Objective Responses In Patients Research Articles

Zongertinib (BI 1810631), an irreversible HER2 TKI, spares EGFR signaling and improves therapeutic response in preclinical models and patients with HER2-driven cancers.

Mutations in HER2 occur in 2-4% of non-small cell lung cancer (NSCLC) and confer poor prognosis. ERBB-targeting tyrosine kinase inhibitors, approved for treating other HER2-dependent cancers, are ineffective in HER2 mutant NSCLC due to dose-limiting toxicities or suboptimal potency. We report the discovery of zongertinib (BI 1810631), a covalent HER2 inhibitor. Zongertinib potently and selectively blocks HER2, while sparing EGFR, and inhibits the growth of cells dependent on HER2 oncogenic driver events, including HER2-dependent human cancer cells resistant to trastuzumab deruxtecan. Zongertinib displays potent anti-tumor activity in HER2-dependent human NSCLC xenograft models and enhances the activities of antibody-drug conjugates and KRASG12C inhibitors, without causing obvious toxicities. The preclinical efficacy of zongertinib translates in objective responses in patients with HER2-dependent tumors, including cholangiocarcinoma (SDC4-NRG1 fusion) and breast cancer (V777L HER2 mutation) thus supporting the ongoing clinical development of zongertinib.

Optimal cut-off value for identifying objective response in patients with nasopharyngeal carcinoma after induction chemotherapy.

We aimed to establish the most suitable threshold for objective response (OR) in the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 in patients with nasopharyngeal carcinoma (NPC). According to RECIST 1.1, we retrospectively evaluated MR images of NPC lesions in patients before and after induction chemotherapy (IC). Restricted cubic spline and maximally selected rank statistics were used to determine the cut-off value. Survival rates and differences between groups were compared with Kaplan-Meier curves and log-rank tests. Of 1126 patients, 365 cases who received IC treatment were suitable for RECIST 1.1 evaluation. The 20% cut-off value maximized between-group differences according to maximally selected rank statistics. No difference in distant metastasis-free survival between OR and non-response groups was shown using the primary threshold of OR (30%), while it differed when 20% was employed. With an optimal cut-off value of 20%, RECIST may assist clinicians to accurately evaluate disease response in NPC patients.

Abstract 4536: MTAP loss alters the epigenetic landscape and demonstrates superior therapeutic sensitivity to concomitant PRMT5 and PARP inhibition in cholangiocarcinoma

Abstract 5’-methylthioadenosine phosphorylase (MTAP), is deleted in 15% of all cancers (estimated 100,000 patients per year in the United States), including 12-15% of cholangiocarcinoma (CCA) cases. MTAP deficiency accumulates 5’-methylthioadenosine (MTA) that subsequently binds protein arginine methyl transferase 5 (PRMT5) and inhibits its activity. This renders selective targeting of MTAP null tumors with agents (MRTX1719, AMG193, TNG462, TNG908) targeting MTA bound PRMT5 (PRMT5:MTA), while sparing surrounding normal MTAP wild-type (WT) tissue. Early signs of clinical activity was seen with MRTX1719, including objective responses in patients with MTAP loss tumors, including biliary tract cancer from the phase I/II study (NCT05245500). Despite these advances, prolonged targeted therapy poses the risk of development of acquired resistance demanding the need for better therapeutic strategies. To address this pressing need, we co-treated CCA cell lines with MRTX1719 and PARP inhibitor olaparib. We hypothesize that since PRMT5 is a critical regulator of splicing and DNA damage pathways, inhibition of PRMT5 disrupts these downstream processes creating an additional vulnerability to DNA damage inducing agents such as PARP inhibitors. Our preliminary data combining MRTX1719 with olaparib in three MTAP loss CCA cell lines (RBE, YSCCC, TFK1) show synergy (combination index; CI<1), and significant reduction in cell viability as well as colony formation ability when compared to monotherapy in vitro. To further gain mechanistic insights into the biology of MTAP loss, we stably expressed MTAP in MTAP null CCA cell line, RBE and demonstrated that MTAP loss drives tumorigenesis in vivo highlighting its tumor suppressor function in CCA. Mass spectrometry-based profiling of histone modifications from the isogenic RBE cell lines showed heightened methylation and reduced acetylation marks in the absence of MTAP. We also noted substantial differences in the distribution of splicing events, with increased intron retention, 3’ alternative splicing and decreased exon skipping as a result of MTAP loss. Similar differences in proportion of splicing events were also observed in MTAP loss CCA patient derived xenografts as compared to WT models. Collectively, these data implicate MTAP to be a crucial player in modulation of the chromatin and splicing events that may drive therapeutic response to PRMT5 inhibition. Citation Format: Pooja A. Shah, Ajay Kumar Saw, William Padron, Ming Zhao, Argun Akcakanat, Kurt Evans, Funda Meric-Bernstam, Milind Javle, Jordi Rodon, Kunal Rai. MTAP loss alters the epigenetic landscape and demonstrates superior therapeutic sensitivity to concomitant PRMT5 and PARP inhibition in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4536.

