Jain, Sonia

Introduction: Pulmonary hypertension (PH) is an independent marker of surgical morbidity. Right ventricular systolic pressure (RVSP) measured by transthoracic echocardiography (TTE), correlates poorly with pulmonary artery systolic pressure (PASP) measured by right heart catheterization, especially in PH. The correlation between TTE derived RVSP and intraoperative PASP, while under general anesthesia, is not known. In this study, the association between preoperative RVSP and intraoperative PASP was tested. Methods: All consenting adult surgical patients requiring intraoperative pulmonary pressure monitoring in a 2 year period were retrospectively identified. Patients who had TTE estimated RVSP ≥ 40 mmHg, measured within a week prior to the index surgery, were included. RVSP was calculated from tricuspid regurgitant velocity using the modified Bernoulli equation. For intraoperative PASP, the median of the first 10 minutes after PAC placement was used. CVP, arterial systolic pressure, minimum alveolar concentration of anesthetic (MAC) and basic demographic data were also collected. Agreement between RVSP and PASP was tested using the concordance correlation coefficient. Multivariate linear regression and Bland-Altman plot were used to further refine the analysis. Results: 129 patients met inclusion criteria. Median age (IQR) was 73 (62 - 79) years; TTE was performed a median (IQR) of 2 (1 - 3) days prior to surgery; mean (SD) RVSP was 56.1 (±12.4) mmHg and mean (SD) PASP was 42.1 (±14.9) mmHg. Concordance correlation coefficient between RVSP and PASP was only 0.13 (95% CI 0.02 - 0.24). On multivariate linear regression, PASP was significantly associated with RVSP and CVP (p < 0.01), but not anesthetic MAC, age or proximity of measurements. Bland-Altman bias was -13.9 mmHg; 95% limits of agreement were -48.0 to +20.1 mmHg. Conclusion: Preoperative RVSP measured by TTE correlates poorly with intraoperative PASP measured by PAC during general anesthesia.

Abstract Glioblastoma (GBM) is one of the most malignant central nervous system (CNS) tumors and accounts for more than 60% of primary brain tumors in adults [1]. While chemotherapy is a frequently employed treatment for GBM, its lack of specificity towards tumor cells leads to toxicity in healthy tissues. Antibody-drug conjugates (ADCs) are a prevalent targeted-drug delivery strategy that may enhance the therapeutic window. ADC development for GBM has progressed in recent years, yet recent clinical trials have thus far failed to demonstrate drug efficacy [2]. This is likely attributed to poor brain penetration and heterogeneous drug distribution within GBM [3]. Convection-enhanced delivery (CED) is an invasive delivery method that can achieve direct administration of therapeutics to brain tumors and potentially could be used to enhance the delivery and efficacy of ADCs. This study investigates the CNS and systemic pharmacokinetics and distribution of similar payload molecules following CED administration of two GBM-targeting ADCs, ABBV-221 and ABT-414. The ADC payloads are monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF), respectively, and both are potent anti-tubulin toxins commonly used as warheads for ADCs. Both ADCs and free MMAE were administered as single doses to FVB mice via CED infusion or intraperitoneal (IP) injection. Plasma and brain samples were collected over 24 hours for ABBV-221 and 96 hours for ABT-414, and unconjugated payload molecules were quantified via LC-MS/MS analysis. The results showed that free (i.e., not bound to the targeting antibody) MMAE has a significantly higher exposure in brain compared to plasma when delivered via CED, and exposure in the right hemisphere was 10-fold higher than the left hemisphere, as the site of CED infusion was located in the right hemisphere for all trials. Similar results for MMAE payload were observed after the CED of ABBV-221. Systemic administration of ABBV-221 resulted in a nearly 100-fold decrease in unconjugated MMAE concentration in brain, indicating the poor brain penetration of the ADC. Similarly, following the CED of ABT-414, unconjugated payload concentration was the highest in right anterior brain among all brain regions, and plasma concentration was below the limit of quantification. Systemic injection of ABT-414 resulted in non-quantifiable payload concentrations in either brain or plasma samples. Taking these results as a whole, this study demonstrated significantly enhanced brain distribution of payload molecules from GBM-targeting ADCs following CED compared to systemic administration. The consistent payload delivery pattern observed in both ADCs further supports the potential of CED as an effective drug delivery method for the treatment of GBM. These findings highlight the promise of CED as a means to address the limitations of conventional chemotherapy and improve therapeutic outcomes in GBM treatment. 1. Sarkaria JN et al. Neuro Oncol. 2018; 20:184–91. 2. Lassman AB et al. Neuro Oncol. 2023; 25:339–50. 3. Marin B-M, et al. Neuro Oncol. 2021; 23:2042–53. Citation Format: Jessica I. Griffith, Jiayan Le, Kendra A. Porath, Sonia Jain, Katrina K. Bakken, Jann N. Sarkaria, William F. Elmquist. CNS and systemic pharmacokinetics of antibody-drug conjugate payloads through convection-enhanced delivery [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr B023.

