Citations

2087 Background: PCNSL is a rare and aggressive form of NHL in the central nervous system or vitreoretinal space. Despite high initial rates of responses to HD-MTX-based induction chemotherapies, most patients relapse in two years. R/R PCNSL is associated with poor prognosis, representing a clear unmet medical need, as there are no currently approved treatments for this disease. IRAK4 kinase activity is required for TLR and IL-1R signaling in a variety of myeloid and lymphoid cell types, including PCNSL. Recruitment of IRAK4 to these receptors and subsequent activation is facilitated by the MyD88 adaptor protein, which is mutated in ~70% of PCNSL. This leads to constitutive activation of the NF-κB signaling pathway, increased inflammation, and tumor growth. Emavusertib is a novel and potent oral inhibitor of IRAK4 and FLT3, which has demonstrated the ability to cross the blood-brain barrier in PCNSL xenografts. In preclinical studies, the combination of emavusertib with ibrutinib overcomes resistance to BTK inhibitors. This combination has an acceptable safety profile across a broad population of R/R NHL patients, including PCNSL. Here we present updated safety and efficacy data for emavusertib in combination with ibrutinib in patients with R/R PCNSL. Methods: The safety, clinical activity, and potential biomarkers of emavusertib in R/R PCNSL are being investigated in the ongoing open-label, Phase 1/2 TakeAim Lymphoma trial (NCT03328078). The eligible patients with R/R PCNSL received emavusertib (100-300 mg BID) in combination with ibrutinib (560 mg QD) in a 21-day cycle until tumor progression or unacceptable toxicity. Results: Here, we present updated data from R/R PCNSL patients with prior ibrutinib exposure who were treated with emavusertib in combination with ibrutinib. The median number of prior lines of anti-cancer therapies was 3 (range: 2-5), all patients were R/R to both frontline therapy and subsequent ibrutinib regimens. Prior responses to ibrutinib based regimens included only 1 CR. Here, we report a higher CR rate when these patients are subsequently treated with emavusertib in combination with ibrutinib.Results revealed no dose-limiting toxicities. Conclusions: Emavusertib in combination with ibrutinib was well tolerated with an acceptable safety profile and promising efficacy in R/R PCNSL patients with previous exposure to ibrutinib (BTKi). Enrollment in this trial is ongoing (NCT03328078). Clinical trial information: NCT03328078 .

Abstract Oncocytic carcinoma (Hurthle cell carcinoma) has the highest incidence of metastasis among the differentiated thyroid cancers. Metastatic disease is reported at the initial diagnosis in 10-20% of patients and 34% overall. Thyroid-stimulating hormone receptor (TSHR) expression is limited to the thyroid gland. It is abundantly expressed on thyroid tumor cells, making TSHR a compelling target for advanced thyroid cancer diagnostics and therapeutics. We developed a potent anticancer strategy for treating oncocytic carcinoma using a novel thyroid hormone stimulating receptor (TSHR)- targeted (chimeric antigen receptor) CAR T cell therapy. TSHR CAR T was generated by transducing T cells derived from healthy donors. In vitro effector functions (cytotoxicity, proliferation, degranulation) were tested in TSHR+ tumor models, and subsequent in vivo studies using NSG mice were performed to assess anti-tumor activity efficacy. We observed strong anti-tumor activity against metastatic oncocytic carcinoma cell line XCT.UC1 using the TSHR CAR T therapy in vivo. Re-challenging treated mice with XCT.UC1 cells reactivated TSHR CART cells with enhanced proliferation and complete suppression of tumor growth of the newly injected tumor cells. Our work represents a promising strategy to improve treatment outcomes of patients with metastatic oncocytic carcinoma that may provide a durable response. Citation Format: Justyna J. Gleba, Aylin Alasonyalilar-Demirer, Matthew Pawlush, Claudia Manriquez-Roman, Elizabeth L. Siegler, Robert C. Smallridge, Abba Zubair, Han W. Tun, Saad S. Kenderian, John A. Copland. Novel TSHR CAR T therapy for targeting oncocytic carcinoma [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 5082.