Abstract 5470: ONC206 inhibits tumour growth and is a potential novel therapeutic strategy for refractory medulloblastoma

Abstract Medulloblastoma is the most common malignant pediatric brain tumor with a for certain molecular subgroups very low overall survival and therefore an urgent need for novel treatment approaches. Dordaviprone (ONC201) and its chemical derivative with nanomolar potency ONC206 are inhibitors of the dopamine receptor 2 (DRD2) and more importantly induce apoptosis of cancer cells by activation of the mitochondrial caseinolytic protease P (ClpP). ONC201 has shown objective responses in patients with diffuse midline gliomas and is currently being evaluated in the Phase 3 ACTION study. ONC206 is currently in Phase I clinical trials for pediatric and adult patients with primary brain tumors. In this study, we evaluated the preclinical therapeutic effects of ONC206 in medulloblastoma in vitro and in vivo and investigated the molecular mode of action for this imipridone. We found evidence for high expression of ClpP at both the RNA and protein level in medulloblastoma tumours, compared to very low expression in normal brain and normal cerebellum. In addition, we saw a pronounced reduction in cell viability of human Group 3 and Group 4 and murine medulloblastoma cells treated with ONC206 with extremely low IC-50s (range: 14nM - 2μM).After treatment with ONC206, we observed a significant downregulation of mitochondrial electron transport chain complexes I and III and mitochondrial hyperpolarization, as well as an induction of the ATF4 pathway, thereby implying that ONC206 induces an integrated stress response and mitochondrial damage. In order to test the efficacy of ONC206 in vivo, we used murine models of SHH-driven and Group 3 medulloblastoma as well as Group 3 patient-derived xenografts (PDXs). ONC206 led to a significant prolongation of survival in both murine models, with the SHH mice demonstrating a remarkable survival benefit. Mice from both Group 3 PDXs also responded to ONC206, with 25% of ONC206 treated animals exhibiting long-term tumor-free survival. Our results highlight ONC206 as a novel attractive therapeutic option for patients with relapsed medulloblastoma and importantly pave the way for a clinical trial testing the efficacy of ONC206 in the treatment of these patients. Citation Format: Theophilos Tzaridis, Jingbo Liu, Varun Prabhu, Robert Wechsler-Reya, Tobey MacDonald. ONC206 inhibits tumour growth and is a potential novel therapeutic strategy for refractory medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5470.

Somatostatin Receptor Subtype-2 Targeting System for Specific Delivery of Temozolomide.

Temozolomide (TMZ) is a DNA alkylating agent that produces objective responses in patients with neuroendocrine tumors (NETs) when the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) is inactivated. At high doses, TMZ therapy exhausts MGMT activity but also produces dose-limiting toxicities. To reduce off-target effects, we converted the clinically approved radiotracer 68Ga-DOTA-TOC into a peptide-drug conjugate (PDC) for targeted delivery of TMZ to somatostatin receptor subtype-2 (SSTR2)-positive tumor cells. We used an integrated radiolabeling strategy for direct quantitative assessment of receptor binding, pharmacokinetics, and tissue biodistribution. In vitro studies revealed selective binding to SSTR2-positive cells with high affinity (5.98 ± 0.96 nmol/L), internalization, receptor-dependent DNA damage, cytotoxicity, and MGMT depletion. Imaging and biodistribution analysis showed preferential accumulation of the PDC in receptor-positive tumors and high renal clearance. This study identified a trackable SSTR2-targeting system for TMZ delivery and utilizes a modular design that could be broadly applied in PDC development.

Carboplatin and paclitaxel after anti-PD-1 or anti-PD-L1 antibody therapy in recurrent and/or metastatic squamous cell carcinoma of head and neck.

The impact of concurrent chemotherapy and immunotherapy has been well characterized in patients with recurrent and metastatic head and neck squamous cell carcinoma (RM-SCCHN). Here, we report outcomes in patients treated sequentially with immune checkpoint inhibition (ICI) followed by carboplatin and paclitaxel. Patients with RM-SCCHN treated with ICI followed by carboplatin/paclitaxel at a single institution were identified retrospectively. ICI therapy history, p16, and PD-L1 status were collected. The best overall response was assessed by RECIST v1.1. Twelve patients met inclusion criteria. Eight patients received pembrolizumab, three durvalumab, and one nivolumab. The median duration of ICI was 3.44 months, median PFS was 5.8 months, and median OS was 15.2 months. 66.7% of patients had an objective response on carboplatin/paclitaxel. Carboplatin/paclitaxel can induce objective responses in patients with prior treatment with ICI and clinical outcomes in this small series compare favorably to those seen in ICI naïve patients.

Abstract B019: Clinical and molecular characterization of chromophobe renal cell carcinoma: A focus on immunotherapy based regimens and the tumor immune microenvironment

