Treatment-limiting Toxicity Research Articles

Linezolid Pharmacokinetic-Anemia Modeling in Children with Rifampicin-Resistant Tuberculosis.

Linezolid, an important component of rifampicin- and multidrug-resistant tuberculosis (RR/MDR-TB) treatment, is associated with treatment-limiting toxicities, including anemia. Patient-level and linezolid pharmacokinetic risk factors for anemia have not been well described in children treated for RR/MDR-TB. We evaluated the pharmacokinetics of linezolid and longitudinal hemoglobin data to validate an existing population linezolid pharmacokinetic model. We assessed the impact of linezolid pharmacokinetics and the risk of developing anemia in a prospectively enrolled cohort of children. The validation of a previously published population pharmacokinetic linezolid model used nonlinear mixed effects modeling. A multivariable ordinal logistic regression model was built to predict the incidence of anemia. A total of 112 children, median age 7.2 (IQR: 2.2-16.3) years, were included from South Africa (n=87) and India (n=25). Of these, 24 children contributed new linezolid pharmacokinetic data. The population pharmacokinetic model which informs the currently recommended linezolid dosing in children (10-15 mg/kg) was validated with these additional new data. For every 1 g/dL lower baseline hemoglobin, the odds of developing grade 3 or 4 anemia increased by 2.64 (95% CI 1.98-3.62). For every 1 mg/L*h higher linezolid area under the concentration-time curve (AUC), the odds of developing a grade 3 or 4 anemia increased by 1.012 (95% CI 1.007-1.017). These data taken together, confirm currently recommended linezolid doses in children. The risk of anemia in children should be carefully considered and monitored throughout. Initiating linezolid in children with low baseline hemoglobin increases the probability of experiencing grade 3 or 4 anemia.

Omalizumab for management of hypersensitivity reactions to anticancer drugs.

Hypersensitivity reactions to anticancer drugs include treatment-limiting toxicity. Standard drug desensitisation offers temporary tolerance and hence requires repetition. We used omalizumab, an anti-immunoglobulin E antibody, to overcome immediate and delayed hypersensitivity reactions to various anticancer drugs. Seven of the eight patients in the current studysuccessfully resumed the desired anticancerdrug regimen without standard desensitisation. No safety issues from omalizumab were observed.

Current Novel Targeted Therapeutic Strategies in Multiple Myeloma.

Multiple myeloma (MM) is a hematologic malignancy caused by the clonal expansion of immunoglobulin-producing plasma cells in the bone marrow and/or extramedullary sites. Common manifestations of MM include anemia, renal dysfunction, infection, bone pain, hypercalcemia, and fatigue. Despite numerous recent advancements in the MM treatment paradigm, current therapies demonstrate limited long-term effectiveness and eventual disease relapse remains exceedingly common. Myeloma cells often develop drug resistance through clonal evolution and alterations of cellular signaling pathways. Therefore, continued research of new targets in MM is crucial to circumvent cumulative drug resistance, overcome treatment-limiting toxicities, and improve outcomes in this incurable disease. This article provides a comprehensive overview of the landscape of novel treatments and emerging therapies for MM grouped by molecular target. Molecular targets outlined include BCMA, GPRC5D, FcRH5, CD38, SLAMF7, BCL-2, kinesin spindle protein, protein disulfide isomerase 1, peptidylprolyl isomerase A, Sec61 translocon, and cyclin-dependent kinase 6. Immunomodulatory drugs, NK cell therapy, and proteolysis-targeting chimera are described as well.

A pilot study of axicabtagene ciloleucel (axi-cel) for relapsed/refractory primary and secondary central nervous system lymphoma (PCNSL and SCNSL).

2006 Background: Prognosis of patients with relapsed/refractory (R/R) CNSL is poor with no standard of care treatment options. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy axicabtagene ciloleucel (axi-cel) has shown efficacy in R/R systemic large B-cell lymphoma (LBCL) and could be considered for R/R CNSL. Methods: We conducted a pilot study of axi-cel in patients with R/R CNS LBCL. No bridging therapy except corticosteroids was allowed after enrollment. Ommaya reservoir was placed before infusion. Patients underwent lymphodepletion with fludarabine and cyclophosphamide followed by axi-cel dosing of 2x106 cells/kg intravenous infusion. The study enrolled 18 patients, of whom the first 6 patients were observed for treatment-limiting toxicities (TLTs). Primary endpoint was safety, measured by rate of TLTs and grade 3+ adverse events (AEs). Secondary endpoints included objective response rate (ORR), complete response (CR) rate, duration of response (DOR), progression-free survival (PFS) and overall survival (OS). Exploratory analyses include paired peripheral blood (PB) and CSF analyses for axi-cel pharmacokinetics, pharmacodynamics, flow cytometry, single-cell RNA-Seq. Results: We report the results of the entire cohort of 18 patients (13 PCNSL, 4 SCNSL, 1 concurrent systemic & ocular L) enrolled. Median age was 62 years (33-80), 8/18 were women. Median number of prior therapies was 3 (1-7). No TLTs were observed; 16/18 (89%) patients developed cytokine release syndrome/CRS (grade 3+, 0%); 8/18 (44%) developed immune effector cell-associated neurologic syndrome/ICANS, 5/18 (28%) grade 3+. Two patients developed Ommaya-related meningitis requiring explant with recovery. One patient had grade 3 seizures that resolved with anti-epileptic agents. The ORR was 94% (17/18); 67% CR (12/18). The median time to best response was 3 months. As of January 25, 2024, the median follow up was 24.2 months, median DOR 13.4 months and 9 patients had progressed. The median PFS was 14.3 months (95% CI: 6.3-NR) and median OS, 26.4 months (95% CI: 11.2-NR). Seven patients have died, all from disease progression. At the time of presentation, there will be a minimum follow-up of 12 months. Correlative data on all 18 patients will be presented at the meeting. Axi-cel pharmacokinetics in the first 12 CNSL patients was similar to that previously reported for DLBCL patients without CNS involvement in ZUMA-1 and ZUMA-7. Patients with CR demonstrated increased peak levels of pro-inflammatory cytokines. CSF CAR T cells exhibit Type I interferon (IFN) transcriptomic signature compared to proliferative signature in blood. Conclusions: Axi-cel was safe and well-tolerated in CNSL patients with encouraging efficacy and median PFS and durability of response of more than 1 year. There was no apparent additional risk of adverse neurologic events including ICANS from axi-cel. Clinical trial information: NCT04608487 .

