Citations

8524 Background: Teliso-V is a c-Met–directed antibody-drug conjugate comprising telisotuzumab and the microtubule polymerization inhibitor monomethyl auristatin E (MMAE) payload. In the Ph2 LUMINOSITY study (NCT03539536), Teliso-V showed durable responses and manageable safety (Camidge et al, JCO 2024;42:3000-11) resulting in its accelerated approval in locally advanced/metastatic NSQ NSCLC with high c-Met protein OE (3+, ≥50%), as determined by an FDA-approved test. MET amp is a negative prognostic risk factor in advanced NSCLC, frequently associated with recurrent disease. High levels of MET amp and c-Met OE are hallmarks of MET -addicted tumors. Here, we analyzed the effects of MET amp on clinical responses to Teliso-V in LUMINOSITY. Methods: MET amp was evaluated by FISH and ctDNA in baseline samples from 108 NSQ EGFR WT NSCLC pts with c-Met OE (3+, ≥25%). MET amp by FISH was defined as having focal MET amp (MET/CEP7 ≥2.0) with MET gene copy number (GCN) ≥4. MET amp (focal) by ctDNA was defined as having plasma MET GCN ≥4 with no co-amplification in CDK6 and EGFR. c-Met OE by Immunohistochemistry (IHC; SP44) was defined as 3+ tissue staining intensity in ≥25% tumor cells (high c-Met OE: 3+, ≥50%; intermediate [int] c-Met OE: 3+, 25% to 49%). Exploratory analysis of tumor response was assessed in 76 efficacy evaluable pts with c-Met OE and MET amp assay results. Results: MET amp was detected in 34% (37/108) of pts with c-Met OE (3+, ≥25%) and was enriched by c-Met levels: 22% (11/50) in pts with Int c-Met OE (3+, 25% to 49%) and 45% (26/58) in pts with high c-Met OE (3+, ≥50%). The effects of MET amp on tumor response in LUMINOSITY are shown in Table 1. The majority of c-Met OE pts (79%) with PFS ≥10 mo (n=14) had GCN ≥10 and/or c-Met IHC 3+ ≥50%. No new safety signals were reported in pts with c-Met OE and MET amp. Conclusions: MET amp is more common in pts with high c-Met OE in this retrospective subgroup analysis. Tumor activity with Teliso-V was observed regardless of MET amp status. The impact of MET amp in pts with c-Met OE will be further evaluated in ongoing Phase 3 study (NCT04928846). Teliso-V efficacy in NSQ EGFR -WT NSCLC pts with c-Met OE with or without MET amp in LUMINOSITY. Total c-Met OE(3+, ≥25%) Total c-Met OE(3+, ≥25%) Intermediate c-Met OE(3+, ≥25%-49%) Intermediate c-Met OE(3+, ≥25%-49%) High c-Met OE(3+, ≥50%) High c-Met OE(3+, ≥50%) MET amp(N) No (N=53) Yes (N=23) No (N=30) Yes (N=7) No (N=23) Yes (N=16) ORR %(95% CI) 28 (18.0, 41.6) 39 (22.2, 59.2) 23 (11.8, 40.9) 57 (25, 84.2) 35 (18.8, 55.1) 31 (14.2, 55.6) PFS,median, mo(95% CI) 5.26 (3.71, 8.11) 8.02 (4.47, 14.65) 5.32 (2.69, 8.11) 7.52 (4.47, NA) 4.17 (3.25, 8.87) 8.02 (3.06, 25.92) OS,median, mo(95% CI) 14.5 (8.18, 17.38) 13.86 (6.54, 22.24) 14.03 (3.65, 17.02) 9.79 (6.54, NA) 16.26 (5.59, 36.44) 13.86 (3.06, 30.29)

Abstract Background Repotrectinib, a next-generation ROS1/TRK tyrosine kinase inhibitor, is approved for ROS1 fusion-positive non-small cell lung cancer and NTRK fusion-positive solid tumors. Its side effects and safety management strategies require further characterization. Patients and Methods The safety profile of repotrectinib (treatment-emergent/related adverse events [TEAEs/TRAEs]) was established in patients who initiated treatment at the recommended dose (160 mg daily [QD] for 14 days, then 160 mg twice daily [BID]) across all cohorts of the global, multicenter phase 1/2 TRIDENT-1 study. AE management strategies were outlined. Results In 472 patients, the most common TRAEs (dizziness [58%] and dysgeusia [50%]) were likely TRK inhibition-related. Median relative dose intensity was 90%; 14% (n = 66/472) of patients did