Hypothesis: AdAPT-001 and pseudoprogression - when seeing is not necessarily believing.

The purpose of this commentary is to highlight the high occurrence of clinical pseudoprogression and delayed responses that have been observed to date with the locally injected oncolytic adenovirus, AdAPT-001, currently in a Phase 1/2 clinical trial (NCT04673942) for the treatment of treatment-refractory tumors. Not surprisingly, these have led to confusion about response assessment and whether to continue patients on treatment. AdAPT-001 carries a transforming growth factor (TGF)-beta trap (TGF-ß), which sequesters TGF-ß, a cytokine that potently regulates inflammation, fibrosis, and immunosuppression in cancer. Pseudoprogression (PsP) or progression prior to response or stabilization, has been widely recognized with radiotherapy for primary brain tumors and immune checkpoint inhibitors (ICIs). PsP has also been described and documented in the context of oncolytic virotherapy but perhaps to a lesser extent. However, repeated intratumoral injections with these immunostimulatory agents may induce a more intense immune response and release more antigenic epitopes than with ICIs, for example, which are strictly T-cell directed rather than also tumor-directed like AdAPT-001.

BETA prime: a first-in-man phase 1 study of AdAPT-001, an armed oncolytic adenovirus for solid tumors.

AdAPT-001 is an oncolytic adenovirus (OAV) with a transforming growth factor beta (TGF-ß) trap, which neutralizes the immunosuppressive and profibrotic cytokine, TGF-ß. The aim or purpose of this phase 1 study was to assess the safety and tolerability and, secondarily, the efficacy of AdAPT-001 after single intratumoral injection (IT) (Part 1) and multidose IT injection (Part 2) in patients with superficially accessible, advanced refractory solid tumors. Part 1 enrolled 9 patients with a 3 + 3 single dose-escalation safety run-in involving 2.5 × 1011, 5.0 × 1011, 1.0 × 1012 viral particles (vps). No dose-limiting toxicities or treatment-related serious adverse events (SAEs) were seen. In Part 2, a dose-expansion phase, 19 patients received AdAPT-001 at 1.0 × 1012 vps until disease progression according to Response Evaluation Criteria in Solid Tumors or RECIST 1.1. The overall responses to treatment included confirmed partial responses (3), durable stable disease ≥ 6 months (5), and progressive disease (13). AdAPT-001 is well tolerated. Evidence of an anti-tumor effect was seen in both injected and uninjected lesions. The recommended Phase 2 dose was 1.0 × 1012 vp administered by intratumoral injection once every 2 weeks. Combination of AdAPT-001 with a checkpoint inhibition is enrolling.

Commentary on oncolytic viruses: past, present, and future.

Whither oncolytic viruses? From the peak of their popularity in the early 2000s, when the ONYX-015 adenovirus had just entered the clinic, and then again in 2015 when the Food and Drug Administration-approved talimogene laherparepvec (also known as OncoVEXGM-CSF), which briefly revived interest, oncolytic viruses (OVs) have mostly fallen out of favor despite the many pharmaceutical companies with OVs in development.This commentary enumerates and addresses the core conceptions, perceptions, and misconceptions that characterize the current 'trough of disillusionment' in which the field of anticancer virotherapy finds itself and suggests reasons for optimism.

Data Management 101 for drug developers: A peek behind the curtain.

In drug development a frequently used phrase is "data-driven". Just as high-test gas fuels a car, so drug development "runs on" high-quality data; hence, good data management practices, which involve case report form design, data entry, data capture, data validation, medical coding, database closure, and database locking, are critically important. This review covers the essentials of clinical data management (CDM) for the United States. It is intended to demystify CDM, which means nothing more esoteric than the collection, organization, maintenance, and analysis of data for clinical trials. The review is written with those who are new to drug development in mind and assumes only a passing familiarity with the terms and concepts that are introduced. However, its relevance may also extend to experienced professionals that feel the need to brush up on the basics. For added color and context, the review includes real-world examples with RRx-001, a new molecular entity in phase III and with fast-track status in head and neck cancer, and AdAPT-001, an oncolytic adenovirus armed with a transforming growth factor-beta (TGF-ß) trap in a phase I/II clinical trial with which the authors, as employees of the biopharmaceutical company, EpicentRx, are closely involved. An alphabetized glossary of key terms and acronyms used throughout this review is also included for easy reference.