Abstract An important aspect to determine the efficacy of a targeted macromolecule in treating brain tumors is penetration and activity in tumor across a heterogeneously intact blood-brain barrier. In this study, novel epidermal growth factor receptor (EGFR)-targeted antibody drug conjugates (ADCs) were constructed with a focus on cytotoxicity in glioblastoma (GBM) with an EGFR heterogeneous cell population. Initially, the cytotoxicity of free payloads with multiple mechanisms of cell kill was assessed. These included tesirine (TS, induces DNA cross-links), deruxtecan (Dxd) and SN38 (inhibit topoisomerase I), and an auristatin (MMAE) and maytansinoid (DM1) (inhibit microtubule polymerization). Across four GBM PDXs with varied EGFR expression (GBM6, 39 and 108- EGFRviii amplified; GBM10 - non-amplified), free TS and MMAE were consistently potent with EC50 values ranging from 0.50-45.9 pM and 7.9-229.1 pM, respectively. In contrast, the other free toxins were less potent; EC50 values: Dxd, 0.21-13.1 nM; SN38, 0.87-5.6 nM; DM1, 2.1-19.9 nM. Based on these results, the 40H3 EGFR-specific IgG was used to construct ADCs with TS and MMAE. 40H3-TS had a drug:antibody ratio (DAR) of 2.5 and was potently cytotoxic in GBM6, GBM39 and GBM108, while minimal cytotoxicity was observed in GBM10 or normal astrocyte SVG-A cells. 40H3-MMAE had a DAR of 3 and was similarly effective in GBM6 and GBM39 but less potent in GBM108, GBM10, and SVG-A. Bystander cytotoxicity was evaluated U87 cells expressing eGFP/fLuc2 (U87eGFP/fluc2) or EGFRviii (U87EGFRviii). Using live-cell imaging, U87EGFRviii cells treated with 40H3-TS or 40H3-MMAE had significantly reduced cell confluence relative to control. The same drug treatments in U87eGFP/fLuc2 cells had no effect on growth/confluence. However, in a 1:1 mixed culture, overall confluence was reduced from 89% in control to 35% and 32% after 40H3-TS (p&lt;0.0001) or 40H3-MMAE (p&lt;0.0001) treatment, respectively. This bystander killing of U87eGFP/fLuc2 cells was indicated by a reduction in confluence of green-fluorescent cells from 50% in control versus 29% with 40H3-TS (p&lt;0.0001) and 26% with 40H3-MMAE (p&lt;0.0001) treatment. In GBM39 orthotopic tumors, a single infusion of 10 or 20 µg 40H3-TS via convection enhanced delivery (CED) reduced the bioluminescence signal 7 days post treatment by ~10-fold (p=0.03) as compared to 40H3 control. However, 50% and 80% mortality was observed within a week of infusing 10 and 20 µg 40H3-TS, respectively. Neurotoxicity was associated with neuron loss in treated hemisphere as determined by NeuN staining. In summary, these data highlight the potential for novel EGFR-targeted ADCs to provide potent direct and bystander cytotoxicity to GBM cells. However, further selection and optimization of the conjugated toxins will be required to balance potency and bystander killing with toxicity for EGFR-targeted ADCs. Citation Format: Sonia Jain, Eric Chun Ho, Kendra A. Porath, Antonella Antignani, David J. FitzGerald, Jann N. Sarkaria. Bystander effects of EGFR-targeting 40H3 antibody-drug conjugates in glioblastoma with heterogeneous EGFR expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 556.

