Superior Tumor Research Articles

Enhancedanti-tumor efficacy through a combination of intramuscularly expressed DNA vaccine and plasmid-encoded PD-1 antibody.

Immune check inhibitors (ICIs) have moderate response rates (~20%-30%) in some malignancies clinically, and, when used in combination with other immunotherapeutic strategies such as DNA tumor vaccines, there is evidence to suggest that they could optimize the efficacy of cancer treatment. In this study, we validated that intramuscular injection of plasmid DNA (pDNA) encoding OVA combined with pDNA encoding α-PD-1 (abbreviated as α-PD-1 in the following treatment groups) may enhance therapeutic efficacy by means of in situ gene delivery and enhanced muscle-specific potent promoter. Mice treated with pDNA-OVA or pDNA-α-PD-1 alone showed weak tumor inhibition in the MC38-OVA-bearing model. In comparison, the combined treatment of pDNA-OVA and pDNA-α-PD-1 resulted in superior tumor growth inhibition and a significantly improved survival rate of over 60% on day 45. In the B16-F10-OVA metastasis model, the addition of the DNA vaccine enhanced resistance to tumor metastasis and increased the populations of CD8+ T cells in blood and spleen. In conclusion, the current research shows that a combination of pDNA-encoded PD-1 antibody and DNA vaccine expressed in vivo is an efficient, safe, and economical strategy for tumor therapy.

Abstract LB077: Analysis of indel and structural variant error profiles in deep next generation sequencing data

Abstract Background: Accurate detection of low frequency mutations is of critical importance in the study of genetic heterogeneity, such as on the detection of minimal residual diseases for leukemias. Our prior work has resulted in successful error suppression for substitutions (10−4-10−5). However, the error profiles of indels and structural variants (SVs) remain elusive. Results: In this work, we generated ultra-deep sequencing data using our previously established dilution models (COLO829) on known somatic indels (n=23) and SVs (n=17). We discovered that the error rate of indels (10−6) and SVs (<2 × 10−7) are 100- to >1000-fold lower than that of SNVs. This finding was fully recapitulated in our analysis of 347 indels and 1248 SVs discovered from a relapsed B-ALL cohort of 103 patients, although homopolymer indels can have high error rates (>1%). We then performed a comprehensive study of homopolymer indels in 361 cancer driver genes by using whole genome data from 1662 healthy donors from the SJLIFE cohort. Our data indicated that the number of repeating units are highly predictive relative to the error rate of homopolymer indels (R2=0.988, p=4.89 × 10−8). Utilizing these insights, we assayed end-of-induction remission samples from 72 B-cell lymphoblastic leukemia patients that relapsed by selecting ~5 somatic clonal SNV/Indel/SV markers, which confirmed that SVs and indels have >10-fold lower error rates than SNVs. Our next generation sequencing (NGS) approach had 44 positive detections (61%) and outperformed the current standard method of clinical flow cytometry (n=37; 51%) for detecting minimal residual disease. The NGS-based method detected 92% of designed markers for samples with MRD>0.3%, and this detection rate dropped to 27% for MRD between 0.1% and 0.01%, indicating the difficulty in recovering mutant molecules when their frequencies are very low. Conclusions: Overall, we established indel and SV error profiles in deep next generation sequencing data enabling superior tumor detection performance at very low burdens, with lower error rates than what is observed for SNVs. Our work will have a significant impact on the clinical diagnosis and monitoring of human cancers and beyond. Citation Format: Ying Shao, Quang Tran, Pandurang Kolekar, Yanling Liu, Andrea McBride, Tyler Jones, Heather Mulder, Lingyun Ji, Benjamin Huang, Soheil Meshinchi, Jeffery Klco, Jinghui Zhang, William Carroll, Mignon Loh, Patrick Brown, John Easton, Xiaotu Ma. Analysis of indel and structural variant error profiles in deep next generation sequencing data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB077.

A tumor microenvironment-stimuli responsive nano-prodrug for overcoming gemcitabine chemoresistance by co-delivered miRNA-21 modulator

Gemcitabine (Gem) has been recommended as a first-line clinical chemotherapeutics for pancreatic ductal adenocarcinoma (PDAC) treatment. Gem treatment could generate chemoresistance associated with abnormal expressions of multiple miRNAs. In the PDAC setting, miRNA-21 (miR-21) overexpression is an important contributing factor of inducing Gem chemoresistance. Inhibition of miR-21 can significantly increase Gem chemosensitivity, which requires an efficient delivery platform to conduct combinational Gem and miR-21 siRNA (miR-21i) therapy. Herein, we synthesized a tumor microenvironment (TME) stimuli-responsive poly(beta-amino ester)s (PBAE)-based polymer nano-prodrug (miR-21i@HA-Gem-SS-P12) that could co-deliver miR-21 siRNA and Gem. The disulfide linkages conjugating GEM onto PBAE can be triggered by elevated reduction stimulus in TME to release the cargo Gem. The hyaluronic acid (HA) fabrication further improved the drug accumulation at the tumor site. Benefiting from the multiple functional improvements and synergism between Gem and miR-21i, the miR-21i@HA-Gem-SS-P12 nano-prodrugs displayed superior tumor inhibition in PDAC in vitro and in vivo. This study established an effective stimuli-responsive nano-prodrug strategy for cooperative treatment with small molecule agents and nucleotide modulators in PDAC.