ROCKET: Phase II Randomized, Active-controlled, Multicenter Trial to Assess the Safety and Efficacy of RRx-001 + Irinotecan vs. Single-agent Regorafenib in Third/Fourth Line Colorectal Cancer.

INTRODUCTION: RRx-001 is a novel cysteine-targeted alkylating agent that releases nitric oxide (NO). The primary biological activities of this hybrid molecule include macrophage repolarizing and vascular normalization. The purpose of this clinical trial (ROCKET) (NCT02096354) was to compare the safety and efficacy of the combination therapy RRx-001 + irinotecan vs. regorafenib in third/fourth line colorectal cancer that previously received treatment with irinotecan. PATIENTS AND METHODS: A total of 34 patients were randomized (24 to RRx-001 + irinotecan (RxI) and 10 to single-agent regorafenib (RegI)) and were the basis for the intention-to-treat analysis (ITT, comprising all 34 patients). RRx-001 treatment was administered as an up-to-2-month "primer" followed by irinotecan for patients randomized to the RRx-001 arm (24). The efficacy and safety data are presented for the 34 patients in the (ITT) efficacy analysis. Therapy consisted of intravenous administration of RRx-001 at 4 mg once weekly for up to 2 months, at which point RRx-001 was discontinued, followed by intravenous infusion of irinotecan at 180 mg/m2 on day 1 in a 21-day cycle vs. 160 mg oral regorafenib daily for 3/4 weeks followed at progression, if applicable, by irinotecan 180 mg/m2 on day 1 in a 21-day cycle. There were 3 patients (3/24 = 12.5%) with prior single agent irinotecan on the RRx-001 randomized arm and 2 (2/10 = 20%) on the regorafenib randomized arm. Numerous patients had irinotecan combination therapies prior to randomized treatment. There were 15 patients on RRx-001 arm that received irinotecan post-RRx-001 in the randomized trial. There were 5 PRs on RRx-001 plus irinotecan leading to an overall response of 20.8% (5/24). There were 37.5% (9/24) of RRx-001 randomized patients with KRAS mutant type while 60% (6/10) regorafenib randomized patients were of KRAS type mutant. There were only 4 patients with available QOL and Edmonton Symptom Assessment System, an insufficient sample size to allow for any meaningful analysis. RESULTS: Median patient follow-up was approximately 14.5 months (SD 4.5 months). Median overall survival was 8.6 months for RxI and 4.7 months for RegI. Median progression free survival was 6.1 months for RxI vs. 1.7 months for RegI (a statistically significant result, 2-sided log-rank test, P = .0030). The toxicity profile of RxI was substantially improved compared with RegI. CONCLUSION: The results of this trial demonstrate improved efficacy of RxI compared with RegI in patients with metastatic colorectal cancer after previous treatment with irinotecan, and late-stage clinical development in this indication is planned on the strength of the observed "signal" accompanied by a sufficient safety profile.

Clinical Course of Two Patients with COVID-19 Respiratory Failure After Administration of the Anticancer Small Molecule, RRx-001.

Two critically ill COVID-19 infected patients, who had exhausted all available treatment options, were treated with the small-molecule RRx-001 with subsequent improvement. RRx-001, a first-in-class small molecule with anti-inflammatory, vascular normalizing and macrophage-repolarizing properties, has been safely administered 300+ patients in clinical trials. This is the first report of RRx-001 treatment of COVID-19.

