Cutaneous T-cell Lymphoma Patients Research Articles

Multi-omic profiling reveals the endogenous and neoplastic responses to immunotherapies in cutaneous T cell lymphoma

Cutaneous Tcell lymphomas (CTCLs) are skin cancers with poor survival rates and limited treatments. While immunotherapies have shown some efficacy, the immunological consequences of administering immune-activating agents to CTCL patients have not been systematically characterized. We apply a suite of high-dimensional technologies to investigate the local, cellular, and systemic responses in CTCL patients receiving either mono- or combination anti-PD-1 plus interferon-gamma (IFN-γ) therapy. Neoplastic Tcells display no evidence of activation after immunotherapy. IFN-γ induces muted endogenous immunological responses, while anti-PD-1 elicits broader changes, including increased abundance of CLA+CD39+ Tcells. We develop an unbiased multi-omic profiling approach enabling discovery of immune modules stratifying patients. We identify an enrichment of activated regulatory CLA+CD39+ Tcells in non-responders and activated cytotoxic CLA+CD39+ Tcells in leukemic patients. Our results provide insights into the effects of immunotherapy in CTCL patients and a generalizable framework for multi-omic analysis of clinical trials.

Dupilumab therapy for atopic dermatitis is associated with increased risk of cutaneous T cell lymphoma: a retrospective cohort study

Dupilumab, a human monoclonal antibody targeting the interleukin 4 alpha receptor, is used for treatment of moderate to severe atopic dermatitis (AD). Previous studies have reported diagnoses of cutaneous T cell lymphoma (CTCL) after dupilumab use. Investigate the risk of CTCL after dupilumab use in patients with AD. Using the TrinetX database, incidence of cutaneous and lymphoid malignancies including CTCL was compared between a cohort of patients with AD who used dupilumab and a cohort of patients with AD who never used dupilumab. A second analysis excluding prior disease-modifying antirheumatic drug use was performed. Propensity score matching was performed to control for covariates. An increased risk of CTCL was found in the cohort of AD patients who used dupilumab (odds ratio 4.1003, 95% confidence interval 2.055-8.192). The increased risk persisted after exclusion of prior disease-modifying antirheumatic drug use. Risk was not increased for other cutaneous or lymphoid malignancies. Most (27/41) cases of CTCL were diagnosed more than 1year after dupilumab use. There is potential for misclassification in the database. Severity of AD could not be assessed. Association between dupilumab and CTCL does not prove causality. Dupilumab use is associated with an increased risk of CTCL in patients with AD in this cohort.

Abrogation of USP9X Is a Potential Strategy to Decrease PEG10 Levels and Impede Tumor Progression in Cutaneous T-Cell Lymphoma

Advanced-stage cutaneous T-cell lymphomas (CTCL) are notorious for its highly aggressive behavior, resistance to conventional treatments and poor prognosis, particularly when large-cell transformation (LCT) occurs. Paternally expressed gene 10 (PEG10) has been recently proposed as a potent driver for LCT in CTCL. However, the targeting of PEG10 continues to present a formidable clinical challenge that has yet to be addressed. Here we report an important post-translational regulatory mechanism of PEG10 in CTCL. Ubiquitin-specific protease 9X (USP9X), a deubiquitinase, interacted with and deubiquitinated PEG10, thereby stabilizing PEG10. Knockdown of USP9X or pharmacological targeting of USP9X resulted in a prominent downregulation of PEG10 and its downstream pathway in CTCL. Moreover, USP9X inhibition conferred tumor cell growth disadvantage and enhanced apoptosis in vitro, an effect that occurred in part through its regulation on PEG10. Furthermore, we demonstrated that inhibition of USP9X obviously restrained CTCL tumor growth in vivo, and that high expression of USP9X is associated with poor survival in CTCL patients. Collectively, our findings uncover USP9X as a key post-translational regulator in the stabilization of PEG10 and suggest that targeting PEG10 stabilization through USP9X inhibition may represent a promising therapeutic strategy for advanced-stage CTCL.

Tailoring Radiation Therapy for Patients With Limited Cutaneous T Cell Lymphoma: Preliminary Clinical Experience With Subtotal Skin Electron Therapy.

Total skin electron beam therapy (TSEBT) is an effective treatment for managing cutaneous T-cell lymphoma (CTCL), but may result in unnecessary toxicity. With the production of a custom rolling shield holding a configurable stack of plastic slats to block uninvolved skin, we implemented a program for subtotal skin electron beam therapy (STSEBT). We report our preliminary experience with STSEBT vs. TSEBT to manage CTCL. A retrospective review of 32 CTCL patients who were treated at a single institution between February 28th, 2017, and May 25th, 2022, was completed. Of these cases, seven patients received STSEBT and 25 received TSEBT. Thirty-two patients underwent a course of STSEBT or TSEBT. The median follow-up was 465 days and the median age at diagnosis was 70.8 years. Stage distribution was as follows: one (3%) IA, 16 (50%) IB, 6 (19%) IIB, two (6%) IIIA, five (16%) IVA, and two (6%) IVB. The overall response rate was 96%. For patients receiving TSEBT (n=25), three (12%), 10 (40%), and 11 (44%) had a CR, NCR, and PR, respectively. For the patients receiving STSEBT, four (57.1%), three (42.9%), and zero (0%) had a CR, NCR, and PR, respectively. There was one patient (4%) with no response. Cumulative incidence of progressive skin disease requiring additional electron therapy at three months was 21.1% [IQR=8.6, 51.5%], 36.8% [IQR=20, 68%] at six months, and 57.9% [IQR=38.5, 87.1%] at one year. Low rates of toxicities were recorded. This analysis demonstrated that treatment of CTCL patients with low disease burden with STSEBT results in similar overall response and time to progression compared to treatment with TSEBT.

