DeltaRex-G, tumor targeted retrovector encoding a CCNG1 inhibitor, for CAR-T cell therapy induced cytokine release syndrome.

Cytokine release syndrome is a serious complication of chimeric antigen receptor-T cell therapy and is triggered by excessive secretion of inflammatory cytokines by chimeric T cells which could be fatal. Following an inquiry into the molecular mechanisms orchestrating cytokine release syndrome, we hypothesize that DeltaRex-G, a tumor targeted retrovector encoding a cytocidal CCNG1 inhibitor gene, may be a viable treatment option for corticosteroid-resistant cytokine release syndrome. DeltaRex-G received United States Food and Drug Administration Emergency Use Authorization to treat Covid-19-induced acute respiratory distress syndrome, which is due to hyperactivated immune cells. A brief administration of DeltaRex-G would inhibit a certain proportion of hyperactive chimeric T cells, consequently reducing cytokine release while retaining chimeric T cell efficacy.

Proceedings of the Think Tank for Osteosarcoma Medical Advisory Board.

A "Think Tank for Osteosarcoma" medical advisory board meeting was held in Santa Monica, CA, USA on February 2-3, 2024. The goal was to develop a strategic approach to prevent recurrence of osteosarcoma. Osteosarcoma metabolism and the genomic instability of osteosarcoma, immunotherapy for osteosarcoma, CAR-T cell therapy, DeltaRex-G tumor-targeted gene therapy, repurposed drugs, alternative medicines, and personalized medicine were discussed. Only DeltaRex-G was voted on. The conclusions were the following: No intervention has been demonstrated to improve survival in a clinical trial. Additionally, the consensus (10/12 in favor) was that DeltaRex-G without immunotherapy may be administered for up to one year. Phase 2/3 randomized studies of DeltaRex-G should be performed to determine whether the incidence of recurrence could be reduced in high-risk individuals. Furthermore, a personalized approach using drugs with minimal toxicity could be attempted with the acknowledgement that there are no efficacy data to base this on. Repurposed drugs and alternative therapies should be tested in mouse models of osteosarcoma. Moreover, unmodified IL-2 primed Gamma Delta (NK) cell therapy may be used to prevent recurrence. Lastly, rapid development of CAR-T cell therapy is recommended, and an institute dedicated to the study of osteosarcoma is needed.

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.

The advent of a pan-collagenous CLOVIS POINT for pathotropic targeting and cancer gene therapy, a retrospective.

The 'Clovis Point'-an enabling prehistoric gain-of-function in stone-age tool technologies which empowered the Paleoindian-Americans to hunt, to strike-deep, and to kill designated target megafauna more efficiently-was created biochemically by molecular-genetic bio-engineering. This Biomedical "Clovis Point" was crafted by adapting a broad-spectrum Pan-Collagen Binding Domain (Pan-Coll/CBD) found within the immature pre-pro-peptide segment of Von Willebrand Factor into a constructive series of advanced medical applications. Developed experimentally, preclinically, and clinically into a cutting-edge Biotechnology Platform, the Clovis Point is suitable for 1) solid-state binding of growth factors on collagenous scaffolds for improved orthopedic wound healing, 2) promoting regeneration of injured/diseased tissues; and 3) autologous stem cell capture, expansion, and gene-based therapies. Subsequent adaptations of the high-affinity Pan-Coll/CBD (exposed-collagen-seeking/surveillance function) for intravenous administration in humans, enabled the physiological delivery, aka Pathotropic Targeting to diseased tissues via the modified envelopes of gene vectors; enabling 4) precision tumor-targeting for cancer gene therapy and 5) adoptive/localized immunotherapies, demonstrating improved long-term survival value-thus pioneering a proximal and accessible cell cycle control point for cancer management-empowering modern medical oncologists to address persistent problems of chemotherapy resistance, recurrence, and occult progression of metastatic disease. Recent engineering adaptations have advanced the clinical utility to include the targeted delivery of small molecule APIs: including taxanes, mAbs, and RNA-based therapeutics.

Phase I-II study using DeltaRex-G, a tumor-targeted retrovector encoding a cyclin G1 inhibitor for metastatic carcinoma of breast.

