Anderson, Peter M.

Abstract Purpose: Tilsotolimod is an investigational synthetic Toll-like receptor 9 (TLR9) agonist that has demonstrated antitumor activity in preclinical models. The ILLUMINATE-101 phase I study explored the safety, dose, efficacy, and immune effects of intratumoral (it) tilsotolimod monotherapy in multiple solid tumors. Patients and Methods: Patients with a diagnosis of refractory cancer not amenable to curative therapies received tilsotolimod in doses escalating from 8 to 32 mg into a single lesion at weeks 1, 2, 3, 5, 8, and 11. Additional patients with advanced malignant melanoma were enrolled into an expansion cohort at the 8 mg dose. Objectives included characterizing the safety, establishing the dose, efficacy, and immunologic assessment. Blood samples and tumor biopsies of injected and noninjected lesions were obtained at baseline and 24 hours after treatment for immune analyses. Results: Thirty-eight and 16 patients were enrolled into the dose escalation and melanoma expansion cohorts, respectively. Deep visceral injections were conducted in 91% of patients. No dose-limiting toxicities (DLT) or grade 4 treatment-related adverse events were observed. Biopsies 24 hours after treatment demonstrated an increased IFN pathway signature and dendritic cell maturation. Immunologic profiling revealed upregulation of IFN-signaling genes and modulation of genes for checkpoint proteins. In the dose escalation cohort, 12 (34%) of 35 evaluable patients achieved a best overall response rate (ORR) of stable disease (SD), whereas 3 (19%) of 16 evaluable patients in the melanoma cohort achieved stable disease. Conclusions: Overall, tilsotolimod monotherapy was generally well tolerated and induced rapid, robust alterations in the tumor microenvironment. See related commentary by Punekar and Weber, p. 5007

AbstractAlthough monoclonal antibody (MoAb) therapy of the human malignant lymphomas has shown success in clinical trials, its full potential for the treatment of hematologic malignancies has yet to be realized. To expand the clinical potential of a promising human-mouse chimeric antihuman B-cell MoAb (chCLL-1) constructed using the variable domains cloned from the murine Lym-2 (muLym-2) hybridoma, fusion proteins containing granulocyte-macrophage colony-stimulating factor (GM-CSF) (chCLL-1/GM–CSF) or interleukin (IL)-2 (chCLL-1/IL–2) were generated and evaluated for in vitro cytotoxicity and in vivo tumor targeting. The glutamine synthetase gene amplification system was employed for high level expression of the recombinant fusion proteins. Antigenic specificity was confirmed by a competition radioimmunoassay against ARH-77 human myeloma cells. The activity of chCLL-1/GM–CSF was established by a colony formation assay, and the bioactivity of chCLL-1/IL–2 was confirmed by supporting the growth of an IL-2–dependent T-cell line. Antibody-dependent cellular cytotoxicity against ARH-77 target cells demonstrated that both fusion proteins mediate enhanced tumor cell lysis by human mononuclear cells. Finally, biodistribution and imaging studies in nude mice bearing ARH-77 xenografts indicated that the fusion proteins specifically target the tumors. These in vitro and in vivo data suggest that chCLL-1/GM–CSF and chCLL-1/IL–2 have potential as immunotherapeutic reagents for the treatment of B-cell malignancies.

