Dose Cohorts Research Articles

Safety and efficacy of first-in-class CXCR1/2 inhibitor SX-682 in combination with pembrolizumab (pem) in patients (pts) with metastatic melanoma (mMEL) with disease progression on anti–PD-1 therapy.

9508 Background: Outcomes for pts with mMEL remain sobering despite access to available immunotherapies as the majority of pts are resistant or become refractory to checkpoint blockade with no approved treatments. CXCR1 and CXCR2 (CXCR1/2) signaling mediate myeloid immunosuppression and MEL growth, inversely correlating with anti-PD-1 response and pt survival. SX-682 is an oral allosteric inhibitor of CXCR1/2. As a single agent, SX-682 increases tumor CD8+ T cell infiltration and inhibits tumor growth in mouse MEL. Methods: This phase 1 dose-escalation with expansion trial (NCT03161431) evaluated pem and escalating doses of SX-682 (25 - 400 mg orally BID) in pts with mMEL in a 21-day cycle. Pts must have had progressive disease (PD) on prior anti-PD-1. Mucosal MEL and asymptomatic brain metastases were allowed. Escalation cohorts had a 21-day SX-682 monotherapy (MONO) run-in. Response assessment by RECIST 1.1 was every 2 cycles during combination (COMBO) treatment. Primary endpoint was safety: adverse events (AEs), dose-limiting toxicity (DLT) and maximally-tolerated dose (MTD). Secondary endpoints included objective response rate (ORR; complete [CR] + partial [PR] response), disease control rate (DCR; CR + PR + stable disease [SD]) and overall survival (OS). Results: As of October 2023, 51 pts were enrolled and treated; median age of 65 (range 24-91), 55% male, 61% elevated LDH, 39% BRAF mutated. All pts received prior anti-PD-1, 37 (73%) received combined anti-PD-1 and anti-CTLA-4, and 23 (45%) had ≥ 3 prior therapies. Steady-state blood SX-682 was dose-proportional. No MONO DLT or MTD was identified. The 200 mg dose cohort was expanded in COMBO based on safety and pharmacodynamics: mg BID dose (n) = 25 (3), 50 (3), 100 (6), 150 (8), 200 (31). Any grade and grade 3/4 treatment-related AEs (TRAEs) occurred in 75% and 43%, respectively, and discontinuation (DC) due to TRAEs in 20% (when uncomplicated neutropenia, a permitted effect from CXCR2 inhibition on bone-marrow trafficking, was excluded there were 25% grade 3/4 TRAEs and 12% DC [rash, transaminitis]). There was no infectious signal. At the 200 mg dose, the ORR was 21% in 19 evaluable pts (4 PR + 0 CR) and the DCR was 63% (8 SD + 4 PR). DCR significantly depended on SX-682 dose ( P vs. ≤100 mg): 0% (0/9) at ≤100 mg, 50% (3/6) at 150 mg ( P = 0.0440) and 63% (12/19) at 200 mg ( P = 0.0028). All 15 pts with disease control had progressed on anti-PD-1 and anti-CTLA-4. Median OS was longer in pts in the 200 mg cohort (14.7 months; 95% CI, 10.5 – NR [not reached], n = 31) than in pts treated with ≤100 mg SX-682 (7.4 months; 95% CI, 5.0 – NR; n = 10). Conclusions: SX-682 combined with pem had a tolerable safety profile and activity reflected by objective responses and clinically meaningful disease control in heavily pretreated mMEL pts with progression on anti-PD-1 and anti–CTLA-4. Clinical trial information: NCT03161431 .

Preliminary data of a phase Ib/II trial evaluating the efficacy and safety of adebrelimab, camrelizumab plus apatinib as first-line therapy in patients with advanced hepatocellular carcinoma.

e16221 Background: The CARES-310 study has demonstrated that the combination of the anti-PD-1 antibody camrelizumab and the VEGFR2 tyrosine kinase inhibitor apatinib exhibits improved progression-free survival (PFS) and overall survival (OS) in patients with advanced hepatocellular carcinoma (HCC). We conducted this study to investigate whether the addition of the anti-PD-L1 antibody adebrelimab to camrelizumab and apatinib would further improve clinical outcomes. Methods: This is a prospective, phase 1b/2 clinical trial employing the i3 + 3 dose escalation design. Eligibility includes adults with unresectable or metastatic HCC, a ECOG PS of 0 or 1, a Child-Pugh score ≤ 7, and at least one measurable lesion per RECIST v 1.1. In phase 1b, patients (pts) received adebrelimab (10 mg/kg or 20 mg/kg, I.V., D1, Q3W), camrelizumab (200mg, I.V., D1, Q3W), and apatinib (250 mg orally daily). Phase 2 is a single arm, open-label trial in the first-line setting. The primary objective were dose-limiting toxicity (DLT), maximal tolerated dose (MTD), and recommended phase II dose (RP2D). With α = 0.05 and 80% power, the pts needed for stage I and total of the Simon 2-stage design was 17 and 41 pts, respectively. Results: As of 4 February 2024, 6 HCC pts progressed after or were intolerant to first-line treatment (systemic therapy ± surgical resection) were treated in 1 dose cohorts. 1 DLT occurred (Grade 3 elevated blood bilirubin increased). The RP2D was adebrelimab (10 mg/kg), camrelizumab (200mg), and apatinib (250 mg). The most common drug-related AEs were Hypertension (83.3%) and Rash (50%); and Serum amylase increased, Itching, ALT/AST increased, and Hypothyroidism (each 33.3%). Immune-related AEs were similar to those seen with other checkpoint blockade agents. No drug-related AEs led to death. 1 pts (16.7%) discontinued due to drug-related AEs. Conclusions: The combination of Adebelimumab, Camrelizumab, and Apatinib demonstrated manageable safety for unresectable HCC. Enrollment in the phase II trial is ongoing and updated clinical data will be presented. Clinical trial information: NCT05924997 .

A first-in-human study of the potent and highly selective BTK degrader ABBV-101 in patients with relapsed/refractory B-cell malignancies.

