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 × 1011 colony-forming units (cfu) 2–3× a week (dose 0–1) to 2 × 1011 cfu 3× 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

Immune and Cell Cycle Checkpoint Inhibitors for Cancer Immunotherapy

The rational design of immunotherapeutic agents has advanced with a fundamental understanding that both innate and adaptive immunity play important roles in cancer surveillance and tumor destruction; given that oncogenesis occurs and cancer progresses through the growth of tumor cells with low immunogenicity in an increasingly immunosuppressive tumor microenvironment. Checkpoint inhibitors in the form of monoclonal antibodies that block cancer’s ability to deactivate and evade the immune system have been widely indicated for a variety of tumor types. Through targeting the biological mechanisms and pathways that cancer cells use to interact with and suppress the immune system, immunotherapeutic agents have achieved success in inhibiting tumor growth while eliciting lesser toxicities, compared to treatments with standard chemotherapy. Development of “precise” bio-active tumor-targeted gene vectors, biotechnologies, and reagents has also advanced. This chapter presents ongoing clinical research involving immune checkpoint inhibitors, while addressing the clinical potential for tumor-targeted gene blockade in combination with tumor-targeted cytokine delivery, in patients with advanced metastatic disease, providing strategic clinical approaches to precision cancer immunotherapy

Our Journey Beyond Sunset Boulevard: Evidence-Based Analysis of Tumor-Targeted Cancer Gene Therapy Shines a Critical Spotlight on Long-Term Cancer-Free Survival

This unique “PERSPECTIVE” on Targeted Genetic Medicine for Cancer represents the third manuscript in a series of medical oncology papers by gene therapy pioneers, Gordon and Hall, a combined medical oncologist’s and layman’s trilogy recorded with the following intents and purposes: (i) documenting significant milestones in clinical oncology for the medical community, (ii) honoring forthright principles of “Informed Consent” for the advanced/refractory oncology patient, and (iii) confronting logical fallacies of popular opinion, in light of recent critical analyses of long-term cancer-free survival data. As with the two previous historical “perspectives,” the authors present noteworthy up-to-date clinical research documenting the successful management of refractory metastatic cancers with tumor-targeted gene therapy vectors—validating “Pathotropic” (disease-seeking) tumor targeting Avant la Lettre. This paper provides additional insights into the molecular and cellular mechanisms of both tumor-targeting and tumor-eradication. As with the prior two papers, the authors utilize the revealing powers of allegory and classic literature, adding shared iconic cinematic experiences of postmodernism at times, to educate, inform, and convey the formidable yet verifiable and important hard-core science (that is, the fundamental chemistries, biophysics, molecular biology, genetics, stem cell biology, regulatory biology, synthetic virology, tumor immunology, clinical oncology, bio-pharmacology, histopathology, and cancer gene therapy) embodied within the “smart” therapeutic nanoparticle, DeltaRex-G: a refined “primal-hunter” & “tumor-killer” that actively seeks out the cryptic/hidden “Biochemical (Jailbreak) Signatures” of metastatic cancers, delivers targeted gene therapy “precisely”totumor cells, and ultimately eradicates both primary and metastatic lesions, including lymphatic metastases. Accomplishment of the “DeltaRex-G Rescue-Mission of 2019” with updated FDA regulatory approvals and sustainable/scalable cGMP bioproduction is considered opportune—while the Right-to-Try experimental therapies legislation in the United States comes face-to-face with the U.S. FDA approval of Expanded Access for DeltaRex-G for advanced pancreatic cancer and sarcoma, and compassionate use for all solid tumors—as such, the authors embrace the legitimate rights of the cancer patient to be more fully informed of such beneficial treatments currently available in the United States

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

Direct Comparison of Radiolabeled Probes FMAU, FHBG, and FHPG as PET Imaging Agents for HSV1-tk Expression in a Human Breast Cancer Model

2′-Deoxy-2′-fluoro-5-methyl-1-β-d-arabinofuranosyluracil (FMAU), 9-(4-fluoro-3-hydroxy-methyl-butyl)guanine (FHBG) and 9-[(3-fluoro-1-hydroxy-2-propoxy)methyl]-guanine (FHPG) have been evaluated in a human breast cancer model as potential radiotracers for PET imaging of HSV1-tk gene expression. In vitro accumulation of [14C]FMAU, [18F]FHBG, and [18F]FHPG in HSV1-tk-expressing cells was 14- to 16-fold (p < .001), 9- to 13-fold (p < .001), and 2- to 3-fold (p < .05) higher than tk-negative control cells, respectively, between 30 and 240 min. Accumulation of FMAU and FHBG in vector-transduced cells was 10- to 14-fold and 6- to 10-fold higher than wild-type cells, respectively. At 2 hr, uptake of [14C]FMAU in tk-positive cells was 6.3-fold and 60-fold higher than [18F]FHBG and [18F]FHPG, respectively. In vivo, tumor uptake of [14C]FMAU in HSV1-tk-expressing cells was 3.7-fold and 5.5-fold (p < .001) higher than tk-negative control cells at 1 and 2 hr, respectively. Tumor uptake of [18F]FHBG was 4.2-fold and 12.6-fold higher (p < .001) than tk-negative cells at the same time points. Incorporation of [14C]FMAU in tk-positive tumor was 18-fold and 24-fold higher (p < .001) than [18F]FHBG at 1 and 2 hr, respectively. Micro-PET images support the biodistribution results and indicate that both [18F]FMAU and [18F]FHBG are useful for imaging HSV1-tk expression in breast cancer. Although FMAU demonstrates higher total incorporation (%dose/g) in tumor tissue compared with the other tracers, FHBG is superior in terms of specific accumulation in transfected cells at later time points