Clinical Response Research Articles

Photodynamic Therapy in Acne Vulgaris: A Systematic Review

Acne is a multifactorial disorder of the pilosebaceous unit. Photodynamic therapy (PDT) is an energy-based treatment shown to be safe in acne vulgaris, although the mechanism of action of PDT in acne is incompletely understood. This review summarizes the clinical features of and treatment efficacy in acne patients treated with PDT. A systematic review of Medline, Embase, and the Cochrane Database of Systematic Reviews was conducted. Title, abstract, full-text screening, and data extraction were completed using Covidence. Studies reporting the use of PDT in patients with acne were included while clinical features and treatment responses were extracted. Treatment outcomes were scored as complete response, partial response, and no response. After screening a total of 1122 studies, 82 studies met the inclusion criteria, representing 56 prospective studies, 25 randomized controlled trials, and 1 retrospective study. Results representing 4340 patients with acne (mean age 24.4 years; 52% females) treated with PDT are summarized. Overall, 2154 (50%) participants underwent aminolevulinic acid PDT, 452 (10%) participants underwent methyl aminolevulinate PDT, 28 (<1%) participants underwent daylight PDT, and 1706 (39%) underwent other modalities of PDT. The average follow-up period after study completion was 3 months, ranging from 2 weeks to 13 months. A partial response was observed in treated patients with outcome measures including clinical response, lesion count, pain, recurrence, and patient satisfaction. This systematic review provides preliminary data summarizing the clinical features and treatment efficacy in patients with acne treated with PDT. Our results suggest a partial clinical response when using PDT to manage acne. Future studies should focus on standardizing study protocols and drawing direct comparisons between PDT and other modalities for acne treatment.

Correlation Between Grade of Clinical Response to Neoadjuvant Therapy for Rectal Cancer and Oncologic Outcomes in the Era of Watch-and-Wait

Background: The watch-and-wait strategy provides an opportunity to pursue non-operative management in rectal cancer patients with clinical complete response after neoadjuvant therapy. The management of those with near complete response remains controversial. Objective: We assessed the oncologic outcomes of patients managed by watch-and-wait versus total mesorectal excision according to clinical response to neoadjuvant therapy. Design: Retrospective cohort study. Settings: Comprehensive cancer center in New York. Patients: Patients with rectal adenocarcinoma diagnosed between January 2006 to December 2020. Interventions: A watch-and-wait strategy of active surveillance was offered to patients if they achieved clinical complete response. Salvage surgery was utilized for watch-and-wait patients with local regrowth. Patients with an incomplete response underwent total mesorectal excision Main Outcome Measures: Local regrowth rate, organ preservation rate, disease-free survival and overall survival. Results: Patients with rectal adenocarcinoma (n = 1230) were divided into 3 response cohorts—incomplete (n = 646), near-complete (n = 189) and complete (n = 395). Eighty-one (43%) patients in the near-complete group and 351 (89%) patients in the complete group entered watch-and-wait. Three-year local regrowth rates were 40% and 24% in the near-complete and complete response cohorts, respectively. The 5-year organ preservation rate was 53% in near-complete responders, and 73% in complete responders. Five-year disease-free survival increased with greater clinical response to neoadjuvant therapy with intermediate outcomes noted for patients with a near-complete (73%) compared to complete (82%) or incomplete response (68%). Overall survival at 5 years was similar between the three cohorts (complete 90%, near-complete 86%, and incomplete 85%). Limitations: Retrospective nature. Conclusion: Greater clinical response to neoadjuvant therapy is associated with improved oncologic outcomes. Near-complete responders may avoid surgery and still achieve high organ preservation rates yet experience greater local regrowth rates than clinical complete response patients. Ongoing prospective trials integrating watch-and-wait after complete response as determined by uniform criteria will bolster the work to help treating physicians better select patients who qualify for active surveillance. See Video Abstract.

Deucravacitinib in Plaque Psoriasis: 4-year Safety and Efficacy Results from the Phase 3 POETYK PSO-1, PSO-2, and LTE Trials

Introduction: Deucravacitinib, an oral, selective, allosteric TYK2 inhibitor, is approved in multiple countries for treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy. Deucravacitinib was superior to placebo and apremilast in the global, 52-week, phase 3 POETYK PSO-1 and PSO-2 parent trials in moderate to severe plaque psoriasis. Upon completion, patients could enroll in the ongoing POETYK long-term extension (LTE) trial. Here, deucravacitinib safety/efficacy are reported through 4 years. Methods: PSO-1/PSO-2 randomized patients 1:2:1 to oral placebo, deucravacitinib 6 mg once daily, or apremilast 30 mg twice daily. At Week 52, patients enrolled in the LTE received open-label deucravacitinib. Safety was evaluated in patients receiving ≥1 deucravacitinib dose. Exposure-adjusted incidence rate (EAIR) per 100 person-years (PY) was used to assess adverse events (AEs). Efficacy outcomes included PASI 75, PASI 90, and sPGA 0/1 and were analyzed using mNRI in LTE patients receiving continuous deucravacitinib from Day 1 of the parent trials. Results: 1519 patients received ≥1 deucravacitinib dose; cumulative exposure was 4392.8 PY. EAIRs/100 PY were decreased/comparable from the 1-year to 4-year cumulative period, respectively, for AEs (229.2, 131.7), serious AEs (5.7, 5.0), deaths (0.2, 0.3), discontinuation due to AEs (4.4, 2.2), herpes zoster (0.8, 0.6), malignancies (1.0, 0.9), major adverse cardiovascular events (0.3, 0.3), and venous thromboembolism (0.2, 0.1). Clinical response rates with continuous deucravacitinib (n=513) were maintained from Year 3 (PASI 75, 73.8% [95% CI, 69.6-78.0]; PASI 90, 49.0% [44.4-53.7]; sPGA 0/1, 55.2% [50.5-59.9]) to Year 4 (PASI 75, 71.7% [67.0-76.3]; PASI 90, 47.5% [42.6-52.4]; sPGA 0/1, 57.2% [52.1-62.2]) by mNRI. Conclusion: Deucravacitinib demonstrated a safety profile through 4 years consistent with 3 years with no emergence of new or long-term safety signals. Efficacy was maintained through 4 years in patients receiving continuous deucravacitinib from Day 1 in PSO-1/PSO-2.

