Sachdev, Jasgit C.

TPS3182 Background: MTAP deletion in solid tumors causes intracellular accumulation of methylthioadenosine (MTA) which partially inhibits activity of the key methylating enzyme, protein arginine methyltransferase 5 (PRMT5) and creates synthetic lethal dependencies on PRMT5 and methionine adenosyltransferase 2A (MAT2A), the rate limiting step in the synthesis of PRMT5 substrate, S-adenosyl methionine. PRMT5 and MAT2A are essential to transcription modulation, gene splicing, and DNA damage response. IDE892 is an MTA-cooperative PRMT5 inhibitor designed to exploit this vulnerability in MTAPdel tumors. Preclinical studies report robust antitumor activity with IDE892 monotherapy in MTAPdel xenograft models and an enhanced response when combined with IDE397 (an allosteric MAT2A inhibitor). IDE892-001 is a Phase 1 study evaluating safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antitumor activity of IDE892 alone and in combination with IDE397. Methods: IDE892-001 is an ongoing, open-label, multicenter four-part study: IDE892 monotherapy dose escalation (Part 1), monotherapy dose expansion in MTAPdel NSCLC (Part 2), IDE892 + IDE397 dose escalation (Part 3), and combination expansion in MTAPdel NSCLC (Part 4). Adults with advanced or metastatic MTAPdel solid tumors including lung, urothelial, gastrointestinal cancers (including pancreatic and biliary tract cancers) and mesothelioma are eligible following disease progression on standard therapies. Key exclusion criteria include symptomatic brain metastases, cardiac disease, active severe infection, and prior treatment with a PRMT5 or MAT2A inhibitor. Part 1 uses a Bayesian optimal interval design to determine maximum tolerated dose (MTD) and recommended doses for expansion (RDE). Part 3 uses a modified toxicity probability interval design to evaluate escalating combinations of IDE892 and IDE397. Oral treatment is given QD in 21-day cycles until progression or unacceptable toxicity. Serial blood samples are collected for PD analyses. Imaging will be performed every 6 weeks through week 24, then every 9–12 weeks. Efficacy endpoints will be assessed by RECIST v1.1. Primary objectives for dose-escalation cohorts (Parts 1 and 3) are safety and tolerability, including determination of MTD/RDE. In expansion cohorts (Parts 2 and 4), co-primary objectives include safety and preliminary antitumor activity (objective response rate and duration of response). Secondary endpoints for all parts include PK of IDE892 alone and in combination with IDE397. Exploratory assessments include progression free survival, changes in circulating and tumor-based markers of PRMT5 pathway modulation, molecular predictors of response, exposure–response relationships, and metabolite characterization. Clinical trial information: NCT07277413 .

Aim Preclinical evidence suggests that oxidized macrophage migration inhibitory factor (oxMIF) may be involved in carcinogenesis. This phase 1 study (NCT01765790) assessed the safety, tolerability, pharmacokinetics and antitumour activity of imalumab, an oxMIF inhibitor, in patients with advanced cancer using ‘3 + 3’ dose escalation. Methods In Schedule 1, patients with solid tumours received doses from 1 to 50 mg/kg IV every 2 weeks. In Schedule 2, patients with metastatic colorectal adenocarcinoma, non‐small‐cell lung, or ovarian cancer received weekly doses of 10 or 25 mg/kg IV (1 cycle = 28 days). Treatment continued until disease progression, unacceptable toxicity, dose‐limiting toxicity, or withdrawal of consent. Results Fifty of 68 enrolled patients received imalumab. The most common treatment‐related adverse events (TRAEs) included fatigue (10%) and vomiting (6%); four grade 3 serious TRAEs (two patients) occurred. The dose‐limiting toxicity was allergic alveolitis (one patient, 50 mg/kg every 2 weeks). The maximum tolerated and biologically active doses were 37.5 mg/kg every 2 weeks and 10 mg/kg weekly, respectively. Of 39 assessed patients, 13 had stable disease (≥4 months in 8 patients). Conclusions Imalumab had a maximum tolerated dose of 37.5 mg/kg every 2 weeks in patients with advanced solid tumours, with a biologically active dose of 10 mg/kg weekly. Further investigation will help define the role of oxMIF as a cancer treatment target.