Abstract Background EGFR targeting antibody-drug conjugates (ADCs) are highly effective against EGFR-amplified tumors, but poor distribution across the blood–brain barrier (BBB) limits their efficacy in glioblastoma (GBM) when administered systemically. We studied whether convection-enhanced delivery (CED) can be used to safely infuse ADCs into orthotopic patient-derived xenograft (PDX) models of EGFRvIII mutant GBM. Methods The efficacy of the EGFR-targeted ADCs depatuxizumab mafodotin (Depatux-M) and Serclutamab talirine (Ser-T) was evaluated in vitro and in vivo. CED was performed in nontumor and tumor-bearing mice. Immunostaining was used to evaluate ADC distribution, pharmacodynamic effects, and normal cell toxicity. Results Dose-finding studies in orthotopic GBM6 identified single infusion of 2 μg Ser-T and 60 μg Depatux-M as safe and effective associated with extended survival prolongation (&gt;300 days and 95 days, respectively). However, with serial infusions every 21 days, four Ser-T doses controlled tumor growth but was associated with lethal toxicity approximately 7 days after the final infusion. Limiting dosing to two infusions in GBM108 provided profound median survival extension of over 200 days. In contrast, four Depatux-M CED doses were well tolerated and significantly extended survival in both GBM6 (158 days) and GBM108 (310 days). In a toxicity analysis, Ser-T resulted in a profound loss in NeuN+ cells and markedly elevated GFAP staining, while Depatux-M was associated only with modest elevation in GFAP staining. Conclusion CED of Depatux-M is well tolerated and results in extended survival in orthotopic GBM PDXs. In contrast, CED of Ser-T was associated with a much narrower therapeutic window.

Abstract Introduction: EGFR targeted antibody-drug conjugates (ADCs) show promise as a novel treatment in a subset of glioblastoma (GBM). Two EGFR targeting ADCs include first generation Depatux-M, with an antimitotic toxin monomethyl auristatin F (MMAF), and ABBV-321, with a DNA crosslinking agent pyrrolobenzodiazepine dimer (PBD) toxin. Due to the large molecular weight, poor drug distribution across the blood-brain barrier significantly limits the efficacy in EGFR-amplified GBM. We studied whether convection enhanced delivery (CED) can be used to safely infuse these two EGFR-targeted ADCs in patient-derived xenograft (PDX) models of EGFR-amplified GBM. Methods: The efficacy of Depatux-M and ABBV-321 was evaluated in vitro and in vivo in two EGFRviii-amplified PDXs (GBM6 and GBM108). Immunofluorescence staining was used to evaluate drug distribution along with pharmacodynamics of the ADCs. CED was performed by stereotactic placement of an infusion catheter in the same location as the original tumor implantation. Immunohistochemistry was used to explore mechanisms of normal cell toxicity. Results: Despite potent activity in vitro (high ng/ml IC50), systemic administration of either ADC conferred minimal extension in survival for either GBM6 or GBM108. In contrast, CED significantly enhanced ADC delivery to tumor and peri-tumoral regions and extended survival. In a pilot study in GBM6 with n=3 mice per group, a single CED infusion of 0.002mg ABBV-321 resulted in extended survival beyond 365 days for two mice, while other doses and placebo were associated with shorter median survival (0 mg - 39 days; 0.03 mg - 105 days; 0.3 mg - 49 days). In a subsequent trial evaluating serial infusions performed every 21 days, four infusions at 0.002 mg ABBV-321 resulted in lethal toxicity. In contrast, limiting ABBV-321 to only two serial CED infusions in GBM108 was associated with extended survival of more than 300 days vs. 53 days for AB095 antibody control infusion. In contrast, serial infusion with Depatux-M was much better tolerated. In a single infusion in GBM6, a 0.06 mg dose was well tolerated and associated with a 49-day extension in median survival. Further, four serial infusions at 0.06 mg given every 21 days in GBM6 and GBM108 was associated with 100 day and more than 250-day extension in survival as compared to AB095 antibody control infusion. To investigate the mechanism of toxicity, infusion of non-tumor bearing C57Bl6 mice with ABBV-321 resulted in a marked loss in NeuN staining and elevated CD68 and GFAP staining 7 days later; Depatux-M infusion was only associated with modest elevation in GFAP without loss of NeuN staining or elevated CD68-positive cells. Conclusion: Depatux-M is well tolerated when infused into normal brain and results in extended survival in orthotopic GBM PDXs. In contrast, ABBV-321, with a distinct PBD toxin, had a much narrower therapeutic window when delivered by CED. Citation Format: Kendra A. Porath, Ann Mladek, Rachael A. Vaubel, Michael S. Regan, Sonia Jain, Danielle Burgenske, Katrina Bakken, Brett Carlson, Margaret Connors, Zeng Hu, Lihong He, Paul A. Decker, Gaspar Kitange, Shiv Gupta, Nathalie Y. Agar, Thomas M. Feldsien, Didier R. Lefebvre, Jann N. Sarkaria. Convection enhanced delivery of EGFR-targeting antibody drug conjugates ABBV-321 and Depatux-M [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 334.