RRx-001 and the "Right stuff": Protection and treatment in outer space.

From antibiotics to aspirin to antimalarials and to anticancer agents, about half of the world's best-selling drugs are derived from nature. However, accelerating climatic disruption, habitat destruction, pollution, and biodiversity loss all negatively impact the potential of natural sources to continue to serve as repositories of novel pharmaceuticals. On that basis, the final frontier for drug development is perhaps not the rainforests, coral reefs, and other natural habitats but rather the aerospace industry with its virtually unlimited and inexhaustible man-made 'library' of potentially bioactive compounds. The first aerospace-sourced therapeutic to reach the clinic is RRx-001, an inhibitor of the NOD-like receptor - Nucleotide-binding oligomerization domain with Leucine rich Repeat and Pyrin domain (NLRP3) inflammasome in a Phase 3 trial for the treatment of small cell lung cancer (SCLC) and in a soon-to-start Phase 3 trial for protection against chemoradiotherapy-induced severe oral mucositis in first line head and neck cancer. As manned missions to the Moon, Mars, and asteroids as well as space tourism beckon, it is perhaps fitting that a compound like RRx-001, which is derived from 1,3,3-Trinitroazetidine (TNAZ), an explosive propellant for rockets, is a potential "all purpose" option to mitigate the major biomedical effects of space radiation exposures including cancer development and other tissue degenerations both within mission and after mission. This article highlights the promise of RRx-001 to attenuate the acute and late effects of radiation exposure on astronauts including the development of cancer.

Subset analysis of safety and efficacy in asian patients treated with RRx-001 across three clinical trials.

RRx-001, a CD47 antagonist via its inhibition of MYC and the γ-subtype of the peroxisome proliferator-activated receptor (PPAR) has been associated to date with minimal toxicity. The aim of this post-hoc analysis was to evaluate the toxicity and efficacy of RRx-001 in Asian patients since RRx-001, in the context of multiple Phase 3 studies, will be administered in China and Chinese territories as well as potentially throughout the rest of Asia. Patients received 4 mg of RRx-001 in three different antitumor clinical trials with chemotherapy and/or radiation and a retrospective subset efficacy and toxicity analysis was conducted for patients with Asian ancestry in comparison to patients with other ethnic backgrounds. The toxicity and efficacy data from these studies were similar between Asians and the rest of the treated patients. While the sample sizes are too small to draw definitive conclusions, at a dose of 4 mg, when RRx-001 is combined with chemotherapy, no apparent differences in terms of safety and efficacy are observed in cancer patients with Asian ancestry.

Toxicology and biodistribution of AdAPT-001, a replication-competent type 5 adenovirus with a trap for the immunosuppressive cytokine, TGF-beta.

Transgene-enhanced oncolytic adenoviruses represent a promising novel therapeutic option for the treatment of cancer. A Phase 1 clinical trial featuring AdAPT-001 is ongoing (NCT04673942). AdAPT-001, a type 5 adenovirus, which carries a TGF-ß trap transgene that neutralizes the immunosuppressive cytokine, TGF-ß, has been shown in an immunocompetent mouse model to eradicate both locally injected and non-injected tumors. Single dose biodistribution of the TGF-ß trap transgene was also evaluated in tumor bearing mice, providing an explanation for systemic activity. The biodistribution and toxicity of a single administration of mouse AdAPT-001 (mAdAPT-001) in 129S1 immunocompetent mice bearing ADS-12 tumors (mouse lung carcinoma) were assessed. mAdAPT-001 was injected intratumorally and intravenously in groups of 25 mice each at varying dose levels. Soluble TGF-ß trap was detected in the serum using ELISA. A single AdAPT-001 injection resulted in non-negligible long-term TGF-ß trap persistence in the serum over the 14-day study after intravenous and intratumoral administration. No TGF-ß-related toxicity was observed. At clinically relevant doses, AdAPT-001 was safe and well tolerated. Systemic levels of the TGF-ß trap transgene were observed from both local and intravenous dosing.

