Mitoxantrone-Loaded Nanoferritin Slows Tumor Growth and Improves the Overall Survival Rate in a Subcutaneous Pancreatic Cancer Mouse Model

Pancreatic cancer (PC) represents an intriguing topic for researchers. To date, the prognosis of metastasized PC is poor with just 7% of patients exceeding a five-year survival period. Thus, molecular modifications of existing drugs should be developed to change the course of the disease. Our previously generated nanocages of Mitoxantrone (MIT) encapsulated in human H-chain Ferritin (HFt), designated as HFt-MP-PASE-MIT, has shown excellent tumor distribution and extended serum half-life meriting further investigation for PC treatment. Thus, in this study, we used the same nano-formulation to test its cytotoxicity using both in vitro and in vivo assays. Interestingly, both encapsulated and free-MIT drugs demonstrated similar killing capabilities on PaCa44 cell line. Conversely, in vivo assessment in a subcutaneous PaCa44 tumor model of PC demonstrated a remarkable capability for encapsulated MIT to control tumor growth and improve mouse survival with a median survival rate of 65 vs. 33 days for loaded and free-MIT, respectively. Interestingly, throughout the course of mice treatment, MIT encapsulation did not present any adverse side effects as confirmed by histological analysis of various murine tissue organs and body mass weights. Our results are promising and pave the way to effective PC targeted chemotherapy using our HFt nanodelivery platforms.

Tumor distribution affects bladder recurrence but not survival outcome of multifocal upper tract urothelial carcinoma treated with radical nephroureterectomy

Tumor multifocality and location are prognostic factors for upper tract urothelial carcinoma (UTUC). However, confounding effects can appear when these two factors are analyzed together. Therefore, we aimed to investigate the impact of tumor distribution on the outcomes of multifocal UTUC after radical nephroureterectomy. From the 2780 UTUC patients in the Taiwan UTUC Collaboration Group, 685 UTUC cases with multifocal tumors (defined as more than one tumor lesion in unilateral upper urinary tract) were retrospectively included and divided into three groups: multiple renal pelvic tumors, multiple ureteral tumors, and synchronous renal pelvic and ureteral tumors included 164, 152, and 369 patients, respectively. We found the prevalence of carcinoma in situ was the highest in the synchronous group. In multivariate survival analyses, tumor distribution showed no difference in cancer-specific and disease-free survival, but there was a significant difference in bladder recurrence-free survival. The synchronous group had the highest bladder recurrence rate. In summary, tumor distribution did not influence the cancer-specific outcomes of multifocal UTUC, but synchronous lesions led to a higher rate of bladder recurrence than multiple renal pelvic tumors. We believe that the distribution of tumors reflects the degree of malignant involvement within the urinary tract, but has little significance for survival or disease progression.

Glutamine Antagonist GA-607 Causes a Dramatic Accumulation of FGAR Which Can be Used to Monitor Target Engagement

Background: Metabolomic analyses from our group and others have shown that tumors treated with glutamine antagonists (GA) exhibit robust accumulation of formylglycinamide ribonucleotide (FGAR), an intermediate in the de novo purine synthesis pathway. The increase in FGAR is attributed to the inhibition of the enzyme FGAR amidotransferase (FGAR-AT) that catalyzes the ATP-dependent amidation of FGAR to formylglycinamidine ribonucleotide (FGAM). While perturbation of this pathway resulting from GA therapy has long been recognized, no study has reported systematic quantitation and analyses of FGAR in plasma and tumors. Objective: Herein, we aimed to evaluate the efficacy of our recently discovered tumor-targeted GA prodrug, GA-607 (isopropyl 2-(6-acetamido-2-(adamantane-1-carboxamido)hexanamido)-6-diazo-5-oxohexanoate), and demonstrate its target engagement by quantification of FGAR in plasma and tumors. Methods: Efficacy and pharmacokinetics of GA-607 were evaluated in a murine EL4 lymphoma model followed by global tumor metabolomic analysis. Liquid chromatography-mass spectrometry (LC-MS) based methods employing the ion-pair chromatography approach were developed and utilized for quantitative FGAR analyses in plasma and tumors. Results: GA-607 showed preferential tumor distribution and robust single-agent efficacy in a murine EL4 lymphoma model. While several metabolic pathways were perturbed by GA-607 treatment, FGAR showed the highest increase qualitatively. Using our newly developed sensitive and selective LC-MS method, we showed a robust >80- and >10-fold increase in tumor and plasma FGAR levels, respectively, with GA-607 treatment. Conclusion: These studies describe the importance of FGAR quantification following GA therapy in cancer and underscore its importance as a valuable pharmacodynamic marker in the preclinical and clinical development of GA therapies.

Concept for using magnetic particle imaging for intraoperative margin analysis in breast-conserving surgery

Breast-conserving surgery (BCS) is a commonly utilized treatment for early stage breast cancers but has relatively high reexcision rates due to post-surgical identification of positive margins. A fast, specific, sensitive, easy-to-use tool for assessing margins intraoperatively could reduce the need for additional surgeries, and while many techniques have been explored, the clinical need is still unmet. We assess the potential of Magnetic Particle Imaging (MPI) for intraoperative margin assessment in BCS, using a passively or actively tumor-targeted iron oxide agent and two hardware devices: a hand-held Magnetic Particle detector for identifying residual tumor in the breast, and a small-bore MPI scanner for quickly imaging the tumor distribution in the excised specimen. Here, we present both hardware systems and demonstrate proof-of-concept detection and imaging of clinically relevant phantoms.