Bactericidal and sterilizing activity of novel regimens combining bedaquiline or TBAJ-587 with GSK2556286 and TBA-7371 in a mouse model of tuberculosis.

The combination of bedaquiline, pretomanid, and linezolid (BPaL) has become a preferred regimen for treating multidrug- and extensively drug-resistant tuberculosis (TB). However, treatment-limiting toxicities of linezolid and reports of emerging bedaquiline and pretomanid resistance necessitate efforts to develop new short-course oral regimens. We recently found that the addition of GSK2556286 increases the bactericidal and sterilizing activity of BPa-containing regimens in a well-established BALB/c mouse model of tuberculosis. Here, we used this model to evaluate the potential of new regimens combining bedaquiline or the more potent diarylquinoline TBAJ-587 with GSK2556286 and the DprE1 inhibitor TBA-7371, all of which are currently in early-phase clinical trials. We found the combination of bedaquiline, GSK2556286, and TBA-7371 to be more active than the first-line regimen and nearly as effective as BPaL in terms of bactericidal and sterilizing activity. In addition, we found that GSK2556286 and TBA-7371 were as effective as pretomanid and the novel oxazolidinone TBI-223 when either drug pair was combined with TBAJ-587 and that the addition of GSK2556286 increased the bactericidal activity of the TBAJ-587, pretomanid, and TBI-223 combination. We conclude that GSK2556286 and TBA-7371 have the potential to replace pretomanid, an oxazolidinone, or both components, in combination with bedaquiline or TBAJ-587.

Gaining Consensus Around Patient Risk Groups and Prognostic Profiles to Guide CMV Management Among Patients With Allogeneic Hematopoietic Stem Cell Transplant: Insights From a Delphi Panel With Hematopoietic Stem Cell Transplant Experts

This study aimed to characterize patient risk groups and prognostic profiles to optimize clinical decision-making and guide appropriate medical cytomegalovirus (CMV) management among patients with allogeneic hematopoietic stem cell transplant (HSCT). Between 8/2021 and 2/2022, a 3-round modified Delphi study was conducted to generate consensus among 10 international experts in HSCT and infectious diseases. Experts were asked about treatment and prognoses for patients in 7 distinct clinical scenarios. Furthermore, experts were asked to risk-stratify patients by pre-/post-transplant characteristics. Consensus around opting for/against a treatment was observed if ≥75% or <25% of experts reported ≥50% likelihood to recommend or if treatments were ranked inside/outside the top 2 options and ≥75% of experts were within 1 SD of mean ranks. Experts agreed on several unmet needs in CMV disease management post-HSCT, particularly avoidance of treatment-limiting toxicities with conventional CMV therapy and the emergence of both refractory and drug-resistant treatment failures. Experts considered CMV viral load, resistance profile, and route of administration as critical to treatment selection. For newer CMV therapeutic options, experts listed a lack of long-term use data, concerns over potential resistance, high cost, and limited availability as challenges restricting adoption and successful patient management. Experts achieved consensus around patient risk stratifications and factors influencing therapeutic options. Recommendations emerging from this Delphi study may support practicing physicians when confronted with challenging CMV scenarios in patients with HSCT.

Phase II Clinical Trial of Trametinib and Low-Dose Dabrafenib in Advanced, Previously Treated BRAFV600/NRASQ61 Wild-Type Melanoma (TraMel-WT).

Patients with BRAFV600/NRASQ61 wild-type melanoma who progress after immune checkpoint inhibitors (ICIs) have a poor prognosis. MEK inhibition has shown activity in this patient population but is associated with treatment-limiting skin toxicity. Combining a BRAF inhibitor with a MEK inhibitor is associated with less skin toxicity. This phase II trial investigated trametinib (2 mg once daily) in patients with advanced BRAFV600/NRASQ61 wild-type, ICI-refractory melanoma. In case of treatment-limiting skin toxicity, low-dose dabrafenib (50 mg twice daily) was added to trametinib. After a trial amendment, both drugs were combined up-front. The confirmed objective response rate (cORR) served as the primary end point. Twenty-four patients were included (50% male; median age 57 years; 92% Eastern Cooperative Oncology Group Performance Status 0-2; 75% stage IV-M1c/stage IV-M1d; median number of prior therapies: two [range, 1-5]). Three patients were enrolled before and 21 patients after the amendment, respectively. Seven confirmed and one unconfirmed partial responses (PRs) were observed (cORR, 29.2%). The median duration of response was 16.6 weeks (95% CI, 5.5 to 27.7). Stable disease (SD) was the best response in an additional five patients. Among the responding patients, genetic alterations causing mitogen-activated protein kinase (MAPK) pathway activation were documented in six patients. The disease control rate in patients with MAPK pathway-activating alterations was 64.3% (five confirmed PR, one unconfirmed PR, and three SD). The median progression-free survival was 13.3 weeks (95% CI, 3.5 to 23.1), and the median overall survival was 54.3 weeks (95% CI, 37.9 to 70.6). Adding low-dose dabrafenib to trametinib effectively mitigated or prevented treatment-limiting trametinib-related skin toxicity. The combination of trametinib plus low-dose dabrafenib demonstrated encouraging efficacy and effective mitigation of skin toxicity in patients with advanced, ICI-pretreated BRAFV600/NRASQ61 wild-type melanoma patients. MAPK pathway-activating alterations hold promise as a predictive biomarker.