Abstract 5163: Local delivery of mRNA immunotherapy encoding HPV16 antigen, IL-12, and LIGHT/TNFSF14 results in superior immunogenicity and tumor clearance in a murine model of HPV16-driven cancer

Abstract While intramuscular vaccination with HPV16 antigens has been shown to induce robust tumor-specific immune responses in the periphery, this has led to limited efficacy in the clinic. One potential explanation is the lack of sufficient infiltration of antigen-specific T cells into the tumor. The few T cells that make their way into the tumor are met with a plethora of negative signals that suppress their activity and abrogate local T cell expansion. To overcome this limitation of intramuscular cancer vaccines, we have developed an approach using in situ vaccination with a combination of immune modulators and tumor antigens, all encoded by mRNAs and delivered using nanoparticles. In this study, we show the superior efficacy and immunogenicity of a locally delivered mRNA cancer vaccine over that of an intramuscular HPV16 cancer vaccine. Both routes of administration result in robust induction of antigen-specific T cells, but local administration of mRNA-encoded antigens and immune modulators also resulted in enhanced infiltration of immune cells into the tumor, local Th1/M1 cytokine induction, and more-complete tumor clearance. Specifically, we found that the inclusion of the immunomodulators IL-12 and TNFSF14/LIGHT enabled tumor clearance in a murine tumor model. While tumors treated with mRNA-encoded HPV16 antigen alone induced robust systemic antigen-specific responses, minimal levels of local T cell expansion and infiltration, proinflammatory cytokine induction, and tumor control were observed. By contrast, tumors treated with mRNA-encoded HPV16 antigen, IL-12p70, and TNFSF14 completely cleared large established HPV16 expressing tumors with long-lasting recurrence free survival and immune memory. This observation was replicated in in a second murine tumor model, confirming the superior potency of locally delivered mRNA cancer vaccines in combination with immunomodulators. Consequently, we are developing a locally administrated mRNA therapy for the treatment of patients with cervical intraepithelial neoplasia (CIN). Citation Format: Weiqun Liu, Diane M. Da Silva, Edward E. Lemmens, Colin J. McKinlay, Sangeeta Nath, Meredith L. Leong, Samuel Deutsch, W. Martin Kast, Ole Audun W. Haabeth. Local delivery of mRNA immunotherapy encoding HPV16 antigen, IL-12, and LIGHT/TNFSF14 results in superior immunogenicity and tumor clearance in a murine model of HPV16-driven cancer. [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 5163.

Abstract 3244: AVA-NP-695, a potent and selective ENPP1 inhibitor, abrogates tumor metastasis in 4T1 syngeneic tumor model and demonstrates strong tumor regression when combined with radiation

Abstract Background: Innate immune modulators such as STING agonists have become attractive approaches to improve the efficacy of Immune Checkpoint Inhibitors (ICI) due to their ability to turn cold tumors hot. Owing to the modest clinical efficacy of STING agonists, there is a need for other approaches for activating the cGAS-STING pathway for cancer immunotherapy. One such approach is through the inhibition of the enzyme ENPP1, a negative regulator of the STING pathway which directly hydrolyses 2′3′- cGAMP. ENPP1 is overexpressed in several tumor cells like human astrocyte tumors and TNBC cells like 4T1 and MDA-MB-231, and plays a key role in tumor progression and block T cell infiltration in breast and lung cancer patients. ENPP1 not only abolishes the cGAS-STING mediated immune activation but also produces adenosine, an immune suppressor which promotes cell migration. AVA-NP-695 is a highly potent orally available ENPP1 inhibitor being developed for cancer immunotherapy. Methods: The inhibition potency of AVA-NP-695 was confirmed by enzymatic assays using various substrate like p-Nitrophenyl-5′-TMP, cGAMP and ATP. The efficacy of AVA-NP-695 was depicted in 4T1 Tumor bearing BALB/c mice as monotherapy and in combination with anti-PD-L1, Olaparib and Paclitaxel. Efficacy of AVA-NP-695 in combination with radiation (6.2Gy X 4) was also evaluated in ENPP1 overexpressing ANV5 tumors. Results: Herein, we demonstrate that AVA-NP-695, a selective and potent ENPP1 inhibitor showed no adverse effect at 1000mg/kg BID in 7 Day repeated dose in BALB/C mice, thereby demonstrating an excellent therapeutic window​. Results from in vivo studies have shown superior tumor growth inhibition (TGI) and impact on tumor metastasis by AVA-NP-695 (6mg/kg BID) compared to Olaparib and Anti-PD1 in a syngeneic 4T1 breast cancer mouse model. Subsequently, combination of AVA-NP-695 with Anti-PDL1, Olaparib and Paclitaxel and demonstrated encouraging combinatorial efficacy of AVA-NP-695 along with Paclitaxel. Monotherapeutic arm for Paclitaxel and AVA-NP-695 depicted 40% and 44% TGI respectively, however their combined treatment resulted in ~60% TGI. Additionally, the AVA-NP-695 treatment alone showed 50% enhanced mean survival time followed by 68%, 68% and 72% when given in combination with anti-PD-L1, Olaparib and Paclitaxel respectively. Finally, AVA-NP-695 showed complete tumor ablation of ANV5 ENPP1 overexpressed tumors when given in combination with radiation. Combination group showed significantly delayed recurrence compared to only radiotherapy. Conclusions: The potent anti-tumor efficacy of AVA-NP-695 both as monotherapy and combination along with its safety profile provides a strong rationale for the therapeutic potential of AVA-NP-695 against solids tumors, particularly breast cancer. Citation Format: Aditya Kulkarni, Avijit Goswami, Sandeep Goyal, Princy Khurana, Ishani Ghoshal. AVA-NP-695, a potent and selective ENPP1 inhibitor, abrogates tumor metastasis in 4T1 syngeneic tumor model and demonstrates strong tumor regression when combined with radiation [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 3244.