TPS7091 Background: Bruton tyrosine kinase (BTK) is a clinically validated target with an integral role in the proliferation and survival of neoplastic cells in several B-cell malignancies. Inhibitors of BTK, such as ibrutinib, have revolutionized the treatment landscape for B-cell malignancies. However, long-term use can lead to disease progression and clinical resistance associated with mutations in BTK. ABBV-101 is a reversible BTK degrader. By preclinical kinome profiling, ABBV-101 has demonstrated high selectivity with the potential for best-in-class AE profile. ABBV-101 has also shown potent activity against BTK wildtype and multiple therapy-resistant mutant forms. Degradation eliminates BTK scaffolding and enzymatic functions, which has led to deeper, more durable responses vs covalent and reversible BTKi in animal models (Pan C, et al. ASH 2023). Herein, we describe the first-in-human study of ABBV-101 monotherapy in patients with relapsed/refractory B-cell NHL. Methods: This international phase 1, open-label, multicenter study (NCT05753501) is evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary efficacy of ABBV-101. Eligible patients(≥18 years) have measurable disease, received ≥2 prior systemic therapies, and have no available therapies known to provide clinical benefit.Primary objectives are to characterize safety and tolerability of ABBV-101; secondary objectives are to evaluate PK and preliminary efficacy. The study is conducted in 2 parts: dose escalation (part 1) and dose expansion (part 2). Part 1 aims to establish the maximum administered dose and maximum tolerated dose of ABBV-101 guided by a Bayesian optimal interval design; additional patients may be enrolled to a previous dose level to further explore safety, PK, and efficacy. Patients with WHO-defined chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, follicular lymphoma, marginal zone lymphoma, lymphoplasmacytic lymphoma (including Waldenström macroglobulinemia), and transformed indolent NHL (including Richter’s transformation) are eligible. Part 2 will further characterize the safety and preliminary efficacy of ABBV-101; patients diagnosed with CLL/SLL (up to 3 dose cohorts) and non-germinal center DLBCL (1 cohort) are being enrolled. ABBV-101 is administered orally until disease progression, intolerable toxicity, or other study discontinuation criteria are met. Safety assessments include, but are not limited to, AEs, clinical laboratory parameters, vital signs, and ECG. Response evaluations are performed per disease-specific response criteria at screening and every 8 weeks (1st year), 3 months (2nd year), or 4 months (3rd year onward) until progressive disease. Enrollment is ongoing with active sites in the US and Japan. Clinical trial information: NCT05753501 .

Updated results from a phase 1/2 study of HPN328, a tri-specific, half-life (T1/2) extended DLL3-targeting T-cell engager in patients (pts) with small cell lung cancer (SCLC) and other neuroendocrine cancers (NEC).

8090 Background: Delta-like canonical Notch ligand 3 (DLL3) is highly expressed on the cell surface of neuroendocrine carcinomas, which have few approved treatment options in the refractory, metastatic setting. HPN328 is DLL3-targeting T-cell engager. HPN328 has 3 binding domains including anti-DLL3 for target engagement, anti-albumin for half-life extension, and anti-CD3 for T cell engagement and activation. Methods: Pts with relapsed/refractory, metastatic SCLC, neuroendocrine prostate cancer (NEPC) and other NEC associated with DLL3 expression are eligible. Primary objectives are safety, maximum tolerated dose (MTD) and pharmacokinetics (PK). Secondary objectives are immunogenicity and efficacy. Overall response rate (ORR) is determined using modified RECIST v1.1 to include extracranial response assessment for pts treated with radiotherapy for brain metastases while on treatment. HPN328 is administered IV QW or Q2W with priming dose preceding target dose in higher dose cohorts. Results: As of January 5, 2024, 86 pts received HPN328 doses of 0.015-24 mg across 14 cohorts (SCLC [n = 54;63%]; other NEC [n = 32;37%]). The median (range) number of prior regimens was 3 (1-7); 83% previously received a PD-1/PD-L1 blocker. Treatment is ongoing in 24 of 46 (52%) pts in the dose optimization cohorts (1 mg priming dose with 12 or 24 mg target doses QW or Q2W). Treatment-related AEs in ≥ 10% of pts included CRS (59% [30% G1, 26% G2, 3% G3+]), dysgeusia (36%), fatigue (34%), diarrhea (19%), nausea (17%), vomiting (14%), decreased appetite and decreased neutrophil count (13% each), and weight decreased (11%). No G3-4 CRS was seen at target doses. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 9% of pts, all G1-2. The maximum tolerated priming dose was 1 mg; dose escalation of target dose continued up to 24 mg QW without reaching a maximum tolerated target dose. Among efficacy evaluable pts treated in dose optimization cohorts, the confirmed ORR in SCLC was 50% (12/24), with one complete response (CR). In NEC (other than NEPC) the confirmed ORR was 44% (4/9), with one CR. Four of eleven pts with NEPC had unconfirmed PRs in 1 mg priming dose cohorts, with 5 NEPC pts remaining on treatment > 20 weeks. HPN328 exhibited linear PK with dose-proportional increases in exposure and a median T1/2 of 71 hrs. Transient increases in cytokines up to 24 hrs post-dose and T-cell activation were observed. Conclusions: HPN328 is well tolerated and clinically active in SCLC, NEC, and NEPC. Current dose optimization cohorts have completed enrollment and data continue to mature; selection of a recommended phase 2 dose will be made based upon complete mature data. Updated safety and efficacy results will be presented. Clinical trial information: NCT04471727 .

Durable complete response and overall survival in patients with heavily pretreated, poor-prognosis non-Hodgkin lymphoma to immunoactivating AVM0703 with few and mild drug-related adverse effects.

7077 Background: In 2022, the majority of new cancer drugs in clinical development are aimed at targets that are already saturated with approved drugs1. This is of concern to patients, payers, sponsor/investors, and regulatory agencies. AVM0703 activates a unique immune response mobilizing an endogenous gamma delta TCR+ and invariant TCR+ bispecific Natural Killer T-like cell (γδTCR+iTCR+NKT) (PCT/US21/19773), that has demonstrated clinical anti-cancer activity against a variety of solid and blood cancers. The potential for AVM0703 to fill a gap in the “no-option” R/R NHL treatment landscape led to the launch of the AVM0703-001 clinical trial (The OPAL Study, NCT04329728). 1) Fougner C et al. Herding in the drug development pipeline. Nat Rev Drug Discov. 2023 Aug;22(8):617-618. Methods: An open-label phase 1 trial evaluating the safety and preliminary efficacy of AVM0703 was completed in patients with hematological malignancies. AVM0703 was administered as a single intravenous (IV) infusion to patients enrolled into a 3+3 dose escalation design. Consolidation therapy of investigator’s choice was allowed, preferably 28 days after AVM0703. For each cohort, 3-6 patients were treated, and dose escalation permitted only after the cohort completed a 7-day dose limiting toxicity (DLT) assessment period with no more than 1 DLT. Patients ≥12 years and >40 kg diagnosed with WHO classified lymphoid neoplasms with R/R disease ineligible for transplant or CAR-T were included. The database has not been formally locked and a cutoff date of Dec 13, 2023, is used for presentation of these Phase 1 results. Results: In summary, 17 patients, 39-86 years of age (median 64) with a median of 4 prior lines (range: 1 to 10) received AVM0703 at 6, 9, 12, 18 and 21 mg/kg. Fifteen (88%) were poor prognosis and 4 had CNS involvement. Only 13 of 17 (76.5%) experienced study-drug related adverse events (AEs) during the DLT period; 15 AEs were grade 1 (78.9%), 2 were grade 2 (10.5%), and 2 were grade 3 (10.5%). The most common AEs were insomnia (N=5), hyperglycemia (N=3), and pruritis (N=2). The total number of All-grade TEAEs recorded in 17 patients was 114 within 30 days post dose, with 98.2% of grades 1-3. Median overall survival (OS) in all dose cohorts was 13.3 months, with 8 of 17 patients alive as of 13 Dec 2023. The recommended Phase 2 dose (RP2D) was determined as 18 mg/kg. For the 18 mg/kg group (N=6), long term durable responses were obtained in 66% (3 CR, 1 PR) with an additional patient converting to late CR, nine months survival was 100%, and median OS has not been reached with follow up between 15.9 and 27.8 months (83% still alive). No safety signals have been identified. Conclusions: RP2D AVM0703, with consolidation therapy at day 28 median (range 7 to 240 days) showed no concerning safety signals and promising long-term survival. Clinical trial information: NCT04329728 .