A phase 1 study of IO102-IO103 vaccine plus pembrolizumab in patients with BCG-intolerant or unresponsive non-muscle invasive bladder cancer (NMIBC).

TPS716 Background: Pembrolizumab, an anti-PD1 antibody, is a treatment option for high-risk BCG-unresponsive NMIBC, but has a modest complete response (CR) rate of 41% at 3 months, and a median duration of CR of 16.2 months. IO102-IO103 is a novel immune-modulating cancer vaccine that stimulates activation of T cells targeting indoleamine-2,3-dioxygenase 1 (IDO1) and PDL1-positive cells, resulting in potentially increased susceptibility to anti-PD-1 blockade. Combination IO102-IO103 with nivolumab showed encouraging clinical activity and tolerability in previously anti-PD-1 naïve metastatic melanoma patients (NCT03047928). The existing data for synergistic effects of IO102-IO103 in combination with anti-PD1 therapy and the known expression of IDO in urothelial carcinoma lend rationale to this phase I trial designed to assess the feasibility, safety, and toxicity of IO102-IO103 plus pembrolizumab in patients with BCG-intolerant or unresponsive NMIBC. Methods: This open-label, single arm, phase 1 study enrolls patients with BCG-unresponsive or intolerant high-risk NMIBC who are ineligible for or have declined cystectomy and have adequate ECOG performance status (0-2), hematologic function, and end organ function. High-risk NMIBC is defined as T1, high-grade Ta, or CIS/Tis, with predominantly urothelial cell histology. Exclusion criteria include known active autoimmune disorders requiring immunosuppressive therapy or prior checkpoint inhibitor therapy. Eligible patients will be treated with pembrolizumab 200 mg IV on Day (D) 1, and IO102-IO103 85 mcg SQ on D1 and 8 of a 21-day cycle for the first two cycles, after which IO102-IO103 dosing will be D1 only, with treatment for up to 2 years. The primary endpoints of feasibility, safety, and toxicity will be evaluated by CTCAE v5.0 criteria and will be met if ≥10 patients out of 12 are able to complete the first cycle without experiencing pre-specified treatment-limiting toxicities. Key secondary endpoints include CR rate at 3 months, median duration of response, and cystectomy-free survival at 18 months. Biopsy specimens and serial urine and blood samples will be collected to evaluate potential biomarkers of response. Clinical trial information: NCT05843448 .

Detectable ctDNA at the time of treatment cessation of ipilimumab and nivolumab for toxicity predicts disease progression in advanced melanoma patients.

Immune checkpoint inhibition (ICI) has led to unprecedented outcomes for melanoma patients but is associated with toxicity. ICI resumption after high grade irAEs poses a significant challenge in the clinical management of melanoma patients and there are no biomarkers that can help identify patients that might benefit from resuming treatment. This study aims to determine if circulating tumor DNA (ctDNA) levels at the time of treatment-limiting irAE could guide treatment decisions in this clinical context. This is a retrospective exploratory biomarker study from 34 patients treated with combination ICI for stage IV melanoma. Patients had a treatment-limiting toxicity and a baseline plasma collection prior to commencing ICI and within 6 weeks of stopping therapy. Blood samples were tested for ctDNA at baseline and cessation therapy. Median progression free survival (PFS) and overall survival (OS) have not been reached (24-month PFS rate 54% and OS rate 72.3%). PD occurred in 47% (16/34) of patients. Median PFS with detectable ctDNA from plasma collected at the time of toxicity was 6.5 months while not reached (NR) with undetectable levels (HR: 4.0, 95% CI 0.95-17.5, p=0.0023). Median OS with detectable ctDNA at cessation for toxicity was 19.4 months and NR for undetectable ctDNA (HR: 3.9, 95%CI 20.8-18.6, p=0.024). Positive ctDNA at the time of cessation was highly specific (specificity 0.94, 95% CI 0.74-0.99, PPV 0.88, 95% CI 0.53-0.99). However, ctDNA negativity has low sensitivity as a predictor of ongoing disease control (sensitivity 0.437, 95% CI 0.23-0.67). Notably, 4/9 (44%) ctDNA negative patients who had disease progression had brain only disease progression. Undetectable ctDNA and CR on imaging after stopping immunotherapy for toxicity results in high rates of long-term durable control. For patients with immunotherapy related toxicity, who have persistent ctDNA at 8 - 12 weeks, the risk of disease progression is significant.