Vitamin D in Cutaneous T-Cell Lymphoma.

Cutaneous T-cell lymphoma (CTCL) is characterized by the proliferation of malignant T cells in inflamed skin lesions. Mycosis fungoides (MF)-the most common variant of CTCL-often presents with skin lesions around the abdomen and buttocks ("bathing suit" distribution), i.e., in skin areas devoid of sun-induced vitamin D. For decades, sunlight and vitamin D have been connected to CTCL. Thus, vitamin D induces apoptosis and inhibits the expression of cytokines in malignant T cells. Furthermore, CTCL patients often display vitamin D deficiency, whereas phototherapy induces vitamin D and has beneficial effects in CTCL, suggesting that light and vitamin D have beneficial/protective effects in CTCL. Inversely, vitamin D promotes T helper 2 (Th2) cell specific cytokine production, regulatory T cells, tolerogenic dendritic cells, as well as the expression of immune checkpoint molecules, all of which may have disease-promoting effects by stimulating malignant T-cell proliferation and inhibiting anticancer immunity. Studies on vitamin D treatment in CTCL patients showed conflicting results. Some studies found positive effects, others negative effects, while the largest study showed no apparent clinical effect. Taken together, vitamin D may have both pro- and anticancer effects in CTCL. The balance between the opposing effects of vitamin D in CTCL is likely influenced by treatment and may change during the disease course. Therefore, it remains to be discovered whether and how the effect of vitamin D can be tilted toward an anticancer response in CTCL.

New Genetic Markers of Skin T-Cell Lymphoma Treatment.

Cutaneous T-cell lymphomas (CTCL) can be described as chronic skin inflammation lesions with the content of malignant T cells and they are considered to be T-cell-mediated skin diseases. CD147 is recognized as a 58-kDa cell surface glycoprotein of the immunoglobulin superfamily; it can induce the synthesis of MMPs (matrix metalloproteinases) on the surface of tumor cells where it was originally identified. It can also function in adjacent tumor fibroblasts using CD147-CD147 interactions. The polymorphism rs8259 T/A is situated in the untranslated region (3'UTR) of the CD147 gene. HLA DRB1*1501 takes part in the process of presentation and recognition of different antigens to T cells. It can be expressed by antigen-presenting cells-macrophages, dendritic cells, and B cells. The aim of the study is to test genotype-phenotype associations of both polymorphisms including therapy in a large cohort of CTCL patients. A final total of 104 CTCL patients were enrolled in the study. For the first remission at the clinic department, they were treated by means of local skin-directed therapy, phototherapy, and systemic therapy. Genomic DNA was isolated from peripheral blood leukocytes. A standard technique using proteinase K was applied. The polymorphisms rs8259 T/A (CD147 gene) and rs3135388 (HLA DRB1*1501) were detected through standard PCR-restriction fragment length polymorphism methods. The severity of the disease (patients with parapsoriasis, stages IA and IB, vs patients with stages IIB, IIIA, and IIIB) was associated with the CD147 genotype: the AA variant was 3.38 times more frequent in more severe cases, which reflects the decision on systemic therapy (p = 0.02, specificity 0.965). The AA genotype in the CD147 polymorphism was 12 times more frequent in patients who underwent systemic therapy of CTCL compared to those not treated with this therapy (p = 0.009, specificity 0.976). The same genotype was also associated with radiotherapy-it was observed 14 times more frequently in patients treated with radiotherapy (p = 0.009, specificity 0.959). In patients treated with interferon α therapy, the AA genotype was observed to be 5.85 times more frequent compared to the patients not treated with interferon therapy (p = 0.03, specificity 0.963). The HLA DRB1*1501 polymorphism was associated with local skin-directed therapy of CTCL. The CC genotype of the polymorphism was observed to be 3.57 times more frequent in patients treated with local therapy (p = 0.008, specificity 0.948). When both polymorphisms had been calculated together, even better results were obtained: the AACC double genotype was 11 times more frequent in patients with severe CTCL (p = 0.009, specificity 0.977). The TACT double genotype was associated with local skin-directed therapy (0.09 times lower frequency, p = 0.007, sensitivity 0.982). The AACC genotype was 8.9 times more frequent in patients treated by means of systemic therapy (p = 0.02, specificity 0.976) and as many as 18.8 times more frequent in patients treated with radiotherapy (p = 0.005, specificity 0.969). Thus, the AACC double genotype of CD147 and DRB1*1501 polymorphisms seems to be a clinically highly specific marker of severity, systemic therapy and radiotherapy of patients with T-cell lymphoma. Although genotyping results were not known during the treatment decision and could not modify it, the clinical decision on severity and therapy reflected some aspects of the genetic background of this complicated T-cell-associated disease very well.