Background: Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of NHL isolated to the central nervous system or vitreoretinal space. Despite high initial rates of responses to available therapies, most PCNLS relapse in two years, presenting a very poor prognosis. Combination with novel therapies may overcome resistance (Guidetti 2023a). Upregulation of the B-cell receptor (BCR/NF-κB) and toll-like receptor (TLR)/NF-κB) signaling axis have been identified as key pathways in the pathogenesis of PCNSL. MYD88 L265P, a widely expressed somatic mutation in more than 70% of PCNSL patients, activates NF-κB signaling through stimulation of BTK and IRAK4. Emavusertib (CA-4948) is a novel, potent oral inhibitor of interleukin 1 receptor-associated kinase 4 (IRAK4), with additional inhibitory activity against FMS-like tyrosine kinase 3 (FLT3) and CDC-like kinases (CLK1/2/4). Targeted inhibition of IRAK4 with emavusertib in PCNSL xenografts indicated sufficient blood brain barrier penetration of emavusertib, target inhibition, and antitumor activity (von Roemeling 2022). Further preclinical studies have demonstrated that emavusertib synergizes with ibrutinib and can re-sensitize and overcome resistance to BTK inhibitors (Guidetti 2023a and 2023b). Initial clinical data have reported responses in BTK-resistant PCNSL and good tolerance of the combination (Iqbal 2022; Grommes 2023). Study Design: This is an ongoing multi-center, open-label trial (NCT03328078) in adult patients with hematologic malignancies to evaluate the safety, PK, and anti-cancer activity of oral administration of emavusertib alone or in combination with ibrutinib. Part Bis an open trial expansion cohort with BTKi relapsed or refractory PCNSL. About 20 evaluable PCNSL patients will be enrolled globally. Patients will receive oral CA-4948 at 100 or 200 mg BID in combination with ibrutinib at 560 mg QD in 28-day cycles until disease progression or intolerable toxicity. The primary endpoint is expanded safety/tolerability; secondary endpoints include ORR, DOR, PFS, OS, and pharmacokinetics. Key inclusion criteria for this expansion cohort: pathologically confirmed diagnosis of PCNSL with evidence of disease progression, measurable disease, relapsed or refractory with no more than 3 lines of prior anti-PCNSL therapy (including BTKi), and absence of residual Grade ≥2 toxicity from prior therapy. Key exclusion criteria: intraocular PCNSL without brain lesion or CSF involvement or significant co-morbidity. Key clinical assessments include brain imaging, CSF- and ocular examinations.

Introduction Primary mediastinal large B-cell lymphoma (PMLBCL) is a rare and aggressive type of non-Hodgkin B-cell lymphoma, accounting for about 3% of all non-Hodgkin lymphomas. The role of radiation therapy following immunochemotherapy is controversial and lately there has been more studies suggesting there is less benefit of adding radiation therapy. Large-scale studies describing and evaluating the effect of radiation therapy on survival outcome are lacking. Materials and Methods The National Cancer Database (NCDB) was queried for patients diagnosed with PMLBCL between 2004 and 2019. All patients aged ³18 years diagnosed with PMLBCL were included. We excluded patients with unknown chemotherapy and radiation therapy status, or received radiation prior to chemotherapy, or received radiation 6 months after chemotherapy or lost to follow-up (unknown vital status of last contact). Kaplan-Meier and multivariate Cox regression were used in the analyses. Results The total cohort consisted of 1,899 patients with PMLBCL. Out of whom 1,177 (62%) were females, 1,560 (76%) were White non-Hispanic, 113 (6%) were White Hispanic and 205 (11%) were African Americans. Among patients with known disease stage, 1,164 (61%) had early-stage disease (stage I and II) and 351 (19%) had advanced stage disease (stage III and IV). 1,443 (76%) received chemotherapy only and 456 (24%) received chemotherapy followed by radiation therapy. The median age at diagnosis was 35 years (range 18-90), 1,215 (64%) were diagnosed at younger age (40 years or less). The median follow-up time was 60 months (95% CI 57-62), the median overall survival (OS) for the whole cohort was not reached, and the 5-year OS was 91%. The 5-year OS for early and advanced stage were 93% and 83%, respectively. In patients with early-stage disease, there was no statistically significant difference in the median OS between patients who received chemotherapy only (N=824) compared to patients who received chemotherapy followed by radiation therapy (N=340) (not reached in both groups, P=0.130) with 5-year OS of 92% and 93%, respectively. In patients with advanced stage disease, there was no statistically significant difference in the median OS between patients who received chemotherapy only (N=294) and patients who received chemotherapy followed by radiation therapy (N=57) (median OS not reached in both groups, P=0.067) with 5-year OS of 82% and 88%, respectively. On multivariate analysis, older age and Charlson-Deyo score ≥3 were associated with worse OS (HR 1.062 95% CI 1.047-1.078; P<0.001 and HR 6.032 95% CI 1.853-19.634; P=0.003, respectively), early stage was associated with better OS (HR 0.508 95% CI 0.364-0.708; P<0.001), whereas adding radiation to chemotherapy did not affect the OS (HR 0.713 95% CI 0.491-1.035; P=0.075). Over the years, there was a significant down trend in using radiation therapy (Figure 1). Using univariate and multivariate logistic regression analysis, we found early-stage disease was associated with increased use of radiation therapy after chemotherapy. Whereas patients who were treated at academic/research programs were less likely to receive radiation therapy (Table 1). Conclusion This large real-world analysis shows a practice change in PMLBCL treatment with a trend in omitting radiation therapy. In our analysis, we found that adding radiation therapy to systemic therapy did not affect the survival outcome in both early and advanced stage disease.