Switching from Dupilumab to Upadacitinib in Adults and Adolescents with Moderate-to-Severe Atopic Dermatitis and Inadequate Response to Dupilumab: Efficacy and Safety Results from the Phase 3b/4 LEVEL UP Study

Atopic dermatitis (AD) is a chronic skin disease characterized by intense itch and eczematous skin lesions. Upadacitinib (UPA), a selective oral Janus kinase (JAK) inhibitor, and dupilumab (DUPI), a monoclonal antibody targeting interleukin-4 and interleukin-13 signaling, are both approved treatments for moderate-to-severe AD. LEVEL UP is a phase 3b/4 efficacy assessor blinded monotherapy study comparing UPA to DUPI for treatment of moderate-to-severe AD in adults and adolescents over a 16-week period (Period 1). Patients not achieving ≥75% improvement in the Eczema Area and Severity Index (EASI 75) from baseline at Week 16 entered an additional 16-week extension phase (Period 2). In Period 2, patients either continued/escalated to UPA 30 mg (UPA/UPA 30) or switched from DUPI to UPA 15 mg (DUPI/UPA), with the potential to escalate to 30 mg based on clinical response. Efficacy for skin and itch outcomes in Period 2 were assessed using observed case analysis while on treatment, without statistical comparisons. Here we report efficacy and safety results for the DUPI/UPA switch group. A total of 355 patients who did not achieve EASI 75 at Week 16 entered Period 2 of the study (DUPI/UPA, N=208). At Week 32, response rates in the DUPI/UPA group were: 79.6%, 58.7%, and 19.9% achieving EASI 75, EASI 90, and EASI 100, respectively; 60.2% achieving WP-NRS improvement ≥4 among those with baseline WP-NRS ≥4; 37.0% achieving WP-NRS 0/1 among those with baseline WP-NRS >1; and 26.8% simultaneously achieving EASI 90 and WP-NRS 0/1 by Week 32. Clinically meaningful outcomes were also observed at an earlier visit (Week 20). No new safety signals through Week 32 were identified compared to the established safety profile of UPA. Most patients with an inadequate response to DUPI at Week 16 experienced clinically meaningful improvements in skin clearance and itch at 4 weeks post-switch to UPA, with additional patients achieving these outcomes by 16 weeks post-switch. These findings suggest that switching from DUPI to UPA is an effective treatment strategy for patients who do not meet moderate or optimal treatment targets with DUPI.

Bimekizumab 4-year Maintenance of Responses in Week 16 Responders with Moderate to Severe Plaque Psoriasis: Results from the BE BRIGHT Open-label Extension Phase 3 Trial

Introduction: Psoriasis is a chronic disease where loss of response to biologic therapies over time is commonly observed; studying long-term efficacy of new treatments is important.1 Maintenance of high responses to bimekizumab (BKZ) has been reported through 3 years (yrs) in patients with moderate to severe plaque psoriasis.2 This study evaluates the maintenance of clinical responses over 4 years among patients with moderate to severe plaque psoriasis who achieved complete or near-complete skin clearance after 16 weeks (wks) of BKZ treatment and entered the BE BRIGHT open-label extension. Responses were compared over 4 years between all patients who were randomized to BKZ and continued to receive bimekizumab (320 mg every 4 wks [Q4W] or Q8W) in the open-label extension, and those who received the BKZ dosing regimen that is approved for most patients: BKZ 320 mg Q4W to Wk 16 followed by 320 mg Q8W. Methods: Patients completing the 52-wk BE VIVID or 56-wk BE SURE/BE READY phase 3 trials could enter the BE BRIGHT open-label extension (OLE).2–5 Maintenance of PASI90/PASI100 (≥90%/100% improvements from baseline in Psoriasis Area and Severity Index) to Yr4 (OLE Wk144) was assessed in Wk16 responders. Analyzed patients were randomized to BKZ 320 mg Q4W to Wk16, received BKZ Q4W or Q8W until OLE entry, then BKZ Q4W or Q8W dependent on PASI response/prior dose (BKZ Total); the subset who received BKZ Q4W/Q8W/Q8W (initial/maintenance/OLE) were also analyzed. All received BKZ Q8W from OLE Wk48 or at their next scheduled visit. Patients who discontinued due to lack of efficacy/treatment-related adverse events were considered non-responders; multiple imputation was used for all other missing data (modified non-responder imputation). Results: Of 989 BKZ-randomized patients, 87.5% achieved PASI90 and 62.7% PASI100 at Wk16 (non-responder imputation). 693 Wk16 PASI90 and 503 PASI100 responders entered the OLE (BKZ Total); 186 and 147, respectively, received BKZ Q4W/Q8W/Q8W. 87.7%/73.3% of Wk16 PASI90/PASI100 responders maintained their responses to Yr4 (BKZ Total). In the Q4W/Q8W/Q8W subset, 89.0%/76.7% maintained their responses to Yr4. Conclusions: Among Wk16 responders, high efficacy responses were sustained through 4 yrs of BKZ treatment, including patients who received the approved Q4W/Q8W/Q8W dosing regimen.