Background: Metastatic breast cancer is associated with a poor prognosis and therefore, innovative therapies are urgently needed. Here, we report on the results of a Phase I-II study using DeltaRex-G for chemotherapy resistant metastatic carcinoma of breast. Patients and Methods: Endpoints: Dose limiting toxicity; Antitumor activity. Eligibility: ≥18 years of age, pathologic diagnosis of breast carcinoma, adequate hematologic and organ function. Treatment: Dose escalation of DeltaRex-G 1-4 x 1011cfu intravenously thrice weekly x 4 weeks with 2-week rest period. Treatment cycles repeated if there is ≤ Grade 1 toxicity until disease progression or unacceptable toxicity. Safety: NCI CTCAE v3 for adverse events reporting, vector related testing. Efficacy: RECIST v1.0, International PET criteria and Choi criteria for response, progression free and overall survival. Results: Twenty patients received escalating doses of DeltaRex-G from 1 × 1011 cfu to 4 × 1011 cfu thrice weekly for 4 weeks with a 2-week rest period. Safety: ≥ Grade 3 treatment-related adverse event: pruritic rash (n = 1), no dose limiting toxicity, no replication-competent retrovirus, nor vector-neutralizing antibodies detected. No vector DNA integration was observed in peripheral blood lymphocytes evaluated. Efficacy: by RECIST v1.0: 13 stable disease, 4 progressive disease; tumor control rate 76%; by PET and Choi Criteria: 3 partial responses, 11 stable disease, 3 progressive disease; tumor control rate 82%. Combined median progression free survival by RECIST v1.0, 3.0 months; combined median overall survival, 20 months; 1-year overall survival rate 83% for Dose Level IV. Biopsy of residual tumor in a participant showed abundant CD8+ killer T-cells and CD45+ macrophages suggesting an innate immune response. Two patients with pure bone metastases had >12-month progression free survival and overall survival and are alive 12 years from the start of DeltaRex-G therapy. These patients further received DeltaRex-G + DeltaVax for 6 months. Conclusion: Taken together, these data indicate that 1) DeltaRex-G has a distinctively high level of safety and exhibits anti-cancer activity, 2) PET/Choi provide a higher level of sensitivity in detecting early signs of tumor response to DeltaRex-G, 3) DeltaRex-G induced 12- year survival in 2 patients with pure bone metastases who subsequently received DeltaVax immunotherapy, and 4) DeltaRex-G may prove to be a biochemical and/or immune modulator when combined with other cancer therapy/immunotherapy.

A Phase I/II Investigation of Safety and Efficacy of Nivolumab and nab-Sirolimus in Patients With a Variety of Tumors With Genetic Mutations in the mTOR Pathway.

BACKGROUND/AIM: Advanced sarcoma has a poor prognosis. Dysregulation of the mammalian target of rapamycin (mTOR) occurs in various types of cancer. We aimed to determine the safety and efficacy of mTOR inhibitor nab-sirolimus when combined with the immune checkpoint inhibitor nivolumab. PATIENTS AND METHODS: Previously treated patients ≥18 years with confirmed diagnosis of advanced sarcoma or tumor with mutations in the mTOR pathway were treated with 3 mg/kg nivolumab intravenously every 3 weeks; escalating doses of nab-sirolimus at 56, 75 or 100 mg/m2 were administered intravenously on days 8 and 15 beginning in cycle 2. The primary aim was to determine the maximum-tolerated dose; we also determined disease control, objective response, progression-free survival, overall survival, and correlation between response using Immune-related Response Evaluation Criteria for Solid Tumors (irRECIST) versus RECIST v1.1. RESULTS: The maximum-tolerated dose was 100 mg/m2 There were two patients with partial response, 12 with stable disease and 11 with progressive disease. Median progression-free and overall survival were 12 and 47 weeks, respectively. The best responders (partial responses) were patients with undifferentiated pleomorphic sarcoma with loss of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), tuberous sclerosis complex 2 (TSC2) mutation and estrogen receptor-positive leiomyosarcoma. Treatment-related adverse events of grade 3 or more included thrombocytopenia, oral mucositis, rash, hyperlipidemia and increased serum alanine aminotransferase. CONCLUSION: The data indicate that (i) treatment with nivolumab plus nab-sirolimus is safe with no unexpected adverse events; (ii) treatment outcome parameters were not improved by combining nivolumab with nab-sirolimus; and (iii) best responders were patients with undifferentiated pleomorphic sarcoma with PTEN loss and TSC2 mutation and estrogen receptor-positive leiomyosarcoma. Future direction in sarcoma research with nab-sirolimus will be biomarker-based (TSC1/2/mTOR, tumor mutational burden/mismatch repair deficiency etc.).