Fine-Tuning Low-Dose Total Skin Electron Therapy for Optimal Management of Cutaneous T-Cell Lymphoma: A Comparative Analysis of Regimens

BackgroundLow-dose total skin electron beam therapy (TSEBT) is a proven treatment for managing cutaneous T-cell lymphoma (CTCL) and Sezary syndrome with skin burden. We performed a retrospective comparison of response rates and time to progression for patients receiving low-dose TSEBT based on dose per fractionation, total dose, and stage. MethodsOne hundred and ten patients with CTCL and Sezary syndrome were treated with 135 courses of low-dose (400-1500 cGy) TSEBT or STSEBT (subtotal skin electron therapy) at multiple centers of a single institution between 8/2003 and 6/2023. Patients were stratified according to total dose, dose per fraction, and stage. ResultsThe median follow-up was 301 days [IQR 141, 767]. The median age at treatment was 69.9 years (range 29.7 – 96.5). T-stage distribution was as follows: 3 (2.7%) T1, 74 (67.3%) T2, 16 (14.5%) T3, and 17 (15.5%) T4. AJCC 8th edition Stage distribution was as follows: 3 (2.7%) IA, 53 (48.2%) IB, 3 (2.7%) IIA, 16 (14.5%) IIB, 8 (7.3%) IIIA, 19 (17.3%) IVA, 8 (7.3%) IVB. There was no significant difference in disease distribution between patients treated with different fractionation schemes. The overall response rate was 89.6%. Forty-four courses (32.6%), 34 courses (25.2%), and 43 (31.9%) resulted in a complete, near-complete, and partial response, respectively. Fourteen courses (10.4%) resulted in no clinical response. For all patients, the median time to response was 43.0 days (IQR 23.0 – 70). The median time to skin progression for all patients was 107.5 days [IQR 67.8 – 233.5]. ConclusionsThis analysis demonstrated that CTCL patients treated with low-dose RT delivered over various fractionation schemes had similar overall response rates and median time to progression.

Evaluation of Quality of Life and Treatment Satisfaction in Newly Diagnosed Cutaneous T-Cell Lymphoma Patients.

Little is known about the impact of MF on quality of life (QoL) in newly diagnosed patients. To describe the impact of the MF diagnosis on QoL, patient expectations, and treatment satisfaction over the first 6 months after diagnosis. Outcomes of this prospective cohort study of newly diagnosed MF patients conducted between 2020 and 2022 at the Leiden University Medical Center included the Skindex-29, RAND-12 Health Survey, degree of itch, pain, and fatigue (Visual Analogue Scale (VAS)), patient expectations, and Client Satisfaction Questionnaire-8 (CSQ-8), measured at baseline and after six months. A total of 28 patients with MF were included. At baseline, 66% (n = 18) "strongly-totally" expected positive effects of the treatment. At the time of diagnosis, 28% of the patients (n = 8) were moderately to severely affected. There was no statistical change in the Skindex-29 score sum score (20 [10-34] vs. 20 [9-36]; p = 0.81) or in the other three subdomains, the RAND-12 scores, and the VAS itch, pain, and fatigue over time. Treatment satisfaction was high overall. Despite that the newly diagnosed MF patients anticipate a positive treatment effect, few improvements in QoL and symptom reduction were found. These data can be used for adequate expectation management and provide a rationale for further evaluation of treatment regimens in these patients.

Chemical exposures and demographic associations in cutaneous T-cell lymphoma: a large single institution physician validated cohort study.

Cutaneous T-cell lymphomas (CTCL) are a rare group of T-cell neoplasms which infiltrate the skin and can result in substantial morbidity and mortality. Risk factors for CTCL are still poorly understood though recent studies suggest chemical exposures may play a role in its development. To further characterize patient-centered risk factors for CTCL, especially compared with matched controls, we performed one of the largest prospective cohort survey studies to date to examine patient-reported exposures and health-related quality of life (HRQoL) in association with concurrent clinical disease characteristics. Patient demographics, lifestyle factors, and chemical exposures were collected via clinical data and surveys. Descriptive statistics, ANOVA, Chi-square tests and t tests were utilized to compare patient-reported exposures and HRQoL in patients with CTCL versus matched healthy controls (HC). Statistically significant differences were identified between patients and HC in terms of race (non-white race 22.4% in CTCL patients vs. 18.8% in HC, P = 0.01), and education level (high school or less 41.6% in CTCL patients vs. 14.3% in HC, P = 0.001), but not with Fitzpatrick skin type (P = 0.11) or smoking status (P = 0.28). Notably, 36.0% of the CTCL patients reported exposures to chemicals, a near threefold increased percentage when compared to HC (12.9%). Among various chemical exposures, 27.0% of the CTCL patients specifically reported industrial chemical exposure, a more than two-fold increased percentage when compared to HC (12.9%). Itch and pain were significantly associated with skin disease severity (as evaluated by CTCL-specific mSWAT score) in advanced stage disease (stages IIB-IVB) (r = 0.48 and 0.57, P < 0.05). Itch and body mass index (BMI) were weakly associated with skin disease severity in early-stage disease (stages IA-IIA) (r = 0.27 and 0.20, P < 0.05).

Gut microbiota analyses of cutaneous T-cell lymphoma patients undergoing narrowband ultraviolet B therapy reveal alterations associated with disease treatment.