Maintenance of Response to Risankizumab in Patients With Psoriatic Arthritis: A 4-Year Analysis of the KEEPsAKE 1 and 2 Trials

Introduction: Risankizumab, a humanized immunoglobulin G1 monoclonal antibody, specifically inhibits the p19 subunit of human interleukin 23 and is approved for treatment of active psoriatic arthritis (PsA) in adults. This post hoc analysis evaluated the long-term maintenance of clinical response through ~4 years of risankizumab treatment using data from 2 ongoing phase 3 trials, KEEPsAKE 1 and KEEPsAKE 2. Methods: Eligible patients had active PsA with inadequate response or intolerance to ≥1 conventional synthetic disease modifying antirheumatic drugs (KEEPsAKE 1 [NCT03675308]; KEEPsAKE 2 [NCT03671148]) and/or inadequate response or intolerance to 1–2 biologic therapies (KEEPsAKE 2 only). Patients received double-blinded risankizumab 150 mg or placebo for 24 weeks and open-label risankizumab 150 mg thereafter. This analysis includes patients who received continuous risankizumab through both treatment periods. Assessments included improvement of ≥20%/50%/70% in PsA symptoms using American College of Rheumatology criteria (ACR20/50/70), achievement of minimal disease activity (MDA), reduction of ≥90% in Psoriasis Area and Severity Index (PASI 90; in patients with ≥3% body surface area affected by psoriasis at baseline), and clinically meaningful reduction in pain (≥10 mm on a visual analog scale [VAS]). All data were reported as observed. Results: Among patients who achieved ACR20 at week 24 in KEEPsAKE 1 or KEEPsAKE 2, 70.7% and 86.4% maintained ACR20 responses at week 196. Similarly, ACR20 response was maintained to week 196 by 85.7% and 83.3% of week 52 responders in KEEPsAKE 1 and 2, respectively. Similar patterns of maintenance of response were observed for ACR50 and ACR70. Most patients also maintained MDA at week 196 from weeks 24 and 52 (Week 24: KEEPsAKE 1, 86.0%; KEEPsAKE 2, 81.3%; Week 52: KEEPsAKE 1, 81.2%; KEEPsAKE 2, 85.5%). The PASI 90 response was maintained at week 196 from weeks 24 and 52 (Week 24: KEEPsAKE 1, 88.2%; KEEPsAKE 2, 94.9%; Week 52: KEEPsAKE 1, 92.6%; KEEPsAKE 2, 97.1%). Weeks 24 and 52 responders maintained clinically meaningful reductions in pain VAS at week 196 (Week 24: KEEPsAKE 1, 90.2%; KEEPsAKE 2, 88.9%; Week 52: KEEPsAKE 1, 88.3%; KEEPsAKE 2, 90.1%), respectively. Conclusion: Risankizumab demonstrated durable long-term efficacy in patients with active PsA. A high proportion of patients receiving continuous risankizumab treatment in KEEPsAKE 1 and KEEPsAKE 2 maintained ACR20/50/70, MDA, or PASI90 responses and meaningful pain reduction through week 196.

Abstract B035: Reciprocal macrophage - T cell interactions regulate anti-tumor immunity

Abstract Cancer immunotherapy (including immune checkpoint blockade (ICB)) has shown great promise in the treatment of some solid cancers, but responses in breast cancer patients are limited. While breast cancer is generally considered poorly immunogenic, the abundance of CD8+ T cells correlates with clinical response. CD8+ T cells are critical mediators of anti-tumor immunity and the main target for ICB. However, the onset of terminal functional T cell exhaustion poses a major challenge. Although T cell exhaustion has been linked to persistent antigen exposure, it remains unclear how the immune composition of the breast tumor microenvironment (TME) contributes to this dysfunctional T cell state. Breast cancers are heavily infiltrated with tumor-associated macrophages (TAMs) and their abundance correlates with T cell exhaustion and poor prognosis. Previously, we discovered a spatiotemporal co-dependency between exhausted T cells (TEX) and TAMs in mouse models of melanoma and breast cancer. We showed that TEX actively recruit monocytes to the TME and shape their differentiation trajectory into TAMs. Reciprocally, these TAMs ‘capture’ T cells in long-lived synaptic interactions that contribute to functional T cell exhaustion. Our current work is focused on studying the TEX-derived chemokines that regulate these TAM – T cell interactions in the breast TME with the ultimate goal to alleviate immune evasion and improve responsiveness of breast cancer to immunotherapy. Citation Format: Meenakshi Sudhakaran, Sofia Lombardi, Sophie Ayma, Matthew F. Krummel, Kelly Kersten. Reciprocal macrophage - T cell interactions regulate anti-tumor immunity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B035.