not increase their initial QD dose to BID (mostly due to CNS AEs). Rates of dizziness (median onset, 7 days) were similar in patients with/without baseline brain metastases. Dose modifications downgraded severity or resolved dizziness in 78% of patients; 58% of patients had pharmacologic intervention without dose modification. Dizziness was downgraded/resolved in 62% (n = 120/195) of patients who did not receive dose modification or pharmacologic intervention. Treatment-related cognitive impairment and weight gain occurred in 19% and 12% of patients, respectively. Treatment-emergent withdrawal pain occurred in 14% of patients (median resolution time, 2.1 weeks). Dose interruption and reduction from TRAEs occurred in 39% and 38% of patients, respectively; 10% reported later re-escalation back to 160 mg BID. Conclusion Many repotrectinib AEs, including neurological AEs secondary to TRK inhibition, were mitigated with appropriate management, including dose modification and/or pharmacologic intervention.

8618 Background: Telisotuzumab vedotin (Teliso-V) is a c-Met–directed antibody-drug conjugate comprising the mAb telisotuzumab and the microtubule polymerization inhibitor monomethyl auristatin E. In the phase 2 LUMINOSITY trial (NCT03539536), Teliso-V monotherapy 1.9 mg/kg showed durable responses and a generally manageable safety profile in patients (pts) with c-Met protein–overexpressing (OE) non-squamous (NSQ) EGFR -wildtype (WT) non-small cell lung cancer (NSCLC). Herein we present an analysis of efficacy outcomes according to prior platinum or prior platinum and immune checkpoint inhibitor (ICI)-based therapies. Methods: Pts (≥18 years) with locally advanced/metastatic c-Met protein–OE NSQ EGFR -WT NSCLC who had ≤2 prior lines of therapy, including ≤1 line of chemotherapy, were treated with 1.9 mg/kg Teliso-V Q2W. c-Met protein overexpression (by immunohistochemistry clinical trial assay for MET [SP44] [Roche]) was defined as ≥25% tumor cells with 3+ staining intensity (high: ≥50% 3+; intermediate [int]: 25 to <50% 3+). The primary endpoint was overall response rate (ORR) by independent central review per RECIST v1.1. Results: As of 21 Feb 2024, 172 pts received ≥1 dose of Teliso-V and 168 pts were included in efficacy analyses (c-Met high, n=84; c-Met int, n=84). In the c-Met OE total population, 97.6% of pts received prior platinum and 78.6% received prior platinum + ICI. Efficacy data for pts with prior platinum and platinum + ICI therapies are shown in the Table. Among the 172 dosed pts, the most common any-grade treatment-related adverse events (TRAEs) were peripheral sensory neuropathy (31%), peripheral edema (16%), and fatigue (14%). The most common grade ≥3 TRAE was peripheral sensory neuropathy (7%). Conclusions: This analysis demonstrated that Teliso-V elicited durable responses in pts with c-Met protein–OE NSQ EGFR -WT NSCLC regardless of whether they had received prior platinum or platinum + ICI therapies; the efficacy outcomes in these subgroups were consistent with those in the overall pt population. Clinical trial information: NCT03539536 . Platinum Platinum + ICI Overall ORR, a n/N (%) [95% CI] c-Met OE total c-Met high c-Met int 48/164 (29.3) [22.4, 36.9]28/81 (34.6) [24.3, 46.0]20/83 (24.1) [15.4, 34.7] 38/132 (28.8) [21.2, 37.3]22/67 (32.8) [21.8, 45.4]16/65 (24.6) [14.8, 36.9] 49/168 (29.2) [22.4, 36.7]29/84 (34.5) [24.5, 45.7]20/84 (23.8) [15.2, 34.3] Median DOR, a mo [95% CI] c-Met OE total c-Met high c-Met int 7.2 [5.5, 11.3]9.0 [3.8, 12.0]7.2 [4.7, 11.5] 7.2 [5.5, 11.0]9.0 [3.8, 11.3]7.2 [5.3, 11.5] 7.2 [5.5, 11.0]7.2 [4.2, 12.0]7.2 [4.7, 11.5] a Per independent central review. DOR, duration of response.