Recent studies have shown a close relationship between cutaneous T-cell lymphoma (CTCL) and its microbiome. CTCL disease progression is associated with gut dysbiosis and alterations in bacterial taxa parallel those observed in immunologically similar atopic dermatitis. Moreover, the microbial profile of lesional skin may predict response to narrowband ultraviolet B (nbUVB), a common skin-directed therapy. However, the relationship between the gut microbiome, an immunologically vital niche, and nbUVB remains unexplored in CTCL. Herein, we performed 16S rRNA sequencing and PICRUSt2 predictive metagenomics on DNA extracted from stool swabs of 13 CTCL patients treated with nbUVB, 8 non-treated patients, and 13 healthy controls. Disease response was assessed with modified Severity Weighted Assessment Tool (mSWAT); of nbUVB-treated patients, 6 improved (decreased mSWAT), 2 remained stable, and 5 worsened (increased mSWAT). Protective commensal bacteria including Lactobacillaceae and Erysipelatoclostridiaceae were significantly less abundant in CTCL patients compared to controls. With treatment, the CTCL gut microbiome exhibited decreased phylogenetic diversity and lower relative abundance of pro-inflammatory Sutterellaceae. Sutterellaceae was also significantly more abundant in patients who worsened, and Eggerthellaceae and Erysipelotrichaceae trended higher in patients who improved. Finally, PICRUSt2 functional predictions based on shifts in abundance of bacterial sequences repeatedly identified alterations in inositol degradation, which plays a key role in host immunomodulation, including inositol phospholipid signaling relevant to T-cell survival and proliferation. Our results bolster the paradigm of gut dysbiosis in CTCL and its functional implications in disease pathogenesis, and further delineate bacterial taxa associated with nbUVB response and with nbUVB treatment itself.

ATF5 promotes malignant T cell survival through the PI3K/AKT/mTOR pathway in cutaneous T cell lymphoma.

Cutaneous T cell lymphoma (CTCL) is a non-Hodgkin lymphoma characterized by skin infiltration of malignant T cells. The biological overlap between malignant T cells and their normal counterparts has brought obstacles in identifying tumor-specific features and mechanisms, limiting current knowledge of CTCL pathogenesis. Transcriptional dysregulation leading to abnormal gene expression profiles contributes to the initiation, progression and drug resistance of cancer. Therefore, we aimed to identify tumor-specific transcription factor underlying CTCL pathology. We analyzed and validated the differentially expressed genes (DEGs) in malignant T cells based on single-cell sequencing data. Clinical relevance was evaluated based on progression-free survival and time to next treatment. To determine the functional importance, lentivirus-mediated gene knockdown was conducted in two CTCL cell lines Myla and H9. Cell survival was assessed by examining cell viability, colony-forming ability, in-vivo tumor growth in xenograft models, apoptosis rate and cell-cycle distribution. RNA sequencing was employed to investigate the underlying mechanisms. Activating transcription factor 5 (ATF5) was overexpressed in malignant T cells and positively correlated with poor treatment responses in CTCL patients. Mechanistically, ATF5 promoted the survival of malignant T cells partially through the PI3K/AKT/mTOR pathway, and imparted resistance to endoplasmic reticulum (ER) stress-induced apoptosis. These findings revealed the tumor-specific overexpression of the transcription factor ATF5 with its underlying mechanisms in promoting tumor survival in CTCL, providing new insight into the understanding of CTCL's pathology.

Immunosequencing applications in cutaneous T-cell lymphoma.

Immunosequencing has emerged as a newer clinical test for assessment of T-cell clonality in the blood and skin of cutaneous T-cell lymphoma (CTCL) patients. Utilization of immunosequencing, also known as high-throughput sequencing of the T-cell receptor (HTS-TCR), enables identification and quantification of the precise genetic signature of dominant T-cell clones. Although immunosequencing is more sensitive than commonly used methods such as polymerase chain reaction (PCR) paired with capillary electrophoresis or flow cytometry, it remains underutilized for CTCL management. Nonetheless, incorporation of HTS-TCR in clinical practice offers distinct advantages compared to other molecular analyses that may improve diagnostic evaluation, prognostication, and disease monitoring in CTCL. The objective of this comprehensive review is to provide a thorough explanation of the application of immunosequencing in the context of CTCL. We describe the significance of T-cell clonality and the methods used to detect it, including a detailed comparison between PCR paired with capillary electrophoresis and HTS-TCR. The utilization of immunosequencing in the blood and skin of CTCL patients is discussed in depth, specifically outlining how HTS-TCR can assist in diagnosing CTCL, predicting outcomes, and tracking disease progression. Finally, we address the potential applications of immunosequencing in clinical management and research as well as the novel challenges it presents.

Gemcitabine and liposomal doxorubicin (GemDox) for the treatment of relapsed and refractory T-cell lymphomas

Aggressive T-cell lymphomas (TCL) account for 10–15% of non-Hodgkin lymphomas (NHL) with weaker responses and shorter durations to chemotherapy than other types of NHL. Current therapies for patients with relapsed/refractory Cutaneous T-cell lymphoma (CTCL) have limited efficacy, and short durations of response. Gemcitabine and liposomal doxorubicin have shown single-agent activity in TCL and combined have activity in relapsed B-cell lymphomas. We evaluated outcomes of 18 patients with relapsed/refractory aggressive TCL (13 CTCL, 5 PTCL) treated with a gemcitabine plus liposomal doxorubicin (GemDox) combination and evaluated outcomes with a specific focus on CTCL patients. Significant responses were observed in CTCL patients with an overall response rate of over 80%. In all patients, objective responses were seen in eight patients (50%), with six patients (5 CTCL) able to proceed to allogeneic stem cell transplant. Given limited treatment options for r/r CTCL, GemDox should be considered a therapeutic option in relapsed/refractory CTCL.

Risk of Cutaneous TCell Lymphoma with Psoriasis Biologic Therapies.