Abstract A027: Acceleration of drug metabolism mediated by CYP3A4 enzyme activation provides a bona fide environmental resistance mechanism to targeted therapies

Abstract Background: Targeted therapies against oncogenic signaling addictions, including one resulting from EML4-ALK fusions, can induce strong and durable clinical responses. However, these therapies are not curative in advanced cancers, as a subset of tumor cells avoid elimination, and these persisting populations evolve resistance that drives tumor relapse. Using a drug screen, we found that the evolving ALK inhibitor (ALKi) persisters display exquisite sensitivity to the histone demethylase inhibitor, JIB04 in vitro. Paradoxically, validation studies in mice revealed that instead of enhancing tumor sensitivity, JIB04 desensitizes tumors to ALKi, alectinib and lorlatinib, suggesting that it activates an unknown environmental modifier. While JIB04 is not used in the clinics, we reasoned that deciphering the underlying mechanism could uncover environment-mediated resistance to ALKi that might be triggered by clinically relevant factors. Results: We found that the resistance-promoting effect of JIB04 in mice is mediated by reducing systemic ALKi concentrations. This reduction is attributable to accelerated pharmacokinetics, due to the hyperactivation of the P450 family member, CYP3A4. Higher CYP3A4 activity leads to faster drug clearance and reduced drug exposure to tumors. Importantly, JIB04 triggers a similar resistance to other clinically relevant CYP3A4 substrates, the frontline EGFR inhibitor, osimertinib and the recently introduced KRASG12C inhibitor, sotorasib. Finally, the resistance- promoting effects of JIB04 could be phenocopied by chemically unrelated activators of CYP3A4, indicating a wide generalizability of this macro-environmental therapy resistance mechanism. Conclusions: Our study uncovered that acceleration of drug metabolism, triggered by CYP3A4 enzyme activators is a bona fide environmental resistance mechanism. Since P450 family liver detoxifying enzymes mediate the metabolism of many drugs, this resistance mechanism is likely to be relevant to a broad range of therapeutic contexts. Significance: While the importance of pharmacokinetic considerations is widely appreciated, modulation of drug metabolism is not typically considered as a candidate mechanism when therapy resistance is encountered in research and clinical settings. Multiple dietary, pharmacological and genetic modifiers are known to modulate P450 family enzymes. Moreover, substantial variability in drug plasma concentrations was documented in patients treated with identical doses of targeted therapies, and this variability strongly correlated with variability in clinical responses. While the direct link between variability in CYP3A4 activity and clinical outcomes in human patients has yet to be established, the mechanism uncovered in our study might represent a substantial but entirely overlooked contributor to resistance. Consequently, consideration of this mechanism and monitoring of CYP3A4 activity and systemic drug levels might improve our understanding of the biology of therapy resistance and enable an actionable path to improve clinical outcomes. Citation Format: Pragya Kumar, Robert Vander Velde, Malgorzata Weh, Andriy Marusyk. Acceleration of drug metabolism mediated by CYP3A4 enzyme activation provides a bona fide environmental resistance mechanism to targeted therapies [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A027.

Finerenone in Women and Men With Heart Failure With Mildly Reduced or Preserved Ejection Fraction: A Secondary Analysis of the FINEARTS-HF Randomized Clinical Trial.

Sex is associated with the clinical presentation, outcomes, and response to treatment in patients with heart failure (HF). However, little is known about the safety and efficacy of treatment with finerenone according to sex. To estimate the efficacy and safety of finerenone compared with placebo in both women and men. Prespecified analyses were conducted in the phase 3 randomized clinical trial Finerenone Trial to Investigate Efficacy and Safety Superior to Placebo in Patients with Heart Failure (FINEARTS-HF). The trial was conducted across 653 sites in 37 countries. Participants were adults aged 40 years and older with symptomatic HF and left ventricular ejection fraction (LVEF) of 40% or greater randomized between September 2020 and January 2023. Finerenone (titrated to 20 mg or 40 mg) or placebo. The primary outcome was a composite of cardiovascular death and total (first and recurrent) HF events (unplanned HF hospitalizations or urgent HF visits). A total of 6001 patients were randomized in FINEARTS-HF, of whom 2732 were women (45.5%), with a mean (SD) age of 73.6 (9.1) years. Women had higher rates of any obesity, higher LVEF (54.6 [7.6%] vs 50.9 [7.6] for men), lower mean (SD) estimated glomerular filtration rate than men (59.7 [19.1] vs 64.1 [20.0] for men; P<.001) , worse New York Heart Association functional class, and lower Kansas City Cardiomyopathy Questionnaire-Total Symptom Scores (KCCQ-TSS) (mean [SD] 62.3 [24.0] vs 71.0 [23.1]). The incident rate of the primary outcome was slightly lower in women (15.7; 95% CI, 14.3-17.3) than in men (16.8; 95% CI, 15.4-18.3) per 100 person-years. Compared with placebo, finerenone reduced the risk of the primary end point similarly in women and men: rate ratio 0.78 (95% CI, 0.65-0.95) in women and 0.88 (95% CI, 0.74-1.04) in men (P = .41 for interaction). Consistent effects were observed for the components of the primary outcome and all-cause mortality. The mean increase (improvement) in KCCQ-TSS from baseline to 12 months was greater with finerenone, regardless of sex (P = .73 for interaction). Finerenone had similar tolerability in women and men. In FINEARTS-HF, finerenone reduced the risk of the primary end point similarly in women and men with heart failure with mildly reduced or preserved ejection fraction. Finerenone had similar tolerability in women and men. ClinicalTrials.gov Identifier: NCT04435626.

