma patients treated in a tertiary-hospital setting.

Melanoma is the deadliest form of skin cancer. The median age at diagnosis is 66. While most patients are treated with immunotherapy, the use of targeted therapy is a valid alternative for patients whose tumors harbor a BRAF or c-KIT driver mutation. These agents, while effective, come with a variety of side effects which limit their use, especially in older patients. We sought to assess the efficacy and toxicity of these agents in older melanoma patients. Melanoma patients over 65 treated with BRAF/MEK or c-KIT inhibitors were retrospectively identified, and their data were analyzed for treatment efficacy and toxicity. All data were compared using the Chi-square test for categorical comparisons and the Kruskal-Wallis method for median comparisons. One hundred and sixteen patients were identified. One hundred and six patients were treated with BRAF/MEK inhibitors. The assessed response rate (RR) was 83% and was comparable across different subgroups, including advanced line patients and those with a more aggressive disease. The median progression free survival (PFS) was 7.9 months, and the median overall survival (OS) was 15.7 months. Twenty-seven percent experienced grade 3-4 toxicity leading to a 24% treatment discontinuation rate. Another 10 patients were treated with the c-KIT inhibitor imatinib, for whom the assessed RR was 55%. The median PFS was 4.3 months, and the median OS was 22.6 months. Forty percent needed dose reductions, yet none had to stop treatment due to adverse effects. The use of targeted therapy in older patients is effective yet challenging due to toxicity. Deploying mitigation strategies can help maximizing their usefulness.

A Phase I Study of sequences of the CDK4/6 Inhibitor, Ribociclib Combined with Gemcitabine in Patients with Advanced Solid Tumors.

Background: Based on preclinical data showing addition of CDK4/6 inhibitors to gemcitabine is synergistic, ribociclib was evaluated in combination with gemcitabine to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT). Methods: In this single arm multicohort phase I trial, we evaluated the safety and efficacy of Ribociclib plus Gemcitabine in patients with advanced solid tumors. Patients received Gemcitabine intravenously on days 1 and 8 followed by Ribociclib days 8-14, with treatment repeated every 3 weeks. Results: The study enrolled 43 patients between October 2017 and September 2019. The escalation phase (19 patients) determined the MTD and recommended phase II dose (RP2D) to be ribociclib 800mg daily and gemcitabine 1000mg/m2 for the expansion phase (24 patients). One patient experienced Grade 4 thrombocytopenia. Eleven patients experienced Grade 3 adverse events (AE), the most common being neutropenia, thrombocytopenia, and anemia. No partial or complete responses were observed. 15/22 (68%) of efficacy evaluable patients who received the MTD achieved best response of stable disease. Conclusions: The addition of Ribociclib to Gemcitabine was tolerated well and yielded stability of tumors in both cohorts. Ribociclib and gemcitabine could have synergistic activity in certain tumor types, and our data provides support for the combination. Clinical Trial Registration: NCT03237390.

Multi-modal efficacy of a chimeric vesiculovirus expressing the Morreton glycoprotein in sarcoma.

Vesiculoviruses are attractive oncolytic virus platforms due to their rapid replication, appreciable transgene capacity, broad tropism, limited preexisting immunity, and tumor selectivity through type I interferon response defects in malignant cells. We developed a synthetic chimeric virus (VMG) expressing the glycoprotein (G) from Morreton virus (MorV) and utilizing the remaining structural genes from vesicular stomatitis virus (VSV). VMG exhibited in vitro efficacy by inducing oncolysis in a broad range of sarcoma subtypes across multiple species. Notably, all cell lines tested showed the ability of VMG to yield productive infection with rapid replication kinetics and induction of apoptosis. Furthermore, pilot safety evaluations of VMG in immunocompetent, non-tumor-bearing mice showed an absence of toxicity with intranasal doses as high as 1e10 50% tissue culture infectious dose (TCID50)/kg. Locoregional administration of VMG in vivo resulted in tumor reduction in an immunodeficient Ewing sarcoma xenograft at doses as low as 2e5 TCID50. In a murine syngeneic fibrosarcoma model, while no tumor inhibition was achieved with VMG, there was a robust induction of CD8+ T cells within the tumor. The studies described herein establish the promising potential for VMG to be used as a novel oncolytic virotherapy platform with anticancer effects in sarcoma.