The risk of developing cutaneous Tcell lymphoma (CTCL) in patients using psoriasis biologics has not been well characterized. The goals of this review were to investigate the incidence of CTCL in patients with psoriasis receiving biologic therapy in clinical trials and psoriasis registries, and to review cases of CTCL and biologic use reported in scientific publications. The US National Library of Medicine clinical trials database (clinicaltrials.gov) was queried to identify phase3 and 4 clinical trials of the 12 biologic agents currently FDA approved for psoriatic disease. The incidence of CTCL in these trials was examined and summarized. To examine the incidence of CTCL in psoriasis registries, a Medline search was conducted. Finally, we performed a systematic review of CTCL cases reported in the literature. Only two cases of CTCL were reported in 35,801 subjects with psoriasis receiving a biologic agent in the active arm of 108 psoriasis phase3 clinical trials. One of these CTCL cases was determined by the investigator to be CTCL misdiagnosed as psoriasis prior to randomization. No cases of CTCL were reported in 5440subjects with psoriasis in 34 phase4 clinical trials. Only one case of CTCL was identified in 34,111 registry subjects. In the literature, tumor necrosis factor (TNF) inhibitors had the highest number of reported cases of CTCL (34 cases), followed by interleukin (IL)-17 inhibitors (7 cases), and IL-12/23 inhibitors (6 cases). No cases of CTCL were found to be reported with IL-23 inhibitors. Our findings indicate that the development of CTCL is rare in the setting of psoriasis biologic use. Of the limited number of cases of CTCL found, most were in the setting of TNF inhibitor use and no cases of CTCL were reported in the setting of IL-23 inhibitor use.

Translated article] Cost of Treating Cutaneous T-Cell Lymphoma in Spain: Analysis of MICADOS Study Data by Disease Stage

Background and objectiveThe cost of treating cutaneous T-cell lymphoma (CTCL) in Spain is unknown. With the advent of new treatments, it is more important than ever to gain an accurate picture of the true costs involved. The MICADOS study had 2 primary objectives: 1)to evaluate the impact of CTCL on patient quality of life, and 2)to evaluate the costs associated with the disease. This article reports the results of the cost analysis. MethodsWe estimated the cost of treating CTCL over a period of 1year from the perspective of the Spanish National Health System. Twenty-three dermatologists and hematologists from 15 public hospitals analyzed data for adult patients with mycosis fungoides (MF) or Sézary syndrome (SS). ResultsA total of 141 patients (57.4% male) with a mean age of 63.6 years (95%CI: 61.4-65.7 years) were included. The mean direct annual cost of treating CTCL was €34,214 per patient. The corresponding costs by stage were €11,952.47 for stageI disease, €23,506.21 for stageII disease, €38,771.81 for stageIII disease, and €72,748.84 for stageIV disease. The total direct annual cost of treating MF/SS in public hospitals in Spain was estimated at €78,301,171; stageI disease accounted for 81% of all costs, stageII for 7%, and stagesIII andIV for 6% each. ConclusionsThe MICADOS study offers an accurate picture of the direct cost of treating CTCL in patients with MF/SS in Spain and shows that costs vary significantly according to disease stage. Patient-borne and indirect costs should be analyzed in future studies.

Gemcitabine and Liposomal Doxorubicin (GemDox) for the Treatment of Relapsed and Refractory T-Cell Lymphomas

Introduction: Aggressive T-cell lymphomas (TCL) account for 10-15% of non-Hodgkin's lymphomas and have lower rates of complete response (CR), overall response (OR), and shorter duration of response (DOR) to chemotherapy than other types of NHL, particularly in the relapsed setting. Cutaneous T-Cell lymphoma (CTCL) is treated initially with skin directed therapies, but systemic therapy or cytotoxic chemotherapy may become necessary to control disease. Second-line chemotherapy benefits only a small minority of TCL patients and more effective treatment regimens are needed. Gemcitabine and liposomal doxorubicin have both shown single agent activity in TCL and have been used in combination in patients with relapsed B-cell lymphomas (BCL) and Hodgkin lymphomas (HL), though responses are typically not durable. Therefore, we evaluated a combination of gemcitabine and liposomal doxorubicin (GemDox) for patients with relapsed/refractory (r/r) TCL. Methods: In this single-center, retrospective study, we evaluated the safety, efficacy, and survival (PFS/OS using Kaplan-Meier method) of GemDox in TCL. Patients either received gemcitabine 1000 mg/m 2 and liposomal doxorubicin 15 mg/m 2 either on days 1 and 8 every 21 days (21-day regimen) or gemcitabine 1000 mg/m 2 and liposomal doxorubicin 15 mg/m 2 on days 1 and 15 every 28 days (28-day regimen). Results: 18 patients (13 CTCL, 5 PTCL) with r/r aggressive TCL were treated with GemDox, with 16 evaluable for treatment response. Patients were heavily pre-treated with a median number of 4 prior therapies (range 2-7). This included 62% of CTCL patients with nodal involvement. The overall response rate (ORR) was 50% (19% CR and 31% PR) with a median PFS and OS of 5 and 15 months respectively. In patients that had a response to treatment, the median PFS was 11 months while median OS was not reached. The clinical benefit rate [CR/Partial response (PR)/stable disease (SD)] for CTCL and PTCL was 82% and 40% respectively. The median PFS and OS for CTCL patients was 6 months and 14 months respectively, with an ORR of 55% (18% CR and 36% PR). For PTCL , the median PFS and OS were 4 and 21 months respectively, with an ORR of 40% (20% CR and 20% PR). The clinical benefit (CR/PR/SD) rate for the 21-day vs 28-day regimen was 71% and 67%, respectively, with similar PFS and OS, and no significant difference in toxicities. The median duration of response (DOR) for patients that obtained a response (CR/PR) in evaluable patients was 13 months; 17 months for CTCL, and 5 months for PTCL. We observed a substantial decrease in CTCL skin manifestations, as patients that had a CR/PR had a mean decrease of 76% in mSWAT BSA of 70%. Further, six patients (38%) (5 CTCL, 1 PTCL) were able to proceed to allogeneic stem cell transplant (allo-HSCT). Interestingly, 4 CD30+ CTCL patients were previously treated with brentuximab vedotin (BV). Of those, three (75%) had a response to GemDox, while only one achieved a response (PR) to BV. This demonstrates that GemDox is a potentially effective regimen in heavily refractory CD30+ CTCL patients that fail treatment with BV. 11 patients (61%) experienced any grade 3/4 toxicity and hematologic toxicities were the most common including: anemia (33%), neutropenia (22%), lymphopenia (17%) and thrombocytopenia (17%)., GemDox was very well tolerated with the most common grade 3/4 non-hematologic toxicity being fatigue (17%). 11% of patients discontinued therapy due to adverse events. Conclusion: GemDox produced an excellent ORR of 50%, with an impressive ORR of 82% in CTCL, suggesting this is an effective regimen for heavily pre-treated TCL patients. Additionally, a large number of patients with CTCL with heavy skin burden, including those refractory to BV, were able to achieve remarkable skin responses. Importantly, in this study, 75% of patients who responded to GemDox were able to proceed to allo-HSCT, with 66% experiencing a sustained response. Based on these findings, GemDox should be further investigated as a therapeutic option in relapsed aggressive TCL, particularly in CTCL and considered as a potential bridging therapy patients with a treatment goal of obtaining allo-HSCT and providing a long-term benefit.