Abstract 2692: The combination of ulixertinib (ERK1/2 Inhibitor) and KRASG12C inhibition demonstrates significant efficacy in preclinical models

Abstract Ulixertinib (BVD-523) is a first-in-class and best-in-class small molecule inhibitor of ERK1/2 currently being investigated in several oncology clinical trials, both as a single agent and in combination with other therapeutics. Ulixertinib has demonstrated efficacy in patients with tumors harboring alterations within the RAS-MAPK pathway. KRAS is the most frequently mutated oncogene in cancer and is a key mediator of the RAS-MAPK signaling pathway resulting in proliferation and cellular growth. The specific KRASG12C mutation occurs in approximately 10% of non-small cell lung cancer (NSCLC), 3% of colorectal cancer, and 1-2% across all other tumor types. KRASG12C mutant-inhibitors, including AMG-510 (sotorasib), MRTX849 (adagrasib), and JDQ443 have demonstrated efficacy in KRASG12C-mutant cancers, including NSCLC. Clinically described mechanisms of acquired resistance to KRASG12C inhibitors converge on reactivation of the RAS-MAPK pathway. We hypothesized combining ulixertinib with a KRASG12C inhibitor would circumvent resistance to single agent KRASG12C inhibition, generating increased magnitude and duration of response compared to either single agent alone. The efficacy of ERK1/2 inhibitor, ulixertinib, in combination with KRASG12C inhibitor, adagrasib, was assessed in cell line derived xenograft models harboring KRASG12C mutations. Models were selected based on response to single agent adagrasib, ranging from sensitive to partially responsive. Combination treatment resulted in superior tumor growth inhibition compared to dosing of either single agent. RNA sequencing was performed on tumor samples that were collected 2 hours after the last dose of treatment. Expression of the mutant KRAS alleles were readily confirmed from RNA sequencing data in all models. Gene expression analysis showed differential expression of MAPK pathway genes in monotherapy versus combination therapy treated groups. In summary, ulixertinib combined with adagrasib exhibited robust pre-clinical activity in a variety of xenograft models with KRASG12C and should be further evaluated. Citation Format: Deborah Knoerzer, Anupama Reddy, Jessica A. Box, Anna Groover, Brent Kreider, Martin Teresk, Caroline M. Emery. The combination of ulixertinib (ERK1/2 Inhibitor) and KRASG12C inhibition demonstrates significant efficacy in preclinical models [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 2692.

Abstract 2693: Combining ulixertinib (ERK1/2 Inhibitor) with EGFR and BRAF inhibition yields significant efficacy in preclinical BRAFV600E mutant colorectal cancer models

Abstract The BRAFV600E mutation occurs in approximately 7% of colorectal cancer (CRC). BRAF plus EGFR inhibition (encorafenib with cetuximab) is an FDA approved treatment option for adult patients with metastatic CRC. Ultimately, patients develop resistance leading to disease progression. The addition of a MEK inhibitor, binimetinib, did not confer overall survival benefit. We hypothesized that addition of ERK inhibition would increase magnitude and duration of response to BRAF plus EGFR inhibition by overcoming MAPK-related acquired resistance mechanisms. ERK is the terminal master regulator kinase of the RAS-MAPK pathway, therefore, targeting this node is likely to be effective in the context of numerous mechanisms of acquired resistance that reactivate the MAPK pathway. Ulixertinib (BVD-523) is a first-in-class and best-in-class small molecule inhibitor of ERK1/2 currently being investigated in several oncology clinical trials, both as a single agent and in combination with other therapeutics. Ulixertinib has demonstrated efficacy in patients with tumors harboring alterations within the RAS-MAPK pathway. The efficacy of ulixertinib, in combination with EGFR inhibition (cetuximab), plus BRAF inhibition (encorafenib), was assessed in CRC cell line derived xenograft models harboring BRAFV600E mutations. The triple combination resulted in superior tumor growth inhibition compared to dosing of any single agent or doublet. RNA sequencing was performed on treated tumor samples. Expression of the mutant BRAF allele was readily confirmed from RNA sequencing data. Gene expression analysis showed differential expression of MAPK pathway genes in triple combination treated groups versus single or doublet therapy. A complete response to ulixertinib in combination with cetuximab and encorafenib for the treatment of a patient with metastatic CRC has been reported (Stuhlmiller, Timothy Joseph, et al. "Updated clinical outcomes from ULI-EAP-100, an intermediate expanded access program for ulixertinib (BVD-523)." (2022): e15101-e15101). The patient was treated under the Expanded Access Protocol (NCT04566393) for compassionate use access to ulixertinib. Preclinical data and clinical complete response warrants further investigation of ulixertinib plus BRAF and EGFR inhibition. Citation Format: Deborah Knoerzer, Anupama Reddy, Jessica A. Box, Anna Groover, Brent Kreider, Martin Teresk, Caroline M. Emery. Combining ulixertinib (ERK1/2 Inhibitor) with EGFR and BRAF inhibition yields significant efficacy in preclinical BRAFV600E mutant colorectal cancer models [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 2693.

Abstract 6172: Characterization of a novel series of highly selective PARP1 inhibitors

Abstract First-generation PARP1 inhibitors have provided significant therapeutic benefit to patients whose tumors exhibit homologous repair deficiencies, including BRCA mutations, however their use has been associated with hematological toxicities that have restricted their application, particularly in combination with standard-of-care chemotherapy. All four FDA-approved PARP1 inhibitors are largely non-selective for the closely related enzyme PARP2, inhibition of which has been shown to drive hematotoxicity. Hence, the development of second-generation molecules highly selective for PARP1 over PARP2 offers a significant opportunity to 1) dramatically enhance therapeutic index, 2) enable additional precision medicine/combination approaches with chemotherapy, radiotherapy, immunotherapy and targeted agents and 3) expand the addressable patient population to those whose tumors harbor additional DDR defects. Utilizing X-ray crystallography and structure-based drug design, we describe the characterization of a novel chemical series of highly selective PARP1 inhibitors. These molecules demonstrate high potency in multiple biochemical and cell-based assays, including viability and colony forming unit read-outs in BRCA-deficient cancer cells, whilst sparing isogenically-paired BRCA wild-type cells and non-transformed primary cell lines. The molecules are potent PARP1-DNA trappers and exhibit high affinity, high selectivity and prolonged residence time in biophysical surface plasmon resonance (SPR) binding assays. The molecules also demonstrate exceptionally high selectivity for PARP1 over PARP2, and across the mono and polyPARP family, using a cell-based NanoBRET target engagement assay. This chemical series generally exhibits highly desirable physico-chemical and in vitro ADME properties, coupled with an excellent in vitro safety profile, which translate to high oral bioavailability and low clearance in rodent PK studies. Lead molecules yield deep and durable anti-tumor efficacy in a BRCA1m MDA-MB-436 breast cancer xenograft model with responses continuing after cessation of treatment. Percent tumor regression and post-dose tumor control was superior to olaparib at 1/10th of the dose. Importantly, our molecules demonstrate prolonged tumor residence time and a markedly superior tumor:plasma ratio compared to competitor PARP1-selective inhibitors. Taken together, these data predict low therapeutic dosing with the potential to demonstrate improved efficacy and tolerability compared to marketed PARP inhibitors. In summary, we describe the characterization of novel potent and selective PARP1 inhibitors. These molecules demonstrate excellent in vitro ADMET and in vivo PK, coupled with profound anti-tumor efficacy and tumor-targeting properties in a genetically-defined mouse model, supporting their progression into clinical studies. Citation Format: Phillip M. Cowley, Barry E. McGuinness, Gillian M. Campbell, Alan Wise. Characterization of a novel series of highly selective PARP1 inhibitors [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 6172.