PURPOSE: Samarium-153 ethylene diamine tetramethylene phosphonate (153Sm-EDTMP), a bone-seeking radiopharmaceutical, provides therapeutic irradiation to osteoblastic bone metastases. Because the dose-limiting toxicity of 153Sm-EDTMP is thrombocytopenia, a dose-escalation trial using peripheral-blood progenitor cells (PBPCs) or marrow support was conducted to treat metastatic bone cancer. PATIENTS AND METHODS: Patients with locally recurrent or metastatic osteosarcoma or skeletal metastases avid on bone scan were treated with 1, 3, 4.5, 6, 12, 19, or 30 mCi/kg of 153Sm-EDTMP. RESULTS: Thirty patients were treated with 153Sm-EDTMP. Transient symptoms of hypocalcemia were seen at 30 mCi/kg. Estimates of radioisotope bound to bone surfaces and marrow radiation dose were linear with injected amount of 153Sm-EDTMP. Cytopenias also occurred in all subjects and were dose-related. At day +13 after 153Sm-EDTMP, residual whole-body radioactivity was 1% to 65% of whole-body radioactivity considered safe for PBPC infusion, 3.6 mCi. After PBPC or marrow infusion on day +14 after 153Sm-EDTMP, recovery of hematopoiesis was problematic in two patients at the 30 mCi/kg dose infused with less than 2 × 106 CD34+/kg on day +14, but not in other patients. Reduction or elimination of opiates for pain was seen in all patients. Patients had no adverse changes in appetite or performance status. CONCLUSION: 153Sm-EDTMP with PBPC support can provide bone-specific therapeutic irradiation (estimates of 39 to 241 Gy). Hematologic toxicity at 30 mCi 153Sm-EDTMP/kg requires PBPC grafts with more than 2 × 106 CD34+/kg to overcome myeloablative effects of skeletal irradiation. Nonhematologic side effects are minimal.

Abstract Background Thyroid carcinoma, which is rare in pediatric patients (age 0–18 years) but more common in adolescent and young adult (AYA) patients (age 15–39 years), carries the potential for morbidity and mortality. Methods Hybrid-capture-based comprehensive genomic profiling (CGP) was performed prospectively on 512 consecutively submitted thyroid carcinomas, including 58 from pediatric and AYA (PAYA) patients, to identify genomic alterations (GAs), including base substitutions, insertions/deletions, copy number alterations, and rearrangements. This PAYA data series includes 41 patients with papillary thyroid carcinoma (PTC), 3 with anaplastic thyroid carcinoma (ATC), and 14 with medullary thyroid carcinoma (MTC). Results GAs were detected in 93% (54/58) of PAYA cases, with a mean of 1.4 GAs per case. In addition to BRAF V600E mutations, detected in 46% (19/41) of PAYA PTC cases and in 1 of 3 AYA ATC cases, oncogenic fusions involving RET, NTRK1, NTRK3, and ALK were detected in 37% (15/41) of PAYA PTC and 33% (1/3) of AYA ATC cases. Ninety-three percent (13/14) of MTC patients harbored RET alterations, including 3 novel insertions/deletions in exons 6 and 11. Two of these MTC patients with novel alterations in RET experienced clinical benefit from vandetanib treatment. Conclusion CGP identified diverse clinically relevant GAs in PAYA patients with thyroid carcinoma, including 83% (34/41) of PTC cases harboring activating kinase mutations or activating kinase rearrangements. These genomic observations and index cases exhibiting clinical benefit from targeted therapy suggest that young patients with advanced thyroid carcinoma can benefit from CGP and rationally matched targeted therapy.

Abstract Although interleukin 2 (IL-2) has been associated with modest anti-tumour responses in man, treatment-related toxicity has limited its widespread use. The local delivery of liposomal formulations of interleukin 2 to the lung as aerosols has been demonstrated to be non-toxic, biologically active, and associated with regression of spontaneous pulmonary metastases in dogs. This study was undertaken to evaluate the physical and biological characteristics of nebulized interleukin 2 liposomes. The aerosol droplet size distribution and the physical stability of interleukin 2 liposomes were examined in-vitro using an Andersen cascade impactor and studies of liposome entrapment of interleukin 2 before and after nebulization. The biological stability of interleukin 2 liposomes after nebulization was demonstrated using the CTLL-2 bioassay for interleukin 2. In-vivo studies of pulmonary biodistribution and clearance of inhaled technetium (99mTc)-labelled interleukin 2 liposomes were undertaken in a normal dog. Aerosols of free interleukin 2 and of interleukin 2 liposomes were compared in both in-vitro and in-vivo experiments. The mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of interleukin 2 liposomes were 1–98 μm and 202, respectively. Independent analysis of aerosol particle-size distribution using the constitutive components of the interleukin 2 liposomes (interleukin 2: lipid: HSA) demonstrated a close correlation of size distributions (r = 0.9445; P < 0.001). The entrapment of interleukin 2 in liposomes was 93 ± 4.3% before nebulization and 90 ± 8.9% after. After delivery to an anaesthetized dog, interleukin 2 liposome aerosols were deposited evenly throughout the lung (mean ± s.d. central lung-to-peripheral lung deposition was 1–12 ± 0.03). After approximately 24 h inhalation, interleukin 2 liposomes were retained within the lung and were taken up in part by the spleen. The results of this study are indicative of the stability of this interleukin 2 liposome formulation to nebulization. Such nebulization might be an attractive immunotherapeutic strategy for treatment of pulmonary metastases and primary lung cancers.