A Pilot Study to Determine the Safety and Efficacy of Repeated Hyperbaric Oxygen Therapy in Multiple Myeloma Patients Undergoing High-Dose Therapy and Autologous Stem/Progenitor Cell Transplantation

Background Serum erythropoietin (EPO) negatively impacts hematopoietic stem cell homing and engraftment. Hyperbaric oxygen (HBO) therapy can reduce serum EPO in healthy volunteers and when given prior to stem cell infusion may improve engraftment after hematopoietic stem cell transplant (HSCT). We previously performed a phase II trial randomizing patients with multiple myeloma undergoing high dose melphalan and autologous HSCT 1:1 between a single HBO treatment and no HBO. HBO was given as 100% oxygen, 2.5 ATA for a total of 90 min, in a single treatment on Day 0 prior to the transplant. A total of 99 patients were enrolled with 52 randomized to HBO. HBO significantly reduced EPO levels for the first 24 hours after auto transplant, but EPO levels quickly rebounded by 48 hours after transplant. We hypothesized multiple HBO treatments will keep EPO levels low during the duration of stem cell homing (i.e: the first 72 hours after HSCT) and may improve neutrophil and NK cell recovery. Methods We performed a pilot study to evaluate the safety and tolerability of multiple HBO treatments during autologous HSCT. Patients with multiple myeloma undergoing autologous HSCT were eligible. Patients received HBO therapy, consisting of hyperbaric oxygen at 2.5 ATA for a total of 90 minutes breathing 100% oxygen on days 0 (prior to HSCT), 1, and 2 of transplant. The primary objective of this pilot study was to determine the safety of repeated HBO therapy in the setting, as defined by treatment limiting toxicity (TLT) including occurrence of seizure disorder, pneumothorax, death, or any irreversible grade Ill or any grade IV toxicity within 24 hours of HBO therapy. Secondary objectives were to determine the effects of multiple HBO therapy on neutrophil count recovery and the effect of multiple HBO on serum EPO. Results 10 patients have been enrolled that are evaluable for the primary objective. All patients had multiple myeloma and 4 were female. 9/10 patients successfully completed all 3 HBO treatments and 1/10 completed HBO on days 1 and 2 only because of ear pain on day 0. No patients experienced treatment limiting toxicity. The median times to neutrophil and platelet engraftment was 12 days (range 11-14) and 16 days (range 14-28), respectively. The median length of hospitalization was 13 days (range 12-16). Febrile neutropenia occurred in 3/10 patients with just one incidence of documented infection. This was significantly less than the rate of febrile neutropenia in patients receiving a single treatment of HBO or no HBO (81% and 47%, respectively, p&amp;lt;0.05). 3 patients required red blood cell transfusion and 5 platelet transfusion. Conclusions Multiple HBO treatment were well tolerated without treatment limiting toxicity during autologous HSCT for multiple myeloma.

CTIM-37. A PILOT STUDY OF AXICABTAGENE CILOLEUCEL (AXI-CEL) FOR THE TREATMENT OF RELAPSED/REFRACTORY PRIMARY AND SECONDARY CENTRAL NERVOUS SYSTEM LYMPHOMA (PCNSL AND SCNSL)

Abstract BACKGROUND Optimal therapy for patients with relapsed/refractory (R/R) CNSL is not defined, and their prognosis is poor. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy axicabtagene ciloleucel(axi-cel) has demonstrated superior efficacy over standard of care in R/R systemic diffuse large B-cell lymphoma and could be an effective regimen for R/R CNSL. METHODS This is a pilot study of axi-cel in patients with R/R CNSL. Only corticosteroids were allowed for bridging. Patients underwent lymphodepletion with fludarabine and cyclophosphamide followed by standard axi-cel dosing of 2x106 cells/kg infusion. An Ommaya reservoir was placed prior to infusion. The first 6 patients enrolled were observed for treatment-limiting toxicities(TLTs). The study enrolled a total of 17 patients. Primary endpoint was safety, measured by rate of TLTs and grade 3+ adverse events(AEs). Secondary endpoints included objective response rate(ORR), complete response(CR) rate, duration of response(DOR), progression-free survival(PFS) and overall survival(OS). Exploratory analyses included paired peripheral blood and CSF analyses for axi-cel pharmacokinetics, cytokine levels, flow cytometry, single-cell RNA-Seq and circulating tumor-DNA. RESULTS We report the results of all 17 patients(13 PCNSL, 4 SCNSL) enrolled. Median age was 64 years (34-80), 8/17 were women. As of 6/2023, 14 treated patients had &amp;gt;1 month follow-up, with 86%(12/14) ORR and 64%(9/14) CR. Six patients progressed. No TLTs were observed; 15/16(94%) patients developed cytokine release syndrome/CRS (grade 3+, 0%), 8/16(50%) developed immune effector cell-associated neurologic syndrome/ICANS, (grade 3+, 5/16(31%)). PFS, OS, DOR and correlatives will be reported at the meeting. Daily examination of CAR T-cells in blood and CSF by scRNA-Seq revealed evolution of a prominent Type I interferon (IFN) transcriptomic signature of CAR-Ts in the CSF. CONCLUSION Axi-cel is safe and well-tolerated in CNSL patients with promising efficacy and no apparent additional risk of adverse neurologic events including ICANS. IFN pathway may play a major role in CAR-T efficacy in CNSL.