Final results of a first-in-human phase I dose escalation trial of daily oral zelenirstat, a n-myristoyltransferase inhibitor, in patients with advanced solid tumors and relapsed/refractory B-cell lymphomas.

3082 Background: Myristoylation, the N-terminal modification of proteins with the fatty acid myristate, regulates multiple membrane-bound signal transduction pathways important in cancer cell biology, including Src and Src family of protein tyrosine kinases. This modification is catalyzed by two N-myristoyltransferases (NMT), NMT1 and NMT2. Zelenirstat is a first-in-class oral small molecule NMT inhibitor with strong affinity for both NMT1 and NMT2 proteins. Transcriptomic analysis of zelenirstat treated cell lines identified a myristoylation inhibition sensitivity signature in cancer cells most likely to respond to NMT inhibitor therapy; high sensitivity scores were seen in a range of solid cancers and diffuse large B-cell lymphoma. Based on tumor regression and safety in preclinical models, we hypothesized zelenirstat would be safe to administer and show anticancer activity. Methods: Patients (pts) with advanced solid tumors and relapsed/refractory (R/R) B-cell lymphomas were enrolled in a multicenter, open label, phase I dose escalation trial of oral daily zelenirstat, administered in 28-day cycles until disease progression or unacceptable toxicity (NCT04836195). The primary endpoints were to evaluate dose-limiting toxicities (DLT) to establish a maximum tolerated dose (MTD). Secondary endpoints were to characterize the pharmacokinetic parameters of zelenirstat and assess anticancer activity. Results: Twenty-nine pts (17 females; 12 males; median age 65 years; median prior systemic treatments 4; 25 advanced solid tumor; 4 R/R B-cell lymphoma) were enrolled and 24 pts were DLT-evaluable. Dose cohorts ranged from 20 mg once daily (OD) to 280 mg OD without DLT until the 280 mg cohort where three DLTs were observed: Gr 3 diarrhea, Gr 3 diverticulitis, and Gr 3 dehydration. MTD and recommended phase 2 dose was established at 210 mg OD. Common adverse events were Gr ≤ 2 nausea, vomiting, diarrhea, and fatigue. Plasma concentrations peaked between 1 and 4 hours across the cohorts with terminal half-lives ranging from 6.7 to 12 hours. Steady state was achieved by Day 8 to 15, and in the higher dose cohorts, trough concentrations exceeded the levels predicted to be therapeutic. Stable disease as best response was seen in 8 (28%) heavily pre-treated pts (3 colorectal, 2 ovarian, 1 pancreatic, 1 appendiceal, and 1 bladder). Progression-free survival, overall survival, and weighted health status were significantly better in pts receiving 210 mg OD compared to those receiving lower doses. Conclusions: Zelenirstat is well-tolerated, reaches plasma concentrations highly active in preclinical models, and shows preliminary signs of encouraging anticancer activity. NMT inhibition represents a new target for ongoing research efforts and further clinical development of zelenirstat is warranted. Clinical trial information: NCT04836195 .

Phase 1 Study of JNJ-81201887 Gene Therapy in Geographic Atrophy Secondary to Age-Related Macular Degeneration

ObjectiveTo evaluate the safety and tolerability of a single intravitreal injection of JNJ-81201887 (JNJ-1887) in patients with geographic atrophy (GA) secondary to advanced dry age-related macular degeneration (AMD). DesignPhase 1, open-label, single-center, first-in-human clinical study. SubjectsAdult patients (aged ≥50 years) with GA secondary to AMD in the study-treated eye (treated eye) with a best corrected visual acuity (BCVA) Snellen equivalent of 20/200 or worse in the treated eye (20/80 or worse after the first 3 patients), a total GA lesion size between 5 and 20 mm2 (2-8 disc area), and BCVA of 20/800 or better in fellow, non-treated eye were included. MethodsPatients (N=17) were sequentially enrolled into low (3.56×1010 viral genome [vg]/eye; n=3), intermediate (1.07×1011 vg/eye; n=3), and high (3.56×1011 vg/eye; n=11) dose cohorts without steroid prophylaxis and assessed for safety and tolerability over 24 months. Main Outcome MeasuresSafety and tolerability outcomes included assessment of ocular and non-ocular treatment-emergent adverse events (AEs) over 24 months. Secondary outcomes included GA lesion size and growth rate. ResultsBaseline patient characteristics were consistent with the disease under study, and all enrolled patients had foveal center–involved GA. JNJ-1887 was well tolerated across all cohorts, with no dose-limiting AEs. There were no serious or systemic AEs related to study intervention. Overall, 5/17 (29%) patients experienced 6 events of mild ocular inflammation related to study treatment; exam findings in all resolved, and AEs resolved in 4 of 5 patients following topical steroids or observation. One unresolved vitritis event, managed with observation, occurred in a patient with an unrelated fatal AE. No endophthalmitis or new-onset choroidal neovascularization was reported. GA lesion growth rate was similar among all cohorts over 24 months. For treated eyes in the high-dose cohort, GA lesion growth rate showed continued decline through 24 months, with a reduction in mean square root lesion growth from 0.211 mm at months 0-6 to 0.056 mm at months 18-24. ConclusionsAll 3 studied doses of JNJ-1887 had a manageable safety profile through 24 months of follow-up. Further investigation of JNJ-1887 for the treatment of GA is warranted.

Preliminary results from a phase 1 study of AC699, an orally bioavailable chimeric estrogen receptor degrader, in patients with advanced or metastatic breast cancer.

