A Case of Sustained Tumor Regression With MP0274, a Novel DARPin Therapeutic Targeting Human Epidermal Growth Factor Receptor 2 Signaling, in Metastatic Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer After Prior Trastuzumab and Pertuzumab.

The human epidermal growth factor receptor 2 (HER2, ERBB2) is amplified or overexpressed in approximately 20% of breast cancers. HER2 amplification results in increased homodimerization and HER3 heterodimerization, with HER2/HER3 heterodimers promoting cell proliferation via the mitogen-activated protein kinase/AKT pathway and also evasion of apoptosis via the phosphatidylinositol 3-kinase (PI3K) signaling cascade. Oncogenic mutations in PI3KCA render tumor cells resistant to drugs that block HER2 dimerization, thereby promoting cell survival. Although several approved HER2-directed agents have shown significant survival improvements for HER2-positive patients, in the metastatic setting, nearly all of these patients will ultimately progress and die of their disease

Phase I study of safety, tolerability, and pharmacokinetics of pazopanib in combination with oral topotecan in patients with advanced solid tumors.

2536 Background: To determine the maximum-tolerated dose (MTD), safety, tolerability and pharmacokinetics of the oral anti-angiogenic drug pazopanib in combination with oral topotecan, an inhibitor of topoisomerase-I. Methods: Two-stage, two-arm, dose escalation and pharmacokinetic phase I study of pazopanib and oral topotecan in patients with advanced solid tumors, (NCT00732420, www.clinicaltrials.gov). This interim report describes the bioavailability and safety results for daily pazopanib combined with oral topotecan (days 1, 8, 15) in a 28-day cycle. Results: Twenty-eight of 32 patients completed at least one cycle and were evaluable for analysis. Three dose-limiting toxicities (DLTs) occurred: grade 3 hand-foot-syndrome, diarrhea and neutropenia. Pazopanib 800 mg/topotecan 10 mg exceeded the MTD with two DLTs in six patients. The most frequent treatment-related toxicities were grade 3 anemia (3/28), leukocytopenia, neutropenia and fatigue (2/28 each). One death due to hepatic failure occurred at pazopanib 800mg/toptecan 2mg in a heavily pre-treated patient with sarcoma that may have been related to paracetamol ingestion but attribution to the pazopanib can not be excluded. Topotecan AUC0-∞ increased 1.58-fold (90%CI: 1.09–1.29) and Cmax increased 1.78-fold (90%CI: 1.08-2.92) when given with pazopanib compared to single administration (n=7). Pazopanib AUC0-24 and Cmax ratios were not increased when co-administered with topotecan: 0.98 (90%CI: 0.95-1.02) and 0.96 (90%CI: 0.92-1.01). Twenty-three patients were evaluable for response (RECIST): PR (2/23; 9%, both ovarian cancer); SD (13/23; 57%) and PD (8/23; 35%). Pazopanib 800 mg/topotecan 8 mg is currently being explored in an expansion cohort. A second treatment arm of pazopanib 800 mg with topotecan daily x5 is ongoing and will be reported separately. Conclusions: Daily pazopanib and weekly oral topotecan is tolerable with handfoot syndrome, neutropenia and fatigue as dose limited side effects. Pazopanib increased topotecan exposure 1.58-fold (AUC0-∞) and 1.78-fold (Cmax). Clinical trial information: NCT00732420. </jats:p

Abstract 1733: MP0317, a CD40xFAP targeting multi-specific DARPin® therapeutic, drives immune activation and reverts myeloid-mediated T-cell suppression in vitro and ex vivo