CD84 (SLAMF5) As a Potential Target for Immunomodulation in Cutaneous T-Cell Lymphoma (CTCL)

Background: Cutaneous T-cell lymphoma (CTCL) develops from clonally expanded, skin-homing CD4 + T cells within a background of chronic inflammation. Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of CTCLs. Patients with advanced-stage MF/SS experience progressively worsening disease and decreased overall survival (Scarisbrick et al., 2015). Immune cells and immune checkpoints (ICs) are essential factors for tumor growth and the host immune response in CTCL. Tumor-associated macrophages (TAMs [M2-like]) play a key role in CTCL growth, and neoplastic T cells escape immune surveillance via the PD-L1/PD1 axis (Wu et al., 2014). However, the approach of ICs inhibition with monoclonal antibodies (mAbs) in CTCL has been challenged due to modest efficacy and remaining immunosuppression. Hence, novel therapeutic strategies are needed to improve anti-tumor immunity in CTCL. We previously characterized CD84 (SLAMF5) as one of the key players in the tumor microenvironment (TME) by regulating multiple ICs, including PD-L1 and PD1, and modulating myeloid cell fractions and T cells in our preclinical MM models. Our CD84 targeting strategy using anti-CD84 mAb significantly reduced PD1 on effector CD8 + T cells and PD-L1 on the tumor and myeloid cells, decreased tumor burden, and increased the survival of the mice with myeloma (Lewinsky and Gunes et al., 2021). The role of CD84 in ICs regulation and anti-tumor immunity in CTCL remains to be explored. Methods and Results: In this study, we evaluated the role of CD84 in CTCL and, for the first time, reported CD84 as a potential target to reduce immunosuppression through the PD-L1/PD1 axis in CTCL. We found upregulated CD84 CD274 (PD-L1) , and PDCD1 (PD1) gene expressions in CTCL patients (n=5) compared to healthy individuals (n=4). We also noted higher CD84 geneexpression in SS patients (n=8) than in MF patients (n=6). We next evaluated CD84 expression on the formalin-fixed paraffin-embedded (FFPE) tumor sections derived from SS patients' skin lesions. We noted that CD84 is highly expressed in the TME and co-expressed in Ki67 + Sézary cells. We further evaluated the CD84 expression in immune cell clusters in SS patients and healthy individuals using publicly available single-cell RNA sequencing (scRNA-seq) datasets. We noted a profound CD84 expression in CD4 + T cells and CD163 + M2-like macrophages in SS patients. We also noted a strong correlation between CD84 and CD274 (p=0.0086) and CD84 and PDCD1 (p=0.0002) in SS patients. We next assessed the expressions of CD84, PD-L1 on CD163 + M2-like macrophages, and PD1 on T cell subsets in a coculturing setting with human SS cell line, Hut78, to determine the impact of Sézary cells on these cell compartments in the TME. We observed a significant increase in the percentages of CD163 + M2-like macrophages and CD4 + T cells and elevated CD84, PD-L1, and PD1 expressions on these cells following the coculturing of peripheral blood mononuclear cells (PBMCs) derived from healthy donors (HDs) with Hut78 cells (n=3, *P &amp;lt; 0.05, **P &amp;lt; 0.01). While the percentages of CD8 + T cells were slightly reduced, CD84 and PD1 expressions were elevated in these cells following the coculturing with Hut78 cells (n=3, *P &amp;lt; 0.05, ***P &amp;lt; 0.001). Dysregulation of STAT proteins, particularly STAT3, has been shown in MF/SS (Olszewska et al., 2020). To explore whether Sézary cells regulate STAT3 in CD163 + M2-like macrophages, we assessed pSTAT3 levels in CD163 + M2-like macrophages following the coculturing of HDs PBMCs with Hut78 cells. We found that Hut78 cellssignificantly increased intracellular pSTAT3 levels inCD163 + M2-like macrophages (n=3, *P &amp;lt; 0.05). Furthermore, we noted the inhibition of STAT signalingusing a pan-STAT inhibitor decreased PD-L1 and PD1 expression onCD163 + M2-like macrophages and T-cell subsets, respectively. Notably, we found the stimulation of CD84 signaling with an agonist anti-CD84 mAb enhanced pSTAT3 levels in CD163 + M2-like macrophages, suggesting the STAT pathway might regulate PD-L1 expression in immunosuppressive CD163 + M2-like macrophages through CD84 signaling in SS. Conclusion: Our preliminary data from this exploratory study indicate that CD84 may be a potential target to reduce immunosuppression in CTCL. Further studies are needed to explore the functions of CD84 as an immune receptor in CTCL TME and its therapeutic potential in CTCL.