Abstract Background: Chromophobe renal cell carcinoma (ChRCC) represents 5% of all kidney cancers. In contrast to clear cell RCC (ccRCC), the immune landscape of ChRCC and its response to immunotherapy remain poorly characterized. We sought to evaluate the clinical outcomes of patients with ChRCC treated with immuno-oncology (IO)-based regimens, and assess the immune cell composition, phenotypic state, and T cell specificity in the tumor microenvironment of ChRCC. Methods: Using real-world data from the International Metastatic RCC Database Consortium, we analyzed the survival outcomes and objective responses of patients with advanced ChRCC to currently adopted IO-based regimens (i.e. dual IO therapy or IO + vascular endothelial growth factor targeted therapy [VEGF-TT]) in the first-line setting, as compared to patients with ccRCC. Single-cell RNA sequencing (scRNA-seq) and single-cell T-cell receptor sequencing (scTCR-seq) were performed on ChRCC and related oncocytic neoplasms (i.e. renal oncocytoma [RO] and low-grade oncocytic tumor [LOT]) samples with matched normal kidney specimens. The infiltration of CD45+ immune cells in renal oncocytic tumors and ccRCC samples was quantified using immunohistochemistry (IHC). Results: Compared to patients with ccRCC (n=856) treated with first-line IO-based regimens, patients with ChRCC (n=31) had a lower overall survival (median: 24.7 vs. 50.5 months, p<0.001) and lower time to treatment failure (median: 4.5 vs. 11.0 months, p<0.001). Similarly, patients with ChRCC had a significantly lower overall response rate than those with ccRCC (12.0 vs. 47.1%, respectively; p<0.001). When evaluating immune cell infiltration, renal oncocytic tumors (ChRCC, RO, and LOT) exhibited a low density of CD45+ cells (mean: 739 ± 114 cells/mm2; n=5) compared to ccRCC (mean: 3,420 ± 1,979 cells/mm2; n=5) (p<0.05). Single-cell analysis was performed on 46,817 cells from 5 tumors (ChRCC: n=3, RO: n=1 and LOT: n=1) and 4 samples from adjacent normal kidney. Across all tumors, CD8+ T cell clusters displayed a lower expression of immune checkpoints (i.e. PDCD1, CTLA4, LAG3, HAVCR2, and TIGIT) as compared to CD8+ T-cells from ccRCC. This was further validated in the analysis of bulk RNA-seq data from the TCGA, with a significantly lower expression of all immune checkpoints in ChRCC compared to both ccRCC (p<0.01) and papillary RCC (pRCC; p<0.01). Analysis of the T cell receptor repertoire (scTCR-seq) of ChRCC, RO and LOT samples did not show any pattern of clonal expansion, and a higher proportion of T cells in ChRCC were inferred to have a viral specificity, compared to ccRCC (0.79 vs. 0.1%, respectively). Conclusions: Patients with metastatic ChRCC appear to display poor clinical outcomes when treated with IO-based regimens, compared to ccRCC. Renal oncocytic tumors, including ChRCC, exhibit a low infiltration of immune cells, and a non-exhausted immune phenotype. Citation Format: Michel Alchoueiry, Chris Labaki, Long Zhang, Yue Hou, Kevin Bi, Charbel Hobeika, J. Connor Wells, Kosuke Takemura, Ziad Bakouny, Sabrina Camp, Carmen Priolo, Damir Khabibullin, Nicholas Schindler, Renee Maria Saliby, Eddy Saad, Samer Salem, Melissa Daou, Rana McKay, Sumanta Pal, Daniel Heng, Eliezer Van Allen, Sachet Shukla, Toni Choueiri, David Braun, Elizabeth Henske. Clinical and molecular characterization of chromophobe renal cell carcinoma: A focus on immunotherapy based regimens and the tumor immune microenvironment [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr B019.

Initial results of a phase II study of nivolumab(N) and ipilimumab(I) in genitourinary malignancies with neuroendocrine differentiation.

569 Background: Patients with metastatic genitourinary malignancies with neuroendocrine have limited therapeutic options following platinum therapy. Given encouraging results in initial cohort analysis for small cell urinary tract carcinoma, a cohort of any genitourinary malignancy with neuroendocrine differentiation was added to a multicenter, single arm, multi-cohort phase II trial to evaluate the efficacy of N and I in this setting. (NCT 03333616) Methods: Eligible patients had metastatic or locally advanced genitourinary malignancy with neuroendocrine differentiation with an ECOG performance status of 0-2; they may have received any line of prior therapy excluding prior immunotherapy. Patients underwent baseline biopsy and received treatment with N 3 mg/kg and I 1 mg/kg intravenously every 3 weeks for 4 cycles with continued maintenance of N 480 mg IV every 4 weeks. Imaging was performed at 12 weeks and then every 8 weeks through month 6 and then every 12 weeks thereafter. The primary endpoint was investigator assessed objective response rate (ORR) by RECIST 1.1. Results: A total of 27 patients were enrolled between 06/27/2018 and 06/21/2021, 10 (37%) had urinary tract cancer and 17 (63%) had prostate cancer (19 in expansion cohort, 3 urinary tract and 5 prostate cancer from earlier cohorts). The majority (n=25, 93%) patients received prior systemic therapy. Nine (33%) patients received all 4 doses of N and I during the induction period. Nine (33%) patients (7 of whom received 4 cycles N+I) received N maintenance (median number of cycles 9 (range, 2-37)). Median follow-up was 6.8 (range, 0.9-37.3) months. Objective response was achieved in 8 (30%, 80% CI 18%-44%) patients (Table). Median duration of response was not reached with 4 patients maintaining response >9 months. Median progression-free survival time was 2.6 (95% CI 1.8-6.5) months At time of analysis, 13 (48%) death events were reported due to progressive disease, in which 3 were bladder and 10 were prostate cancer. 8 (30%) patients developed treatment-related grade 3 or higher toxicities; one grade 5 toxicity was deemed treatment-unrelated. Conclusions: In this study we demonstrate N+I resulted in objective responses in patients with genitourinary malignancy with neuroendocrine differentiation. ORR of 50% in small cell carcinoma is bladder cancer is noteworthy and will be evaluated further in ongoing expansion cohort of bladder or upper tract carcinoma with variant histology. Clinical trial information: NCT03333616. [Table: see text]