BACKGROUND: Recent World Health Organization (WHO) classifications (5 th edition), International Consensus Classification (ICC) recognized TP53-mutated ( TP53mut) myeloid neoplasms (MNs) as a distinct subcategory, acknowledging their uniformly poor outcomes. However, there are critical differences between the two guidelines in how TP53 allelic status is assigned. Both WHO-5 and ICC acknowledged the poor outcome of multi-hit TP53mut but excluded single-hit TP53mut. These changes are driven by a pivotal study demonstrating favourable outcome of single-hit TP53mut, however this study predominantly included de novo myelodysplastic syndromes (MDS) cases (Bernard et al. Nat Med 2020). In contrast, we previously reported poor outcome of TP53mut therapy-related myeloid neoplasm (t-MN) irrespective of the allelic status of TP53 (Hiwase et al Blood 2022andShah et al BCJ 2023). Finally, the ICC removed the subcategory of “therapy-related,” substituting it with diagnostic qualifiers instead. The WHO has grouped t-MN with secondary MN and renamed it as “myeloid neoplasm post cytotoxic therapy,” with the assertion that only multi-hit T P53mut MDS occurring post-cytotoxic therapy have poor outcome compared with single-hit. METHODS: We analyzed one of the largest international cohorts of TP53mut MN (n=544) with full characterization of TP53mut allele status utilizing uniform ICC criteria and similar large numbers of de novo and t-MN cases managed at Mayo Clinic Enterprise (USA) and South Australian MDS Registry, Adelaide (Australia) with clinical, integrated genomic profiling, and long-term follow-up. RESULTS: In our cohort of TP53mut MN (n=544), 475 (87.3%) MN had TP53mut variant allele frequency (VAF) of ≥10% and thus satisfied ICC criteria for TP53mut MN. Majority of TP53mut t-MN presented with MDS (bone marrow (BM) blasts 0-9%) compared de novo MN (62% vs. 48%; P=0.0012). While acute myeloid leukemia (AML) (BM blasts ≥20%) were more prevalent in TP53mutde novo MN compared to t-MN (38% vs. 24%; P= 0.001) and there was no difference in frequency of MDS/AML (BM blasts 10-19%) between the two cohorts (14% vs. 14%; P=0.8) ( Figure 1A). Majority of TP53mut were observed in the DNA-binding domain in t-MN and de novo MN (95% vs. 96.2%; P=0.48). However, mutations in Tetramer Domain were more frequent in t-MN (4.3% vs. 0.3%; P=0.002), whereas those in the TAD2 domain were more frequent in de novo TP53mut MN (2.4 vs. 0%; P =0.006). Integrating the mutation, conventional G-banding cytogenetic, copy number variation (CNV), FISH, and SNP array analysis, TP53mut MDS (BM blast 0-9%; n=260) were classified as multi-hit (n=179, 68.9%) or multi-equivalent (n=35, 13.5%) and single-hit (n=46, 17.7%) (Arber et al. Blood 2022). Striking enrichment of multi-hit/multi-hit equivalent was observed in TP53mut t-MDS compared to de novo MDS (91% vs. 72%; P&lt;0.0001). While single-hit TP53mut were prevalent in de novo MDS compared to t-MDS (28% vs. 9%; P&lt;0.0001). Importantly, median overall survival (OS) of single-hit was significantly longer than multi-hit de novo MDS (25.4 vs. 7.2 months; P=0.0002). In contrast to this we did not observe OS difference between single-hit and multi-hit TP53mut t-MDS (11.6 vs. 10.9 months; P =0.73) ( Figure 1B). CONCLUSION: Our study based on a large international cohort of T53mut MN provides compelling evidence that in contrast to de novo MDS, single hit TP53mut t-MDS is associated with poor outcome. Our data supports the consideration of single hit t-MDS as a multi-hit equivalent.