Introduction: Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a low-grade B cell non-Hodgkin lymphoma that originates in lymphoid tissue of epithelial lined structures. The commonest site for this lymphoma is the stomach (gastric MALT lymphoma). MALT lymphoma in other mucosal sites, including other gastrointestinal sites, lungs, salivary glands, and lacrimal glands, has been well-described. However, MALT lymphoma in urothelial organs (kidneys, ureters, and urinary bladder) has not been well-characterized. This study aimed to investigate the clinicopathological features and therapeutic outcomes in urologic MALT lymphoma (U-MALT). Methods: We identified patients with U-MALT who were treated at the Mayo Clinic Cancer Center between March 2013 and May 2022 through electronic medical chart review. Clinical, pathologic, radiologic, therapeutic, and survival data were extracted. Kaplan-Meier analysis was used to determine the survival outcomes. Results: The characteristic features of six patients (N=6) with U-MALT are summarized in Table-1. 4/6 (67%) are Caucasian, and 3/6 (50%) are males. The median age at diagnosis was 73.5 years. Urologic sites are the urinary bladder (3/6), kidneys (3/6), and ureter (1/6, this patient had both kidney and ureter involvement). 4/6 patients had primary U-MALT. Concurrent non-urologic involvement was identified in 3/6 patients and included bone marrow, lungs, stomach, and axillary lymph nodes. Bone marrow involvement was observed in 2/6 patients.Next-generation sequencing was performed on one patient's peripheral blood, revealing an ATM mutation. Regarding the initial clinical presentation, kidney-involved U-MALT patients presented with renal failure, and those with urinary bladder/ureteric involvement, U-MALT was diagnosed incidentally upon cystoscopic evaluation and biopsy. Various management strategies were used, including observation, surgical resection, and rituximab treatment. Notably, all patients achieved complete remission (CR) except one with partial response to rituximab, who subsequently achieved CR with the Bendamustine/Rituximab regimen. Median follow-up is 6 years (range, 1-10). All six patients are alive without relapse at the time of analysis, with the flat overall survival curve at 100%, indicating excellent long-term survival. Conclusions: Our study indicates that urologic MALT lymphomas are extremely rare and predominantly affect elderly people. The most common urologic sites are the kidneys and urinary bladder. Urologic manifestations are dependent on the urologic site involved. They can be primary to the urologic structures or part of the disseminated systemic marginal zone lymphoma. They can be treated like other low-grade lymphomas with observation, surgical resection, and systemic therapy. They appear to be quite responsive to CD-20 targeted therapy with Rituximab. Prognosis appears to be excellent with long overall survival. Further research with multi-institutional studies is needed to study this rare lymphoma entity and identify optimal therapy.