Abstract P4-01-02: A spectrum of secondary mutations in HER2 augment breast cancer cell growth and reduce neratinib sensitivity in HER2-mutant breast cancer

Abstract Activating mutations in HER2 (ERBB2) drive tumor growth and antiestrogen resistance in ~5% of metastatic ER+ breast cancers. Treatment with the irreversible HER2 tyrosine kinase inhibitor neratinib, in combination with fulvestrant, leads to objective responses in patients with HER2-mutant ER+ breast cancer. However, acquired resistance is common. The majority of HER2-mutant tumors progressing on neratinib-based therapy acquire secondary mutations in HER2. Except for the HER2T798I gatekeeper mutation, whether these secondary HER2 mutations are causal to neratinib resistance is not known. We hypothesized that secondary HER2 mutations augment HER2 pathway activation and promote neratinib resistance. We first studied acquired secondary HER2 mutations found in circulating tumor DNA (ctDNA) of 2 patients with breast cancer harboring the primary HER2L869R hotspot mutation. The following mutations were absent at baseline but detected in ctDNA at the time of progression on neratinib: S310Y, L755S, D769Y, and T798I (patient 1, partial response to neratinib/fulvestrant >16 months); and T862A, T798I, S310F, and I767M (patient 2, stable disease >7 months). We stably expressed each mutation alone or in combination with HER2L869R in MCF10A breast epithelial cells. All single mutations, with the exception of T862A and T798I, promoted growth factor-independent proliferation and growth in 3D Matrigel. Enhanced growth was blocked by treatment with 10 nM neratinib. Cells expressing HER2L869R together with S310F, I767M, and D769Y remained highly sensitive to neratinib (IC50 <6 nM). In contrast, HER2L869R/L755S and HER2L869R/T862A (double-mutant) cells formed large acini in 3D Matrigel in the presence of neratinib, and exhibited a 3- to 5-fold higher IC50 than HER2L869R in 2D cell viability assays. Western blot analysis revealed that HER2L869R/L755S and HER2L869R/T862A cells required a higher concentration of neratinib (50-100 nM; 4 h) to block phosphorylation of HER2 and downstream targets AKT, ERK, and S6 relative to cells transduced with HER2L869R alone (10 nM neratinib). While HER2T862A alone did not increase HER2 pathway activation or growth factor-independent growth compared to wild type (WT) HER2, phosphorylation of HER2, AKT, ERK, and S6 was elevated in cells expressing HER2L869R/T862A relative to each single-mutant. Likewise, cells expressing HER2L869R/T862A formed larger and more invasive acini in 3D Matrigel. Computational modeling predicted that the active state of HER2 was stabilized in the HER2L869R/T862A double-mutant relative to that of either single mutant. The overall energetic barrier for the active to inactive state transition also increased for the double mutant compared to that of each single mutant. Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) simulations showed that neratinib binding affinity is higher for HER2L869R/T862Arelative to HER2L869R or HER2WT. Two secondary HER2 juxtamembrane domain mutations, E698del and P699L, were also acquired in HER2V777L-driven breast cancers that had progressed on neratinib. However, MCF10A cells co-transduced with V777L/E698del and with V777L/9669L remained highly sensitive to neratinib. Conclusions: In tumors with an oncogenic primary HER2 mutation, acquired secondary mutations in HER2L755S and HER2T862A reduced neratinib sensitivity. The HER2L869R/T862A double-mutant stabilizes the HER2 activation state and enhances HER2 signaling output which, in turn, was incompletely blocked by neratinib. Some but not all acquired secondary HER2 mutations enhance breast tumor growth and/or are causal to neratinib resistance. Citation Format: Arnaldo Andres Marin, Abdullah Al Mamun, Hiroaki Akamatsu, Dan Ye, Dhivya Sudhan, Benjamin Brown, Monica Red Brewer, Lisa Eli, Jens Meiler, Carlos L Arteaga, Ariella B Hanker. A spectrum of secondary mutations in HER2 augment breast cancer cell growth and reduce neratinib sensitivity in HER2-mutant breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-01-02.