3074 Background: Endocrine therapy is a critical component of treatment for over 200,000 patients diagnosed yearly with estrogen receptor positive (ER+)/HER2- breast cancer. Although selective ER degraders (SERDs) have improved progression-free survival in this patient population, as monotherapy they have shown very limited overall response rates (ORR). AC699 is a novel chimeric degrader that binds, ubiquitinates and degrades ERα by bringing it into close proximity with an E3 ligase. This mechanism of action may result in greater specificity and more complete target blockade compared to SERDs. Initial results from the ongoing first-in-human dose escalation study of AC699 (NCT05654532) are presented here. Methods: The study employed a 3+3 design, with the option of adding backfill patients to each cohort cleared and deemed safe. Patients must have had locally advanced or metastatic ER+/HER2- breast cancer and received at least 2 prior lines of endocrine treatment, or at least 1 prior line if combined with a CDK4/6 inhibitor. AC699 was administered orally once daily in 28-day cycles. Tumor responses were assessed every 2 cycles using RECIST v1.1 criteria. The relationship between ESR1 mutational status and anti-tumor activity was investigated as an exploratory analysis. Results: A total of 22 patients had received AC699 in 3 dose cohorts (100, 200 and 300 mg) at the time of data cutoff. The median age was 61 years and the median lines of prior therapy was 5 (range 2-10). Prior treatments included CDK4/6 inhibitor (100%), aromatase inhibitor (91%), fulvestrant (82%), novel oral SERD or covalent antagonist (SERCA) (23%), and ER chimeric degrader (14%). Eighteen patients had measurable disease while 4 had bone lesions only. There were no dose-limiting toxicities, dose reductions or discontinuations for treatment-related AEs, and the maximum tolerated dose was not reached. The most common treatment-emergent AEs were fatigue (23%), dehydration (18%) and nausea (18%). All treatment-related AEs were Grade 1 or 2, including nausea (18%) and hot flushes (14%). Fifteen patients had at least 1 scan before the data cutoff date and of these, 3 were not evaluable for ORR due to having bone lesions only. Among the 12 evaluable patients, 4 (33%) achieved partial response: 3 confirmed and one unconfirmed. The clinical benefit rate (CBR) which also includes patients with stable disease ≥24 weeks was 42% (5/12). In the subgroup of evaluable patients harboring a confirmed ESR1 mutation, the ORR was 67% (4/6), the CBR was 83% (5/6) and the median time on treatment was 168 days (range 56-336), with 4 of 7 patients still receiving AC699. Conclusions: Preliminary data from the ongoing phase 1 trial evaluating AC699 indicate promising safety, tolerability, and anti-tumor activity, at doses up to 300 mg orally once daily. A phase 2 study will begin enrolling in early 2024. Clinical trial information: NCT05654532 .

Intralesional nivolumab in oral potentially malignant disorders: A phase 1 pilot study on safety, tolerability, and preliminary efficacy.

6016 Background: Oral Potentially Malignant Disorders (OPMD) encompass a diverse group of oral mucosal diseases, including the prevalent oral leukoplakia (OL), serving as precursors to invasive oral squamous cell carcinoma. OPMD exhibits an annual malignant transformation rate up to 36%. Despite the breadth of research on OPMD the standard-of-care remains surgery or observation. We aim to evaluate the safety and tolerability of intralesional injections of Nivolumab in patients with OPMD. Secondary objectives include assessing objective response rate and pathologic complete response rate. We describe the results of an immune prevention trial designed to avoid systemic toxicities of immunotherapy in patient with pre-malignancy by administrating aPD1 intralesionaly. Methods: Phase 1, single-arm, open-label, dose-escalation pilot study that involves intralesional injections of Nivolumab (index lesion) in patients with high-risk OPMD lesions every 3 weeks (total of 4 doses, 12 weeks). Non-index, non-injected, oral lesion(s) were also documented and monitored. The study includes two dose cohorts (10 mg and 20 mg) to assess maximally tolerated dose with a 3 + 6 dose-escalation design. Adverse events were reported according to NCI CTCAE Version 5.0. Serial biopsies at baseline and up to 8 weeks after treatment were taken to assess efficacy using a composite score (i.e., size and degree of dysplasia) in index lesion. Major response was defined as >80% decrease in score; partial response as 40%-80% decrease. Freshly frozen tumors were subjected to RNA sequencing and gene pathway analysis to identify biomarkers of response or progression. Results: At the time of data analysis, 13 patients have completed treatment (61.5% males), both dose levels were well tolerated. The adverse event grades ranged from grade 1 (i.e. diarrhea, elevated LFT and skin rash) constituting the majority at 80.5% of reported adverse events, grade 2 (i.e. skin rash, cellulitis) at 13.9%, and grade 3 (i.e. hypertension) at 5.6%. Ten patients had multifocal disease. Major response was observed in 22.5% and partial response in 50% of the patients. One patient progressed to invasive SCC in a non-index lesion. RNA sequencing based immune phenotyping revealed increased infiltration of CD8 cytotoxic T cells in index lesions after treatment. Pathway analysis revealed significant alterations in immune pathways including Th1 and Th2 pathways, Natural killer and immunoregulatory pathways. Spatial transcriptome analysis and pharmacokinetics data are pending. Conclusions: Intralesional nivolumab is well tolerated in OPMD with suggested potential biological and clinical activity. A randomized phase II trial to assess cancer free survival is recommended to determine the efficacy in preventing cancer progression. We recommend dose of 20mg for phase II as it was well tolerated. Clinical trial information: NCT05327270 .

EMITT-1: Proof-of-mechanism immunopeptidome (ImPD) effects at target PK exposure, in a phase 1 study of GRWD5769 (a first-in-class inhibitor of Endoplasmic Reticulum Aminopeptidase 1 [ERAP1]) in patients with solid malignancies.

2589 Background: GRWD5769 is a first-in-class, orally bioavailable ERAP1 inhibitor that significantly modulates the peptide repertoire displayed on MHC-1 on tumor cells, driving novel T cell response and causing tumor cell killing in preclinical studies. This unique approach has potential to overcome central mechanisms of immune resistance by driving de-novo recognition of previously hidden tumor neoantigens and addressing T cell exhaustion. Here we report initial safety, pharmacokinetic (PK) and pharmacodynamic (PD) endpoints from Part A (monotherapy dose escalation) in the ongoing multicentre, modular phase I dose escalation study (ACTRN12623000108617). Methods: Patients with advanced refractory solid tumors are enrolled using a BOIN escalation design. GRWD5769 is administered BID on days 1-14 during 21-day cycles. The first cycle is the dose-limiting toxicity (DLT) observation period. The PK / PD relationship of GRWD5769 is being evaluated using mass spectrometry analysis of the ImPD. Tumor responses are evaluated by RECIST v1.1 / iRECIST. Results: As of 03 January 2024, a total of 12 patients had been treated with GRWD5769 in 3 dose cohorts (25 mg, 50 mg, 100 mg BID). On average patients have remained on treatment for 4 cycles (range 1-10) No Serious Adverse Reactions, DLTs, immune related AEs or deaths were reported. Two Gr 3 serious adverse events have occurred in 2 treated subjects (aspiration pneumonia and Urinary Tract Infection, neither attributable to GRWD5769). Gr 1+2 AEs were infrequent and manageable. PK analyses for the first 3 cohorts show dose proportional plasma levels, with Tmax at ~3 h and a ~8 h Thalf. The minimum biologically active dose (MBAD) is defined as an average steady state plasma concentration above the IC50 for ERAP1, which was achieved at the 100 mg BID dose level. PD data shows dose-dependent target engagement, with marked shifts in the ImPD. This is consistent with the expected mechanistic effects of ERAP1 inhibition seen in preclinical models and is the first demonstration that the human ImPD can be manipulated pharmacologically in cancer patients, potentially allowing T cells to recognise new targets on tumors. Dose escalation with GRWD5769 monotherapy continues to determine the recommended phase 2 dose (RP2D). GWRD5769 in combination with Immune Checkpoint Inhibition will be investigated in Part B now that the MBAD has been reached. Conclusions: GRWD5769 has been well tolerated at doses up to 100 mg BID. PK / PD data support dose-dependent target engagement of ERAP1. Proof of mechanism has been achieved for this first-in-class therapy, and this is the first demonstration that the human ImPD can be manipulated pharmacologically in cancer patients. Further PD analyses will explore shifts in the T cell repertoire and modulation of immune cell phenotypes. Clinical trial information: ACTRN12623000108617.