Abstract BACKGROUND: nal-IRI is a liposomal formulation of irinotecan (topoisomerase-1 inhibitor). Preclinical data show that nal-IRI accumulates in BMs and prolongs survival in animal models of BM. Findings from a phase 1 expansion study (NCT01770353), evaluating patients with mBC and active BM, are reported. METHODS: This phase 1 expansion study enrolled patients with mBC who received multiple prior lines of cytotoxic therapy in the metastatic setting, including one cohort with mBC and active BM, defined as radiographic evidence of new or progressive central nervous system (CNS) metastases after radiation therapy with ≥1 lesion of ≥1 cm in the longest dimension on gadolinium-enhanced magnetic resonance imaging. Patients received nal-IRI 50 mg/m2 (free-base equivalent; FBE) every two weeks (q2w) as an intravenous infusion over 90 minutes, escalating to 70 mg/m2 FBE q2w, if tolerated. RECIST v1.1 and modified RECIST criteria were used to assses non-CNS and CNS disease, respectively. RESULTS: In total, 30 patients were enrolled (10 with active BM). Median age was 53 years (range 29–70 years) and median number of prior cytotoxic anti-cancer regimens was 3 (range 0–6); 29 patients received ≥1 dose of nal-IRI 50 mg/m2 FBE. Overall, nal-IRI monotherapy appeared to be well tolerated, and achieved ≥30% objective response rates for both CNS and non-CNS disease. Among the 10 patients with active BM, 6 achieved CNS disease control (3 partial responses [PRs] and 3 stable disease [SD]), including one patient with durable CNS SD and non-CNS PR for 2 years. Among 7 patients with serial evaluation of CNS metastases posttreatment, 6 patients achieved a reduction in target CNS lesions compared with baseline. CONCLUSION: Treatment with nal-IRI resulted in CNS disease control among 6 of 10 heavily pretreated patients with mBC and active BM. Further exploration of nal-IRI in patients with mBC and active BM is warranted.

Abstract Background nal-IRI is a liposomal formulation of irinotecan (topoisomerase-1 inhibitor), using intraliposomal stabilisation technology to enable high drug load and in-vivo stability. The expansion of Phase I NCT01770353 evaluated nal-IRI in patients (pts) with mBC. Methods This Phase I expansion study enrolled mBC pts (Cohort 1: ER+ and/or PR+ HER2 BC (C-1); Cohort 2: Triple Negative BC (TNBC, C-2); Cohort 3: BC with active Brain Metastasis (C-3)). Key inclusion criteria: ECOG ≤1; adequate organ function; received >1 to ≤5 prior lines of cytotoxic therapy in metastatic setting, except TNBC pts who could have progressed within 12 months of adjuvant therapy. Pts received nal-IRI 50 mg/m2 (Free-base equivalent, FBE) q2w iv infusion, escalating to 70 mg/m2 FBE q2w, if tolerated. Results 30 pts (10 per cohort) were enrolled: 29 received >1 dose nal-IRI 50 mg/m2 FBE (median age 53 yrs, range 29-70 yrs). Median number of cytotoxic therapies prior to study entry was 3. The most frequent treatment emergent adverse events (TEAEs) were gastrointestinal disorders (all cohorts, 100%), primarily diarrhea (C-1, 100% / C-2, 100% / C-3, 70%), nausea (C-1, 80% / C-2, 56% / C-3, 30%), and vomiting (C-1, 60% / C-2, 33% / C-3, 30%). The incidence of neutropenia was low (C-1, 10% / C-2, 0% / C-3, 10%), all grade 1 / 2. Most common grade 3 TEAEs were diarrhea (28%), nausea (17%), fatigue (14%), hypokalemia (10%) and asthenia (10%), with none reported as grade 4. No grade 5 TEAEs were reported. Partial response (per RECIST) was observed in 10 pts for an objective response rate (ORR) of 35% (C-1, 40% / C-2, 33%) / C-3, 30%). Stable disease was observed in 5 pts (17%). Duration of Response (median, months) was C-1, 7.5 (6.4-13.0) / C-2, 5.6 (3.7-7.4) / C-3, 4.1 (0.0-22.2, extracranial: RECIST) / C-3, 1.8 (0.0-1.9, intracranial: mRECIST). Table 1.Study Demographics, Adverse Events, and Best Overall ResponseDemographicsCohort 1ER+ and/or PR+ Breast Cancern=10Cohort 2Triple Negative Breast Cancern=10Cohort 3Breast Cancer with Active Brain Metastasisn=10Total PopulationN=30Gender, Female, n (%)10 (100%)10 (100%)10 (100%)30 (100%)Age, Years Median (range)56 (49-68)52.5 (37-70)45.5 (29-63)53 (29-70)Race, n (%)WhiteBlack/AfricanOther8 (80%)02 (20%)8 (80%)1 (10%)1 (10%)7 (70%)1 (10%)2 (20%)23(77%)2 (7%)5(16%)Months Since Metastatic diagnosis, Months Median (Range)63.7 (16-87)20.7 (0-34)32.4 (8-55)24.0 (0-87)Number of Prior Cytotoxic Anti-cancer Regimens Median (Range)3.0 (1-6)3.0 (0-5)32.4 (1-6)3.0 (0-6)Safety PopulationCohort 1ER+ and/or PR+ Breast Cancern=10Cohort 2Triple Negative Breast Cancern=9Cohort 3Breast Cancer with Active Brain Metastasisn=10Total PopulationN=29ExposureTreatment Duration, Weeks Median (range)6.1 (0-78)12.3 (0-49)13.9 (1-105)12.3 (0-105)Adverse EventsAny TEAE10 (100%)9 (100%)10 (100%)29 (100%)Grade 38 (80%)6 (67%)10 (100%)20 (69%)Grade 41 (10%)06 (60%)3 (10%)TEAE Related to nal-IRI10 (100%)8 (89%)10 (100%)28 (97%)Grade > 36 (60%)3 (33%)3 (30%)12 (41%)TEAE Related to nal-IRILeading to Dose Adjustment*7 (70%)3 (33%)4 (40%)14 (48%)SAEs6 (60%)4 (44%)7 (70%)17 (59%)SAE Related to nal-IRI4 (40%)1 (11%)1 (10%)6 (21%)Duration of Objective ResponseRECIST 1.1RECIST 1.1RECIST 1.1mRECISTMonths Median (Range)7.5 (6.4-13.0)5.6 (3.7-7.4)4.1 (0.0-22.2)1.84 (0.0-1.9)Best Overall ResponseRECISTRECISTRECISTmRECISTComplete Response (CR)0000Partial Response (PR)4 (40%)3 (33%)3 (30%)3 (30%)Stable Disease (SD)03 (33%)2 (20%)3 (30%)Progressive Disease (PD)5 (50%)2 (22%)3 (30%)2 (20%)Not Evaluable (NE)1 (10%)1 (11%)2 (20%)2 (20%)Objective Response RateCR+PR(95% CI)4 (40%)12.2 -73.83 (33%)7.5-70.73 (30%)6.7-65.33 (30%)(6.7-65.3)*n=1 patient in Cohort 1 discontinued treatment due to TEAE related to treatment with nal-IRI CI, Confidence Interval; nal-IRI, Irinotecan Liposome Injection; SAE, Serious Adverse Event; TEAE, Treatment Emergent Adverse EventSystemic tumor response was evaluated according to RECIST version 1.1CNS tumor response was evaluated according to mRECIST (Anders C. et al., Breast Cancer Res Treat, 2014: 146(3):557-66) Conclusion nal-IRI monotherapy 50g/m2 FBE Q2W appears well tolerated, and achieved >30% ORR for systemic and CNS disease among heavily pre-treated mBC pts regardless of receptor status. Citation Format: Jasgit Sachdev, Pamela Munster, Donald Northfelt, Hyo S. Han, Cynthia MA, Fiona Maxwell, Tiffany Wang, Bruce Belanger, Bin Zhang, Yan Moore, Carey Anders. Phase I expansion study of irinotecan liposome injection (nal-IRI) in patients with metastatic breast cancer (mBC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT048.