Introduction: Gray zone lymphoma (GZL) is a rare lymphoid neoplasm exhibiting features intermediate between diffuse large B-cell lymphoma and Hodgkin lymphoma. Due to its rarity and relatively recent recognition by the World Health Organization in 2008, the natural history, clinical behavior, and best treatment strategies are still evolving. We present a retrospective review of GZL patients diagnosed and managed at the Mayo Clinic. This study aims to explore the clinical characteristics, treatment modalities, and outcomes of this poorly understood disease. Methods: After reviewing the electronic medical records of patients presented to the Mayo Clinic Cancer Center between March 2012 and July 2022 at the Mayo Clinic, we identified the patients who were diagnosed with GZL. Clinicopathological characteristics, disease features, treatment modalities, and outcomes were analyzed. The Kaplan-Meier method was utilized to assess survival outcomes. Results: Six patients (n=6) with GZL, all Caucasian and predominantly male 4/6 (67%), were identified. The median age at diagnosis was 37 years (range 24-57). Disease characteristics included high rates of mediastinal involvement 5/6 (83%) and bulky disease 4/6 (67%), with various stages of Ann Arbor classification represented. First-line treatment regimen varied between R-CHOP, ABVD, and DA R-EPOCH. The R-CHOP regimen was received in 3/6 patients (50%); the first patient achieved Complete Remission (CR), then managed with R-ICE, followed by consolidative autologous stem cell transplantation (auto-SCT) when relapsed. The second patient had Partial Response (PR) to R-CHOP and required consolidative radiotherapy to achieve CR, and the third R-CHOP patient achieved CR however, after multiple disease progressions that were managed with multiple regimens including R-ICE, R-CODOX-M/IVAC regimen, Nivolomab/Ipilumuab, consolidative radiotherapy, and Brentuximab vedotin. The ABVD regimen was received by 2/6 patients (33%). The first patient had CR, and the second patient had disease progression, which required treatment with R-ICE, followed by consolidative radiotherapy and auto-SCT. One patient (17%) received the DA R-EPOCH regimen and achieved CR, consolidated with auto-SCT. The median follow-up for our cohort is nine years (range, 5-13). All six GZL patients are alive and in CR (since 2019 or before) at the time of the study analysis, with an excellent flat overall survival curve. For this reason and due to the small patient sample, we could not calculate the progression-free survival data. Conclusions: Our Mayo Clinic review provides unique insights into managing Gray Zone Lymphoma (GZL), a rare disease. We reported 100% survival and remission in six GZL patients using diverse treatment strategies, contrasting with varied outcomes from other institutions. This underscores the potential of individualized treatments for GZL and the need for further, broader studies to validate our findings and refine optimal treatment approaches for this rare disease entity.

Background: Emavusertib (CA-4948) is a novel oral inhibitor of interleukin-1 receptor-associated kinase 4 (IRAK4), which is essential for toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling in B cell proliferation. Additional inhibitory activity against FMS-like tyrosine kinase 3 (FLT3) and CDC-like kinases (CLK1/2/4) is also present in emavusertib. IRAK4 forms a Myddosome complex with MYD88 adaptor protein and drives overactivation ofnuclear factor-kappa B (NF-κB), causing inflammation and tumor growth. Emavusertib has been reported to be well tolerated and active as monotherapy in heavily pretreated patients with relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL) (Nowakowski 2020). Preclinical studies demonstrated that tumor resistance and survival via IRAK4 activation could be delayed or reversed. Emavusertib crossed the blood-brain barrier in a murine PDX model of PCNS lymphoma, blocked the activated IRAK4 pathway, and induced tumor response and prolonged survival (von Roemeling 2022). In combination with Bruton tyrosine kinase (BTK) inhibitors, emavusertib showed in vitro synergy and re-sensitization of resistant cell lines, overcoming BTK resistance (Guidetti 2023a and 2023b). In vivo synergy in B-cell NHL was also demonstrated. Adaptive chemotherapy treatment resistance through IRAK4 upregulation and activation was also described in other disease models (Melgar 2019, Li 2019). This abstract presents preliminary efficacy and safety data of emavusertib + ibrutinib in R/R NHL patients. Aim:Assessment of safety and clinical activity of emavusertib in combination with ibrutinib. Methods: This is an ongoing open-label trial (NCT03328078) of emavusertib as monotherapy and in combination with ibrutinib. Part A1 - completed; dose escalation of emavusertib as monotherapy; the recommended phase 2 dose (RP2D) is 300 mg BID with continuous oral dosing (Nowakowski 2020). Part A2 - completed; dose escalation of emavusertib in combination with ibrutinib at 420 and 560 mg QD (Joffe 2022). Part B - ongoing; an expansion cohort of PCNSL patients with resistance to prior BTK inhibitors for additional safety and efficacy related to exposure: emavusertib at 100 or 200 mg BID + ibrutinib at 560 mg QD in 28-Day cycles. Results:As of 19 July 2023, 18 heavily pretreated NHL (including five PCNSL) patients received emavusertib at 100, 200, or 300 mg BID in combination with full ibrutinib doses per label. Median age was 63.5 years (range 50-92). Median number of prior lines of anti-cancer therapies was 3 (range 1-10). Eleven of 18 patients failed prior BTK inhibitors. Median treatment duration was 95.5 days (21-587 days), suggesting acceptable safety and tolerability. No DLTs were observed at the 200 mg BID dose level, and two reversible DLTs (stomatitis and syncope) were observed at the 300 mg BID dose level. The preliminary efficacy data of 16 evaluable patients in combination with ibrutinib showed 5 CRs (2 MCL, 3 PCNSL) and 1 PR (1 CLL). All 3 PCNSL patients with CR were previously treated with BTK inhibitors. Conclusion: The combination ofemavusertib plus ibrutinib (ema+ibr) is well tolerated with an acceptable long-term safety profile and promising efficacy, showing several objective responses in heavily pretreated and/or BTK inhibitor resistant patients. Emavusertib may have the potential to overcome BTK inhibitor resistance and the combination of ema+ibr has the potential to show increased anti-cancer activity compared to ibrutinib monotherapy.