The Midwest Sarcoma Trials Partnership: Bridging Academic and Community Networks in a Collaborative Approach to Sarcoma.

The treatment of sarcoma necessitates a collaborative approach, given its rarity and complex management. At a single institution, multidisciplinary teams of specialists determine and execute treatment plans involving surgical, radiation, and medical management. Treatment guidelines for systemic therapies in advanced or nonresectable soft tissue sarcoma have advanced in recent years as new immunotherapies and targeted therapies become available. Collaboration between institutions is necessary to facilitate accrual to clinical trials. Here, we describe the success of the Midwest Sarcoma Trials Partnership (MWSTP) in creating a network encompassing large academic centers and local community sites. We propose a new model utilizing online platforms to expand the reach of clinical expertise for the treatment of advanced soft tissue sarcoma.

Phase II Study of Olaparib and Temozolomide for Advanced Uterine Leiomyosarcoma (NCI Protocol 10250).

PURPOSE: Uterine leiomyosarcoma (uLMS) is an aggressive subtype of soft-tissue sarcoma with frequent metastatic relapse after curative surgery. Chemotherapy provides limited benefit for advanced disease. Multiomics profiling studies have identified homologous recombination deficiency in uLMS. In preclinical studies where olaparib and temozolomide provided modest activity, the combination was highly effective for inhibiting uLMS tumor growth. PATIENTS AND METHODS: NCI Protocol 10250 is a single-arm, open-label, multicenter, phase II study evaluating olaparib and temozolomide in advanced uLMS. Patients with progression on ≥1 prior line received temozolomide 75 mg/m2 orally once daily with olaparib 200 mg orally twice a day both on days 1-7 in 21-day cycles. The primary end point was the best objective response rate (ORR) within 6 months. A one-stage binomial design was used. If ≥5 of 22 responded, the treatment would be considered promising (93% power; α = .06). All patients underwent paired biopsies that were evaluated with whole-exome sequencing (WES)/RNAseq and a RAD51 foci formation assay. RESULTS: Twenty-two patients were evaluable. The median age was 55 years, and 59% had received three or more prior lines. Best ORR within 6 months was 23% (5 of 22). The overall ORR was 27% (6 of 22). The median progression-free survival (mPFS) was 6.9 months (95% CI, 5.4 months to not estimable). Hematologic toxicity was common (grade 3/4 neutropenia: 75%; thrombocytopenia: 32%) but manageable with dose modification. Five of 16 (31%) of tumors contained a deleterious homologous recombination gene alteration by WES, and 9 of 18 (50%) were homologous recombination-deficient by the RAD51 assay. In an exploratory analysis, mPFS was prolonged for patients with homologous recombination-deficient versus homologous recombination-proficient tumors (11.2 v 5.4 months, P = .05) by RAD51. CONCLUSION: Olaparib and temozolomide met the prespecified primary end point and provided meaningful clinical benefit in patients with advanced, pretreated uLMS.

DNA methylation analysis of ALOX12 and GSTM1 in acute myeloid leukaemia identifies prognostically significant groups.