A Patient-Derived Orthotopic Xenograft Model of Gastroesophageal-Junction Adenocarcinoma Translated to the Clinic by Tumor-Targeting Fluorescent Antibodies to Carcinoembryonic-Antigen-Related Cell-Adhesion Molecules.

BACKGROUND/AIM: During surgical resection of gastroesophageal-junction (GEJ) adenocarcinoma, the margin status is often difficult to visualize resulting in high recurrence rates. The aim of the present study was to develop a labelling technique that would allow improved visualization of GEJ tumor margins for surgeons to reduce recurrence rates in a patient-like model. MATERIALS AND METHODS: A patient GEJ tumor was obtained from an endoscopic biopsy and implanted subcutaneously in a nude mouse. A patient-derived orthotopic xenograft (PDOX) model was established by implanting tumor fragments grown from a subcutaneous model to the cardia of the stomach of nude mice. CC1/3/5-SAB, an antibody to carcinoembryonic-antigen-related cell-adhesion molecules, was conjugated with infrared dye IRDye800 to create SAB-IR800. Forty-eight hours after i.v. injection of SAB-IR800, GEJ-PDOX mice were imaged. RESULTS: Fluorescence imaging with SAB-IR800 brightly visualized the GEJ adenocarcinoma demonstrating specific targeting. In the PDOX model, injection of SAB-IR800 (50 µg) resulted in a tumor to background ratio of 1.78 at 48 hours and 1.86 at 72 hours. CONCLUSION: PDOX models of GEJ tumors can be established from patients by endoscopic biopsy without undergoing surgical resection. GEJ PDOX models should be useful for developing novel diagnostics and therapeutics for this recalcitrant disease.

Discovery of RRx-001, a Myc and CD47 Downregulating Small Molecule with Tumor Targeted Cytotoxicity and Healthy Tissue Cytoprotective Properties in Clinical Development.

After extensive screening of aerospace compounds in an effort to source a novel anticancer agent, RRx-001, a first-in-class dinitroazetidine small molecule, was selected for advancement into preclinical and clinical development. RRx-001 is a minimally toxic small molecule with a distinct chemical structure and mechanism of action. The paradox of RRx-001 is that it mediates both antitumor cytotoxicity and normal tissue protection. The question of exactly how RRx-001 does this, and by means of what mechanism(s), depending on the route of delivery, intravenous or intratumoral, are explored. RRx-001 is currently in phase 2 and 3 clinical trials for the treatment of multiple solid tumor malignancies and as a supportive care drug.

In small cell lung cancer patients treated with RRx-001, a downregulator of CD47, decreased expression of PD-L1 on circulating tumor cells significantly correlates with clinical benefit.

BACKGROUND: Small cell lung cancer (SCLC) is the most aggressive lung tumor, characterized by a rapid doubling time and the development of widespread metastases, for which immune checkpoint inhibitors have been approved to overcome T cell anergy. In light of its dismal prognosis, and lack of curative options, new therapies for extensive-disease SCLC are desperately needed. METHODS: RRx-001 is a small molecule Myc inhibitor and down-regulates CD47 expression on tumor cells. We evaluated the programmed death-ligand 1 (PD-L1) status of circulating tumor cells (CTCs) pre and post RRx-001 treatment in a phase 2 clinical trial, called QUADRUPLE THREAT, where patients with previously treated SCLC received RRx-001 in combination with a platinum doublet. The trial was registered with ClinicalTrials.gov, number NCT02489903. Fourteen patients with SCLC were analyzed to investigate the association between clinical outcome and PD-L1 expression on CTCs pre and post RRx-001. The correlation between the binary clinical outcome (clinical benefit vs. progressive disease) and the change of PD-L1 expression on CTCs after RRx-001 was analyzed using a logistic regression adjusting for baseline PD-L1 expression. RESULTS: The logistic model McFadden goodness of fit score was 0.477. The logistic model analyzing the association between decreased PD-L1 expression on CTCs after RRx-001 and response to reintroduced platinum doublet had an approximate 92.8% accuracy in its prediction of clinical benefit. The estimated receiver operating characteristic (ROC) displayed a ROC area under the curve (AUC) of 0.93 (95% confidence interval, 0.78-0.99). CONCLUSIONS: These results suggest that PD-L1 expression on CTCs decreased after RRx-001 was significantly correlated with response to reintroduced platinum-based doublet therapy. Monitoring PD-L1 expression on CTCs during RRx-001 treatment may serve as a biomarker to predict response to RRx-001-based cancer therapy.

