Evaluable Patients Research Articles

A randomized controlled trial of shared decision-making treatment planning process to enhance shared decision-making in patients with MBC

PurposeOpportunities exist for patients with metastatic breast cancer (MBC) to engage in shared decision-making (SDM). Presenting patient-reported data, including patient treatment preferences, to oncologists before or during a treatment plan decision may improve patient engagement in treatment decisions.MethodsThis randomized controlled trial evaluated the standard-of-care treatment planning process vs. a novel treatment planning process focused on SDM, which included oncologist review of patient-reported treatment preferences, prior to or during treatment decisions among women with MBC. The primary outcome was patient perception of shared decision-making. Secondary outcomes included patient activation, treatment satisfaction, physician perception of treatment decision-making, and use of treatment plans.ResultsAmong the 109 evaluable patients from December 2018 to June 2022, 28% were Black and 12% lived in a highly disadvantaged neighborhood. Although not reaching statistical significance, patients in the intervention arm perceived SDM more often than patients in the control arm (63% vs. 59%; Cramer’s V = 0.05; OR 1.19; 95% CI 0.55–2.57). Among patients in the intervention arm, 31% were at the highest level of patient activation compared to 19% of those in the control arm (V = 0.18). In 82% of decisions, the oncologist agreed that the patient-reported data helped them engage in SDM. In 45% of decision, they reported changing management due to patient-reported data.ConclusionsOncologist engagement in the treatment planning process, with oncologist review of patient-reported data, is a promising approach to improve patient participation in treatment decisions which should be tested in larger studies.Trial registrationNCT03806738.

Organoids for Functional Precision Medicine in Advanced Pancreatic Cancer

BackgroundPatient-derived organoids (PDO) are promising tumor avatars that could enable ex vivo drug tests to personalize patients’ treatment in the frame of functional precision oncology (FPM). Yet, clinical evidence remain scarce. This study aims to evaluate whether PDO can be implemented in clinical practice to benefit patients with advanced refractory pancreatic adenocarcinoma (PDAC). MethodsDuring 2021-2022, 87 patients were prospectively enrolled in an IRB-approved protocol. Inclusion criteria were: histologically-confirmed PDAC, tumor site accessible. A panel of 25 approved antitumor therapies (chemogram) was tested and compared to patient responses to assess PDO predictive values and map the drug sensitivity landscape in PDAC. ResultsFifty-four PDOs were generated from 87 pretreated patients (take-on rate 62%). The main PDO mutations were KRAS (96%), TP53 (88%) and CDKN2A/B (22%), with 91% concordance rate with their tumor of origin. The mean turnaround-time to chemogram was 6.8 weeks. In 91% of cases, ≥1 hit was identified (gemcitabine (n=20/54), docetaxel (n=18/54) and vinorelbine (n=17/54) with a median of 3 hits/patient [range:0-12]).Our cohort included 34 evaluable patients with full clinical follow-up. We report a chemogram sensitivity of 83.3% and specificity of 92.9%. The overall-response rate and progression-free survival were higher when patients received a “hit” treatment as compared to patients that received a “non-hit” drug (as part of routine management).Finally, we leveraged our PDO collection as a platform for drug validation and combo identification. We tested the anti-KRASG12D (MRTX1133), alone or combined, and identified a specific synergy with anti-EGFR therapies in KRASG12D variants. ConclusionWe report the largest prospective study aiming at implementing PDO-based FPM and identify very robust predictive values in this clinical setting. In a clinically relevant turnaround-time, we identify putative hits for 91% of patients, providing unexpected potential survival benefits in this very aggressive indication. While this remains to be confirmed in interventional precision oncology trials, PDO collection already provide powerful opportunities for drugs and combinatorial treatment development.

Omission of lymphadenectomy in patients with advanced epithelial ovarian cancer treated with primary or interval cytoreductive surgery after neoadjuvant chemotherapy: The CARACO phase III randomized trial.

LBA5505 Background: Lion trial demonstrated the lack of benefit of retroperitoneal pelvic and paraaortic lymphadenectomy (RPPL) in primary surgery in advanced epithelial ovarian cancer (AEOC) with clinically negative lymph nodes. As a consequence, the question of RPPL during interval cytoreductive surgery after neoadjuvant chemotherapy remains open. Methods: CARACO was a prospective multi-institutional phase III trial including patients with newly diagnosed AEOC FIGO III-IV, with no pre- and intra-operative suspicious lymph nodes, randomized intra-operatively to RPPL versus no-RPPL, stratified by surgical strategy (primary surgery, surgery after neoadjuvant chemotherapy). The primary endpoint was progression free survival (PFS). The target sample size was 450 evaluable patients, providing 80% power at 5% alpha based on the hypothesis of a 5 years PFS of 41%. Results: Between December 2008 and March 2020, 379 patients were randomly assigned to RPPL (n=181) or no-RPPL (n=187), 11 patients were excluded. Our required sample size was not reached because of a stop of inclusion after the publication of the Lion trial. The median number of removed lymph nodes in patients randomized to RPPL was 27 [IQR=19-36]. 75% of the patients were treated with neoadjuvant chemotherapy (244 patients treated with 3 or 4 cycles before interval surgery and 41 patients treated with 6 cycles before delayed surgery) and 83 patients treated with primary surgery followed with adjuvant platinum-based chemotherapy. The rate of surgery with no residual was 86% and 88% respectively in the No RPPL and the RPPL arm. Lymph node metastases were diagnosed in 49% of the patients in the RPPL arm, with a median of 3 involved lymph nodes [IQR=2-7]. After a median follow up of 9 years, median PFS in the no-RPPL arm and in the RPPL arm was 14.8 months and 18.5 months respectively (HR 0.98, 95%CI 0.78-1.22, p=0.86). Median OS was not significantly different: 48.9 months and 58.0 months in the No RPPL and RPPL arm respectively (HR 0.96, 95%CI 0.75-1.22 p=0.72). Results considering progression free and overall survival were not different in the subgroup of patients with a complete surgery or a neoadjuvant chemotherapy. Serious post-operative complications occurred more frequently in the RPPL arm: re-laparotomies 8.3% vs 3.2% [p=0.03], transfusion rate (34% vs 25%, p=0.05). Mortality within 60 days after surgery was similar between arms (1.1 vs 0.5% [p=0.54]) respectively. Conclusions: CARACO trial is the first randomized trial showing that systematic lymphadenectomy should be omitted in AEOC with clinically negative lymph nodes also in patients undergoing neoadjuvant chemotherapy and interval complete surgery. This surgical de-escalation allows to significantly reduce serious post operative morbidity. Clinical trial information: NCT01218490 .