Abstract Therapeutic agonists targeting CD40 have shown encouraging signs of anti-tumor efficacy in patients. Despite their initial promise however, optimal dosing of systemically active agents has been limited by toxicity and their full therapeutic potential not achieved. We have previously demonstrated in vitro the ability of MP0317, a novel multi-specific DARPin® therapeutic, to selectively activate CD40 bearing B-cells, dendritic cells and macrophages in the presence of fibroblast activation protein (FAP). FAP is highly expressed in the stroma of many solid tumors and is found only at lower levels in other tissues. MP0317 utilizes FAP and CD40 binding domains to selectively cross-link and activate CD40 in the presence of FAP and thus avoid systemic CD40 activation classically associated with toxicity. Here we present new data which confirm the unique therapeutic potential of MP0317 in ex vivo model systems, demonstrate modulation of macrophage phenotype and reveal a release of T-cells from macrophage-mediated suppression. Ex vivo functional assays performed with MP0317 on dissociated human tumors demonstrated FAP-dependent activation of CD40-expressing B-cell and myeloid cell populations. Immunohistochemical analysis of tissue micro-arrays demonstrated FAP levels consistent with those required for immune cell activation in a broad range of solid tumor indications. Furthermore, by mining publicly available data, we classified tumor indications based on their immune cell content, pathway activation and MP0317 ex vivo mode of action (T cell/macrophage ratio, FAP and CD40 expression) and proposed patient populations and indications for the upcoming clinical trials. To further investigate the functional impact of MP0317, macrophages were differentiated in vitro using canonical polarising cytokines. Suppressive tumor-associated macrophage (TAM)-like cells, were repolarized by MP0317 to an anti-tumor-like phenotype. Furthermore, we explored whether modulation of macrophage phenotype by MP0317 could relieve their suppressive effect on T-cells. TAM-like macrophages potently supressed anti-CD3/28 driven T-cell activation and indeed the addition of MP0317 was found to restore T-cell response. Together these data further support MP0317's FAP targeted multimodal mechanism of action in human tumors, provide evidence for an improved therapeutic window over existing CD40 agonists and support progression to the clinic with an informed target patient profile. Citation Format: Kyriaki Ioannou, Simone Ragusa, Joanna Roquette, Ana Florescu, Mariam Gachechiladze, Eliane Müller, Julia M. Martinez-Gomez, Sophie Barsin, Sarah Jetzer, Nicolo Rigamonti, Clara Domke, Tamara Lekishvili, Karolin Rommel, Ivana Tosevski, Anne Goubier, Philippe Legenne, Vladimir Kirkin, Mitch Levesque, Hong Ji, Rupert Kenefeck. MP0317, a CD40xFAP targeting multi-specific DARPin® therapeutic, drives immune activation and reverts myeloid-mediated T-cell suppression in vitro and ex vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1733.</jats:p

A phase 1b/2 study evaluating efficacy and safety of MP0250, a designed ankyrin repeat protein (DARPin) simultaneously targeting vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), in combination with bortezomib and dexamethasone, in patients with relapsed or refractory multiple myeloma

Abstract MP0250 is a designed ankyrin repeat protein that specifically inhibits both vascular endothelial growth factor A (VEGF‐A) and hepatocyte growth factor (HGF), aiming at potentiating cancer therapy by disrupting the tumour microenvironment. Encouraging results from a phase 1 trial of MP0250 in patients with solid tumours prompted further investigation in multiple myeloma (MM) as both MP0250 targets are reported to be drivers of MM pathogenesis. In this open‐label, single‐arm phase 1b/2 study (NCT03136653) in patients with proteasome inhibitor‐ and/or immunomodulatory drug‐relapsed or refractory MM, MP0250 was administered every 3 weeks with standard bortezomib/dexamethasone regimen. Thirty‐three patients received at least one dose of MP0250. The most frequent treatment‐related adverse events were arterial hypertension (58.1%), thrombocytopenia (32.3%), proteinuria (29.0%) and peripheral oedema (19.4%). Of the 28 patients evaluable for response (median age: 60 [range 44–75]), nine achieved at least partial response, corresponding to an overall response rate of 32.1% (95% confidence interval [CI]: 17.9%, 50.7%), with a median duration of response of 8 months (95% CI 5–NR). An additional three patients achieved minimal response and nine stable diseases as the best overall response. Overall median progression‐free survival was 4.2 months (95% CI 1.9–7.1). These findings are in line with the results of recent trials testing new agents on comparable patient cohorts and provide initial evidence of clinical benefit for patients with refractory/relapsed MM treated with MP0250 in combination with bortezomib/dexamethasone. Further clinical evaluation in the emerging MM treatment landscape would be required to confirm the clinical potential of MP0250.MP0250 is a designed ankyrin repeat protein that specifically inhibits both vascular endothelial growth factor A (VEGF-A) and hepatocyte growth factor (HGF), aiming at potentiating cancer therapy by disrupting the tumour microenvironment. Encouraging results from a phase 1 trial of MP0250 in patients with solid tumours prompted further investigation in multiple myeloma (MM) as both MP0250 targets are reported to be drivers of MM pathogenesis. In this open-label, single-arm phase 1b/2 study (NCT03136653) in patients with proteasome inhibitor- and/or immunomodulatory drug-relapsed or refractory MM, MP0250 was administered every 3 weeks with standard bortezomib/dexamethasone regimen. Thirty-three patients received at least one dose of MP0250. The most frequent treatment-related adverse events were arterial hypertension (58.1%), thrombocytopenia (32.3%), proteinuria (29.0%) and peripheral oedema (19.4%). Of the 28 patients evaluable for response (median age: 60 [range 44-75]), nine achieved at least partial response, corresponding to an overall response rate of 32.1% (95% confidence interval [CI]: 17.9%, 50.7%), with a median duration of response of 8 months (95% CI 5-NR). An additional three patients achieved minimal response and nine stable diseases as the best overall response. Overall median progression-free survival was 4.2 months (95% CI 1.9-7.1). These findings are in line with the results of recent trials testing new agents on comparable patient cohorts and provide initial evidence of clinical benefit for patients with refractory/relapsed MM treated with MP0250 in combination with bortezomib/dexamethasone. Further clinical evaluation in the emerging MM treatment landscape would be required to confirm the clinical potential of MP0250.</p