Vocal Fold Cyst Formation after Photoangiolytic KTP Laser Treatment of Early Glottic Cancer

Objective: The incidence of post-operative glottic cyst (POGC) formation in patients treated with transoral laser microsurgery with potassium-titanyl-phosphate laser (TLM-KTP) photoablation of early glottic carcinoma (EGC) has not previously been described. Methods: A retrospective chart review was performed to identify all patients with early glottic cancer who underwent with single-modality TLM-KTP at our institution. Each patient received regular follow up with videostroboscopy for tumor surveillance. New glottic cysts seen on surveillance examinations were noted and their management was documented. Results: A total of 33 patients met inclusion criteria. Eight patients (24%) developed POGC’s within the original geographic perimeter of the cancerous vocal fold(s): 6 in the infraglottic region and 2 near the vocal process, at an average of 8 months after their initial cancer surgery. Of these 8 POGC’s, 7 were at the periphery of the original tumor distribution and 1 was in the center of it. No POGC’s were associated with any change in voice. Four of the 8 POGC’s were phonosurgically excised, all without evidence of malignancy on pathology. The remaining 4 were monitored: 2 were stable for an average of 49 months of follow up; the remaining 2 resolved spontaneously by 7 and 31 months after first identification. Conclusions: POGC’s are a frequent sequela of TLM-KTP for EGC. While these results suggest that they are unlikely to represent submucosal recurrences, surgeons should have a low threshold to biopsy if there is clinical concern for such and should counsel patients pre-operatively about the potential for their formation.

Pathologic and radiographic responses in a window of opportunity for durvalumab plus metformin trial for squamous cell carcinoma of the head and neck (HNSCC).

6068 Background: Durvalumab is a human monoclonal IgG1 antibody directed against programmed death-ligand 1 (PD-L1). PD-1/PD-L1 immune checkpoint inhibition (ICI) shows promise in HNSCC, but durable responses have been seen in only a fraction of patients. Metformin, a biguanide oral anti-hyperglycemic, has shown promise in altering immunity within the tumor microenvironment (TME) towards a stronger anti-tumor distribution of immune cells. We aimed to investigate the combined effect of metformin and durvalumab in patients with HNSCC. Methods: This was a single-center prospective phase 1, window of opportunity clinical trial in which previously untreated patients with any stage resectable HNSCC were randomized 3:1 to durvalumab + metformin (Arm A) or durvalumab alone (Arm B) during a four-week period between diagnosis and surgical resection. Six patients were included in a safety lead-in of durvalumab and metformin and an additional 32 patients were randomized. The primary endpoint was immune cell polarization. Here we report pathologic and radiographic effect. Pathologic effect was graded independently by two pathologists. Radiographic effect was evaluated using the immune-related Response Criteria (irRC). Results: Thirty-eight patients were enrolled (29 Arm A, 9 Arm B). Three patients withdrew consent prior to intervention (2 Arm A, 1 Arm B) and were excluded from analysis. AJCC 8th edition staging was as follows: Stage I (n = 21), Stage II (n = 2), Stage III (n = 3), Stage IVa (n = 6), Stage IVb (n = 3). Primary tumor sites included the oropharynx (n = 20, all p16+), oral cavity (n = 11), larynx (n = 2), maxillary sinus (n = 1), and unknown (n = 1). Pathologic effect was observed in 55% (18/33) of evaluable patients: 60% in Arm A vs 37.5% in Arm B (p = 0.418). 40% of patients with involved lymph nodes had discordance of pathologic effect at the primary site versus lymph node. Radiographic response based on irRC among 30 evaluable patients included 1 CR, 1 PR, 24 SD, and 4 PD. There was a significant correlation between pathologic effect and radiographic disease control, defined as CR, PR, and SD (p = 0.021), but no correlation when looking only at radiographic responders (p = 0.925). No patients experienced Grade 3–4 treatment or immune-related adverse events or a delay in surgery due to trial participation. All patients remained resectable. Conclusions: Our data demonstrate that the study intervention was well-tolerated in HNSCC patients. There was a trend towards an increased proportion of pathologic responders in the group receiving metformin. Additional studies targeting the TME are needed to further elucidate whether synergistic effects between metformin and durvalumab were seen in this patient cohort. Clinical trial information: NCT03618654.

Development and Validation of a Predictive Model for Early Refractoriness of Transarterial Chemoembolization in Patients With Hepatocellular Carcinoma

Objectives: To develop and validate a predictive model for early refractoriness of transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC).Methods: In this multicenter retrospective study, a total of 204 consecutive patients who initially underwent TACE were included. Early TACE refractoriness was defined as patients presented with TACE refractoriness after initial two consecutive TACE procedures. Of all patients, 147 patients (approximately 70%) were assigned to a training set, and the remaining 57 patients (approximately 30%) were assigned to a validation set. Predictive model was established using forward stepwise logistic regression and nomogram. Based on factors selected by logistic regression, a one-to-one propensity score matching (PSM) was conducted to compare progression-free survival (PFS) between patients who were present or absent of early TACE refractoriness. PFS curve was estimated by Kaplan-Meier method and compared by log-rank test.Results: Logistic regression revealed that bilobar tumor distribution (p = 0.002), more than three tumors (p = 0.005) and beyond up-to-seven criteria (p = 0.001) were significantly related to early TACE refractoriness. The discriminative abilities, as determined by the area under the receiver operating characteristic (ROC) curve, were 0.788 in the training cohort and 0.706 in the validation cohort. After PSM, the result showed that patients who were absent of early TACE refractoriness had a significantly higher PFS rate than those of patients who were present (p < 0.001).Conclusion: This study presents a predictive model with moderate accuracy to identify patients with high risk of early TACE refractoriness, and patients with early TACE refractoriness may have a poor prognosis.