CTNI-65. INVESTIGATING SAFETY AND EFFICACY OF TTFIELDS PRIOR AND CONCOMITANT TO RADIOTHERAPY IN NEWLY DIAGNOSED GLIOBLASTOMA - FIRST RESULTS OF THE PRICOTTF PHASE I/II TRIAL

Abstract BACKGROUND A synergistic inhibiting effect on glioblastoma cell proliferation was reported for the combination of TTFields and radiotherapy. Based on these preclinical findings, we performed the phase I/II PriCoTTF trial in adult nGBM patients to investigate the safety and efficacy of TTFields therapy initiated prior and concomitant to radiochemotherapy. Material and METHODS In this phase I/II trial, TTFields therapy was initiated following surgery and continued throughout radiochemotherapy and adjuvant chemotherapy for a total of approximately 9 months. TTFields rechallenge was allowed at recurrence. Radiotherapy was conducted with arrays applied on the patients’ scalp. Safety and tolerance are the study’s primary endpoint, determined by a selection of pre-specified treatment-limiting toxicities (TLTs). RESULTS A total of 33 patients have been enrolled. Patients' characteristics were mostly typical for glioblastoma, except for a rather low fraction of patients with gross total resection (GTR, 22.5%). The distribution of adverse events of ≥ common toxicity criteria (CTC) grade 3 was comparable to that of established glioblastoma trials. Notably, skin toxicity of ≥ CTC grade 3 was uncommon (n = 2, 6%). No patient developed TLTs. Median TTFields treatment duration was 8.4 months. Overall survival data was not mature enough (event rate 48%) to allow for a definite conclusion. Notably, on multivariable Cox regression, the number of days with TTFields adherence &amp;gt;23 hours was independently associated with overall survival (HR 0.96, 95% confidence interval 0.93 - 0.99, p = 0.008). CONCLUSION The PriCoTTF trial met its primary endpoint indicating that combined TTFields and radiotherapy is safe and well tolerated. High-grade skin toxicity was quite uncommon and the patients with high TTFields adherence seem to perform particularly well. An extended follow-up is required to provide first estimates regarding putative efficacy. At that point in time, the reduced overall TTFields duration and fraction of patients with GTR need to be factored in.

Pelabresib in Combination with Ruxolitinib for Janus Kinase Inhibitor Treatment-Naïve Patients with Myelofibrosis: Results of the MANIFEST-2 Randomized, Double-Blind, Phase 3 Study

Background Myelofibrosis (MF) is characterized by bone marrow fibrosis, anemia, splenomegaly and MF-associated symptoms. These hallmarks result from dysregulation of the JAK/STAT pathway and BET-mediated MF target gene modulation. Pelabresib (CPI-0610; pela) is an investigational oral small-molecule drug designed to inhibit BET-mediated gene transcription involved in MF pathogenesis. Preclinical data support the potential of combining pela with therapiesthat target overlapping pathways, such as JAK/STAT, to improve response by inhibiting the molecular drivers of MF. The Phase 3 MANIFEST-2 trial was initiated based on compelling data from Arm 3 of the ongoing Phase 2 MANIFEST study (NCT02158858), which is evaluating the combination of pela and ruxolitinib (rux) in JAK inhibitor (JAKi) treatment-naïve patients (pts) with MF. In Arm 3 of MANIFEST, primary endpoint analyses at 24 Weeks (Wks) for the 84 pts enrolled reported SVR35 (≥35% reduction in spleen volume from baseline) in 68% of pts and TSS50 (≥50% reduction in Total Symptom Score [TSS] from baseline) in 56% of pts (Mascarenhas, et al. 2023). Aims MANIFEST-2 (NCT04603495) is a global, Phase 3, randomized, double-blind, active-control study of pela + rux versus placebo + rux in JAKi treatment-naïve pts with primary MF, post-polycythemia vera MF or post-essential thrombocythemia MF. The aim of this study is to evaluate the efficacy and safety of pela + rux. Here we present the study design and baseline patient stratification for MANIFEST-2. Results from the primary analysis of MANIFEST-2 will be presented at the ASH Annual Meeting 2023. Methods The MANIFEST-2 study schema is shown in Figure 1. Key eligibility criteria include a DIPSS score of Intermediate-1 (Int-1) or higher, platelet count ≥100 × 10 9/L, spleen volume ≥450 cm 3 by CT or MRI, ≥2 symptoms with an average score ≥3 or a TSS of ≥10 using the MFSAF v4.0, peripheral blast count &amp;lt;5% and an ECOG performance status ≤2. Patient randomization was stratified by DIPSS risk category (Int-1 vs Int-2 vs High), platelet count (&amp;gt;200 × 10 9/L vs 100-200 × 10 9/L) and spleen volume (≥1800 cm 3 vs &amp;lt;1800 cm 3). Double-blind treatment of pela (125-175 mg) or placebo was administered once daily for 14 consecutive days, followed by a 7-day break, which is considered one cycle of treatment. Rux (5-25 mg) was administered twice daily based on platelet counts and spleen response for all 21 days of the cycle. The primary endpoint is SVR35 response at Wk 24. Secondary endpoints include TSS50, percentage change in TSS, safety, pharmacokinetics, changes in bone marrow fibrosis, progression-free survival, overall survival, conversion from transfusion dependence to independence and rate of red blood cell transfusion for the first 24 wks. Results A total of 591 pts were screened at 138 sites. Following the screening process, 431 pts from North America, Europe, Asia and Australia were randomized. The number of pts assigned to each randomization stratum are presented in Table 1; the majority of pts presented with DIPSS Int-1 or -2, had a platelet count above 200 × 10 9/L and spleen volume below 1800 cm 3. The study opened for enrolment in November 2020; the first patient received their initial treatment on April 22, 2021, and the last patient received their first treatment on March 2, 2023. The last patient is expected to reach the 24-wk primary endpoint on August 31, 2023, following which a primary analysis will occur. As of June 27, 2023 there were 383 pts ongoing in the study. Conclusion The Phase 3 MANIFEST-2 study was initiated based on compelling data from the ongoing Phase 2 MANIFEST study, in which the combination of pela and rux in Arm 3 demonstrated significant clinical activity and disease-modifying potential without clinically relevant treatment-limiting toxicity. MANIFEST-2 has completed recruitment and will provide definitive efficacy results of combination therapy in JAKi treatment-naïve pts with MF. As DIPSS Int-1 pts have been excluded or underrepresented in prior randomized trials in MF, MANIFEST-2 will also provide important insights in assessing the benefits of starting treatment at an earlier stage of the disease. Primary results from the pivotal Phase 3 MANIFEST-2 trial of pela and rux versus placebo and rux in JAKi treatment-naïve pts may have the potential to influence the MF treatment paradigm and will be presented at the ASH Annual Meeting 2023.