BACKGROUND: The association between myeloid neoplasm (MN) and autoimmune rheumatological diseases (AIRD) is increasingly recognized. Furthermore, prolonged cytotoxic disease modifying anti-rheumatological drugs (DMARD) for AIRD may potentially induce therapy-related MN (t-MN), a lethal haematological malignancy with dismal outcomes. However, the genetic association and mechanism underpinning immune dysfunction in patients with between MN and AIRD is not fully elucidated. METHODS: In this collaborative study across the two disciplines and continents (Australia and USA), we assessed the burden of well-defined AIRD in a large cohort of MN (n=1702) that included myelodysplastic syndrome (MDS; n=861), acute myeloid leukaemia (AML; n=640), myeloproliferative neoplasm (MPN; n=89) and MDS/MPN overlap (n=112). We characterized the cytogenetic and mutational landscape of MN with AIRD (MN-AIRD) and without AIRD. In order to assess the mechanistic link between AIRD and MN, we investigated the bone marrow microenvironment in MN-AIRD vs. well-curated age matched controls. RESULTS: 132 (7.75%) of MN (n=1702) had concomitant AIRD. Although association of AIRD was observed across all subtypes of MN, enrichment of AIRD was observed in patients with MDS, MDS/MPN and MPN compared to AML (9.5% vs. 9.8% vs 10.1% vs. 4.67%; P &lt;0.001). Inflammatory arthritis (n=65; 49.24%) followed by inflammatory connective tissue diseases (CTD, n=23; 17.42%), polymyalgia rheumatica (PMR, n=18; 13.63%) and vasculitis (n=16; 12.12%) were the most prevalent AIRD in the MN cohort. Notably, 87.7% of inflammatory arthritis were rheumatoid arthritis (RA; n=57). Striking survival differences were observed between t-MN without AIRD and MN-AIRD (14.0 vs. 33.7 months; P &lt;0.0001) and t-MDS no-AIRD and MDS-AIRD (16.1 vs. 33.4 months, P =0.001). Chromosomal abnormalities including complex karyotype, monosomal karyotype, del 5q, del 7q, marker chromosome and TP53 mutations were enriched in t-MN following independent primary cancer (t-MN without AIRD). However striking enrichment of IDH1 and IDH2 (henceforth referred as IDH) mutations in MN with AIRD compared to MN without AIRD (20% vs. 11%, P =0.02), particularly in MDS-AIRD compared to MDS without AIRD (21% vs. 7%; P =0.001). The enrichment of IDH mutations were particularly prevalent in in MN cases with RA compared to other AIRD (34% vs. 11%; P =0.005). While IDH mutations were observed in only 8% and 6% of PMR and inflammatory CTD patients, respectively. Surprisingly higher frequency of IDH mutations was observed in evaluable seronegative compared to seropositive RA patients (62% vs. 0%; P =0.006). We also observed that majority of IDH mutations in seronegative RA were IDH1 (6/8; 75%) while IDH2 mutations were common other AIRD (6/6; 100%) ( P =0.009). We also assessed the impact of DMARDs on genomics of myeloid neoplasm. The majority of MN-AIRD patients treated with methotrexate did not harbor poor risk cytogenetic and mutation features such as complex karyotype, monosomal karyotype, del 5q, del 7q and/or TP53 mutation. In contrast, the majority of patients who had cyclophosphamide harbored high risk cytogenetic and molecular features. To assess pathogenic mechanisms linking MN and AIRD, we evaluated bone marrow microenvironment in myeloid neoplasm patients with and without AIRD. Bone marrow mesenchymal stromal cells (MSC) isolated from MN-AIRD were highly senescent compared to age matched healthy controls, MN without AIRD, with defective proliferating and differentiation capacity of MN-AIRD and secretion of highly proinflammatory cytokines and chemokines. CONCLUSIONS: In summary, our key findings include: 7.8% of MN were associated with AIRD with stronger association of AIRD with MDS and MDS/MPN compared to AML and striking enrichment of IDH mutations in MN with inflammatory arthritis compared to MN with other AIRD (29% vs 11%; P =0.02), especially in seronegative RA compared to seropositive RA (62% vs. 0%; P =0.006). In contrast to cyclophosphamide and azathioprine, majority of cases treated with methotrexate did not harbor poor risk cytogenetic and/or TP53 mutation. As methotrexate is widely used as an anchor drug in many rheumatology treatment regimens, this is a highly significant finding of clinical relevance.