Abstract A040: A novel stroma-mediated positive interaction between resistant and sensitive cells in non-small cell lung cancer facilitates drug resistance

Abstract Resistance to targeted therapies, particularly those inhibiting oncogenic tyrosine kinases (TKIs), presents a significant challenge in the treatment of advanced non-small cell lung cancer (NSCLC). Despite initial robust clinical responses, tumors often relapse due to the emergence of resistant cell populations. The origins of this resistance—whether it is pre-existing in a subset of tumor cells or arises de novo during treatment—remains a critical question in understanding and combating therapeutic failure. To investigate this, we developed in silico mathematical models that integrate both pre-existing and de novo resistance mechanisms within a framework that explicitly integrates the stromal niche. Our study focused on the evolutionary dynamics of NSCLC in response to therapy, using a hybrid agent-based spatial modeling framework (HAL) to simulate tumor behavior under treatment. These models were designed to simulate the complex interactions between resistant and sensitive tumor cells, mediated by the stroma, and to predict the timing of relapse based on these interactions. Our findings suggest that stroma-mediated interactions play a crucial role in the evolutionary dynamics of therapy responses, influencing the fitness and survival of both resistant and sensitive cells. Specifically, our models predict that pre-existing resistance is unlikely to be compatible with the long remission periods observed in a substantial subset of patients treated with advanced anaplastic lymphoma kinase (ALK) inhibitors. This conclusion was supported by the observed relapse times and volumetric tumor growth data from subsequent animal models. Moreover, our analyses highlight the importance of ecological factors within the tumor microenvironment in shaping the response to therapy. The spatial models we developed reveal that the stroma can foster positive interactions between resistant and sensitive cells, thereby accelerating the emergence of resistance. These insights underscore the need to consider the stromal niche when developing new therapeutic strategies and when interpreting the dynamics of drug resistance. In conclusion, our study provides new insights into the role of stroma in mediating resistance to TKIs in NSCLC. By combining mathematical modeling with experimental data, we have elucidated how stroma-mediated interactions between tumor cells can influence the evolution of resistance, challenging the assumption that pre-existing resistance alone drives relapses in TKI-treated patients. Our findings emphasize the need for adaptive therapeutic approaches that anticipate and disrupt these microenvironmental interactions to improve patient outcomes. Citation Format: Rishi M. Shah, Sagnik Yarlagadda, Mark Robertson-Tessi, Bina Desai, Tatiana Miti, Daria Miroshnychenko, David Basanta, Andriy Marusyk, Alexander Anderson. A novel stroma-mediated positive interaction between resistant and sensitive cells in non-small cell lung cancer facilitates drug resistance [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A040.

Abstract B008: Therapy-protective peristromal niches mediate positive ecological interaction between therapy-sensitive and therapy-resistant cells, altering the evolutionary dynamics of acquired targeted therapy resistance in lung cancers

Abstract Pharmacological inhibitors of oncogenic signaling, such as drugs that target ALK kinase (ALKi) in ALK+ lung cancers, can induce strong and durable clinical responses. However, targeted therapies are not curative in advanced cancers and even strong responders eventually develop resistance. While therapy resistance is typically attributed to cell-intrinsic (epi)mutational characteristics of tumor cells, it can also result from interactions of tumor cells with the tumor microenvironment (TME). In contrast to the detailed elucidation of the molecular mediators of therapy resistance, our knowledge of the evolutionary dynamics underlying the resistance emergence, including the impact of TME, remains poorly defined. A key open question in understanding the evolutionary dynamics of therapy resistance is whether relapse results from an expansion of pre-existing therapy-resistant subpopulations or from a bona fide gradual evolutionary process. To elucidate this question, we integrated experimental mouse studies with mathematical modeling, interrogating therapeutic responses of therapy-naïve experimental xenograft ALK+ tumors, spiked-in with differentially labeled resistant cells. We found that ALKi treatment induced a rapid expansion of resistant cells, which drastically reduced the magnitude and duration of remissions. Surprisingly, our in silico analyses pointed to the existence of a strong positive ecological interaction between therapy-resistant and therapy-sensitive competitors. Using a combination of spatial analyses, experimental studies, and mathematical modeling, we found that this interaction was mediated by peristromal niches that protected therapy-sensitive tumor cells. Specifically, by limiting tumor regression, the therapy- induced expansion of resistant cells limited the loss of protective peristromal niches, while the subsequent resumption of tumor growth created new peristromal niches capable of supporting the survival and proliferation of therapy-sensitive cells. While this niche-mediated interaction had only a marginal impact on the transition from remission to relapse, enhanced survival of therapy-sensitive cells potentiated their ability to adapt to ALKi, leading to a higher diversity of resistance phenotypes. In summary, our study has revealed a new type of indirect, niche-mediated ecological interaction between therapy-resistant and therapy-sensitive cells. The rapid expansion of rare pre-existent resistant cells and fast transition to relapse challenge a common assumption of the pre-existence of therapy resistance. Finally, our results highlight the essentiality of TME considerations in understanding the evolutionary dynamic underlying the development of therapy resistance. Citation Format: Mark Robertson-Tessi, Bina Desai, Tatiana Miti, Pragya Kumar, Sagnik Yarlagadda, Rishi Shah, Robert Vander Velde, Daria Miroshnychenko, David Basanta, Alexander Anderson, Andriy Marusyk. Therapy-protective peristromal niches mediate positive ecological interaction between therapy-sensitive and therapy-resistant cells, altering the evolutionary dynamics of acquired targeted therapy resistance in lung cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B008.