Atezolizumab Combined with Immunogenic Salvage Chemoimmunotherapy (R-GemOx+Atezo) in Patients with Transformed Diffuse Large B-Cell Lymphoma

Atezolizumab Combined with Immunogenic Salvage Chemoimmunotherapy (R-GemOx+Atezo) in Patients with Transformed Diffuse Large B-Cell Lymphoma

Combining CD47 blockade with trastuzumab eliminates HER2-positive breast cancer cells and overcomes trastuzumab tolerance

Trastuzumab, a targeted anti-human epidermal-growth-factor receptor-2 (HER2) monoclonal antibody, represents a mainstay in the treatment of HER2-positive (HER2+) breast cancer. Although trastuzumab treatment is highly efficacious for early-stage HER2+ breast cancer, the majority of advanced-stage HER2+ breast cancer patients who initially respond to trastuzumab acquire resistance to treatment and relapse, despite persistence of HER2 gene amplification/overexpression. Here, we sought to leverage HER2 overexpression to engage antibody-dependent cellular phagocytosis (ADCP) through a combination of trastuzumab and anti-CD47 macrophage checkpoint immunotherapy. We have previously shown that blockade of CD47, a surface protein expressed by many malignancies (including HER2+ breast cancer), is an effective anticancer therapy. CD47 functions as a "don't eat me" signal through its interaction with signal regulatory protein-α (SIRPα) on macrophages to inhibit phagocytosis. Hu5F9-G4 (magrolimab), a humanized monoclonal antibody against CD47, blocks CD47's "don't eat me" signal, thereby facilitating macrophage-mediated phagocytosis. Preclinical studies have shown that combining Hu5F9-G4 with tumor-targeting antibodies, such as rituximab, further enhances Hu5F9-G4's anticancer effects via ADCP. Clinical trials have additionally demonstrated that Hu5F9-G4, in combination with rituximab, produced objective responses in patients whose diffuse large B cell lymphomas had developed resistance to rituximab and chemotherapy. These studies led us to hypothesize that combining Hu5F9-G4 with trastuzumab would produce an anticancer effect in antibody-dependent cellular cytotoxicity (ADCC)-tolerant HER2+ breast cancer. This combination significantly suppressed the growth of ADCC-tolerant HER2+ breast cancers via Fc-dependent ADCP. Our study demonstrates that combining trastuzumab and Hu5F9-G4 represents a potential new treatment option for HER2+ breast cancer patients, even for patients whose tumors have progressed after trastuzumab.

TTI-621 (SIRPαFc), an Immune Checkpoint Inhibitor Blocking the CD47 “Do Not Eat” Signal, Induces Objective Responses in Patients with Advanced, Relapsed/Refractory Diffuse Large B-Cell Lymphoma (DLBCL)

BackgroundCD47 is an immune checkpoint that binds to signal regulatory protein alpha (SIRPα) and delivers a “do not eat” signal to suppress macrophage phagocytosis. Tumor cells frequently overexpress CD47 to evade macrophage-mediated destruction. TTI-621 (SIRPαFc) is an immune checkpoint inhibitor consisting of the CD47 binding domain of human SIRPα linked to the Fc region of human IgG1 designed to both: 1) block the CD47 “do not eat” signal, and 2) engage macrophage Fcγ receptors with IgG1 Fc to enhance phagocytosis and antitumor activity.MethodsA phase 1, open-label, multicenter study is ongoing to evaluate the activity of weekly IV infusions of TTI-621 in multiple cohorts of adult patients (pts) with relapsed or refractory malignancies. Eligible pts are those who have progressed on standard anticancer therapy (including rituximab for pts with B-cell lymphomas), or those for whom no other approved therapy exists (NCT02663518). This data disclosure comprises all consecutively enrolled pts with diffuse large B-cell lymphoma (DLBCL) who received, at a minimum, 0.2 mg/kg/week TTI-621 monotherapy or 0.1 mg/kg TTI-621 in combination with 375 mg/m2/week rituximab for 8 weeks, after which TTI-621 monotherapy was permitted.ResultsAs of June 1, 2017, 14 evaluable pts with DLBCL (7M/7F, age 42-72 years) have been enrolled and treated: 6 pts received TTI-621 monotherapy and 8 pts received TTI-621 plus rituximab. The number of prior systemic therapies ranged from 2 to 13; 6 pts had received prior autograft. Weekly outpatient treatments have been well tolerated. Mild-to-moderate infusion-related reactions were experienced by 9 pts following the first dose of TTI-621. Transient, dose-dependent decreases in platelets and leukocytes were generally without clinical sequelae. Objective responses were observed for 5/14 pts (36%): 1/6 pts treated with TTI-621 monotherapy and 4/8 pts treated with TTI-621 plus rituximab. Two pts attained complete responses (CR). One CR occurred in a pt treated with TTI-621 monotherapy who remains in continued CR at 20+ weeks. The second CR was in a pt treated with TTI-621 plus rituximab who remains in continued CR at 12+ weeks.ConclusionsWeekly IV dosing employing TTI-621 to block the CD47 “do not eat” signal as monotherapy or in combination with rituximab was well tolerated. Treatment was associated with preliminary and promising anti-tumor activity in pts with advanced DLBCL as evidenced by 2 CRs and 3 PRs among 14 pts. DisclosuresAnsell:Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Merck: Research Funding; Celldex: Research Funding; Seattle Genetics: Research Funding. Flinn:Genentech: Research Funding; Janssen: Research Funding; Janssen: Research Funding; Acerta: Research Funding; AbbVie Company: Research Funding; Seattle Genetics: Research Funding; KITE: Research Funding; Verastem: Research Funding; Curis: Research Funding; Infinity: Research Funding; TG Therapeutics: Research Funding; Agios: Research Funding; Beigene: Research Funding; Forty Seven: Research Funding; Pfizer: Research Funding; Merck: Research Funding; Pharmacyclics: Research Funding; Incyte: Research Funding; Gilead: Research Funding; Novartis: Research Funding; Constellation: Research Funding; Celgene: Research Funding; Pharmacyclics LLC: Research Funding; Takeda: Research Funding; Portola: Research Funding; Trillium: Research Funding; Calithera: Research Funding. O'Connor:Celgene: Honoraria, Research Funding; Trillium Therapeutics: Research Funding. Advani:Pfizer: Consultancy; Takeda/ Millenium: Research Funding. Percival:FLXbio: Research Funding. Johnson:Trillium Therapeutics: Employment. Catalano:Trillium Therapeutics: Employment; Apotex Inc.: Employment. Irwin:Hoffmann La Roche: Employment, Equity Ownership; Trillium Therapeutics: Employment, Equity Ownership. Petrova:Trillium Therapeutics: Employment, Equity Ownership. Uger:Trillium Therapeutics: Employment, Equity Ownership, Patents & Royalties. Sievers:Trillium Therapeutics: Employment, Equity Ownership. Chen:Genentech: Speakers Bureau; Merck: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Research Funding; Pfizer: Consultancy; Pharmacyclics: Consultancy, Research Funding; Affimed: Research Funding.