Abstract 5175: DX-002, a dual EP2 and EP4 antagonist, alters the tumor microenvironment to enhance tumor immunogenicity and responses to immune checkpoint inhibitors

Abstract Prostaglandin E2 (PGE2) generated by the cyclooxygenase (COX) pathways regulates both inflammation and tumor microenvironment (TME). Among the four E-type prostanoid receptors EP1-4, it has been demonstrated that PGE2 exhibits its immune suppression and tumorigenic function through engagement with EP2 and EP4. Mechanistically, tumor-derived PGE2 acts on EP2 and EP4 in immune cells (e.g., NK cells and dendritic cells) and elicits immunosuppression in TME1,2. Importantly, the deletion of both EP2 and EP4, but not deletion of either receptor, is required to reverse PGE2-mediated immune evasion. Furthermore, high levels of PGE2-EP2/EP4 associated inflammatory signature have been shown in multiple human cancer types to correlate with poor prognosis and worse response to immune checkpoint blockade in the clinic1. Therefore, PGE2-EP2/EP4 signaling likely acts as a key regulatory node linking inflammation and immunosuppression in TME, and its inhibition may lead to a less immunosuppressive TME and enhance the response to immune checkpoint inhibitors. COX inhibitors have been used to block PGE2 synthesis but cause cardiovascular and gastrointestinal risks due to the inhibition of all prostanoids synthesis3. Thus, therapeutically targeting both EP2 and EP4 is an effective and more selective approach to limit the immunosuppressive functions of PGE2 while avoiding potential side effects associated with COX inhibition. Here we describe the discovery of a potent and selective EP2/EP4 dual antagonist DX-002. At 10 nM concentration, it displayed >90% inhibition of PGE2 binding to EP2 or EP4, whereas no significant inhibition was seen towards PGE2 binding to EP1 or EP3. In human NK cells DX-002 reversed PGE2-mediated inhibition of IFN-γ production more potently than selective EP2 or EP4 antagonist. DX-002 has excellent pharmacokinetics profiles across all animal species. In the mouse tumor model, treatment of DX-002 produced superior tumor regression as a monotherapy over selective EP2 or EP4 antagonists. In addition, DX-002 also provided significant synergistical effect for tumor regression in combination with anti-PD1 in both immune checkpoint inhibitor insensitive and sensitive models, in association with increased tumor infiltration of CD8+ T cells. Based on its in vitro and in vivo profiles along with other properties, DX-002 is being profiled as a development candidate as a potential cancer immunotherapeutic agent. Citation Format: Lintong Li, Guorui Yao, Wei Zheng, Yongshuai Chai, Zhongying Huang, Guojian Ma, Linlin Nie, Dengfeng Xu, Jiuquan Yang, Nanxin Li. DX-002, a dual EP2 and EP4 antagonist, alters the tumor microenvironment to enhance tumor immunogenicity and responses to immune checkpoint inhibitors. [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 5175.

Abstract 5677: MB101, a novel PD-L1 x CD3 targeted bispecific antibody, exhibits potent tumor-killing efficacy with minimal off-tumor toxicity

Abstract Bispecific antibody (bsAb) which targets tumor-associated antigens and simultaneously induces CD3-mediated T cell activation, is one of the promising therapeutic approaches for cancer treatment. However, despite numerous CD3-based bsAb have been developed, the clinical application faces pronounced hurdles, such as increased on-target off-tumor toxicity and cytokine release syndrome (CRS) by using high-affinity anti-CD3 moieties. Accordingly, there are still needs for the development of CD3-based bsAb with more favorable properties, which are tumor-specific targeting and potent tumor killing activity without excessive cytokine release. Thus, we developed MB101, a novel PD-L1 x CD3 bsAb with low affinity to CD3, which is uncoupled potent tumor cytotoxicity from severe cytokine release. MB101 showed a strong binding affinity to PD-L1 (KD = 0.4 nM) but a weak binding affinity to CD3 (KD = 1.0 μM), indicating preferentially targeting to PD-L1+ tumor cells. MB101 showed an effective tumor cell killing activity with higher Emax compared to avelumab mono- or combination treatment with CD3 mAb in PD-L1+ MDA-MB-231 cells. T cell-mediated cytotoxicity stimulated by MB101 in co-culture with target cells was accompanied by lower secretion of pro-inflammatory cytokines than CD3 mAb and bsAb comparator with high-affinity anti-CD3 arm. Additionally, in the absence of target cells, MB101 treatment to PBMC induced a very low level of pro-inflammatory cytokines, suggesting the possibility of reduced CRS risk. Furthermore, we proved that T cell-mediated cytotoxicity by MB101 was increased in a PD-L1 expression-dependent manner of tumor cells, but not normal cells, indicating minimal on-target off-tumor toxicity. Consistently with in vitro results, MB101 effectively regressed tumor volume (TGI=83%) without induction of excessive cytokine release in human CD3 knock-in mouse model. In addition, MB101 showed superior tumor growth inhibition (TGI=70%) than that of avelumab (TGI=44%) in humanized mouse xenograft model. In summary, MB101 selectively triggers robust PD-L1-dependent tumor cytotoxicity while inducing very low cytokine release, suggesting that MB101 might be a promising therapeutic option as CD3-based bsAb for cancer treatment. Citation Format: Suna Kim, Hyojoo Bang, Yongjun Jung, Sunjung Cho, Youngsam Kim, Sang-hyun Park, Seok Chan Kang, Youngjin Park, Sungyoub Jung. MB101, a novel PD-L1 x CD3 targeted bispecific antibody, exhibits potent tumor-killing efficacy with minimal off-tumor toxicity. [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 5677.