An open-label, multicenter, phase 2 study to evaluate the safety and efficacy of BB-1701, a novel antibody drug conjugate (ADC) targeting human epidermal growth factor receptor 2 (HER2), in previously treated patients with HER2-positive (HER2+) or HER2-low unresectable or metastatic breast cancer (BC).

TPS1122 Background: Treatment options for patients (pts) with unresectable or metastatic BC have improved with the development of novel targeted therapies including trastuzumab deruxtecan (T-DXd), an ADC directed against HER2 with a cytotoxic topoisomerase I inhibitor as a payload. Currently, there are limited treatment options for pts with HER2+ or HER2-low metastatic BC that has progressed on T-DXd. BB-1701 is an ADC consisting of a monoclonal antibody targeting HER2 with eribulin (microtubule inhibitor) as a payload that is capable of exerting a bystander effect. A first-in-human dose-finding Study 101 of BB-1701 is ongoing. Here we describe Study 205, an open label, multicenter, phase 2 study of BB-1701 in pts with HER2+ or HER2-low unresectable or metastatic BC who have disease progression after treatment with T-DXd. Methods: Study 205 (NCT06188559) includes dose-optimization and dose-expansion parts for BB-1701. Eligible pts must have histologically confirmed HER2+ or HER2-low, unresectable or metastatic BC, with measurable disease per RECIST v1.1. Prior treatment must include 1–3 prior chemotherapy-based regimens for unresectable or metastatic BC, including T-DXd. The primary objectives of the dose-optimization part include determining the recommended dose (RD) and evaluating safety and tolerability of BB-1701. The RD will be assessed by randomly assigning ~50 pts into 1 of 3 dosing cohorts (1.6 mg/kg on day 1 Q3W, 0.8 mg/kg on days 1 and 8 Q3W, and 1.2 mg/kg on day 1 Q3W; IV) in a 2:2:1 ratio. Randomization will be stratified by HER2 status (HER2+ vs. HER2-low) documented prior to T-DXd treatment. The dose-expansion part will enroll ~85 pts at RD; the primary objective includes evaluating the efficacy of BB-1701 at the RD. In both study parts, secondary objectives include assessment of additional efficacy measures (i.e., duration of response [DOR], progression free survival [PFS], overall survival [OS], disease control rate [DCR], clinical benefit rate [CBR], and time to response [TTR]), and pharmacokinetics. Efficacy endpoints will be assessed per RECIST v1.1 by the investigator during the dose-optimization part or by Blinded Independent Central Review during the dose-expansion part. Safety assessments will consist of recording, monitoring, and grading of adverse events (AEs) based on CTCAE v5.0, AEs of special interest, and serious AEs. In both study parts, exploratory objectives will include evaluation of biomarkers of response to BB-1701 and BB-1701 immunogenicity; other efficacy measures (i.e., PFS on the next line of therapy) and population pharmacokinetics will be analyzed in the dose-expansion part only. Pt enrollment is currently open. Clinical trial information: NCT06188559 .

The FIPO23 trial: First-in-human phase I/II study of XON7 in advanced solids tumors.

TPS2673 Background: XON7 is a first-in-class glyco-humanized polyclonal antibody (GH-pAb) targeting selectively multiple tumor-associated antigens. XON7 induces tumor cell apoptosis and promotes the elimination of tumor cells by immune effector cells through CDC (Complement Dependent Cytotoxicity) and ADCP (Antibody-Dependent Cell Phagocytosis). XON7 demonstrated anti-tumor efficacy in mice xenograft models with human solid tumors such as colon, prostate, lung and triple negative breast cancers. Safety pharmacology and toxicology studies in non-human primates demonstrated an acceptable safety profile for XON7. Taken together, these preclinical data support the initiation of human trials in patients with advanced solid tumors. Methods: First-in-patient, multicenter, open-label, two phases (dose-escalation (ESC) followed by dose expansion (EXP)) study of XON7 single agent, in patients with relapsed refractory, locally advanced or metastatic solid tumors without standard available treatments ( NCT06154291). Key eligibility criteria include disease progression after ≤ 4 lines of therapy; age > 18 years; ECOG performance status ≤2; adequate organ functions; no known CNS involvement. All advanced or metastatic tumor types except glioblastoma, can be included during ESC. Primary endpoints: safety, tolerability and determination of MTD/RP2D. Secondary endpoints: pharmacokinetics (PK), pharmacodynamics, immunogenicity and preliminary anti-tumor activity (RECIST 1.1). AEs graded according to CTCAE 5.0. In the ESC part, XON7 is administered as 60-min intravenous infusion every 2 weeks according to an escalating schedule of doses from 1.5 to 20 mg/kg for up to 12, 28-day cycles. Dose escalation/de-escalation is based on the Bayesian Optimal Interval (BOIN) design, up to 45 pts are planned. At the recommended dose, up to 7 EXP cohorts (30 pts each) defined according to the primary tumor site are planned. Bayesian sequential monitoring will be used. Patient recruitment is planned or ongoing at 25 sites worldwide. Results: As of Feb 3rd, 2024, 3 pts are enrolled in the first dose cohort and have received XON7 at dose 1,5 mg/kg Q2W for the first 28-days cycle. Conclusions Accrual is ongoing in this first-in-human trial of XON7. Clinical trial information: NCT06154291 .

A phase I dose escalation trial of BCD-145 in patients with unresectable or metastatic melanoma.