Background: It is generally perceived that sample sizes of randomized clinical trials (RCTs) have increased over the years, particularly in specialties such as cardiology, with a robust evidence base. The aim of this study was to analyze temporal trends in sample sizes of RCTs in cardiology journals compared to other specialties. Methods: Abstracts of RCTs involving humans from PubMed for 1970-2013 were analyzed using a digital search algorithm. Sample sizes of studies were extracted from each abstract. Date of publication and journal name were collected. Journals from several medical subspecialties were selected for comparison, using the journal impact factor as a measure of clinical relevance. Sample sizes of studies in 1990 were compared to 2010 for each of the journals using the Mann-Whitney U test. Graphical comparisons of sample size trends are presented. Results: 272,054 abstracts of human RCTs were identified. Median sample sizes for the years 1990 and 2010 is shown in table 1. The median sample size for all RCTs published in Circulation was 99 subjects per study in 1990, increasing to 630 subjects per study in 2010 (p < 0.01). All cardiology journals had a significant increase in study sample size over the 20 year period, as did the multispecialty journals (JAMA, NEJM, Lancet). In contrast, only a few non-cardiology specialty journals published studies with increasing sample sizes (table 1). Figure 1 shows the sample size trend for 1970-2013. Conclusions: Our study demonstrates a dramatic temporal trend of increasing sample sizes in RCTs in cardiology compared to other specialties. Since sample size is estimated based on the effect size studied, one explanation for this observation is that the more obvious larger effects have been previously elucidated, leaving only smaller associations to be studied. This requires increasing resources, highlighting the importance of alternate study designs and collaborative registries to develop a cost effective evidence base.

BACKGROUND: Idiopathic recurrent pericarditis (IRP) is a debilitating condition that can be recalcitrant to conventional therapy. Some patients develop steroid dependency with the attendant risks of systemic side effects and increased future recurrence. Anakinra is a recombinant human interleukin-1 receptor antagonist that reduces systemic inflammatory responses. The aim of this study was to evaluate the therapeutic role of anakinra in IRP. Methods: We retrospectively studied consenting patients with treatment refractory IRP who received anakinra, between January 2009 and November 2013. The primary end points were symptom resolution and steroid discontinuation. Results: Nine patients were followed for a median of 16.8 (IQR 1.3-24) months. Study subjects were predominantly female (7 [78%]) with a median age of 53 (IQR 38 - 58) years. All 9 patients had failed maximum tolerated doses of NSAIDs, colchicine and prednisone (median dose 20 mg [IQR 15 - 22.5]). Primary symptom was chest pain in 9 (100%), with concurrent dyspnea in 5 (56%) patients. Symptom duration prior to anakinra initiation was 24 (IQR 13 - 71) months. Indication for anakinra was steroid sparing agent in 7 (78%) and symptom control in 2 (22%) patients. The dosage was 100 mg once daily via subcutaneous injection. Baseline LVEF was 62% (IQR 59% - 67%). Echocardiographic findings include pericardial effusion in 3 (33%), pericardial thickening in 6 (67%), and constrictive physiology in 4 (44%). Pericardial enhancement on cardiac MRI was seen in 7 (78%) patients. All 9 patients (100%) had symptom improvement with complete resolution in 8 (89%) and partial resolution in 1 (11%) patient. At last follow up, all 9 (100%) patients had discontinued NSAIDs and colchicine, 5 (56%) patients discontinued and 4 (44%) had reduced prednisone dosage. All patients remained on anakinra at the end of follow up. The only reported side effect was transient injection site reaction in 4 (44%) patients. In 2 (22%) patients, attempted anakinra weaning was unsuccessful due to symptomatic flare after 6 weeks. Conclusion: Anakinra is an effective alternative agent for the management of steroid dependent IRP. It provides remarkable symptomatic amelioration, limits steroid dependency, and is associated with minimal side effects.