To determine the role of DNA methylation in the progression of acute myeloid leukaemia (AML), we analysed the methylation status of ALOX12, GSTM1, HS3ST2 and FZD9 in 127 AML patients. Aberrant methylation of ALOX12 was associated with the subcategory AML with myelodysplasia-related changes (P = 0·0439) and specifically with megakaryocytic dysplasia (P = 0·0003). An association between HS3ST2 and AML patients with favourable cytogenetic risk was identified (P = 0·0469). In univariate and multivariate analysis, methylation of GSTM1 was associated with worse overall survival (OS) and disease-free survival (DFS), with hazard ratios of 2·57 and 1·86, respectively. Furthermore, the significance of methylation of GSTM1 in predicting poor prognosis was maintained within the subcategories of AML not otherwise specified (NOS), AML with intermediate cytogenetic risk and normal karyotype AML. Finally, patients with both GSTM1 and ALOX12 methylated, demonstrated worse outcomes when all AML patients were assessed (OS; P = 0·000411) as well as within AML NOS (DFS; P = 0·0023), AML with intermediate cytogenetic risk (OS; P = 0·0104) and normal karyotype AML (OS; P = 0·00636). This study implicates methylation of specific genes in the classification and prognostication of AML and suggests that the morphological feature of multilineage dysplasia may be a surrogate marker of gene methylation in at least a subset of AML cases.

Pulmonary Artery Angiomatoid Fibrous Histiocytoma Mimicking a Large Pulmonary Embolism.

ABSTRACT: A 39-year-old man presented with progressive dyspnea and lower extremity edema. Doppler ultrasound demonstrated bilateral leg partially occluded venous thromboses. A V/Q scan revealed a mismatched perfusion defect involving the entire right middle and lower lobes. Subsequent CT pulmonary angiogram revealed a mass lesion occluding the right interlobar pulmonary artery. Endobronchial ultrasound-guided fine-needle aspiration of the mass was concerning for neoplasm. 18 F-FDG PET/CT demonstrated marked hypermetabolism of the mass lesion. Patient underwent transmediastinal right pneumonectomy with histopathologic diagnosis of pulmonary artery angiomatoid fibrous histiocytoma, a rare etiology mimicking large pulmonary artery embolism.

Early Experience Using Proton Beam Therapy for Extremity Soft Tissue Sarcoma: A Multicenter Study.

Purpose: Proton beam therapy (PBT) may provide an advantage when planning well-selected patients with extremity soft tissue sarcoma (eSTS), specifically for large, anatomically challenging cases. We analyzed our early experience with PBT on toxicity and outcomes. Materials and Methods: A retrospective study was performed for eSTS treated between June 2016 and October 2020 with pencil beam scanning PBT at 2 institutions. Diagnostic, treatment, and toxicity characteristics were gathered from baseline to last follow-up or death. Wound complications were defined as secondary operations for wound repair (debridement, drainage, skin graft, and muscle flap) or nonoperative management requiring hospitalization. Statistical analysis was performed with R software. Results: Twenty consecutive patients with a median age 51.5 years (range, 19-78 years) were included. Median follow-up was 13.7 months (range, 1.7-48.1 months). Tumor presentation was primary (n = 17) or recurrent after prior combined modality therapy (n = 3). Tumor location was either lower extremity (n = 16) or upper extremity (n = 4). Radiation was delivered preoperatively in most patients (n = 18). Median pretreatment tumor size was 7.9 cm (range, 1.3 -30.0 cm). The 1-year locoregional control was 100%. Four patients (20%) had developed metastatic disease by end of follow-up. Maximum toxicity for acute dermatitis was grade 2 in 8 patients (40%) and grade 3 in 3 patients (15%). After preoperative radiation and surgical resection, acute wound complications occurred in 6 patients (35%). Tumor size was larger in patients with acute wound complications compared with those without (medians 16 cm, range [12-30.0 cm] vs 6.3 cm, [1.3-14.4 cm], P = .003). Conclusion: PBT for well selected eSTS cases demonstrated excellent local control and similar acute wound complication rate comparable to historic controls. Long-term follow-up and further dosimetric analyses will provide further insight into potential advantages of PBT in this patient population.

Pan-cancer efficacy of pralsetinib in patients with RET fusion-positive solid tumors from the phase 1/2 ARROW trial.