Early-stage CCNG1+ HR+ HER2+ Invasive Breast Carcinoma in Older Women: Current Treatment and Future Perspectives for DeltaRex-G, a CCNG1 Inhibitor.

Women with HR+HER2+ early-stage breast cancer are disadvantaged by the lack of clinical trials focused on women ≥70 years of age. In the past years, there has been increasing controversy on the use of toxic chemotherapy as standard of care treatment for early- stage HR+ HER2+ breast carcinoma in older women. With precision medicine coming of age, molecular profiling of tumors and circulating tumor DNA has identified target oncogenes that could be used in designing an optimal treatment for this group of women. This article reviews the current treatment of early-stage triple receptor positive breast cancer, the risks of chemotherapy in older women, and CCNG1, a novel biomarker in development for the use of DeltaRex-G, a CCNG1 inhibitor. Further, future perspectives for DeltaRex-G in older women with early stage CCNG1+ HR+ HER2+ breast cancer are discussed.

Activity of TNT: a phase 2 study using talimogene laherparepvec, nivolumab and trabectedin for previously treated patients with advanced sarcomas (NCT# 03886311).

Background: Intratumoral injection of talimogene laherparepvec evokes a cytotoxic immune response. Therefore, the combination of talimogene laherparepvec with trabectedin and nivolumab may have synergistic effects in advanced sarcomas. Patients and methods: This phase 2 trial was conducted from May 30, 2019 to January 31, 2022. Endpoints: Primary: Progression free survival rate at month 12. Secondary: Best overall response, progression free survival rate at 6 and 9 months, overall survival rate at 6, 9, and 12 months, incidence of conversion of an unresectable tumor to a resectable tumor, and incidence of adverse events. Eligible patients had to be ≥ 18 years of age, have advanced histologically proven sarcoma, at least 1 previous chemotherapy regimen, and at least one accessible tumor for intratumoral injection. Treatment: Trabectedin intravenously (1.2 mg/m2 q3 weeks), nivolumab intravenously (3 mg/kg q2 weeks), and intratumoral talimogene laherparepvec (1x108 plaque forming units/ml q2 weeks). Results: Median time of follow-up: 15.2 months. Efficacy analysis: Thirty-nine patients who had completed at least one treatment cycle and had a follow-up computerized tomography were evaluable for efficacy analysis. Median number of prior therapies: 4 (range 1-11). Progression free survival rate at month 12, 36.7%. Confirmed Best Overall Response by Response Evaluation Criteria in Solid Tumors v1.1 = 3 partial responses, 30 stable disease, 6 progressive disease. Best Overall Response Rate, 7.7%, Disease Control Rate, 84.6%; median progression free survival, 7.8 (95% Confidence Intervals: 4.1-13.1) months; 6-, 9-, 12-month progression free survival rates, 54.5%/45.9%/36.7%; median overall survival 19.3 (95% Confidence Intervals: 12.8 -.) months; 6-, 9- and 12-month overall survival rate, 86.9%/73.3%/73.3%. One patient had a complete surgical resection. Fifty percent of patients had a ≥ grade 3 treatment related adverse events which included anemia (6%), thrombocytopenia (6%), neutropenia (4%), increased alanine transaminase (4%), decreased left ventricular ejection fraction (4%), dehydration (4%), hyponatremia (4%). Conclusions: Taken together these data suggest that the TNT regimen is effective and safe for advanced previously treated sarcomas, and is worth being further studied in a randomized phase 3 trial as first- or second- line treatment for patients with advanced sarcomas.