Health-Related Quality of Life (HRQL) in Cutaneous T-Cell Lymphoma: Psychological Burden and Influencing Factors from Mycosis Fungoides and Sézary Syndrome Patients in China

Introduction: Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of cutaneous T-cell lymphomas (CTCL). However, beyond the clinical and economic burden, psychological burden from CTCL patients in China has not been reported and requires further evaluation. Methods: The analysis used data from adults (≥18 years) clinically diagnosed with MF or SS, and have been receiving or have received disease-related treatment in the past year. MF patients with stage IA-IIA, patch or plaque phase were categorized into early stage, while stage IIB-IVA, tumor phase were late stage. All SS patients are late stage. HRQL data from the EQ-5D-5L, Skindex-29 and Functional Assessment of Cancer Therapy - General (FACT-G) were analysed at the item level and scored according to instrument guidelines. Multivariate analyses were used to identify factors associated with poor HRQL. Results: Data were collected from a quantitative survey of 56 MF patients and 5 SS patients residing in 38 cities of 21 provinces across China: 56% were male, with a mean (SD) age of 39 (13) years (median was 38, ranged 19 to 74 years old). 51% were late stage. Based on emotional domain questions of Skindex-29, among all patients, 39% always or often worried about the disease progression, while 45% of late-stage patients were always and often worried. 36% of all patients often or always felt CTCL was annoying. Based on FACT-G, in physical well-being domain, 39% of all patients, and 48% of late-stage patients felt they were ill in “quite a bit” or “very much” scale, respectively. In social well-being domain, 35% of all, and 39% of early-stage patients felt “not at all” or only “a little bit” satisfied with their sex life. In emotional well-being domain, 38% of all patients were “not at all” or “a little bit” satisfied with their coping with the disease, while 36% of all patients “quite a bit” or “very much” worried about the condition getting worse. In the functional well-being domain, 29% of all patients felt they were “not at all” or “a little bit” able to work. In multivariate analysis, regression on EQ-5D-5L score showed that younger patients were more likely to report severe anxiety and depression. Skindex-29 score showed that female patients worried more that the disease get more serious and causing scars on their skin. Conclusions: In China, psychological burden with MF and SS, included anxiety, depression, worrying about disease progression, unable to work, and unsatisfied sex life. Younger patients and female patients reported greater psychological impact of the disease. Optimal medical management of MF and SS should address psychological impacts of the disease.

Dynamic Changes in Lymph Node Size and Skin Scoring Predict Response to Treatment in CTCL: An Interim Analysis

Cutaneous T-cell lymphoma (CTCL) is a heterogenous group of non-Hodgkin T-cell lymphomas with predominant skin involvement. Mycosis fungoides and Sézary syndrome are the most common subtypes and present with a wide spectrum of cutaneous and extra-cutaneous manifestations. Early-stage disease is often controlled with skin-directed therapies while advanced-stage disease can be treatment-refractory and often requires multiple lines of systemic therapy. It is therefore of great interest to identify early predictors of treatment response to tailor therapeutic management decisions. Modified Severity-Weighted Assessment Tool (mSWAT) scoring and lymph node evaluation are important components of treatment response assessment in clinical practice and in trials. A major limitation of current assessment methods is the use of relative changes in mSWAT and lymph node size which do not account for heterogeneous treatment effects. Novel assessment techniques that reflect the dynamic changes occurring within the tumor environment during treatment have the potential to offer more accurate insights into treatment response than current methods. Among these novel approaches is kinetic modeling of tumor growth rate ( g), which has been validated as a biomarker for treatment response and survival in other types of cancer but has never been used in CTCL. Kinetic modeling provides the benefit of evaluating the simultaneous rates of growth of treatment-resistant cells and regression of treatment-responsive cells. We hypothesized that dynamic changes in lymph node size and mSWAT scores over time could predict response to treatment in CTCL patients. We retrospectively analyzed clinical data and computed tomography scans from 119 patients enrolled in the MAVORIC trial. An open-source imaging platform with integrated semi-automated segmentation algorithms was used to quantify lymph node volumes for each patient. Kinetic modeling was applied to estimate the simultaneous rates of growth ( g) and regression ( d) of lymph node size and mSWAT scores during treatment. Patients were divided into two groups based on g and correlation with time to treatment failure (TTF) was evaluated. Tumor doubling times were estimated using the equation dt = 0.693/ g. For most patients, g and d could be estimated, and these values could be determined early in the treatment course. Volumetric lymph node growth rate had an inverse correlation with TTF (p &amp;lt; 0.0001). Patients with with faster rates of nodal growth (median g = 0.0077 d -1, doubling time = 90 days) had a median TTF of 2.9 months, whereas patients with slower rates of nodal growth (median g = 0.0013 d -1, doubling time = 533 days) had a median TTF of 8.8 months. Rate of growth of mSWAT scores also had an inverse correlation with TTF (p &amp;lt; 0.0001). Those with the fastest rate of increase in mSWAT scores (median g = 0.0057 d -1, doubling time = 122 days) had a median TTF of 2.9 months while those with the slowest rate of increase (median g = 0.0013 d -1, doubling time = 533 days) had a median TTF of 8.5 months. In this interim analysis, we use a novel kinetic model to demonstrate that g correlates with time to treatment failure, suggesting that lymph node and mSWAT growth kinetics may be early predictors of treatment response in CTCL. Our findings have potential implications for both clinical practice and trials. Lymph node and mSWAT growth rates may support clinicians in making early decisions about adapting treatment regimens for individual patients. In clinical trials and early drug development, the incorporation of g as an endpoint may accelerate the recognition of promising drug candidates. Our findings require validation in a larger cohort as well as prospective studies.