Abstract 3427: ICP-490 is a highly potent and selective IKZF1/3 degrader with robust anti-tumor activities against multiple myeloma and non-Hodgkin’s lymphoma

Abstract Background: Cereblon (CRBN)-targeting immunomodulatory drugs (IMiDs), i.e., thalidomide and lenalidomide, play pivotal roles in treating multiple myeloma (MM) patients. This class of drugs induce rapid ubiquitination and degradation of two lymphoid transcription factors (IKZF1 and IKZF3) by recruiting them to CRBN-CRL4 E3 ubiquitin ligase, which result in pleiotropic anti-tumor effects including autonomous tumor cell death and immune activation. However, prolonged IMiD treatment eventually becomes resistant and leads to tumor relapse in MM patients, mostly due to down-regulation of CRBN. All approved IMiDs also exert adverse effects such as teratogenicity, attributed to CRBN-mediated degradation of neo-substrates SALL4, PLZF1 and ΔNp63/TAp63. Here we report the development of a novel selective IKZF1/3 degrader ICP-490, which can robustly inhibit MM and NHL tumor growth, and overcome lenalidomide resistance. Results: ICP-490 induces potent, deep, and selective degradation of IKZF1 and IKZF3 with sub-nanomolar IC50, but no significant degradation of IKZF2, IKZF4, GSPT1, SALL4 and PLZF1. Cell viability assays reveal robust in vitro efficacies of ICP-490 against various MM and NHL(DLBCL) cell lines with nanomolar IC50. It also exhibits potent anti-proliferative activity in lenalidomide-resistant cell lines. In contrast to its tumor killing effect, ICP-490 shows no cytotoxicity against normal human cells, such as HEK293 and PBMC cells. ICP-490 induces IKZF1/3 degradation in distinct human lymphocyte lineages, leads to immune cell activation with elevated IL-2 and IFN-γ production and down-regulation of TNF-α in PBMC. The immune modulation activity of ICP-490 has also been illustrated in a combinatory treatment with daratumumab, where low dose of ICP-490 leads to robust induction of IL-2 and granzyme B, and much improved efficacy of daratumumab in MM cell line NCI-H929. In vivo efficacy studies have further confirmed the effectiveness of ICP-490 against MM and DLBCL xenografts, including MM1.S, MM1.R, NCI-H929 multiple myeloma lines, and TMD-8, WSU-DLCL2 DLBCL lines. ICP-490 also eradicates lenalidomide-resistant NCI-H929 xenografts. ICP-490 has overall favorable pharmacokinetic parameters with high oral bioavailability. Nonclinical safety evaluations of ICP-490 exhibit acceptable drug tolerability in SD rats and cynomolgus monkeys. Conclusions: ICP-490 is a highly potent, orally bioavailable, next-generation CRBN-targeting IMiD with selective IKZF1/3 degradation. In various MM and NHL tumor models, it demonstrates superior tumor killing activities than currently approved IMiDs, including overcoming lenalidomide resistance. ICP-490 is now in phase I clinical trial. Citation Format: Ruixia Liang, Yucheng Pang, Yingrui Han, Haipeng Xu, Zuopeng Wang, Richard Liu, Charles Ying Wang, Jason Bin Zhang, Xiangyang Chen, Davy Xuesong Ouyang. ICP-490 is a highly potent and selective IKZF1/3 degrader with robust anti-tumor activities against multiple myeloma and non-Hodgkin’s lymphoma [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 3427.

Abstract 1074: The potential of 18β-glycyrrhetinic acid benefit lenvatinib induced cytotoxicity on hepatocellular carcinoma

Abstract Hepatocellular carcinoma (HCC) is usually caused by long-term inflammation such as infected by hepatitis B and C viruses. The current standard treatment methods of HCC has included with general surgery, radiation, etc. However, the recurrence rate remain high even after standard treatment, it is necessary to find a better treatment option to control the progression of HCC. Lenvatinib is a multi-endothelial angiogenesis factor inhibitor which is a first-line target drug for the treatment of advanced HCC. Some studies indicated that activation of the PI3K/AKT pathway could lead to the resistance effect of lenvatinib in HCC. 18β-glycyrrhetinic acid (18β-GA) is a hydrolyzed product of glycyrrhizic acid in the intestine. Studies reported that 18β-GA can effectively treat inflammatory diseases and may have antitumor potential. Some studies also indicated that 18β-GA can down-regulate the signaling transduction of PI3K/AKT pathway in various type of cancers. Therefore, in this study, we focused on exploring whether 18β-GA can be used as an adjuvant to downregulate PI3K/AKT signaling and thus enhance the efficacy of lenvatinib on HCC cells and animal model. Here, we used the MTT assay to investigate the cytotoxicity of HCC cells (Huh7 and Hep3B) after various dose of lenvatinib and (or) 18β-GA treatment. We also used combination index (CI) to evaluate the suitable combination condition. In our results, the CI value of lenvatinib 30 μM combined with 18β-GA 100 μM is smaller than 1, which indicated the synergistic effect of combination. We confirmed the superior extrinsic/intrinsic apoptosis induction ability was found in lenvatinib combined with 18β-GA as compared to single treatment. The activation of Fas/FasL pathway, Annexin V, cleaved caspase-3, -8 and -9 were used to confirm the apoptosis induction by lenvatinib combined with 18β-GA. Transwell invasion and wound healing assays results also indicated the invasion/migration suppression ability of lenvatinib combined with 18β-GA on HCC cells. The phosphorylation of AKT were markedly decreased by lenvatinib combined with 18β-GA in HCC cells. Hep3B bearing animal data proved the superior tumor control of lenvatinib combined with 18β-GA. Additionally, the liver function and normal tissue pathology may not affect by combination of lenvatinib and 18β-GA. To conclude, our result demonstrated that 18β-GA may sensitize HCC to lenvatinib via inactivation of PI3K/AKT signaling pathway and induction of extrinsic/intrinsic apoptosis signaling. Citation Format: Yeh Pei-Wen, Yu-Chiang Liu, Yuan Chang, Jiann-Hwa Chen. The potential of 18β-glycyrrhetinic acid benefit lenvatinib induced cytotoxicity on hepatocellular carcinoma [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 1074.