Abstract C035: Spatially limited stroma-mediated resistance potentiates targeted therapy resistance through an integration of multiple juxtacrine and paracrine mechanisms

Abstract Despite the ability to induce strong clinical responses, therapies that target mutational drivers of oncogenic signaling are not curative in advanced cancers, as a subset of cancer cells is capable of surviving therapy and evolving resistance. While therapy resistance is commonly viewed as a cell-intrinsic phenomenon, multiple factors produced by tumors can also confer strong therapy resistance. In contrast to the detailed elucidation of molecular mediators of cell-intrinsic and stroma-mediated (SM) resistance, the relative importance of cell-intrinsic and SM resistance to in vivo therapeutic responses remains poorly defined. To address this gap of knowledge, we used a well-characterized experimental model of ALK+ lung cancer H3122 cell line that exemplifies a duality observed across common models of targetable cancers. Under standard stroma-free in vitro cultures, H3122 cells can survive under therapeutically relevant concentrations of ALK inhibitors (ALKi), eventually acquiring cell-intrinsic therapy resistance. At the same time, co-culture with stromal fibroblasts drastically reduces the sensitivity of H3122 cells to ALKi, indicating the relevance of SM resistance. To understand the impact of SM resistance on in vivo responses, we sought to identify the mechanism(s) responsible for the therapy-protective effects of stromal fibroblasts, subsequently interrogating the impact of the disruption of this mechanism on in vivo therapeutic responses. Our in vitro studies with a large panel of primary stromal fibroblast isolates identified the HGF-cMET axis as the major mechanism responsible for ALKi desensitization. Surprisingly, xenograft validation studies demonstrated a weak effect of HGF-cMET modulation. Histological analyses of tumor tissues revealed that this relative weakness is attributable to a strong, spatially limited HGF-independent component of SM resistance. Mechanistic follow-up demonstrated that the HGF-independent component of SM resistance integrates the effect of multiple well-known juxtacrine and paracrine-acting mechanisms. Whereas the multifactorial nature of stroma-mediated resistance prevented a clear assessment of its relative contribution to in vivo therapy responses, our spatial analyses indicate that SM resistance dominates the ability of tumors to avoid therapeutic elimination. Surprisingly, we found that SM resistance was also a substantial contributor to tumor relapse, indicating that in vivo therapy resistance can integrate both cell-intrinsic and cell-extrinsic effects. This duality of therapy resistance and the multifactorial underpinning of both cell-intrinsic and stroma-mediated resistance present a challenge to therapeutic strategies focused on identifying and targeting specific resistance mechanisms. Our studies suggest that this limitation can be overcome by shifting the therapeutic focus towards shared orthogonal therapeutic sensitivities of tumor cells within residual disease. Citation Format: Bina Desai, Tatiana Miti, Sandhya Prabhakaran, Daria Miroshnychenko, Menkara Henry, Viktoriya Marusyk, Chandler Gatenbee, Marilyn Bui, Jacob Scott, Philipp M. Altrock, Eric Haura, Alexander R.A. Anderson, David Basanta, Andriy Marusyk. Spatially limited stroma-mediated resistance potentiates targeted therapy resistance through an integration of multiple juxtacrine and paracrine mechanisms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C035.

Case report: VEXAS syndrome with excellent response to treatment with azacitidine.

Vacuoles, E1 enzyme, X-linked, auto inflammatory, somatic (VEXAS) syndrome is an inflammatory disorder caused by somatic UBA1 variants and is characterized by late-onset systemic autoimmune inflammation and blood abnormalities. Glucocorticoids ameliorate symptoms effectively. However, other treatment options have limited efficacy and a transient effect. Herein, we describe a case of a 69-year-old male patient with VEXAS syndrome with skin, lung and hematologic involvement. He was treated with glucocorticoids and after the failure with anti IL-1 he began treatment with azacitidine with excellent hematological and clinical response. Azacitidine may be a suitable option for treating VEXAS syndrome, especially due to the relationship between inflammatory symptoms and response to azacitidine.

Late onset pancytopenia post chimeric antigen receptor T cell therapy triggered by a COVID-19 vaccination: a case report

Cytopenia is a common side effect after chimeric antigen receptor T cell (CAR-T) therapy but is unusual at late timepoints when it is most commonly due to bone marrow (BM) failure, myelodysplasia (MDS) or other secondary malignancies. In this case report, we describe a patient who developed severe aplastic anaemia 18 months after CD19 CAR-T therapy, and shortly after COVID-19 vaccination. This is the first description of severe aplastic anaemia triggered by COVID-19 vaccination as a cause of post-CAR-T cytopenia. The patient described was treated with a combination of eltrombopag and ciclosporin due to frailty and had a rapid and complete clinical response to this therapy, providing an effective option for the treatment of immune-related cytopenia post-CAR-T in an increasingly elderly and frail population.