Three year results of Blessed: Expanded access for DeltaRex-G for an intermediate size population with advanced pancreatic cancer and sarcoma (NCT04091295) and individual patient use of DeltaRex-G for solid malignancies (IND# 19130).

Background: Innovative treatments are urgently needed for metastatic cancer. DeltaRex-G, a tumor-targeted retrovector encoding a dominant-negative/cytocidal cyclin G1 (CCNG1 gene) inhibitor construct-has been tested in over 280 cancer patients worldwide in phase 1, phase 2 studies and compassionate use studies, demonstrating long term (>10 years) survivorship in patients with advanced cancers, including pancreatic cancer, osteosarcoma, malignant peripheral nerve sheath tumor, breast cancer, and B-cell lymphoma. Patient and Methods: Endpoints: Survival, response, treatment-related adverse events. Study one is entitled "Blessed: Expanded Access for DeltaRex-G for Advanced Pancreatic Cancer and Sarcoma (NCT04091295)". Study two is entitled "Individual Patient Use of DeltaRex-G for Solid Malignancies (Investigational New Drug#19130). In both studies, patients will receive DeltaRex-G at 1-3 x 10e11 cfu i.v. over 30-45 min, three x a week until significant disease progression or unacceptable toxicity or death occurs. Results: Seventeen patients were enrolled, nine sarcoma, two pancreatic adenocarcinoma, one non-small cell lung cancer, two breast carcinoma, one prostate cancer, one cholangiocarcinoma and one basal cell carcinoma and actinic keratosis. Three patients were enrolled in Study 1 and 14 patients were enrolled in Study 2. Twelve of 17 enrolled patients were treated with DeltaRex-G monotherapy or in combination with United States Food and Drug Administration-approved cancer therapies. Five patients died before receiving DeltaRex-G. Efficacy Analysis: Of the 12 treated patients, 5 (42%) are alive 15-36 months from DeltaRex-G treatment initiation. Two patients with early-stage HR + HER2+ positive or triple receptor negative invasive breast cancer who received DeltaRex-G as adjuvant/first line therapy are alive in complete remission 23 and 16 months after DeltaRex-G treatment initiation respectively; three patients with metastatic chordoma, chondrosarcoma and advanced basal cell carcinoma are alive 36, 31, and 15 months after DeltaRex-G treatment initiation respectively. Safety Analysis: There were no treatment-related adverse events reported. Conclusion: Taken together, the data suggest that 1) DeltaRex-G may evoke tumor growth stabilization after failing standard chemotherapy, 2) DeltaRex-G may act synergistically with standard chemotherapy/targeted therapies, and 3) Adjuvant/first line therapy with DeltaRex-G for early-stage invasive carcinoma of breast may be authorized by the USFDA when patients refuse to receive toxic chemotherapy.

Advanced phase I/II studies of targeted gene delivery in vivo: intravenous Rexin-G for gemcitabine-resistant metastatic pancreatic cancer.

Rexin-G, a nonreplicative pathology-targeted retroviral vector bearing a cytocidal cyclin G1 construct, was tested in a phase I/II study for gemcitabine-resistant pancreatic cancer. The patients received escalating doses of Rexin-G intravenously from 1 x 10(11) colony-forming units (cfu) 2-3x a week (dose 0-1) to 2 x 10(11) cfu 3x a week (dose 2) for 4 weeks. Treatment was continued if there was less than or equal to grade 1 toxicity. No dose-limiting toxicity (DLT) was observed, and no vector DNA integration, replication-competent retrovirus (RCR), or vector-neutralizing antibodies were noted. In nine evaluable patients, 3/3 patients had stable disease (SD) at dose 0-1. At dose 2, 1/6 patients had a partial response (PR) and 5/6 patients had SD. Median progression-free survival (PFS) was 3 months at dose 0-1, and >7.65 months at dose 2. Median overall survival (OS) was 4.3 months at dose 0-1, and 9.2 months at dose 2. One-year survival was 0% at dose 0-1 compared to 28.6% at dose 2, suggesting a dose-response relationship between OS and Rexin-G dosage. Taken together, these data indicate that (i) Rexin-G is safe and well tolerated, and (ii) Rexin-G may help control tumor growth, and may possibly prolong survival in gemcitabine-resistant pancreatic cancer, thus, earning US Food and Drug Administration's (FDA) fast-track designation as second-line treatment for pancreatic cancer.