9526 Background: BCD-145 (nurulimab) is a fully human IgG1 mAb with modified Fc-fragment (the 1st Gln is replaced by Glu in the heavy chain sequence, and there is no terminal dipeptide composed by Gly and Lys residues) that binds to cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and blocks the interaction between CTLA-4 and its ligands. This allows to stimulate T-cell proliferation, cytokine production and induces antitumor immune response. Here we present the results of multicenter open-label single-arm multi-cohort phase I trial of pharmacokinetics (PK), pharmacodynamics (PD), safety, and immunogenicity of BCD-145 in pts with unresectable/metastatic melanoma (unr/mM). Methods: BCD-145 monotherapy in 3+3 dose escalation [0.1, 0.3, 1, 3, 10 mg/kg intravenously Q3W] was given to 15 pts with unr/mM with measurable disease, who had failed prior therapy, ECOG 0-2. Pts with brain mts, previous therapy with aCTLA-4 and/or aPD-1/PD-L1 drugs were not allowed. The main objective of the study was to evaluate PK, PD, tolerability, immunogenicity, safety, dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) identification. Secondary objectives included tumor response rate (irRECIST). Results: BCD-145 proved safety and overall was well tolerated. DLT and MTD were not reached. Any grade (Gr) adverse events (AEs) occurred in 100% (15/15) of pts. 33.3% (5/15) of pts had AE/SAE of Gr 3-4, including hypertension Gr 3 (1 at 1 mg/kg), hypercalcemia Gr 4 (2 at 1 mg/kg), hypokalemia Gr 3 (2 at 1 mg/kg), neutropenia Gr 3 (1 at 0.3 mg/kg), anemia Gr 3 (1 at 1 mg/kg), lung infection Gr 3 with hospitalization (1 at 1 mg/kg). Only 2 pts had a treatment-related AE Gr 3-4. Immuno-related AE were identified in 46.7% (7/15), manifested by symptoms of thyroiditis (mainly Gr 1) and diarrhea Gr 2 (1 at 10 mg/kg). There was 1 death (at 1 mg/kg) due to progression. There is dose-dependent peak study drug serum concentrations and systemic exposure. Two dosage regimens (1 mg/kg, 3 mg/kg Q3W) allowed to achieve the optimal concentration. BCD-145 increased subpopulations of activated HLA-DR+ CD4+ and CD8+ T lymphocytes, CD4+ICOS+ T-lymphocytes, absolute lymphocyte counts in all cohorts without significant differences. Binding and neutralizing Abs against BCD-145 were detected in 2 pts from different dose cohorts (0.3 mg/kg, 1 mg/kg). PR and SD were registered in 2 pts of each response group. 30.8% of pts achieved disease control, which is consistent with published data on other CTLA-4 inhibitors. A dose of 1 mg/kg is determined as recommended phase 2 dose (RP2D). Conclusions: BCD-145 demonstrated a tolerable safety profile and preliminary anti-tumor activity in pts with unr/mM. Anti-tumor effects of BCD-145 were observed in pts who had progressed on prior treatment. Further co-targeting PD-1 and CTLA-4 simultaneously will achieve a better anti-tumor activity due to cooperative binding to exhausted T-cell subsets. Clinical trial information: NCT03472027 .

A phase 1, multi-center, safety, feasibility, and preliminary efficacy study evaluating a single dose of UNO101 in relapsed or refractory, unresectable, primary, or metastatic cutaneous and subcutaneous malignancies.

TPS2686 Background: Tumor ablation is a minimally invasive technique commonly used to treat solid tumors in the liver, kidney, bone, and lung and is usually based on thermal and nonthermal approaches. Local and in-situ tumor ablation methods demonstrate enhanced anti-tumor immune responses resulting in the destruction of residual malignant cells in primary tumors and distant metastases. Nitric oxide (NO) is a colorless gas and a short-lived free radical. It is a ubiquitous, endogenously generated gas implicated in the homeostatic regulation of physiological processes. Preclinical studies evaluating the effect of high concentration exogenously administered NO demonstrated its anti-cancer properties and suggested that it may serve as a potent tumoricidal agent. We have previously shown that treating mouse colon carcinoma (CT26) tumor-bearing mice with ultra-high concentrations of nitric oxide (UNO101) upregulates innate and adaptive immune cells both locally and systemically. Beyond Cancer is currently conducting a first-in-human, first-in-class, Phase 1 safety, feasibility, and preliminary efficacy clinical study of UNO101 at multiple institutions in Israel. Methods: The study is a 2-part Phase 1 trial with a Dose Escalation and a Dose Expansion portion (NCT05351502). A conventional 3+3 dose escalation will evaluate three cohorts of UNO101 single dose: 25,000, 50,000 and 100,000 parts per million (PPM) delivered intratumorally over 5 minutes in subjects with an ECOG PS of 0–3, at least 3 months of life expectancy, with relapsed or refractory unresectable primary or metastatic cutaneous and subcutaneous measurable solid tumors being eligible for enrollment. Upon determination of the maximum tolerated dose or biological effective dose, whichever occurs first, the proposed recommended Phase 2 dose will be further evaluated in the Dose Expansion portion of the study. RECIST version 1.1 and iRECIST will be utilized to assess the rate of malignant tumor response after UNO administration and toxicity will be graded per NCI CTCAE version 5.0. Evaluation of response per itRECIST will also be explored. Up to thirty-eight enrolled subjects are anticipated. Cohort 1, 25,000 PPM have been completed without a reported DLT. Enrollment to Cohort 2, 50,000 PPM, began in January 2024. This study was approved by Israel Ministry of Health (IMOH) as well as the participating institution’s Ethics Board. Written informed consent was obtained for all enrolled subjects and a copy of the written consent is available for review. Clinical trial information: NCT05351502 .

Phase 1 dose escalation and cohort expansion study evaluating safety, PK, PD and clinical activity of STC-15, a METTL-3 inhibitor, in patients with advanced malignancies.

2586 Background: RNA modifications are involved in cancer initiation and progression. The most abundant modification of mRNA is m6A generated by METTL3. Inhibition of METTL3 causes double-stranded RNA formation and activation of cellular T1 IFN response. IFN signaling induces IFN-stimulated gene families i.e. IFIT and OAS, characteristic of an anti-viral response, and secretion of cytokines and chemokines. STC-15, a first in class small molecule inhibitor of METTL3 developed by Storm Therapeutics, demonstrated in pre-clinical models, activation of IFN signaling and remodeling of the TME towards pro-inflammatory state. We report the dose escalation results from a FIH trial in patients with advanced malignancies. Methods: This is a multi-center, open-label, dose escalation study. STC-15 oral capsules are administered daily or t.i.w. in 21-d treatment cycles. Dose escalation follows 3+3 modified Fibonacci regimen. Primary objectives are safety and PK. Secondary objectives are preliminary evidence of anticancer activity and RP2D. Exploratory objectives are PD (i.e. target engagement and immune activation biomarkers) and correlation of primary pharmacology with observed clinical efficacy. Results: As of 02/01/2024, 31 patients enrolled across 4 dose levels and 5 cohorts: 60mg QD (6 pats), 60mg t.i.w. (3 pats), 100mg t.i.w. (14 pats), 160 mg t.i.w. (5 pats) and 200mg t.i.w. (3 pats). PK profile supports t.i.w. dosing. A total of 169 AEs were observed with 45 AEs attributed to STC-15 treatment. AEs were manageable, mostly hematology (thrombocytopenia 31%; 4% Grade 3), skin (pruritis, rash 14% G1/2) and GI (N/V and diarrhea 14% G1/2). 12 SAEs occurred; 1 pt (60mg QD) had DLT with G3 pneumonitis. Of 14 patients with at least 1 on-treatment scan, DCR is 78% with 2 confirmed PR ongoing in angiosarcoma (60mg, 32 weeks) and IO-refractory NSCLC (100mg, 33 weeks) and 9 SD. An average of 63% reduction in m6A on mRNA in peripheral blood within the first 24h post dosing was observed in 60mg cohorts, confirming target engagement. Whole blood Nanostring and pathway analysis of gene expression confirms upregulation of innate immune pathways (i.e. T1,2 IFN activation and anti-viral responses) as early as 8h after first dose and throughout the treatment cycle. Updated PK/PD and clinical data will be presented. Conclusions: Treatment with STC-15 is well tolerated across pharmacologically active dose range with encouraging signs of clinical activity. Early biomarker data provide proof of mechanism in target engagement, strong activation of innate immune responses and correlation of pharmacological activity with clinical response. The study is ongoing and expansion cohorts are underway to further evaluate PK/PD, safety and clinical efficacy at optimized pharmacologically active doses. Clinical trial information: NCT05584111 .