Abstract Background Antibody drug conjugates (ADCs) targeting the epidermal growth factor receptor (EGFR), such as depatuxizumab mafodotin (Depatux-M), is a promising therapeutic strategy for glioblastoma (GBM) but recent clinical trials did not demonstrate a survival benefit. Understanding the mechanisms of failure for this promising strategy is critically important. Methods PDX models were employed to study efficacy of systemic vs intracranial delivery of Depatux-M. Immunofluorescence and MALDI-MSI were performed to detect drug levels in the brain. EGFR levels and compensatory pathways were studied using quantitative flow cytometry, Western blots, RNAseq, FISH, and phosphoproteomics. Results Systemic delivery of Depatux-M was highly effective in nine of 10 EGFR-amplified heterotopic PDXs with survival extending beyond one year in eight PDXs. Acquired resistance in two PDXs (GBM12 and GBM46) was driven by suppression of EGFR expression or emergence of a novel short-variant of EGFR lacking the epitope for the Depatux-M antibody. In contrast to the profound benefit observed in heterotopic tumors, only two of seven intrinsically sensitive PDXs were responsive to Depatux-M as intracranial tumors. Poor efficacy in orthotopic PDXs was associated with limited and heterogeneous distribution of Depatux-M into tumor tissues, and artificial disruption of the BBB or bypass of the BBB by direct intracranial injection of Depatux-M into orthotopic tumors markedly enhanced the efficacy of drug treatment. Conclusions Despite profound intrinsic sensitivity to Depatux-M, limited drug delivery into brain tumor may have been a key contributor to lack of efficacy in recently failed clinical trials.

Objectives Cleft-like indentations (CLI) are deep separations between scallops of the mitral posterior leaflet observed in myxomatous mitral valve disease (MMVD), but their diagnosis, mechanisms and implications are unknown. Using 3D transoesophageal echocardiography (3DTOC), we aimed at assessing diagnostic accuracy and defining mechanisms of CLI in patients undergoing surgery for MMVD. Methods 3DTOC of mitral valve was acquired in 49 patients with MMVD and severe regurgitation prior to valve repair. Qualitative review compared 3DTOC diagnosis of CLI with surgical inspection. Mitral, annular and leaflet dimensions were quantified with dedicated software and compared between those with and without CLI. Results Diagnosis of CLI was made by 3DTOC in 17 (35%) while none was identified by 2D and was confirmed in 15 (88%) by surgical inspection. Mechanistically, LV diameters and mitral regurgitant volume (RVol) were similar with and without CLI (p>0.49). Conversely, mitral annulus was smaller with CLI (anteroposterior diameter 42.2±7.1 vs 47.0±7.5 mm, p=0.04; circumference 133±16 vs 148±19 mm, p=0.009; area 1289±326 vs 1619±427 mm2, p=0.008). Prolapse volume tended to be smaller with CLI (1.9±1.2 vs 4.0±4.3 mL, p=0.06) involving single posterior scallop at surgery (82% vs 44%, p=0.007) with smaller 3DTOC leaflet area (1574±409 vs 2019±652 mm2, p=0.01). During valve repair, surgical closure of all surgically diagnosed CLI was required. Conclusions Posterior leaflet CLI are frequent in MMVD, are identified by 3DTOC with high accuracy and require closure during valve repair. CLI are mechanistically not related to excess annular enlargement or excess prolapse. Conversely, CLI occur in the context of single scallop prolapse with tissue paucity causing excess separation of scallops. These 3DTOC data enhance diagnostic and mechanistic comprehension of the diversity of MMVD phenotypical presentation.