Clinical Activity and Safety of Cediranib and Olaparib Combination in Patients with Metastatic Pancreatic Ductal Adenocarcinoma without BRCA Mutation.

Lessons Learned Cediranib and olaparib combination did not result in clinically meaningful activity in patients with metastatic pancreatic ductal adenocarcinoma without known BRCA mutation. BackgroundCediranib, a vascular endothelial growth factor receptor inhibitor, suppresses expression of BRCA1/2 and RAD51 inducing homologous recombination DNA repair deficiency (HRD) in several cancer cell lines and xenograft models [1]. Olaparib provides a clinical benefit in patients with metastatic pancreatic adenocarcinoma (mPDAC) with germline BRCA mutation (gBRCAmt) [2]. We hypothesized that cediranib induces HRD in the absence of gBRCAmt and synergizes with olaparib, resulting in an objective response in patients with mPDAC.MethodsPatients with mPDAC with at least one prior systemic chemotherapy were enrolled. Patients with known gBRCAmt were excluded. Patients took cediranib 30 mg daily and olaparib 200 mg twice daily, orally. The primary endpoint was objective response (OR) rate.ResultsNineteen patients received the study drugs. Seven patients came off treatment before the first restaging scan: six because of clinical progression and one because of an adverse event. No OR was observed. Six patients had stable disease (SD) as a best overall response. The median duration of SD was 3.1 months. The median overall survival was 3.4 months. Common treatment‐related adverse events were fatigue, hypertension, and diarrhea.ConclusionCediranib and olaparib combination did not result in clinically meaningful activity in patients with mPDAC without gBRCAmt.

BXCL701, first-in-class oral activator of systemic innate immunity pathway, combined with pembrolizumab (Keytruda) in men with metastatic castration-resistant prostate cancer (mCRPC).

124 Background: BXCL701 (talabostat), oral small molecule inhibitor of dipeptidyl peptidases (DPP), primarily DPP8 and DPP9, triggers inflammasome mediated pyroptosis in macrophages, leading to induction of IL-18 and IL-1ß, bridging between innate and adaptive immunity. PD-L1 expression correlates with amplification of DPP8 and DPP9. In syngeneic animal models, significant tumor growth inhibition was observed with BXCL701 plus checkpoint inhibition. In a prior clinical study, single-agent BXCL701 resulted in objective responses in patients with Stage IV melanoma (unpublished). Methods: Eligible patients included in Phase 1b portion of this multicenter study, had progressing mCRPC (PCWG3), ≥1 prior systemic therapy, ≤2 lines of cytotoxic chemotherapy for mCRPC, no prior anti-PD-1/PD-L1 or other T-cell directed anticancer therapy. In Phase 2 portion, patients with adenocarcinoma must have received 1 or 2 2nd generation androgen signaling inhibitors; patients with SCNC/t-NEPC must have received ≥1 prior line of chemotherapy. Patients received fixed-dose pembrolizumab (200 mg IV q21-days) with BXCL701 on days 1-14 at recommended Phase 2 dose (RP2D)/schedule. Primary endpoint is Composite Response (RECIST 1.1, PSA, CTC). Change in relevant immune effector cells was also evaluated. Results: In Phase 1b portion 13 patients were treated with BXCL701 in 3 cohorts: 0.4 mg qd (n = 3); 0.6 mg qd (n = 3) and 0.6 mg split dose (n=7). 7 patients had adenocarcinoma, 6 had small cell/neuroendocrine prostate cancer phenotype. Prior treatment included androgen deprivation therapy (n = 10), 2nd-generation androgen signaling inhibitors (n = 9), chemotherapy (n = 11), radiation therapy (n = 11). On-target adverse events (AEs) consistent with cytokine activation were seen at highest dose levels. In 0.6 mg qd cohort, all patients had events consistent with cytokine release syndrome: 3/3 had hypotension, including 1 grade 3 syncope—dose-limiting toxicity (DLT)—and 2 patients each had dizziness and lower extremity edema. Splitting 0.6 mg dose improved tolerability while maintaining total daily dose (TDD) previously associated with objective response; 3/7 patients had fatigue, and 1 patient each had low grade hypotension, dyspnea, chills, myalgia. Preliminary anti-tumor activity was seen with 1 patient achieving a PSA response and 4 patients with RECIST1.1 stable disease. Consistent dose and time dependent increases in serum IL-18 levels were observed. Conclusions: BXCL701 0.3 mg BID (0.6mg TDD) administered on days 1-14 was identified as RP2D when administered with pembrolizumab 200 mg every 21 days. Splitting TDD was associated with improved tolerability as evidenced by no reported DLTs and lower rates of other AEs of interest e.g. hypotension and peripheral edema. Preliminary data from Phase 2 portion will be presented. Clinical trial information: NCT03910660.