A phase I/II open-label clinical trial of CPI-613 in combination with modified FOLFIRINOX in patients with locally advanced (LAPC) or borderline resectable pancreatic cancer (BRPC).

4172 Background: Pancreatic ductal adenocarcinoma (PDA) carries a poor prognosis with a 5-year relative survival rate of 13%. Surgical resection is the only curative treatment option, but less than 20% of patients are eligible at diagnosis. A subset of patients with locally advanced disease can become candidates for resection with neoadjuvant (NA) therapy. mFOLFIRINOX is the standard of care in the adjuvant setting, with extrapolated data supporting its use in the NA setting. CPI-613/Devimistat (D) is a small molecule that targets mitochondrial metabolism in tumor cells leading to ROS-mediated apoptosis. A phase III trial of mFOLFIRINOX + D at 500 mg/m2 in metastatic PDA did not meet primary endpoint of overall survival (OS). Here we present the results of the combination’s use at standard and escalated doses in LAPC and BRPC. Methods: In this investigator-initiated, single-center, phase I/II, open-label trial treatment-naïve patients with investigator assessed LAPC or BRPC were treated with mFOLFIRINOX in 14 day cycles + D. In the standard dosing (SD) cohort, patients received D at 500mg/m2 while in the dose escalation (DE) cohort; D at 750 mg/m2 or 1000 mg/m2 was used. Radiographic response was assessed every 8 weeks. Patients who remained unresectable after 12 cycles could receive additional standard treatments, including chemoradiotherapy. The primary endpoint was median overall survival (mOS), with the study powered to show a mOS improvement from the historical standard of 14 months to 28 months with mFOLFIRINOX + D. Secondary endpoints were median progression free survival (mPFS), percent resected, and safety outcomes. NCT03699319 Results: Between Dec 2018 and Mar 2022, 37 patients and 11 patients enrolled in the SD and DE cohorts. Median age 69 years (range 47-78), male/female (27/21), Caucasian (83%), LAPC/BRPC (34/14). One patient (2%) withdrew, 4 patients (8%) discontinued treatment due to toxicity, 9 patients (19%) had progressive disease prior to completion of 12 cycles. In all patients mOS was 16.3 months and mPFS was 10.7 months. By cohort: SD/DE mOS: 16.2/17.6 months (p=0.56). Fourteen patients (29%) had partial response by RECIST 1.1. Twenty patients (41.7%) had resection; mOS 29.7 months. In the SD cohort, 78% and 24% of patients had grade 3 and/or 4 AEs. There were no dose limiting toxicities (DLT) in the DE cohort, and eight patients received the maximum dose of 1000 mg/m2 of D. After the DLT period, 100% patients in DE cohort had grade 3 toxicity and 55% had grade 4 toxicity. For all the most common toxicities (gr3,4) were neutropenia (27%,25%), diarrhea (25%,0), anorexia wt. loss (23%,0), nausea/vomiting (23%,0). Conclusions: The combination of mFOLFIRINOX and D is feasible in the LAPC/BRPC population at increased dose levels of D; however, it did not meet the primary endpoint of doubling OS compared to historical controls. Clinical trial information: NCT03699319 .

Anti-TNFR2 monoclonal antibody LBL-019 in patients with advanced malignant tumors: A phase I, first-in-human, open-label, multicenter, dose escalation Study.

e14580 Background: LBL-019 is a humanized monoclonal IgG1 antibody against TNF receptor 2 (TNFR2). It specifically binds to TNFR2 with high affinity, co-stimulates TNFR2 in Fc crosslinking-dependent manner, results in activation of NF-κB signaling and T cell activation and expansion, promoting antitumor immunity. Here we report the preliminary safety and efficacy of LBL-019 in patients with advanced malignant tumors. Methods: This is a phase Ⅰ, open-label, multicenter, dose-escalation study to evaluate the safety, tolerability, and PK of LBL-019 in patients with advanced solid tumors that progressed after standard systemic therapy. The dose escalation phase consists of 7 dose cohorts of LBL-019 at 0.2, 0.8, 3, 10, 15, 20, and 30 mg/kg (iv Q2W), using accelerated titration design (first dose) followed by 3+3 design. The primary endpoints were tolerability and safety. The second objectives were pharmacokinetics, pharmacodynamics, and preliminary efficacy (per RECIST 1.1). Results: As of January 02, 2024, 26 patients [17 (65.4%) male, median age 57 years (range:27, 72), 22 (84.6%) ECOG score of 1] were treated in phase Ⅰ. Tumor types include 7 (26.9%) hepatocellular carcinoma (HCC), 4 (15.4%) melanoma, and 15 (57.7%) other tumors. 19 (73%) previously received anti-PD(L)-1 treatment. During the study, no DLT was observed, and the MTD was not reached. The median follow-up was 12.2 months (95%CI: 7.5, 15.9). 19 patients (73.1%) experienced TRAEs of all grades, with 2 (7.7%) having grade ≥3 TRAEs. The most common TRAEs (≥10%) included lipase increased (19.2%), anaemia (19.2%), aspartate aminotransferase increased (15.4%), pruritus (11.5%), rash (11.5%). Treatment interruption and permanent discontinuation due to TEAEs occurred in 12 (46.2%) and 1 (3.8%) patient, respectively. Thirteen patients (50.0%) experienced SAEs, and one of SAE was related to treatment. Out of 23 who underwent efficacy evaluation, 1 patient with HCC achieved PR, and 7 patients achieved SD. The patient with PR and 6 patients with SD received prior immunotherapy, the ORR and DCR were 4.3% and 34.8%, respectively. The DoR in the patient with PR has exceeded 10 months. Conclusions: LBL-019 is well tolerable and has demonstrated preliminary efficacy in patients with advanced malignant tumors. Clinical trial information: NCT05223231 .

Phase 1 Open-Label Study of Omigapil in Patients With LAMA2- or COL6-Related Dystrophy.