Tumor protein p53 mutation in archived tumor samples from a 12-year survivor of stage 4 pancreatic ductal adenocarcinoma may predict long-term survival with DeltaRex-G: A case report and literature review.

DeltaRex-G is a replication-incompetent amphotropic murine leukemia virus-based retroviral vector that displays a collagen-matrix-targeting decapeptide on its surface envelope protein, gp70, and encodes a cytocidal 'dominant negative', i.e. a truncated construct of the executive cyclin G1 (CCNG1) oncogene. DeltaRex-G inhibits the CCNG1 function of promoting cell competence and survival through the commanding CCNG1/cyclin-dependent kinase (CDK)/Myc/mouse double minute 2 homolog (Mdm2)/p53 axis. In 2009, DeltaRex-G was granted Fast Track designation from the US Food and Drug Administration for the treatment of pancreatic cancer. In 2019, the results of a phase 1/2 study that used DeltaRex-G as monotherapy for stage 4 chemotherapy-resistant pancreatic ductal adenocarcinoma (PDAC) were published. A unique participant of the aforementioned phase 1/2 study is now an 84-year-old Caucasian woman with chemoresistant PDAC who was treated with DeltaRex-G, 3x1011 colony forming units (cfu)/dose, 3 times/week for 4 weeks with a 2-week rest period, for 1.5 years. During the treatment period, the patient's tumors in the liver, lymph node and peritoneum exhibited progressive decreases in size, which were accompanied by a reduction and normalization of serum carbohydrate antigen 19-9 levels, and the patient achieved complete remission after 8 months of DeltaRex-G therapy with minimal side effects (grade 2 fatigue). Henceforth, the patient has been in remission for 12 years with no evidence of disease, no late therapy-related adverse events, and no further cancer therapy following DeltaRex-G treatment. The present study reports a mutation of tumor protein p53 (TP53) (G199V) found retrospectively in the patient's archived tumor samples. TP53 is a well-characterized tumor suppressor gene, and a critical regulatory component of the executive CCNG1/CDK/Myc/Mdm2/p53 axis, which regulates proliferative cell competence, DNA fidelity and survival. Studies are underway to determine whether TP53 mutations in pancreatic cancer can help identify a subset of patients with advanced metastatic cancer with an otherwise poor prognosis who would respond favorably to DeltaRex-G, which would broaden the treatment options for patients with otherwise lethal PDAC.

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.

Phase I/II and phase II studies of targeted gene delivery in vivo: intravenous Rexin-G for chemotherapy-resistant sarcoma and osteosarcoma.

Rexin-G, a pathotropic nanoparticle bearing a cytocidal cyclin G1 construct was tested in a phase I/II study for chemotherapy-resistant sarcomas and a phase II study for chemotherapy-resistant osteosarcoma. Twenty sarcoma patients and 22 osteosarcoma patients received escalating doses of Rexin-G intravenously from 8 x 10(11) to 24 x 10(11) colony forming units (cfu)/cycle. Treatment was continued if there was or=3 months and median OS, 6.9 months. These studies suggest that Rexin-G is safe, may help control tumor growth, and may possibly improve survival in chemotherapy-resistant sarcoma and osteosarcoma.

The 'timely' development of Rexin-G: first targeted injectable gene vector (review).

In an age where we can i) know precisely where a misplaced automobile resides by its global positioning, ii) send mechanistic probes to Mars with pinpoint accuracy, iii) calculate exactly how many mutations are required to create (i.e., to transform) a cancer cell, and iv) determine how many fewer genes it takes to develop a human being than it does a rice plant, it is difficult to fathom the previously unanswered question: 'Whatever happened to the promise and potential of cancer gene therapy?' This review answers that question with a resounding clinical dénouement. In addition, it provides a 'Cooks tour' of applied molecular genetics and nanotechnology as these fields relate to the development of Rexin-G the world's first tumor-targeted genetic medicine to be fully validated in the clinic. The commentary will expose certain fallacies and ideologies that have retarded the progress of cancer gene therapy as it advances our instruments and understanding of the finespun fabric of our nature.