Phase II study of apatinib in combination with oral vinorelbine in heavily pretreated HER2-negative metastatic breast cancer and clinical implications of monitoring ctDNA.

Objective:Apatinib is an oral TKI targeting VEGFR-2. Single-agent apatinib treatment has been shown to produce an objective response in patients with pretreated mBC. Oral vinorelbine also holds promise as a treatment of choice in patients with mBC. This study aimed to investigate the efficacy and safety of the oral vinorelbine-apatinib combination in patients with pretreated mBC. In addition, we detected gene variants in ctDNA to explore the therapeutic implications.Methods:This study enrolled patients with HER2-negative mBC who were pretreated with anthracycline/taxanes. Patients were treated with apatinib at 500 mg/425 mg daily plus oral vinorelbine 60 mg/m2 on days 1, 8, and 15 of every cycle (3 weeks). The primary endpoint was PFS. The secondary endpoints were ORR, CBR, OS, and safety. Patients eligible for ctDNA detection were evaluated before and during treatment.Results:Forty patients were enrolled. The median PFS was 5.2 months (95% CI, 3.4–7.0 months), and the median OS was 17.4 months (95% CI, 8.0–27.0 months). The ORR was 17.1% (6/35), and the CBR was 45.7% (16/35). The most common AEs included gastrointestinal reaction, myelosuppression, and hypertension. In 20 patients, ctDNA was detected at baseline and during treatment. A significant difference was found in PFS for undetected vs. detected baseline ctDNA (13.9 months vs. 3.6 months, P = 0.018).Conclusions:All-oral therapy with apatinib plus vinorelbine displayed objective efficacy in patients with heavily pretreated HER2-negative mBC, with acceptable and manageable toxicity profiles. Patients with no gene variant detected and lower variant allele frequencies in ctDNA at baseline showed longer PFS.

Ex vivo blockade of PI3K gamma or delta signaling enhances the antitumor potency of adoptively transferred CD8+ T cells.

Adoptive T cell transfer therapy induces objective responses in patients with advanced malignancies. Despite these results, some individuals do not respond due to the generation of terminally differentiated T cells during the expansion protocol. As the gamma and delta catalytic subunits in the PI3K pathway are abundant in leukocytes and involved in cell activation, we posited that blocking both subunits ex vivo with the inhibitor IPI‐145 would prevent their differentiation, thereby increasing antitumor activity in vivo. However, IPI‐145 treatment generated a product with reduced antitumor activity. Instead, T cells inhibited of PI3Kγ (IPI‐549) or PI3Kδ (CAL‐101 or TGR‐1202) alone were more potent in vivo. While T cells coinhibited of PI3Kγ and PI3Kδ were less differentiated, they were functionally impaired, indicated by reduced production of effector cytokines after antigenic re‐encounter and decreased persistence in vivo. Human CAR T cells expanded with either a PI3Kγ or PI3Kδ inhibitor possessed a central memory phenotype compared to vehicle cohorts. We also found that PI3Kδ‐inhibited CARs lysed human tumors in vitro more effectively than PI3Kγ‐expanded or traditionally expanded CAR T cells. Our data imply that sole blockade of PI3Kγ or PI3Kδ generates T cells with remarkable antitumor properties, a discovery that has substantial clinical implications.

Targeting Krasg12c‐mutant cancer with a mutation‐specific inhibitor

The RAS genes, which include H, N, and KRAS, comprise the most frequently mutated family of oncogenes in cancer. Mutations in KRAS - such as the G12C mutation - are found in most pancreatic, half of colorectal and a third of lung cancer cases and is thus responsible for a substantial proportion of cancer deaths. Consequently, KRAS has been the subject of exhaustive drug-targeting efforts over the past 3-4 decades. These efforts have included targeting the KRAS protein itself but also its posttranslational modifications, membrane localization, protein-protein interactions and downstream signalling pathways. Most of these strategies have failed and no KRAS-specific drugs have yet been approved. However, for one specific mutation, KRASG12C , there is light on the horizon. MRTX849 was recently identified as a potent, selective and covalent KRASG12C inhibitor that possesses favourable drug-like properties. MRTX849 selectively modifies the mutant cysteine residue in GDP-bound KRASG12C and inhibits GTP-loading and downstream KRAS-dependent signalling. The drug inhibits the in vivo growth of multiple KRASG12C -mutant cell line xenografts, causes tumour regression in patient-derived xenograft models and shows striking responses in combination with other agents. It has also produced objective responses in patients with mutant-specific lung and colorectal cancer. In this review, we discuss the history of RAS drug-targeting efforts, the discovery of MRTX849, and how this drug provides an exciting and long-awaited opportunity to selectively target mutant KRAS in patients.