Nano-adjuvants and immune agonists promote antitumor immunity of peptide amphiphiles.

Immunostimulatory cues play an important role in priming antitumor immunity and promoting the efficacy of subunit cancer vaccines. However, the clinical use of many immunostimulatory agents is often hampered by their inefficient in vivo delivery which may decrease immune response to the vaccination. To promote vaccine efficacy, we develop vaccine formulations which integrate three key elements: (1) a nano-adjuvant formulated by conjugating an agonistic anti-CD40 monoclonal antibody (αCD40) to the surface of a polyIC-loaded lipid nanoparticle, (2) a peptide amphiphile containing an optimized CD8+ T-cell epitope that derived from a melanoma antigen gp100, (3) an agonistic anti-4-1BB monoclonal antibody (α4-1BB) that boosts the efficacy of vaccinations. In a syngeneic mouse model of melanoma, the vaccine formulations enhanced innate immunity and activated multiple innate immune signaling pathways within draining lymph nodes, as well as promoted antigen-specific immune responses and reduced immunosuppression in the tumor microenvironment, leading to profound tumor growth inhibition and prolonged survival. Thus, our vaccine formulations represent an attractive strategy to stimulate antitumor immunity and control tumor progression. STATEMENT OF SIGNIFICANCE: The clinical use of many immunostimulatory agents is often hampered by their inefficient in vivo delivery which may decrease immune response to the vaccination. To promote the antitumor immunity of subunit vaccines, we develop novel vaccine formulations that integrate multifunctional modalities including (1) a nano-adjuvant containing anti-CD40 monoclonal antibody (αCD40) and TLR3 agonist which activate innate immunity through diverse signaling pathways, (2) a peptide amphiphile containing an optimized CD8+ T-cell epitope from tumor antigen, (3) an anti-4-1BB monoclonal antibody (α4-1BB) that boosts the efficacy of vaccinations. In this study, our vaccine formulations stimulate superior antitumor immunity and control tumor progression. The above nano-engineered platform and immunogenic biomacromolecules can be further applied to other T-cell-inducing vaccines.

Wavelength engineerable porous organic polymer photosensitizers with protonation triggered ROS generation

Engineering excitation wavelength of photosensitizers (PSs) for enhanced reactive oxygen species (ROS) generation has inspired new windows for opportunities, enabling investigation of previously impracticable biomedical and photocatalytic applications. However, controlling the wavelength corresponding to operating conditions remains challenging while maintaining high ROS generation. To address this challenge, we implement a wavelength-engineerable imidazolium-based porous organic photocatalytic ROS generation system (KUP system) via a cost-effective one-pot reaction. Remarkably, the optimal wavelength for maximum performance can be tuned by modifying the linker, generating ROS despite the absence of metal ions and covalently attached heavy atoms. We demonstrate that protonated polymerization exclusively enables photosensitization and closely interacts with oxygen related to the efficiency of photosensitizing. Furthermore, superior tumor eradication and biocompatibility of the KUP system were confirmed through bioassays. Overall, the results document an unprecedented polymerization method capable of engineering wavelength, providing a potential basis for designing nanoscale photosensitizers in various ROS-utilizing applications.

Adrenergic receptor signaling regulates the CD40-receptor mediated anti-tumor immunity.

Anti-CD40 agonistic antibody (αCD40), an activator of dendritic cells (DC) can enhance antigen presentation and activate cytotoxic T-cells against poorly immunogenic tumors. However, cancer immunotherapy trials also suggest that αCD40 is only moderately effective in patients, falling short of achieving clinical success. Identifying factors that decrease αCD40 immune-stimulating effects can aid the translation of this agent to clinical reality. Here, we reveal that β-adrenergic signaling on DCs directly interferes with αCD40 efficacy in immunologically cold head and neck tumor model. We discovered that β-2 adrenergic receptor (β2AR) activation rewires CD40 signaling in DCs by directly inhibiting the phosphorylation of IκBα and indirectly by upregulating levels of phosphorylated-cAMP response element-binding protein (pCREB). Importantly, the addition of propranolol, a pan β-Blocker reprograms the CD40 pathways, inducing superior tumor regressions, increased infiltration of cytotoxic T-cells, and a reduced burden of regulatory T-cells in tumors compared to monotherapy. Thus, our study highlights an important mechanistic link between stress-induced β2AR signaling and reduced αCD40 efficacy in cold tumors, providing a new combinatorial approach to improve clinical outcomes in patients.