Nomogram for Predicting Risk of Cancer Therapy-Related Cardiac Dysfunction in Patients With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer.

Cancer therapy-related cardiac dysfunction (CTRCD) is an important treatment-limiting toxicity for patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer that adversely affects cancer and cardiovascular outcomes. Easy-to-use tools that incorporate readily accessible clinical variables for individual estimation of CTRCD risk are needed. From 2004 to 2013, 1440 patients with stage I to III HER2-positive breast cancer treated with trastuzumab-based therapy were identified. A multivariable Cox proportional hazards model was constructed to identify risk factors for CTRCD and included the 1377 patients in whom data were complete. Nine clinical variables, including age, race, body mass index, left ventricular ejection fraction, systolic blood pressure, coronary artery disease, diabetes, arrhythmia, and anthracycline exposure were built into a nomogram estimating risk of CTRCD at 1 year. The nomogram was validated for calibration and discrimination using bootstrap resampling. A total of 177 CTRCD events occurred within 1 year of HER2-targeted treatment. The nomogram for prediction of 1-year CTRCD probability demonstrated good discrimination, with a concordance index of 0.687. The predicted and observed probabilities of CTRCD were similar, demonstrating good model calibration. A nomogram composed of 9 readily accessible clinical variables provides an individualized 1-year risk estimate of CTRCD among women with HER2-positive breast cancer receiving HER2-targeted therapy. This nomogram represents a simple-to-use tool for clinicians and patients that can inform clinical decision-making on breast cancer treatment options, optimal frequency of cardiac surveillance, and role of cardioprotective strategies.

A comprehensive analysis of adverse events in the first 30 days of phase 1 pediatric CAR T-cell trials

AbstractThe tremendous success of chimeric antigen receptor (CAR) T cells in children and young adults (CAYAs) with relapsed/refractory B-cell acute lymphoblastic leukemia is tempered by toxicities such as cytokine release syndrome (CRS). Despite expansive information about CRS, profiling of specific end-organ toxicities secondary to CAR T-cell therapy in CAYAs is limited. This retrospective, single-center study sought to characterize end-organ specific adverse events (AEs) experienced by CAYAs during the first 30 days after CAR T-cell infusion. AEs graded using Common Terminology Criteria for Adverse Events were retrospectively analyzed for 134 patients enrolled in 1 of 3 phase 1 CAR T-cell trials (NCT01593696, NCT02315612, and NCT03448393), targeting CD19 and/or CD22. A total of 133 patients (99.3%) experienced at least 1 grade ≥3 (≥Gr3) AE across 17 organ systems, of which 75 (4.4%) were considered dose- or treatment-limiting toxicities. Excluding cytopenias, 109 patients (81.3%) experienced a median of 3 ≥Gr3 noncytopenia (NC) AEs. The incidence of ≥Gr3 NC AEs was associated with the development and severity of CRS as well as preinfusion disease burden (≥ 25% marrow blasts). Although those with complete remission trended toward experiencing more ≥Gr3 NC AEs than nonresponders (median, 4 vs 3), nonresponders experiencing CRS (n = 17; 37.8%) had the highest degree of NC AEs across all patients (median, 7 vs 4 in responders experiencing CRS). Greater understanding of these toxicities and the ability to predict which patients may experience more toxicities is critical as the array of CAR T-cell therapies expand. This retrospective study was registered at www.clinicaltrials.gov as NCT03827343.

Gastrointestinal mucosal toxicities from immune checkpoint inhibitors: Current understanding and future directions.

Immune checkpoint inhibitor (ICI) therapy has revolutionized the field of oncology over the past decade, leading to durable remissions in some patients but also producing a wide spectrum of treatment-limiting inflammatory toxicities that are referred to as immune-related adverse events (irAEs). Although irAEs can involve any organ system in the body, they most commonly affect the barrier tissues, including the gastrointestinal tract with colitis and enterocolitis affecting a significant fraction of patients on ICIs. We are beginning to understand the mechanisms that drive ICI colitis, with early experiments indicating a role for CD8+ resident memory T cells (TRMs) in the gut, which become activated and differentiate into cytotoxic cells in response to ICI therapy. The risk factors that define who will develop ICI colitis are not understood and substantial efforts are underway to identify potential biomarkers for risk of this and other toxicities. Optimal management of ICI colitis is also an area of active investigation. Current standard treatments are based largely on small, retrospective analyses, and while drugs like systemic glucocorticoids or the TNFα inhibitor infliximab do appear to be highly active in ICI colitis, the impact of these therapies on antitumor responses is poorly understood. As discussed in this review, future work will have to define the immune mechanisms driving ICI colitis in more detail and in comparison to antitumor responses in order to identify candidate pathways that can be targeted to improve ICI colitis without interfering in antitumor immunity. Studying these interventions will require randomized, controlled trials with both tumor and colitis endpoints, a goal that will necessitate collaboration across institutions and funding agencies. We are at a point where such collaborative trials are feasible, and have the potential to greatly improve the care of patients with ICI colitis as well as other irAEs.

Phase Ib, open-label study of add on therapy with CK0804 in participants with myelofibrosis, with suboptimal response to ruxolitinib.