e12003 Background: Irinotecan liposome injection (nal-IRI) uses intraliposomal stabilisation technology to enable high drug load and in-vivo stability. This analysis characterizes the PK profile of nal-IRI in pts with mBC. Methods: The expansion of NCT01770353 enrolled 30 pts with mBC over three cohorts (Cohort 1: ER+ and/or PR+ BC [C-1]; Cohort 2: Triple Negative BC [C-2]; and Cohort 3: BC with active Brain Metastasis [C-3]). Key inclusion criteria: ECOG ≤1; adequate organ function; and >1 and ≤5 prior lines of cytotoxic therapy in metastatic setting. Most pts received nal-IRI 60 mg/m2 salt-based equivalent (50 mg/m2 free base equivalent [FBE]) or 80 mg/m2 (70 mg/m2 FBE) q2w by iv infusion, based on tolerance; 2 pts were treated at 40 mg/m2 (35 mg/m2 FBE). Plasma samples were collected over 360h across cycles 1, 2 &3, and analysed using LC-MS/MS for total irinotecan. Data were analysed by a non-compartmental approach using Phoenix Winnonlin, and were compared with values from studies in other tumor types. Results: 21 patients were evaluable for PK analysis (C-1, n=6; C-2, n=7; and C-3, n=8). No trend for accumulation was observed in cycle 2 or 3, when comparing total irinotecan Cmax & exposure (area under the curve at 168 h [AUC168]) versus cycle 1. At 40-80 mg/m2 (35-70 mg/m2 FBE), Cmax of irinotecan tended to increase proportionally with total dose, and was comparable to studies in other tumour types (see Table). Among 29 pts who received nal-IRI, partial response (per RECIST) was observed in 10 pts. The most related TEAEs (≥ 25%) were diarrhea, nausea, vomiting, hypokalaemia, decreased appetite and fatigue. Stable disease was observed in 5 pts. Conclusions: PK parameters in patients with mBC were comparable to historical studies in patients with other tumour types. The safety profile of nal-IRI monotherapy appeared consistent with gastrointestinal and blood disorders. [Table: see text]