Oncogenic RET fusions occur in diverse cancers. Pralsetinib is a potent, selective inhibitor of RET receptor tyrosine kinase. ARROW ( NCT03037385 , ongoing) was designed to evaluate pralsetinib efficacy and safety in patients with advanced RET-altered solid tumors. Twenty-nine patients with 12 different RET fusion-positive solid tumor types, excluding non-small-cell lung cancer and thyroid cancer, who had previously received or were not candidates for standard therapies, were enrolled. The most common RET fusion partners in 23 efficacy-evaluable patients were CCDC6 (26%), KIF5B (26%) and NCOA4 (13%). Overall response rate, the primary endpoint, was 57% (95% confidence interval, 35-77) among these patients. Responses were observed regardless of tumor type or RET fusion partner. Median duration of response, progression-free survival and overall survival were 12 months, 7 months and 14 months, respectively. The most common grade ≥3 treatment-related adverse events were neutropenia (31%) and anemia (14%). These data validate RET as a tissue-agnostic target with sensitivity to RET inhibition, indicating pralsetinib's potential as a well-tolerated treatment option with rapid, robust and durable anti-tumor activity in patients with diverse RET fusion-positive solid tumors.

Dual checkpoint targeting of B7-H3 and PD-1 with enoblituzumab and pembrolizumab in advanced solid tumors: interim results from a multicenter phase I/II trial.

BACKGROUND: Availability of checkpoint inhibitors has created a paradigm shift in the management of patients with solid tumors. Despite this, most patients do not respond to immunotherapy, and there is considerable interest in developing combination therapies to improve response rates and outcomes. B7-H3 (CD276) is a member of the B7 family of cell surface molecules and provides an alternative immune checkpoint molecule to therapeutically target alone or in combination with programmed cell death-1 (PD-1)-targeted therapies. Enoblituzumab, an investigational anti-B7-H3 humanized monoclonal antibody, incorporates an immunoglobulin G1 fragment crystallizable (Fc) domain that enhances Fcγ receptor-mediated antibody-dependent cellular cytotoxicity. Coordinated engagement of innate and adaptive immunity by targeting distinct members of the B7 family (B7-H3 and PD-1) is hypothesized to provide greater antitumor activity than either agent alone. METHODS: In this phase I/II study, patients received intravenous enoblituzumab (3-15 mg/kg) weekly plus intravenous pembrolizumab (2 mg/kg) every 3 weeks during dose-escalation and cohort expansion. Expansion cohorts included non-small cell lung cancer (NSCLC; checkpoint inhibitor [CPI]-naïve and post-CPI, programmed death-ligand 1 [PD-L1] <1%), head and neck squamous cell carcinoma (HNSCC; CPI-naïve), urothelial cancer (post-CPI), and melanoma (post-CPI). Disease was assessed using Response Evaluation Criteria in Solid Tumors version 1.1 after 6 weeks and every 9 weeks thereafter. Safety and pharmacokinetic data were provided for all enrolled patients; efficacy data focused on HNSCC and NSCLC cohorts. RESULTS: Overall, 133 patients were enrolled and received ≥1 dose of study treatment. The maximum tolerated dose of enoblituzumab with pembrolizumab at 2 mg/kg was not reached. Intravenous enoblituzumab (15 mg/kg) every 3 weeks plus pembrolizumab (2 mg/kg) every 3 weeks was recommended for phase II evaluation. Treatment-related adverse events occurred in 116 patients (87.2%) and were grade ≥3 in 28.6%. One treatment-related death occurred (pneumonitis). Objective responses occurred in 6 of 18 (33.3% [95% CI 13.3 to 59.0]) patients with CPI-naïve HNSCC and in 5 of 14 (35.7% [95% CI 12.8 to 64.9]) patients with CPI-naïve NSCLC. CONCLUSIONS: Checkpoint targeting with enoblituzumab and pembrolizumab demonstrated acceptable safety and antitumor activity in patients with CPI-naïve HNSCC and NSCLC. TRIAL REGISTRATION NUMBER: NCT02475213.