TPS7087 Background: Drugs targeting JAK2 inhibition including ruxolitinib have led to significant improvement in quality of life and survival of myelofibrosis (MF) patients, however almost 30% have suboptimal response and disease remains incurable. Novel therapies are urgently needed. In addition to mutation-driven stem cell-derived clonal myeloproliferation, recent data support role of reactive cytokine- and chemokine-driven inflammatory fibrosis that contribute to MF pathogenesis, specifically, abnormal CXCR4/CXCL12 axis can drive disease progression and extramedullary hematopoeisis. Targeting bone marrow inflammation is emerging as potential therapeutic strategy for MF. Adoptive therapy with allogeneic, cord blood (CB) derived Regulatory T cells (Tregs) have shown to be safe in bone marrow failure patients. CXCR4 enriched CB Tregs (CK0804) show faster egress across transwell membrane in response to SDF1α and preferential homing to bone marrow, in vivo. We hypothesize that multiple infusions of CK0804 may decrease inflammation and improve clinical outcomes in MF. Methods: Single arm study consisting of safety run-in of 9 participants followed by expansion cohort of additional 15 participants using 3+3+3 study design. MF patients receiving ruxolitinib therapy &gt; 3 months prior to enrollment with stable dose for at least 8 weeks prior to Day 1, unlikely to benefit from further ruxolitinib monotherapy in opinion of investigator would be eligible. Each participant will receive single infusion of CK0804 at fixed dose of 100 million Treg cells administered every 28 days. Participants will continue their ruxolitinib therapy. Participants with no treatment limiting toxicity (TLT) after 28 days or those with toxicity with clear alternative explanation (e.g. disease progression) or transient (≤72 hrs) abnormal laboratory values without associated clinically significant signs or symptoms based on investigator determination will receive up to six 28-day treatment cycles AND 6 months of follow up after last infusion of CK0804. Primary Objective: Determine safety and tolerability of CK0804 as add-on therapy in MF, with suboptimal response to ruxolitinib. Primary endpoint: Safety, tolerability and TLTs of CK0804 as assessed by incidence and severity of AE and SAEs determined by NCI CTCAE Version 5.0. Secondary Objective: Determine efficacy of CK0804 as add-on therapy in MF, with suboptimal response to ruxolitinib. Secondary endpoint: Assessment of overall response rate and its duration, using modified International Working Group Myeloproliferative Neoplasm Research and Treatment and European Leukemia Net consensus report; Rate of anemia response and Rate of spleen response by imaging at and after 24 weeks; Symptom burden assessed using Myeloproliferative Neoplasms Symptom Assessment Form Total Symptom Score scale. Safety data from cohort 1 will be presented. Clinical trial information: NCT05423691 .

Factors impacting outcomes in individuals ≥80 years with non-small cell lung cancer (NSCLC): A national cancer database (NCDB) analysis.

9043 Background: Older individuals with advanced/metastatic NSCLC have inferior outcomes compared to younger patients. Aside from baseline comorbidities and treatment-limiting toxicities, identifying factors that impact overall survival (OS) in this population is needed. The aim of this study is to assess characteristics impacting outcomes in patients ≥80 years with NSCLC using the NCDB. Methods: Adults ≥80 years with NSCLC, stage III/IV disease, diagnosed between 2015-2018, and available demographic data were included. Age, sex, race, insurance status, hospital subtype, Charelson-Deyvo comorbidity (CDCC) index, cancer stage (III/IV), geographic region in the United States (US), and histologic NSCLC subtypes were compared. Kaplan-Meier methodology assessed differences in median OS, and differences were compared using hazard ratios (HR) with 95% confidence intervals (CI). Pearson Chi-Squared test assessed the significance of covariates, and a p value &lt; 0.05 was considered statistically significant. Results: There were 42,356 patients included. Median age was 83 (80-90) years, 20,422 were (48.2%) female, 35,653 (84.2%) were white, 37,738 (89.1%) had medicare coverage, 11,055 (26.1%) received treatment at an academic hospital, and 14,383 (33.9%) received care in the southern United States. Treatment at an academic hospital (HR: 0.91 [95% CI: 0.87, 0.95], p &lt; 0.001), females (HR: 0.82 [95% CI 0.81, 0.84], p &lt; 0.001), Medicaid (HR: 0.77 [95% CI: 0.65, 0.93], p = 0.005) vs no insurance, and adenocarcinoma (HR: 0.79 [95% CI: 0.74, 0.84], p &lt; 0.001) or squamous cell carcinoma (HR: 0.84 [95% CI: 0.80, 0.90, p &lt; 0.001] had better outcomes. Patients in the Northeastern (HR: 0.90 [95% CI: 0.87, 0.93], p &lt; 0.001), Southern (HR: 0.92 [95% CI: 0.89, 0.94], p &lt; 0.001), and Western (HR: 0.89 [95% CI: 0.88, 0.93], p &lt; 0.001) US had better OS compared to the Midwest. Compared to whites, patients who were black (HR: 0.92 [95% CI: 0.88, 0.85], p &lt; 0.001), Asian (HR: 0.77 [95% CI: 0.72, 0.82], p &lt; 0.001), Hispanic (HR: 0.83 [95% CI: 0.78, 0.88], p &lt; 0.001), or other (HR: 0.88 [95% CI: 0.79, 0.97) had better outcomes. Per year increase in age (HR 1.009 [95% CI: 1.006, 1.013], p &lt; 0.001), patients with CDCC score of 1 (HR: 1.16 [95% CI: 1.14, 1.19], p &lt; 0.001), 2 (HR: 1.22 [95% CI: 1.18, 1.27], p &lt; 0.001), and ≥3 (HR: 1.33 [95% CI: 1.284, 1.380], p &lt; 0.001) vs 0, and stage IV NSCLC (HR: 1.83 [95% CI: 1.79, 1.88], p = 0.000) had poorer survival. Conclusions: White race, males, uninsured status, receipt of treatment in the Midwest, community hospital treatment, large cell histology, advancing age, stage IV disease, and increasing CDCC score all had poorer outcomes in adults ≥80 years with advanced NSCLC. These factors should be taken into consideration when discussing the diagnosis, management, and expectations of the disease course with patients in the geriatric age group.