Abstract P4-01-12: BAT8006, a novel FRα ADC with strong bystander effect, for the treatment of advanced solid tumor

Abstract FRα is overexpressed in a number of cancers, including ovarian, breast, lung cancer, and endometrial carcinoma, yet limited expression in normal tissue. Efficacy of anti-FRα ADC have been demonstrated in clinical trials for high FRα expression ovarian cancer. These results validate FRα as a viable target for cancer treatment. We have developed a novel FRα ADC with strong bystander killing effect, BAT8006, which consists of a high-affinity antibody, an enzymatically cleavable linker and a topoisomerase I inhibitor as the payload, with DAR of 8. BAT8006 shows high affinity for the FRα antigen (KD < 0.5 nM) and FRα-expressing tumor cells. Upon binding to FRα on cell surface, BAT8006 internalizes effectively and traffics to the lysosome where payload is proteolytically released. BAT8006 demonstrated potent in vitro cell growth inhibitory activity to FRα-positive cells with IC50 values of ~ 1 nM. In an in vitro bystander killing assay, proliferation of FRα-negative cells was potently inhibited by addition of culture medium of BAT8006-treated FRα-positive cells, but not that of BAT8006-treated FRα-negative cells, indicating the bystander killing effect of the released payload in the culture medium. Less than 0.03% of the payload was released from BAT8006 when incubated with human or monkey plasma for 4 days in 37oC, suggesting the stability of BAT8006 in blood circulation. BAT8006 led to potent and dose-dependent tumor regression in patient-derived xenograft (PDX) model of SCLC. Furthermore, single dose of 2.5 mg/kg of BAT8006 showed complete eradication of tumor in choriocarcinoma JeG-3 xenograft mice model. In PDX of ovarian cancer, 2.5 mg/kg of BAT8006 (DAR8) demonstrated superior tumor inhibition activity than 5 mg/kg of BAT8006 with DAR4, suggesting the high DAR approach of BAT8006 would be more effective. In addition, BAT8006 showed favorable pharmacokinetic and safety profiles in cynomolgus monkeys with the highest non-severely toxic dose (HNSTD) of 30 mg/kg when dosed once every three weeks for 3 times. Together these results indicate that BAT8006 could potentially provide a therapeutic benefit to treat FRα-positive tumors including breast cancer in clinical trial. Citation Format: siqi mai, xingxing Mei, weijia Tang, Xin Zhou, Xuekang qi, Zhi Zhong, Shuoxu Li, Jianjun fan, Jirong Gan, Binghua Tan, Yao Qi, Yanling Guo, Shengfeng li, Jin-Chen Yu. BAT8006, a novel FRα ADC with strong bystander effect, for the treatment of advanced solid tumor [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-12.

Multifunctional gold nanorods in low-temperature photothermal interactions for combined tumor starvation and RNA interference therapy.

Collateral damage to healthy tissue, uneven heat distribution, inflammatory diseases, and tumor metastasis induction hinder the translation of high-temperature photothermal therapy (PTT) from bench to practical clinical applications. In this report, a multifunctional gold nanorod (GNR)-based nanosystem was designed by attaching siRNA against B7-H3 (B7-H3si), glucose oxidase (GOx), and hyaluronic acid (HA) for efficient low-temperature PTT. Herein, GOx can not only exhaust glucose to induce starvation therapy but also reduce the heat shock protein (HSP), realizing the ablation of tumors without damage to healthy tissues. Evidence shows that B7-H3, a type I transmembrane glycoprotein molecule, plays essential roles in growth, metastasis, and drug resistance. By initiating the downregulation of B7-H3 by siRNA, siRNA-GOx/GNR@HA NPs may promote the effectiveness of treatment. By targeting cluster of differentiation 44 (CD44) and depleting B7-H3 and HSPs sequentially, siRNA-GOx/GNR@HA NPs showed 12.9-fold higher lung distribution than siRNA-GOx/GNR NPs. Furthermore, 50% of A549-bearing mice in the siRNA-GOx/GNR NPs group survived over 50 days. Overall, this low-temperature phototherapeutic nanosystem provides an appropriate strategy for eliminating cancer with high treatment effectiveness and minimal systemic toxicity. STATEMENT OF SIGNIFICANCE: To realize efficient tumor ablation under mild low-temperature (42-45℃) and RNA interference simultaneously, here we developed a multifunctional gold nanorod (GNR)-based nanosystem (siRNA-GOx/GNR@HA NPs). This nanoplatform can significantly inhibit tumor cell proliferation and induce cell apoptosis by downregulation of HSP90α, HSP70, B7-H3, p-AKT, and p-ERK and upregulation of cleaved caspase-9 at mild low-temperature due to its superior tumor homing ability and the combined effect of photothermal effect, glucose deprivation-initiated tumor starvation, and B7-H3 gene silence effect. It is believed that this multifunctional low-temperature photothermal nanosystem with efficient and specific anticancer properties, shows a potential application in clinical tumor treatment.

Abstract P4-01-32: BAT8008, a novel Trop-2 ADC with strong bystander effect, for the treatment of Trop-2 positive cancer

Abstract Trophoblast cell surface antigen 2 (Trop-2) is overexpressed on many epithelial carcinomas, yet is expressed at much lower level on normal tissue. Elevated expression of TROP-2 is often associated with tumor invasion/aggression, progression, and metastasis. Efficacy of anti-TROP2 ADC have been demonstrated in clinical trials for both TNBC (triple negative breast cancer) and HR+/HER2- breast cancer. We have developed a novel Trop-2 ADC with strong bystander killing effect, BAT8008, which consists of an enzymatically cleavable linker and a topoisomerase I inhibitor as the payload, with DAR of 6. BAT8008 demonstrated potent in vitro cell growth inhibitory activity to Trop2-positive cells with IC50 values of < 1 nM. In an in vitro bystander killing assay, proliferation of Trop-2-negative cells was potently inhibited by addition/transfer of culture medium of BAT8008-treated Trop-2-positive cells, but not that of BAT8008-treated Trop-2-negative cells, indicating the bystander killing effect of the released payload in the culture medium. Less than 0.1% of the payload was released from BAT8008 when incubated with human or monkey plasma for 7 days in 37°C, suggesting the stability of BAT8008 in blood circulation. Single dose of BAT8008 at 1 and 2.5 mg/kg could inhibit 73% and 81% tumor growth in the Trop-2-positive MDA-MB-468 and MX-1 xenograft mice model, respectively. BAT8008 also demonstrated superior tumor inhibition activity than a modified ADC using Daiichi’s ADC technology or Trodelvy in a pancreatic BxPC-3 xenograft mice model. In addition, BAT8008 showed favorable pharmacokinetic and safety profiles in cynomolgus monkeys with the highest non-severely toxic dose (HNSTD) of at least 25 mg/kg when dosed once every two weeks for 3 times. Together these results indicate that BAT8008 could potentially provide a therapeutic benefit to treat TROP2-positive breast cancers in clinical trial. Citation Format: Xingxing Mei, Weijia Tang, Xin Zhou, Xuekang Qi, Siqi Mai, Zhi Zhong, Shuoxu Li, Jianjun Fan, Jirong Gan, Binghua Tan, Yao Qi, Yanling Guo, Jin-Chen Yu, Shengfeng Li. BAT8008, a novel Trop-2 ADC with strong bystander effect, for the treatment of Trop-2 positive cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-32.