RRx-001, a downregulator of the CD47- SIRPα checkpoint pathway, does not cause anemia or thrombocytopenia.

Introduction: The CD47 and SIRPα checkpoint pathway has garnered much interest within the anti-cancer research community, with multiple experimental checkpoint inhibitors targeting CD47 and SIRPα in development. The use of such checkpoint inhibitors may however be limited by hematologic toxicity.Areas covered: We report on RRx-001, the first known small molecule downregulator of CD47 and SIRPα, which has shown a lack of hematologic toxicity in clinical trials.Expert opinion: RRx-001 is the first reported small molecule downregulator of CD47 and SIRPα and lacks any notable hematologic or systemic toxicity as demonstrated in clinical trials to date. Small molecule RRx-001 could be used in combination with or in place of CD47 targeting antibodies for anti-cancer treatment.

Desperate Times, Desperate Measures: The Case for RRx-001 in the Treatment of COVID-19.

This article summarizes the likely attenuation properties of RRx-001 in COVID-19 based on its mechanism of action and the putative pathogenesis of the disease, which appears to activate inflammatory, oxidative, and immune cascades with the potential to culminate in acute respiratory distress syndrome, cytokine storm and death. An ongoing pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19 appears to present with 3 major patterns of clinical symptomatology: (1) mild upper respiratory tract infection, (2) non-life-threatening pneumonia, and (3) severe pneumonia and acute respiratory distress syndrome that initially manifest as a mild prodrome lasting for 7-8 days before rapid clinical and radiological deterioration requiring ICU transfer. RRx-001 is a targeted nitric oxide donor. This small molecule, which has been evaluated in multiple Phase 1-2 clinical trials for cancer as well as a Phase 3 clinical trial for the treatment of small cell lung cancer called REPLATINUM (NCT03699956), is minimally toxic and demonstrates clear evidence of antitumor activity. During the course of these clinical trials it was noted that the rate of chronic obstructive pulmonary disease exacerbation and pneumonia in actively smoking small cell lung cancer patients treated with RRx-001 is less than 1%. Due to extensive history of tobacco use, 40%-70% of patients with lung cancer have chronic obstructive pulmonary disease and the expected rate of pulmonary infection in this population is 50%-70%, which was not observed in RRx-001 clinical trials. Moreover, in preclinical studies of pulmonary hypertension, RRx-001 was found to be comparable with or more effective than the FDA approved agent, Bosentan. The potential pulmonary protective effects of RRx-001 in patients with recurrent lung infections coupled with preclinical models demonstrating RRx-001-mediated reversal of pulmonary hypertension suggests RRx-001 may have therapeutic activity in patients with acute respiratory symptoms due to COVID 19. Clinical trials have been initiated to confirm the hypothesis that RRx-001 may be repurposed to treat SARS-CoV-2 infection.

TGF-beta: a master immune regulator.