Molecular predictors and immunomodulatory role of dual checkpoint inhibitor blockade using ipilimumab/nivolumab in patients with extensive stage small cell lung cancer.

8597 Background: Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma with poor prognosis. In extensive stage patients, frontline treatment with chemoimmunotherapy shows modest clinical benefit. However, the biological impact of immunotherapy in SCLC is poorly understood with no clear predictive biomarkers to guide patient selection in this setting. Methods: We collected paired baseline (pre-treatment), on-treatment (week 4), and progression biopsies from patients with relapsed advanced-stage SCLC treated with combination nivolumab (nivo) and ipilimumab (ipi) in a single-arm, phase 2 clinical trial (NCT03670056). Nivo 1 mg/kg and ipi 3 mg/kg were administered every 3 weeks for 4 cycles, followed by nivo maintenance until progressive disease (PD) by RECIST 1.1 or treatment-limiting toxicity. Paired pre/on-treatment samples were available from 16/22 patients, as well as 3 biopsies at progression. The tumor samples were studied using whole exome DNA sequencing (including germline DNA) and RNA-sequencing coupled to Ocean Genomics TxomeAI data analysis pipeline. Results: 6/11 evaluable patients had PD; 5 patients showed clinical activity of treatment (3 with stable disease, 2 with partial response). The frequency of deleterious mutations in TP53 and RB1 was 91% and 64%, respectively. Mutations in HLA-A were more common in baseline samples from patients with PD than those with clinical activity. New TP53 and PLEC mutations were found 4 of 6 patients with PD in week 4 samples vs baseline. The baseline tumor mutational burden was not associated with treatment sensitivity and prominently increased in week 4 biopsies of PD patients. All four molecular SCLC transcriptomic subtypes based on the expression of ASCL1, NEUROD1, and POU2F3 were present in the trial with SCLC-A being the most common (9/16 cases). All patients with clinical activity to ipi/nivo were of SCLC-A subtype. 2/16 of cases showed a different molecular subtype after 4 weeks of treatment: one case with SCLC-N switched to SCLC-A and another case converted from SCLC-A to SCLC-N. Comparison of baseline and on-treatment samples showed upregulation of transcripts associated with T-cell activation and PD-1 signaling. In the 3 biopsies at progression, transcriptomic changes included reduction of neutrophil degranulation, type 1/2 interferon and signatures, as well as down-regulation of β-2 microglobulin, while cell cycle and mitotic prophase pathways were overexpressed. Conclusions: Dual checkpoint blockade using nivo/ipi has a prominent immunomodulatory role in extensive stage SCLC characterized by increased local adaptive immune responses, reduced HLA class-I antigen presentation and change in the molecular subtype in a subset of cases. We identified genomic features associated with treatment sensitivity/resistance. Clinical trial information: NCT03670056 .

Safety and efficacy of tumor treating fields (TTFields) prior and concomitant to radiotherapy in patients with newly diagnosed glioblastoma: Results from PriCoTTF.

2050 Background: Tumor Treating Fields (TTFields) therapy is a locoregional, antimitotic cancer modality that utilizes electric fields delivered noninvasively to the tumor region using arrays. Preclinical findings have demonstrated that TTFields have an enhanced inhibitory effect on glioblastoma (GBM) cell proliferation when used concomitantly with radiotherapy (RT). These results provided the rationale for the phase 1/2 PriCoTTF study that investigated the safety and efficacy of TTFields therapy initiated prior and concomitant to radio-chemotherapy in adult patients with newly diagnosed (nd)GBM. Methods: TTFields therapy was initiated following surgery and continued concomitant with radio-chemotherapy and adjuvant chemotherapy for a total of approximately 9 months. TTFields rechallenge was permitted upon GBM recurrence. RT was conducted with arrays placed on the patients’ scalp. The primary endpoint was safety and tolerability gauged by a series of pre-selected treatment-limiting toxicities (TLTs). Results: The baseline characteristics of 33 patients enrolled to date were typical for GBM, except for a small proportion of patients with gross total resection (22.5%). The frequency of adverse events (AEs) grade ≥ 3 was comparable to other studies in GBM. Of note, grade ≥ 3 skin AEs only occurred in 2 patients (6%) and no patients developed a TLT. The median duration of TTFields therapy was 8.4 months. Median overall survival (OS) was not reached (48% of events had occurred), which precluded conclusions regarding efficacy. However, notably, multivariable Cox regression found that OS was independently associated with the number of days patients achieved &gt; 23 h TTFields therapy (HR 0.96, 95% CI 0.93–0.99, P = 0.008). Conclusions: The PriCoTTF study met its primary endpoint by finding that TTFields therapy concomitant with RT was well tolerated in patients with ndGBM. This included that high-grade skin toxicities were rare. Longer follow up is needed to estimate the efficacy of TTFields therapy in this setting, and will need to consider the relatively low overall duration of TTFields therapy and proportion of patients who received GTR.