Factor VII (FVII) is an important, vitamin K-dependent clotting factor. Acquired FVII deficiency is a rare entity that is associated with serious bleeding complications. We report a case of acquired FVII deficiency in a patient with recurrent chronic myeloid leukemia in blast crisis who developed bilateral retinal hemorrhages. The coagulopathy was corrected with the initiation of chemotherapy and subsequent reduction in peripheral blast count.

Abstract Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Tyrosine kinase inhibitors (TKIs) are approved as a first-line treatment for unresectable HCC. Lenvatinib and cabozantinib are two of the most used TKIs, but the therapeutic duration is limited due to the development of drug resistance. Therefore, understanding the mechanisms of resistance and combining TKIs with other drugs antagonizing resistance should lead to antitumor synergy, eliminating drug resistance. It turns out that the simultaneous use of TKIs together with an inhibitor of stearoyl-CoA desaturase 1 (SCD1) prevents the development of drug resistance, leading to a durable response. SCD1 is the enzyme responsible for de novo fatty acid (FAs) synthesis, converting saturated fatty acids (SFAs) into monounsaturated fatty acids (MUFAs). MUFAs are an alternative energy source to glucose, integral to cellular membranes, and prevent endoplasmic reticulum (ER) stress and other signaling pathways. In our laboratory, we developed a novel, highly specific SCD1 inhibitor - SSI-4. We have tested the biological activity of SSI-4 against different HCC cell lines and patient-derived xenografts (PDX) mouse models. Of the twelve tested HCC cell lines, four were highly sensitive to SSI-4 (IC50 1-50 nM). Other cell lines showed moderate or no sensitivity to SSI-4. We tested the concomitant use of SSI-4 with lenvatinib and cabozantinib, tyrosine kinase inhibitors (TKIs) FDA-approved for HCC, in HCC cell lines in vitro and using HCC PDX in vivo mouse models. Our studies showed that the combination of the SCD1 inhibitor with both lenvatinib and cabozantinib showed a highly synergistic effect and no development of drug resistance i.e. durable response versus single TKI therapy. Ongoing mechanistic studies are examining whether known molecular targets of tested TKI’s such as VEGFR1, 2, and 3, PDGFRα, FGFR, KIT, and RET dominate in HCC drug resistance to lenvatinib and cabozantinib, and how the use of SSI-4 overcomes the phenomenon of resistance. Citation Format: Justyna J. Gleba, Aylin Alasonyalilar-Demirer, Matthew L. Pawlush, Ahmet Bilgili, Peyton G. Hickman, Kabir Mody, Lewis R. Roberts, Steven R. Alberts, Mark J. Truty, Tushar C. Patel, Han W. Tun, John A. Copland. Synergistic activity of SCD1 blockade in combination with tyrosine kinase inhibitors lenvatinib and cabozantinib in hepatocellular carcinoma (HCC). [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 5489.