A Phase I-II Study Using Rexin-G Tumor-Targeted Retrovector Encoding a Dominant-Negative Cyclin G1 Inhibitor for Advanced Pancreatic Cancer.

Rexin-G is a replication-incompetent retroviral vector displaying a cryptic SIG-binding peptide for targeting abnormal Signature (SIG) proteins in tumors and encoding a dominant-negative human cyclin G1 construct. Herein we report on the safety and antitumor activity of escalating doses of Rexin-G in gemcitabine-refractory pancreatic adenocarcinoma, with one 10-year survivor. For the safety analysis (n = 20), treatment-related grade 1 adverse events included fatigue (n = 6), chills (n = 2), and headache (n = 1), with no organ damage and no DLT. No patient tested positive for vector-neutralizing antibodies, antibodies to gp70, replication-competent retrovirus (RCR), or vector integration into genomic DNA of peripheral blood lymphocytes (PBLs). For the efficacy analysis (n = 15), one patient achieved a complete response (CR), two patients had a partial response (PR), and 12 had stable disease (SD). Median progression-free survival (PFS) was 2.7, 4.0, and 5.6 months at doses 0-I, II, and III, respectively. Median overall survival (OS) and 1-year OS rate at dose 0-I were 4.3 months and 0%, and at dose II-III they were 9.2 months and 33.3%. To date, one patient is still alive with no evidence of cancer 10 years after the start of Rexin-G treatment. Taken together, these data suggest that Rexin-G, the first targeted gene delivery system, is uniquely safe and exhibits significant antitumor activity, for which the FDA granted fast-track designation.

Targeting metastatic cancer from the inside: a new generation of targeted gene delivery vectors enables personalized cancer vaccination in situ.

The advent of pathotropic (disease-seeking) targeting technologies, combined with advanced gene delivery vectors, provides a unique opportunity for the systemic delivery of immunomodulatory cytokine genes to remote sites of cancer metastasis. When injected intravenously, such pathotropic nanoparticles seek out and accumulate selectively at sites of tumor invasion and neo-angiogenesis, resulting in enhanced gene delivery, and thus cytokine production, within the tumor nodules. Used in conjunction with a primary tumoricidal agent (e.g., Rexin-G) that exposes tumor neoantigens, the tumor-targeted immunotherapy vector is intended to promote the recruitment and activation of host immune cells into the metastastic site(s), thereby initiating cancer immunization in situ. In this study, we examine the feasibility of cytokine gene delivery to cancerous lesions in vivo using intravenously administered pathotropically targeted nanoparticles bearing the gene encoding granulocyte/macrophage colony-stimulating factor (GM-CSF; i.e., Reximmune-C). In vitro, transduction of target cancer cells with Reximmune-C resulted in the quantitative production of bioactive and immunoreactive GM-CSF protein. In tumor-bearing nude mice, intravenous infusions of Reximmune-C-induced GM-CSF production by transduced cancer cells and paracrine secretion of the cytokine within the tumor nodules, which promoted the recruitment of host mononuclear cells, including CD40+ B cells and CD86+ dendritic cells, into the tumors. With the first proofs of principle established in preclinical studies, we generated an optimized vector configuration for use in advanced clinical trial designs, and extended the feasibility studies to the clinic. Targeted delivery and localized expression of the GM-CSF transgene was confirmed in a patient with metastatic cancer, as was the recruitment of significant tumor-infiltrating lymphocytes (TILs). Taken together, these studies provide the first demonstrations of cytokine gene delivery to cancerous lesions following intravenous administration and extend the applications of cancer immunization in vivo.

Cell cycle checkpoint control: The cyclin G1/Mdm2/p53 axis emerges as a strategic target for broad-spectrum cancer gene therapy - A review of molecular mechanisms for oncologists.