ASTX660-01 Phase 2: A Case Study of Tolinapant-Induced Pseudoprogression in CTCL

Background: Cutaneous T-Cell Lymphomas (CTCL) are rare malignancies that comprise &amp;lt;10% of Non-Hodgkin Lymphoma. Limited treatment options exist for these patients, especially after progression following front-line therapy. Tolinapant is an oral non-peptidomimetic antagonist of the inhibitor of apoptosis proteins (IAPs), cIAP1/2 and XIAP. It plays a role in regulated tumor cell death and immunomodulation (Ferrari et al., Blood Adv. 2021) and has been evaluated in the clinic (ASTX660-01 trial, NCT02503423). Previously, we reported an overall response rate of 28% in CTCL patients treated with tolinapant, with a median duration of response of 8.8 months (Michot et al., EHA 2022). During this trial, in which the patients were given tolinapant on Weeks 1 and 3 in 4-week cycles, clinical investigators have described multiple instances of tumor flare and pseudoprogression, consistent with the described immunomodulatory effects associated with tolinapant treatment. Here, we present one such case, a 58-year-old male, who was diagnosed with mycosis fungoides in 2010, which had previously transformed despite multiple therapies. This subject was selected for a more detailed study due to their clinical course with multiple blood samples and biopsies collected, permitting longitudinal histological and molecular characterization. At enrollment in March 2021, the subject presented with red, scaly plaques and cutaneous tumors scattered on the extremities and trunk. At one-month follow up, the subject had an excellent initial symptomatic response with the visual resolution of several tumors. Moreover, the itch reported as “moderate” at baseline had improved with tolinapant treatment. However, during continued therapy, the remaining plaques and tumors progressively swelled, appearing pink and indurated on dosing, indicative of flare. During off-dosing weeks, these signs of flare were reduced. The subject also reported increased itch during treatment that partly resolved during off-dosing weeks. Considering the disappearance of some tumors and the improved appearance during off-dosing weeks, this was pseudoprogression. Methods: Cell surface phenotype of the lymphoma was determined by flow cytometry (Standard Leukemia/Lymphoma and T-Cell Therapy Panel, NeoGenomics Laboratories) on blood samples collected at screening and during Cycles 1, 3 and 5. To characterize the clinical observations, skin biopsies including tumor tissues were collected at baseline and during Cycles 1, 2, 6, 7 and 10. We used multiplex immunofluorescence analysis (COMET™, Lunaphore Technologies SA), gene expression profiling (PanCancer IO 360™ and Pathways panels, NanoString Technologies, Inc.), genomic profiling (FoundationOne™ Heme, Foundation Medicine, Inc.) and cytokine/chemokine measurements (Human ExplorerMAP™ v. 1.0, xMAP® Technology, Luminex Corporation). Results: Blood samples collected at screening and post-treatment confirmed the presence of lymphoma cells that were CD3 +, CD4 +, CD7 -, CD8 - and CD26 -. Multiplex immunofluorescence analysis of the biopsies was able to detect lymphoma cells as CD4 +, CD7 - and CD8 -. Sparsely distributed CD8 + cells were observed at baseline (screening sample). In the biopsy taken on Cycle 2 Day 1, the level of CD8 + cells was markedly increased. Representative images are shown below (left: baseline; right: post-treatment). Analysis of genes associated with CD8 + T cells, cytotoxic cells, B cells and NK cells showed an increase in gene probe signals for CD8A, CD8B, GZMA, GZMH and PRF1. Post-treatment plasma samples showed an elevation in chemokines involved in leukocyte recruitment, such as, CXCL1, CXCL10 and CCL25. Similarly, consistent systemic changes in CXCL10, the chemokine directing recruitment of CXCR3 + cytotoxic T cells, were also detected in tolinapant-treated peripheral TCL patients in the same trial. Conclusions: Our data offer a cellular and molecular insight into a case of clinical pseudoprogression observed during tolinapant treatment. Understanding pseudoprogression is important for clinical investigators and patients to ensure treatment with tolinapant, or other IAP antagonists, are not discontinued prematurely.