Effectiveness of Ustekinumab for patients with moderate to severe Ulcerative Colitis: A Multi-Center Real-World Canadian Study

Background: We aimed to evaluate the real-world effectiveness and safety of ustekinumab for the treatment of both bio-naïve and bio-exposed ulcerative colitis (UC) patients in a real-world setting. Methods: Retrospective, Canadian multicenter cohort study. Primary outcomes were clinical remission and endoscopic remission. Key secondary outcomes included composite clinical and endoscopic response, safety, and persistence. Univariable logistic regression was conducted to examine associations between baseline factors and 12 month clinical and endoscopic response and remission. The primary focus was on the association between these outcomes and bio-exposure status. Results: A total of 198 patients were included, of whom 47.5% were female and 85.9% under 65 years. The majority had severe endoscopic activity at baseline (47.5%, n=87) and were bio-exposed (88.8%, n=176; 33%, n=66 prior failure of 3 or more biologics). Patients were followed for a median of 12.8 (IQR 8.2 to 22.1) months after induction. The overall clinical remission rates were 41.3% (69/167), 38.1% (56/147), and 43.6% (58/133) at 3, 6 and 12 months, respectively. Endoscopic remission rates (MES=0) were 8.0% (7/88), 18.7% (23/123), and 12.5% (11/88) at 3, 6, and 12 months, respectively, and consistently higher in bio-naïve patients compared to bio-exposed patients through 12 months (p&lt;0.05 at all time points). Bio-naive patients were more likely to achieve endoscopic remission compared to bio-exposed (HR=5.40, 95% CI: 1.08-26.93). Adverse events were reported in 14.1% (18/198). Discussion: In a highly refractory and largely bio-exposed population, a substantial proportion of patients with UC treated with ustekinumab can achieve clinical and endoscopic outcomes of importance after 12 months. Prior biologic exposure is associated with lower rates of endoscopic remission.

Postoperative NEOadjuvant TEMozolomide followed by chemoradiotherapy vs. upfront chemoradiotherapy for Glioblastoma multiforme (NEOTEM) trial: interim results

Abstract Background Glioblastoma (GBM) is an aggressive brain tumor with poor survival rates despite current treatments. The standard of care (SOC) includes surgery, followed by radiotherapy plus concurrent and adjuvant chemotherapy with temozolomide (TMZ). This phase II trial assessed the safety and efficacy of neoadjuvant TMZ (nTMZ) before and during chemoradiotherapy in newly diagnosed GBM patients. Methods Newly diagnosed GBM patients who underwent maximal safe resection were randomized into two groups. One received nTMZ before standard chemoradiotherapy and adjuvant TMZ (intervention). The other received standard chemoradiotherapy followed by adjuvant TMZ (control). Primary endpoints were progression-free survival (PFS) at 6 and 12 months. Secondary endpoints included overall survival, radiological and clinical responses, and adverse events. Results Of 35 patients, 16 were in the intervention group and 19 in the control group. Median PFS was 3 months [95%CI:1.98-4.01] and 9 months [95%CI: 3.93-14.06] in the intervention and control group, with a high progression rate (73.4%) during nTMZ treatment. The 6-month PFS rates were 58% vs. 25% (P=0.042), and 12-month PFS rates were 26% vs. 25% (P=0.039) in the control and intervention groups. Patients with unmethylated MGMT, poor performance status (PS), or those undergoing biopsy or subtotal resection had worse PFS with nTMZ. Adverse events were similar between groups. Conclusions Neoadjuvant TMZ before SOC chemoradiotherapy did not improve outcomes for newly diagnosed GBM patients and is unsuitable for those with unmethylated MGMT or poor PS. It may benefit patients with near or gross total resection. Further research is needed to refine GBM treatment strategies.

Abstract I008: Antisense Oligonucleotides as Therapeutics for Difficult-to-Drug Targets in Oncology

Abstract Many potential oncology targets are difficult to modulate by conventional classes of agents. Interfering with these targets at the level of RNA is a novel approach for difficult-to target proteins, as well as for non-coding RNAs, emerging targets that are part of the “dark matter’ of the genome. Antisense oligonucleotide (ASO) therapeutics are short sequences of 12- 30 DNA/RNA residues, designed to bind the cognate transcribed RNA. The ASO is chemically modified to increase stability, improve binding affinity, optimize pharmacokinetic properties and reduce immunostimulatory potential. The hybridization of ASO to cognate RNA results in cleavage of bound RNA by RNAse H1 and subsequent degradation. Several ASOs are marketed for treatment of rare diseases, but to date none have been approved for oncology indications. The long-noncoding RNA (lncRNA) MALAT1 is an example of an oncology target uniquely suited for an ASO therapeutic. This lncRNA is not translated and resides mostly in the nucleus, limiting access for most therapeutic approaches. MALAT1 is highly upregulated in various cancers, appears to play a role in epithelial to mesenchymal transition, and is associated with disease progression in patients. Inhibition of MALAT1 in preclinical breast cancer models, either genetic or pharmacologic using a murine ASO, leads to changes in tumor architecture and reduction in metastasis. FLM-7523 is a 16-mer ASO designed to bind to human MALAT1. It is a generation 2.5 design based on the constrained ethyl (cEt) modification to the 3 residues on the 3’ and 5’ ends of the ASO, and administered in a saline solution without any delivery vehicle. Preclinical studies have shown that FLM-7523 effectively inhibits MALAT1 expression in in vitro and in vivo models, and GLP toxicology studies have been completed to support a First-in-Human clinical trial. The signal transduction molecule STAT3 is another oncology target of interest that has, to date, been difficult to modulate. Danvatirsen is a 16-mer generation 2.5 ASO targeting human STAT3 mRNA and is currently in clinical trials. Preclinical in vivo studies in murine tumor models have demonstrated a reduction in STAT3 mRNA and protein following treatment with a STAT3 targeting ASO, along with tumor growth inhibition. Combination treatments with immune checkpoint inhibitors, including anti-PD-1 and anti-PD-L1, demonstrate improved tumor growth inhibition relative to monotherapy. In clinical trials, tumor uptake of danvatirsen is observed in post-treatment biopsies, with corresponding reduction in STAT3 protein. Danvatirsen is generally well tolerated with the most common adverse events being increased liver function tests and decreased myeloid hematologic parameters, both of which are easily monitored, manageable, and reversible. Clinical responses have been observed with the most robust being in combination with a PD-L1 inhibitor in recurrent/metastatic head and neck squamous cell carcinoma. In conclusion, ASOs are novel therapies that can inhibit oncology targets not tractable by traditional approaches. Citation Format: Andrew Denker. Antisense Oligonucleotides as Therapeutics for Difficult-to-Drug Targets in Oncology [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr I008.