Basic research in genetics, biochemistry and cell biology has identified the executive enzymes and protein kinase activities that regulate the cell division cycle of all eukaryotic organisms, thereby elucidating the importance of site-specific protein phosphorylation events that govern cell cycle progression. Research in cancer genomics and virology has provided meaningful links to mammalian checkpoint control elements with the characterization of growth-promoting proto-oncogenes encoding c-Myc, Mdm2, cyclins A, D1 and G1, and opposing tumor suppressor proteins, such as p53, pRb, p16INK4A and p21WAF1, which are commonly dysregulated in cancer. While progress has been made in identifying numerous enzymes and molecular interactions associated with cell cycle checkpoint control, the marked complexity, particularly the functional redundancy, of these cell cycle control enzymes in mammalian systems, presents a major challenge in discerning an optimal locus for therapeutic intervention in the clinical management of cancer. Recent advances in genetic engineering, functional genomics and clinical oncology converged in identifying cyclin G1 (CCNG1 gene) as a pivotal component of a commanding cyclin G1/Mdm2/p53 axis and a strategic locus for re-establishing cell cycle control by means of therapeutic gene transfer. The purpose of the present study is to provide a focused review of cycle checkpoint control as a practicum for clinical oncologists with an interest in applied molecular medicine. The aim is to present a unifying model that: i) clarifies the function of cyclin G1 in establishing proliferative competence, overriding p53 checkpoints and advancing cell cycle progression; ii) is supported by studies of inhibitory microRNAs linking CCNG1 expression to the mechanisms of carcinogenesis and viral subversion; and iii) provides a mechanistic basis for understanding the broad-spectrum anticancer activity and single-agent efficacy observed with dominant-negative cyclin G1, whose cytocidal mechanism of action triggers programmed cell death. Clinically, the utility of companion diagnostics for cyclin G1 pathways is anticipated in the staging, prognosis and treatment of cancers, including the potential for rational combinatorial therapies.

Le morte du tumour: histological features of tumor destruction in chemo-resistant cancers following intravenous infusions of pathotropic nanoparticles bearing therapeutic genes.

The pathotropic targeting of therapeutic nanoparticles to cancerous lesions is an innovative concept that has recently been reduced to practice in clinical trials for the treatment of metastatic cancer. Previously, we reported that intravenous infusions of Rexin-G, a pathotropic nanoparticle (or vector) bearing a cyto-ablative construct, induced tumor regression, reduced tumor burden, and improved survival, while enhancing the overall quality-of-life of patients with otherwise intractable chemotherapy-resistant cancers. In this report, we describe the major histopathological and radiologic features that are characteristic of solid tumors under the destructive influences of Rexin-G administered as a single therapeutic agent. To further promote tumor eradication and enhance cancer survival, we explored the potential of an auxiliary gene transfer strategy, specifically intended to induce a localized cancer auto-immunization in addition to assisting in acute tumor destruction. This immunization strategy uses Rexin-G in combination with Reximmune-C, a tumor targeted expression vector bearing a granulocyte macrophage-colony stimulating factor (GM-CSF) gene. Intravenous infusions of Rexin-G were given first to induce apoptosis and necrosis in the metastatic tumor nodules, thus exposing tumor neo-antigens, followed by Reximmune-C infusions, intended to recruit immune cells discretely into the same compartments (or lesions). The intent of this two-step approach is to bring a complement of cells involved in humoral and cell-mediated immunity in close proximity to the immunizing tumor antigens in a concerted effort to assist in tumor eradication and to promote a cancer vaccination in situ. Herein, we also describe the distinctive histopathologic and immunocytochemical features of tumors in terminal cancer patients who received Rexin-G infusions in combination with Reximmune-C. In addition to documenting the first histological indications of clinical efficacy achieved by this novel personalized approach to cancer vaccination, we discuss new methods and strategies for advancing its therapeutic utility. Taken together with the clinical data, these histological studies serve as valuable landmarks for medical oncology, and as definitive benchmarks for the emerging field of cancer gene therapy.