Self-delivery biomedicine for enhanced photodynamic therapy by feedback promotion of tumor autophagy.

Reactive oxygen species (ROS) generated during photodynamic therapy (PDT) can induce autophagy to protect tumor cell from PDT-induced apoptosis. In this work, a self-delivery autophagy regulator (designated as CeCe) is developed for autophagy promotion sensitized PDT against tumor. Briefly, CeCe is prepared by the assembly of a photosensitizer of chlorin e6 (Ce6) and autophagy promoter of celastrol. By virtue of intermolecular interactions, Ce6 and celastrol are able to self-assemble into nanomedicine with great photodynamic performance and autophagy regulation capacity. Under light irradiation, CeCe would produce ROS in tumor cells to amplify the oxidative stress and promote cell autophagy. As a result, CeCe exhibits an enhanced photo toxicity by inducing autophagic cell death. In vivo experiments indicate that CeCe can predominantly accumulate in tumor tissue for a robust PDT. Moreover, CeCe has a superior therapeutic efficiency compared to monotherapy and combined treatment of Ce6 and celastrol, suggesting a synergistic antitumor effect of PDT and autophagy promotion. This self-delivery nanomedicine may advance the development of the co-delivery nanoplatform to improve the antitumor efficacy of PDT by promoting autophagy. STATEMENT OF SIGNIFICANCE: Autophagy is a "double-edged sword" in cellular homeostasis and metabolism, which can promote tumor progression but also induce an unknown impact on tumor inhibition. In this work, a self-delivery autophagy regulator (designated as CeCe) was developed for autophagy promotion sensitized photodynamic therapy (PDT). By virtue of intermolecular interactions, Ce6 and celastrol were found to self-assemble into stable CeCe without drug excipients, which exhibited great photodynamic performance and autophagy regulation capacity. In vitro and in vivo findings demonstrated a superior tumor suppression ability of CeCe over the monotherapy as well as the combined treatment of Ce6 and celastrol, suggesting a synergistic antitumor efficacy by PDT and autophagy promotion.

An Extremely Inhomogeneous Gross Tumor Dose is Suitable for Volumetric Modulated Arc-Based Radiosurgery with a 5-mm Leaf-Width Multileaf Collimator for Single Brain Metastasis.

Introduction Single or multi-fraction (mf) stereotactic radiosurgery (SRS) is an indispensable treatment option for brain metastases (BMs). The integration of volumetric modulated arc therapy (VMAT) into linac-based SRS is expected to further enhance efficacy and safety and to expand the indications for the challenging type of BMs. However, the optimal treatment design and relevant optimization method for volumetric modulated arc-based radiosurgery (VMARS) remain unestablished with substantial inter-institutional differences. Therefore, this study was conducted to determine the optimal dose distribution suitable for VMARS of BMs, especially regarding dose inhomogeneity of the gross tumor volume (GTV). The GTV boundary, not margin-added planning target volume, was regarded as a basis for planning optimization and dose prescription. Materials and methods This was a planning study for the clinical scenario of a single BM. Eight sphere-shaped objects with diameters of 5-40 mm in 5-mm increments were assumed as GTVs. The treatment system included a 5-mm leaf width multileaf collimator (MLC) Agility® (Elekta AB, Stockholm, Sweden)and a dedicated planning system Monaco® (Elekta AB). The prescribed dose (PD) was uniformly assigned to just cover 98% of the GTV (D98%). Three VMARS plans with different dose inhomogeneities of the GTV were generated for each GTV: the % isodose surfaces (IDSs) of GTV D98%, normalized to 100% at the maximum dose (Dmax), were ≤70% (extremely inhomogeneous dose, EIH); ≈80% (inhomogeneous dose, IH); and ≈90% (rather homogeneous dose, RH). VMARS plans were optimized using simple and similar cost functions. In particular, no dose constraint to the GTV Dmax was assigned to the EIH plans. Results Intended VMARS plans fulfilling the prerequisites were generated without problems for all GTVs of ≥10 mm, whereas 86.4% was the lowest IDS for the D98%for 5-mm GTV. Therefore, additional plans for 9-and 8-mm GTVs were generated, which resulted in 68.6% and 75.1% being the lowest IDSs for the D98%values of 9- and 8-mm GTVs, respectively. The EIH plans were the best in terms of the following: 1) dose conformity, i.e., minimum spillage of PD outside the GTV; 2) moderate, not too excessive, dose attenuation outside the GTV, i.e., appropriate marginal dose 2-mm outside the GTV boundary as a function of GTV size; and 3) lowest dose of the surrounding normal tissue outside the GTV. In contrast, the RH plans were the worst based on all of theaforementioned measures. Conclusions On the assumption of uniform dose assignment to the GTV margin, a very inhomogeneous GTV dose is basically the most suitable for SRS of BMs in terms of 1) superior dose conformity; 2) minimizing the dose of the surrounding normal tissue outside the GTV; and 3) moderate dose spillage margin outside the GTV with a tumor volume-dependent rational increase, i.e., appropriate dose of the common PTV boundary. The concentrically laminated steep dose increase inside the GTV boundary for the EIH plan may also be advantageous for achieving superior tumor response, although early and excessive GTV shrinkage caused by the EIH plan during mfSRS can lead to surrounding brain injury.