Abstract Purpose: Osteosarcoma most commonly recurs in the lung. Based on preliminary data on the antitumor effects of granulocyte-macrophage colony stimulating factor (GM-CSF) in animal models, and promising phase I trials, we embarked on a feasibility study of inhaled GM-CSF in patients with first isolated pulmonary recurrence of osteosarcoma. Experimental Design: Forty-three eligible patients received inhaled GM-CSF at doses from 250 to 1,750 μg twice daily on alternate weeks. Following two cycles, patients underwent thoracotomy to resect tumor and analyze pulmonary nodules for expression of Fas/Fas ligand (Fas/FasL), and the presence of dendritic cells by immunostaining for CD1a, clusterin, and S100. Following surgery, patients received 12 additional cycles of therapy on alternating weeks or until progression. Event-free survival and survival, and feasibility of therapy delivery were evaluated. Results: Dose escalation to 1,750 μg twice daily was feasible with no dose-limiting toxicity. Mean scores for Fas/FasL in nodules from patients with bilateral recurrence who underwent unilateral thoracotomy pretreatment (using a scoring system of 0-3) were 1.3 and 0.88, respectively, compared with 0.78 and 0.62 in nodules resected following two cycles of therapy. Only 11 of 30 nodules postinhalation were positive for CD1a, 4 of 30 for S100, and 6 of 30 for clusterin. Event-free and overall survival at 3 years were 7.8% and 35.4%, respectively. Conclusions: Inhalation of GM-CSF at doses from 250 to 1,750 μg twice daily on alternate weeks was feasible with low toxicity. However, no detectable immunostimulatory effect in pulmonary metastases or improved outcome postrelapse was seen. Clin Cancer Res; 16(15); 4024–30. ©2010 AACR.

Abstract Osteoblastic metastases and osteosarcoma can avidly concentrate bone-seeking radiopharmaceuticals. We sought to increase effectiveness of high-dose 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP, Quadramet) on osteosarcomas using a radiosensitizer, gemcitabine. Fourteen patients with osteoblastic lesions were treated with 30 mCi/kg 153Sm-EDTMP. Gemcitabine was administered 1 day after samarium infusion. Residual total body radioactivity was within the safe range of <3.6 mCi on day +14 (1.1 ± 0.4 mCi; range, 0.67-1.8 mCi). All patients received autologous stem cell reinfusion 2 weeks after 153Sm to correct expected grade 4 hematopoietic toxicity. Peripheral blood progenitor cells were infused in 11 patients; three patients had marrow infused. Blood count recovery was uneventful after peripheral blood progenitor cells in 11 of 11 patients. Toxicity from a single infusion of gemcitabine (1,500 mg/m2) in combination with 153Sm-EDTMP was minimal (pancytopenia). However, toxicity from a daily gemcitabine regimen (250 mg/m2/d × 4-5 days) was excessive (grade 3 mucositis) in one of two patients. There were no reported episodes of hemorrhagic cystitis (hematuria) or nephrotoxicity. At the 6- to 8-week follow-up, there were six partial remissions, two mixed responses, and six patients with progressive disease. In the 12 patients followed >1 year, there have been no durable responses. Thus, although high-dose 153Sm-EDTMP + gemcitabine has moderate palliative activity (improved pain; radiologic responses) in this poor-risk population, additional measures of local and systemic control are required for durable control of relapsed osteosarcoma with osteoblastic lesions. The strategy of radioactive drug binding to a target followed by a radiosensitizer may provide synergy and improved response rate.