Myelofibrosis (MF) is a chronic myeloproliferative neoplasm that typically manifests with debilitating symptoms that progressively worsen, negatively impacting patients’ quality of life. Fatigue is a multifactorial and burdensome MF-related symptom due to its severity, persistence, and prevalence, with anemia a contributing factor and major unmet need. Clinical trials of the Janus kinase (JAK)1/JAK2/activin A receptor type 1 inhibitor momelotinib have shown consistent anemia benefits, in addition to improvements in MF-related symptoms. The phase 3 MOMENTUM trial in symptomatic and anemic patients met its primary end point, with a greater proportion having a Myelofibrosis Symptom Assessment Form (MFSAF) Total Symptom Score (TSS) reduction ≥50% at week 24 with momelotinib versus danazol. To support the positive primary end point result, we conducted longitudinal, responder, and time-to-event analyses of patient-reported outcomes from MOMENTUM, as measured by the MFSAF, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), and Patient-Reported Outcomes Measurement Information System (PROMIS) assessments. These analyses demonstrated rapid and durable response benefits with momelotinib, with achievement of first TSS response by day 29 and continued improvement over time. Improvements favored momelotinib versus danazol for each MFSAF individual item, and greater improvements were observed for disease- and cancer-related fatigue and physical functioning at week 24, with significant results for multiple items/domains across the 3 assessments. These findings are consistent in demonstrating that momelotinib provides substantial symptom benefit.

AbstractBackgroundMyelofibrosis (MF)‐associated constitutional symptoms can severely impact health‐related quality of life. Clinical trials in MF traditionally measure symptom response to treatment as a landmark endpoint of total symptom score (TSS) reduction ≥50% from baseline. However, this dichotomous assessment provides a limited view of clinically relevant symptomatic changes. Herein we evaluated longitudinal change from baseline in TSS over the continuous 24‐week period and individual symptom scores to obtain a more comprehensive understanding of symptom benefits experienced by patients with MF receiving therapy.MethodsLongitudinal symptom change was evaluated using mixed‐effect model repeated measure (MMRM) methodology with individual item‐level analyses to complement the interpretation of the landmark symptom results in the completed phase III SIMPLIFY studies of momelotinib in MF. MMRM compared mean change in TSS from baseline with Week 24 using data from all patient visits. Generalized estimating equations were used to estimate item‐level odds ratios using multiple predictive imputations for missing data.ResultsMomelotinib and ruxolitinib groups reported similar overall symptom improvements, with a TSS difference of <1.5 points between groups for each post‐baseline visit in SIMPLIFY‐1. In SIMPLIFY‐2, the improvement in TSS observed in momelotinib‐treated patients was consistent with that observed in SIMPLIFY‐1, whereas progressive TSS deterioration was observed with control. Item‐level scores were heterogeneous in both studies. A similar and greater proportion of momelotinib‐treated patients were categorized as “improved” or “stable” compared with control in SIMPLIFY‐1 and SIMPLIFY‐2, respectively. Odds ratios for between‐group comparison ranged from 0.75 to 1.21 in SIMPLIFY‐1, demonstrating similarity in likelihood of symptom improvement. In SIMPLIFY‐2, the likelihood of symptom improvement in each item was higher in the momelotinib arm.ConclusionsThese findings suggest that momelotinib provides clinically relevant symptom benefits in the JAK inhibitor‐naïve and JAK inhibitor‐exposed settings.