A Phase II Study of Pembrolizumab in Combination With Palliative Radiotherapy for Hormone Receptor-positive Metastatic Breast Cancer

BackgroundThe purpose of this study was to investigate whether combining pembrolizumab with palliative radiation therapy (RT) improves outcomes in patients with hormone receptor-positive (HR+) metastatic breast cancer (MBC). Patients and MethodsEligible patients had HR+/human epidermal growth factor receptor 2-negative MBC; were candidates for RT to ≥ 1 bone, soft tissue, or lymph node lesion; and had ≥ 1 lesion outside the RT field. Patients received 200 mg pembrolizumab intravenously 2 to 7 days prior to RT and on day 1 of repeating 21-day cycles. RT was delivered to a previously unirradiated area in 5 treatments each of 4 Gy. The primary endpoint was objective response rate. The study used a 2-stage design: 8 women were enrolled into the first stage, and if at least 1 of 8 patients experienced an objective response, 19 more would be enrolled. Secondary endpoints included progression-free survival, overall survival, and safety. Exploratory endpoints included association of overall response rate with programmed death-ligand 1 status and tumor-infiltrating lymphocytes. ResultsEight patients were enrolled in stage 1. The median age was 59 years, and the median prior lines of chemotherapy for metastatic disease was 2. There were no objective responses, and the study was closed to further accrual. The median progression-free survival was 1.4 months (95% confidence interval, 0.4-2.1 months), and the median overall survival was 2.9 months (95% confidence interval, 0.9-3.6 months). All-cause adverse events occurred in 87.5% of patients, including just 1 grade 3 event (elevation of aspartate aminotransferase). ConclusionsRT combined with pembrolizumab did not produce an objective response in patients with heavily pre-treated HR+ MBC. Future studies should consider alternative radiation dosing and fractionation in patients with less heavily pre-treated HR+ MBC.

APLIKASI SPIRITUAL CARE MEMPERBAIKI RESPON SUBJEKTIF DAN OBJEKTIF PADA PASIEN INFARK MIOKARD AKUT DI RUANG ICU RSUD SYARIFAH AMBAMI RATO EBHU BANGKALAN

Acute myocardial infarction is a conditionof heart muscle necrosis due to an imbalance ofoxygen supply which almost always occurs due toa total blockage of the coronary artery bythrombus in unstable atherosclerosis (Robbin,2007 ; Kumar, et al. 2015). The purpose of thisstudy was to determine the effect of spiritual carein improving vascular response in patients withacute myocardial infarction This study was a Pre-ExperimentalAnalysis with One Group Pre Test-Post TestDesign. The population was 28 patients with AMIin the ICU Syarifah Ambami Rato Ebu BangkalanHospital and a sample of 17 patients taken bysimple random sampling technique. Therespondent filled out the cardiovascular functionquestionnaire at first. Then they were asked tolisten the asmaul husna for 10-15 minutes 3 timesa day; every morning, afternoon and night beforegoing bed. As a post test, the respondent filledquestionnaires after treatment. The results of study showed us the significant value by Wilcoxontest was ᾳ ≤ 0.05. Spiritual care can significantly improve thesubjective response of AMI patients with p value(0.001) < 0.05 and improve the objective responsewith p value (0.024) <0.05. Spiritual care improvesstress perception and stress response so that itcan regulate subjective and objective responsesin patients with acute myocardial infarction in theICU Syarifah Ambami Hospital Rato EbuBangkalan.

TAS-121, A Selective Mutant EGFR Inhibitor, Shows Activity Against Tumors Expressing Various EGFR Mutations Including T790M and Uncommon Mutations G719X.

TAS-121 is a novel orally active selective covalent inhibitor of the mutant EGFR. We performed preclinical characterization of TAS-121 and compared its efficacy and selectivity for common EGFR mutations (Ex19del and L858R), first- and second- generation EGFR-tyrosine kinase inhibitor (EGFR-TKI) resistance mutation (T790M), and uncommon mutations (G719X and L861Q) with those of other EGFR-TKIs. We also commenced investigation of the clinical benefits of TAS-121. The IC50 for intracellular EGFR phosphorylation was determined by using Jump-In GripTite HEK293 cells transiently transfected with EGFR expression vectors. Mouse xenograft models were used to evaluate the antitumor activity of TAS-121. TAS-121 potently inhibited common activating and resistance EGFR mutations to the same extent as another third-generation EGFR-TKI (osimertinib). In addition, TAS-121 showed equivalent inhibitory activity against some uncommon mutations such as G719X and L861Q. Furthermore, TAS-121 demonstrated greater selectivity for mutant EGFRs versus the wild-type EGFR compared with other EGFR-TKIs. Moreover, TAS-121 displayed antitumor activity in SW48 (EGFR G719S) and NCI-H1975 (EGFR L858R/T790M) xenograft models, and achieved an objective response in patients with NSCLC with EGFR mutations including G719A mutation. In conclusion, TAS-121 is a novel third-generation EGFR-TKI and demonstrates antitumor activities in patients with NSCLC expressing either common or uncommon EGFR mutations.