Introduction: Transforming Growth Factor-Beta (TGF-ß) is a master regulator of numerous cellular functions including cellular immunity. In cancer, TGF-ß can function as a tumor promoter via several mechanisms including immunosuppression. Since the immune checkpoint pathways are co-opted in cancer to induce T cell tolerance, this review posits that TGF-ß is a master checkpoint in cancer, whose negative regulatory influence overrides and controls that of other immune checkpoints.Areas Covered: This review examines therapeutic agents that target TGF-ß and its signaling pathways for the treatment of cancer which may be classifiable as checkpoint inhibitors in the broadest sense. This concept is supported by the observations that 1) only a subset of patients benefit from current checkpoint inhibitor therapies, 2) the presence of TGF-ß in the tumor microenvironment is associated with excluded or cold tumors, and resistance to checkpoint inhibitors, and 3) existing biomarkers such as PD-1, PD-L1, microsatellite instability and tumor mutational burden are inadequate to reliably and adequately identify immuno-responsive patients. By contrast, TGF-ß overexpression is a widespread and profoundly negative molecular hallmark in multiple tumor types.Expert Opinion: TGF-ß status may serve as a biomarker to predict responsiveness and as a therapeutic target to increase the activity of immunotherapies.

A Review of Newly Diagnosed Glioblastoma.

Glioblastoma is an aggressive and inevitably recurrent primary intra-axial brain tumor with a dismal prognosis. The current mainstay of treatment involves maximally safe surgical resection followed by radiotherapy over a 6-week period with concomitant temozolomide chemotherapy followed by temozolomide maintenance. This review provides a summary of the epidemiological, clinical, histologic and genetic characteristics of newly diagnosed disease as well as the current standard of care and potential future therapeutic prospects.

RRx-001, a first-in-class small molecule inhibitor of MYC and a downregulator of CD47, is an "erythrophagoimmunotherapeutic".

The main mechanism of action of RRx-001, a pharmaceutically unprecedented sui generis Phase 3 small molecule that is derived from the aerospace industry, is clarified. RRx-001 has demonstrated anticancer activity through antiangiogenic, immune, epigenetic, antioxidant, apoptotic and nitric oxide (NO) pathways, resulting in its pleiomorphic description as an antiangiogenic/vascular normalizer.

Extended treatment with MY-NEOVAX, personalized neoantigen-enhanced oncolytic viruses, for two end-stage cancer patients.

Neoantigen vaccines involving multi-peptides and poly-epitope-encoding RNA or DNA have undergone early phase clinical testing with modest reported antitumor effects [ 1]. The less-than-expected activity of these neoantigenic vaccines may correspond with the development of immune escape mechanisms. One permutation on neoantigen vaccines, which may counter or prevent these adaptive immune escape mechanisms, are 'personalized' oncolytic viruses that encode one or more tumor-specific transgenes. Herein, positive therapeutic effects for MY-NEOVAX™, personalized neoantigen-enhanced oncolytic adenoviruses, are described for two heavily pretreated end-stage patients, one with high-grade metastatic neuroendocrine carcinoma of the pancreas and the other with colorectal cancer metastatic to the brain, liver and lungs. To date, treatment benefit has exceeded 12 months without dose-limiting toxicities or related serious adverse events and with documented radiologic stabilization and improved performance status.

REPLATINUM Phase III randomized study: RRx-001 + platinum doublet versus platinum doublet in third-line small cell lung cancer.

RRx-001 is a cysteine-directed anticancer alkylating agent with activity in a Phase II study in platinum refractory small cell lung cancer. Here, we describe the design of REPLATINUM, an open-label, Phase III trial. 120 patients with previously platinum-treated small cell lung cancer in third line will be randomized 1:1 to receive RRx-001 followed by four cycles of a platinum doublet, and then alternating cycles of RRx-001 and single agent platinum until progression versus four cycles of a platinum doublet. At radiologic progression on the platinum doublet, patients may cross over to the RRx-001 arm. Primary objective: to demonstrate superior progression-free survival in the RRx-001 population. Secondary objectives: to demonstrate superiority for overall survival and objective response rate. Clinical Trial registration: NCT03699956.