Omigapil is a small molecule which inhibits the GAPDH-Siah1-mediated apoptosis pathway. Apoptosis is a pathomechanism underlying the congenital muscular dystrophy subtypes LAMA2-related dystrophy (LAMA2-RD) and COL6-related dystrophy (COL6-RD). Studies of omigapil in the (dyw/dyw) LAMA2-RD mouse model demonstrated improved survival, and studies in the (dy2J/dy2J) LAMA2-RD mouse model and the (Col6a1-/-) COL6-RD mouse model demonstrated decreased apoptosis. A phase 1 open-label, sequential group, ascending oral dose, cohort study of omigapil in patients with LAMA2-RD or COL6-RD ages 5-16 years was performed (1) to establish the pharmacokinetic (PK) profile of omigapil at a range of doses, (2) to evaluate the safety and tolerability of omigapil at a range of doses, and (3) to establish the feasibility of conducting disease-relevant clinical assessments. Patients were enrolled in cohorts of size 4, with each patient receiving 4 weeks of vehicle run-in and 12 weeks of study drug (at daily doses ranging from 0.02 to 0.08 mg/kg). PK data from each cohort were analyzed before each subsequent dosing cohort was enrolled. A novel, adaptive dose-finding method (stochastic approximation with virtual observation recursion) was used to allow for dose escalation/reduction between cohorts based on PK data. Twenty patients were enrolled at the NIH (LAMA2-RD: N = 10; COL6-RD: N = 10). Slightly greater than dose-proportional increases in systemic exposure to omigapil were seen at doses 0.02-0.08 mg/kg/d. The dose which achieved patient exposure within the pre-established target area under the plasma concentration-vs-time curve (AUC0-24h) range was 0.06 mg/kg/d. In general, omigapil was safe and well tolerated. No consistent changes were seen in the disease-relevant clinical assessments during the duration of the study. This study represents the thus far only clinical trial of a therapeutic small molecule for LAMA2-RD and COL6-RD, completed with an adaptive trial design to arrive at dose adjustments. The trial met its primary end point and established that the PK profile of omigapil is suitable for further development in pediatric patients with LAMA2-RD or COL6-RD, the most common forms of congenital muscular dystrophy. While within the short duration of the study disease-relevant clinical assessments did not demonstrate significant changes, this study establishes the feasibility of performing interventional clinical trials in these rare disease patient populations. This study provides Class IV evidence of omigapil in a dose-finding phase 1 study. Clinical Trials NCT01805024.

An open-label, multicenter phase 1 study to characterize safety, tolerability, preliminary antitumor activity, pharmacokinetics, and pharmacodynamics of VIP943 monotherapy in patients with advanced CD123+ hematologic malignancies.

TPS3167 Background: VIP943 is an anti-CD123 antibody-drug conjugate (ADC) with a unique linker cleaved only by legumain and a novel kinesin spindle protein inhibitor payload. The linker-payload was engineered to increase the therapeutic index thereby improving efficacy and reducing severe toxicities compared with current ADCs. In an in vivo MOLM-13 model, VIP943 had statistically significant (p <0.001) improvement in tumor growth inhibition compared with the only ADC approved for the treatment of acute myeloid leukemia (AML), gemtuzumab ozogamicin (GO). In a nonhuman primate (NHP) single dose toxicology study, VIP943 (20 mg/kg) showed no signs of toxicity as measured by hematology, serum chemistry and survival. In contrast, NHP treated with a single dose of GO (3 mg/kg) had significant toxicity including death and mandatory euthanasia. The single-dose toxicity of GO was ameliorated by substituting the VIP943 proprietary linker and payload on an anti-CD33 antibody (3 mg/kg) as measured by hematology, serum chemistry and survival. (1,2). Methods: This trial in progress (NCT06034275) is an open-label, multicenter, Phase 1, first-in-human (FIH), dose-escalation and dose-optimization study of VIP943 in subjects with relapsed or refractory CD123+ hematologic malignancies including AML, myelodysplastic syndrome, and B-cell acute lymphoblastic leukemia. A cycle of VIP943 treatment is 28 days of once weekly intravenous infusions with no pause between cycles. The dose-escalation portion of this study follows a standard 3+3 design. Dose escalation decisions will be made by the safety review committee, and decisions will be based on the incidence of dose-limiting toxicities (DLTs). Based on FDA guidance, a dose-optimization portion of this study will randomize subjects into ≥2 dose cohorts to derive a recommended dose range for Phase 2. The study will also characterize the pharmacokinetics of VIP943 and its components and explore potential biologic activity by assessing pharmacodynamic/exploratory biomarkers, and antitumor activity using standard response criteria. As this is a FIH study, only subjects with CD123+ hematologic malignancies who have exhausted all available therapies or are not fit for standard of care can be enrolled. The results from this study will form the basis for decisions for future studies. Enrollment for cohorts 1 (no DLTs) and 2 (safety review ongoing) has completed. 1. Stelte-Ludwig et al ASH 2022. 2. Stelte-Ludwig et al ASH 2023. Clinical trial information: NCT06034275 .

Phase 2 study of novel HER2-targeting, TLR7/8 immune-stimulating antibody conjugate (ISAC) BDC-1001 (trastuzumab imbotolimod) +/- pertuzumab (P) in patients (pts) with HER2-positive metastatic breast cancer (MBC) previously treated with trastuzumab deruxtecan (T-DXd).

TPS1121 Background: Therapies to manage pts with HER2+ MBC have significantly improved, but better agents are still needed. BDC-1001 (trastuzumab imbotolimod) is being studied for MBC and other HER2+ cancers. The ISAC BDC-1001 consists of a trastuzumab biosimilar conjugated to a cell membrane impermeable TLR7/8 agonist via a non-cleavable linker and is given IV every 2 wks. Designed to trigger the innate immune system, BDC-1001 causes a durable tumor-targeted adaptive immune response. Early studies show that HER2-targeted ISACs elicit potent and durable immune-mediated antitumor efficacy, and tumor regression, in a TLR- and Fc receptor-dependent manner (1). Preclinical studies with a murine surrogate of BDC-1001 (trastuzumab-T785 ISAC) show better efficacy with trastuzumab-T785 compared to trastuzumab + P. In the BDC-1001 dose-escalation trial (BBI-20201001), 6 PRs and 12 SDs ≥ 24 weeks in 8 tumor types were observed, particularly in 20mg/kg q2w dose cohorts. The most frequent drug-related AE was low grade (grade 1/2) infusion-related reactions (29%) (2). We showed the combination of a surrogate ISAC (trastuzumab-T785) + P significantly enhances efficacy in multiple HER2-expressing tumors, including those with lower HER2 expression (1). The addition of P lowered the quantity of ISAC required for anti-tumor activity in the JIMT-1 HER2 IHC2+ model. The combination of P with the ISAC significantly increased the tumor cytokine and chemokine concentration compared to monotherapy or antibody-alone, indicating enhanced tumor myeloid activation suggesting this combination may enhance the clinical activity of trastuzumab-based ISACs. Methods: The Phase 2 multicenter, open-label, randomized study (BBI-20231001) is enrolling up to 66 patients with HER2-positive (ASCO/CAP 2018) MBC previously treated with 2 or more anti-HER2 therapies including T-DXd. Patients must be > 18 years, have measurable disease, and have ECOG performance status of 0 or 1. Patients will be randomized 1:1 to receive BDC-1001 20mg/kg every 2 weeks with or without P (840mg initial dose, followed by 420mg IV q 3w). Each arm has a Simon 2 stage design. The primary objective is anti-tumor activity of BDC-1001 alone and in combination with P. Secondary objectives will evaluate safety, PK, and immunogenicity of BDC-1001 alone and in combination with P. Exploratory objectives will include PD biomarkers in tumor tissue and in peripheral blood to elucidate the MOA and biomarkers associated with BDC-1001 activity with or without P. This study began accrual in Nov 2023. 1. Ackerman S, et al. Nature Cancer. 2021. 2. Li B, et al. ASCO 2023, Abstract 2538. Clinical trial information: NCT05954143 .