Meta-Analysis: Evaluating Placebo Rates Across Outcomes in Eosinophilic Oesophagitis Randomised Controlled Trials.

High placebo responses have limited drug development in eosinophilic oesophagitis. The optimal configuration of trial outcomes is uncertain. To inform more efficient future trial designs, to characterise clinical, endoscopic and histologic placebo responses in eosinophilic oesophagitis randomised controlled trials (RCTs). We updated a Cochrane systematic review and meta-analysis, searching multiple databases to January 1, 2024, to identify placebo-controlled RCTs evaluating medical therapies for patients with eosinophilic oesophagitis. The primary outcome was the pooled proportion of study-defined clinical, endoscopic and histologic responders and remitters randomised to placebo, using an intention-to-treat approach and random-effects model. Sources of heterogeneity were explored using meta-regression. We included 25 RCTs. The pooled proportion of clinical response was 41.0% [95% CI: 29.7%-52.8%] with substantial heterogeneity (I2 = 74.9%). On meta-regression, older age and a higher probability of being randomised to placebo reduced the likelihood of clinical response to placebo. The pooled proportion of histologic remission defined as a peak eosinophil count [PEC] ≤ 6 eosinophils per high power field [HPF] or ≤ 1 eosinophil/HPF was 4.3% [95% CI: 2.6%-6.2%] (I2 = 23.6%) and 1.3% [95% CI: 0.5%-2.5%] (I2 = 0%), respectively. The standardised mean difference in the Eosinophilic Oesophagitis Endoscopic Reference Score to placebo was -0.25 [95% CI: -0.41, -0.10]. Over 40% of patients in eosinophilic oesophagitis trials respond clinically to placebo, and this is associated with trial design factors such as randomisation ratio and trial population. Objective endoscopic and histologic measures are associated with very low placebo responses.

The impact of CYP2D6 on donepezil concentration and its lack of effect on the treatment response and adverse effect in Korean patients with Alzheimer's disease.

Donepezil, an acetylcholinesterase inhibitor, is widely used for managing the symptoms of Alzheimer's disease (AD), yet its clinical response varies widely among individuals. This study aims to investigate the influence of CYP2D6 genetic variants on donepezil concentration, treatment response, and adverse effects in Korean patients with AD dementia. We conducted a longitudinal study involving 76 patients receiving either 5 mg or 10 mg of donepezil. Genetic testing identified 9 CYP2D6 alleles, categorizing patients by metabolizing abilities. Blood sampling for plasma concentrations of donepezil were performed at steady-state. Mini-Mental State Examination (MMSE) were conducted at 12, 24 and 36 months after the initiation of treatment. Adverse events were collected throughout the study period. Donepezil plasma concentrations differed significantly among metabolizer statuses (mean 56.8 ± 27.1 ng/ml in normal metabolizers vs. 69.6 ± 30.1 ng/ml in intermediate metabolizers, p = 0.042), but these differences did not affect cognitive function over three years as assessed by MMSE. Additionally, there was no significant correlation between donepezil plasma concentration and adverse events. Our study is the first to elucidate the associations between CYP2D6 genotype and the concentration, clinical response or adverse events of donepezil in Korean patients with AD dementia. Larger studies are necessary to fully understand the impact of CYP2D6 genetic variants on therapeutic outcomes with donepezil.

Safety and Effectiveness of Glucagon-like Peptide-1 Receptor Agonists in Inflammatory Bowel Disease

INTRODUCTION: The safety and effectiveness of glucagon-like peptide (GLP) 1 receptor agonists (GLP1-RA) in inflammatory bowel disease (IBD) patients are poorly understood. METHODS: IBD patients treated with GLP1-RA were retrospectively identified for outcomes of adverse events, weight change, and clinical, endoscopic, and biomarker response. RESULTS: Among a total of 120 IBD patients, GI side effects being the most common (11.5%). Semaglutide showed the most significant weight reduction. CRP levels decreased after one year (p=0.005). No differences were observed in IBD-related hospitalizations or endoscopic scores. DISCUSSION: GLP1-RA therapy appears safe and effective, with an associated CRP reduction, in IBD patients.