Long-term outcomes following proton therapy for non-metastatic central nervous system germinoma in children and adolescents

Background/PurposeRadiation is a key component in the treatment of central nervous system pure germinoma (PG) in children and adolescents. Proton therapy (PT) improves normal tissue sparing and potentially reduces adverse effects (AE). The aim of this study was to present the largest single institution experience utilizing PT for the management of PG. Materials MethodsWe enrolled 35 non-metastatic patients with PG that were treated with PT at our institution between July 2007 – September 2021. Most received induction chemotherapy (n = 31, 89 %) and whole ventricular irradiation with an involved field boost (n = 29, 83 %). The most common total dose was 30 CGE (n = 18, 51.4 %). We utilized the cumulative incidence method to estimate local control (LC), freedom from distant metastases (FFDM), freedom from progression (FFP), and overall survival (OS). Treatment related toxicity was assessed per CTCAE version 5. ResultsMedian follow-up was 6.2 years (range, 0.9–––15.2). The 10-year Kaplan-Meier estimates for LC, FFDM, FFP, and OS were 100 %, 100 %, 100 %, and 94 % respectively. The most common AE were hearing impairment requiring hearing aids (n = 3), transient hypersomnia requiring medication (n = 3), and new onset endocrinopathy (n = 1). Of the 23 evaluable patients ≥ 18 years old at last follow-up, 8 were high school graduates/in college, 8 college graduates, and 7 others gainfully employed. ConclusionsWhen utilized in modern multimodality treatment of non-metastatic PG, the precise dosimetry of PT does not compromise disease control. Although serious radiation side effects are rare, the 100% cure rate supports further investigation into selective radiation dose and volume de-escalation.

Ramucirumab in combination with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma: a single-centre, phase 1/2 trial

VEGF, a key mediator of angiogenesis and resistance to immunotherapy, is overexpressed in head and neck squamous cell carcinoma (HNSCC). We aimed to determine the recommended phase 2 dose of ramucirumab, a selective VEGFR2 inhibitor, given with pembrolizumab and the objective response rate of this combination as first-line treatment for recurrent or metastatic HNSCC. In this single-centre, phase 1/2 trial, which was done at Washington University (St Louis, MO, USA), eligible patients were aged 18 years or older with incurable recurrent or metastatic HNSCC and an Eastern Cooperative Oncology Group performance status of 0-2. Patients in phase 2 were required to have had no previous systemic therapy for recurrent or metastatic disease. In a dose de-escalation phase 1 design, patients received ramucirumab (starting dose 10 mg/kg given intravenously) and pembrolizumab (200 mg intravenously) on day 1 of each 21-day cycle. The recommended phase 2 dose of ramucirumab was defined as the highest dose at which one or fewer of three patients had dose-limiting toxicity during cycle one (primary endpoint of phase 1). In a Simon's two-stage phase 2 design, patients received the recommended phase 2 dose of ramucirumab and pembrolizumab. Tumour response (primary endpoint of phase 2) was assessed by Response Evaluation Criteria in Solid Tumours (version 1.1). We hypothesised that there would be an objective response rate of 32% or higher (null ≤13%). Eight or more responses among 33 evaluable patients (those with at least one response assessment) was evidence for activity (80% power; one-sided α=0·05). Analyses were done per protocol. The trial is registered with ClinicalTrials.gov, NCT03650764, and is closed to enrolment. Between June 18, 2019, and Feb 11, 2021, three patients enrolled and were treated in phase 1 and 37 patients in phase 2. Median age of all patients was 64 years (IQR 59-72). 36 (90%) of 40 patients were men and four (10%) were women, and 36 (90%) patients were White, three (8%) were Black or African American, and one (3%) was Asian. In phase 1, no dose-limiting toxicity event occurred. The recommended phase 2 dose of ramucirumab was 10 mg/kg. Median follow-up for patients on phase 2 was 14·8 months (IQR 4·9-31·0). In phase 2, 18 (55%; 95% CI 38-70) of 33 evaluable patients had an objective response, including confirmed complete response in 11 patients, confirmed partial response in six patients, and unconfirmed partial response in one patient. The most common grade 3 or worse adverse events were dysphagia (14 [38%] of 37 patients), lung infection (11 [30%]), lymphocyte count decrease (ten [27%]), hypophosphataemia (nine [24%]), and hypertension (eight [22%]). No treatment-related deaths were recorded. Ramucirumab and pembrolizumab were safe to administer to patients with recurrent or metastatic HNSCC, and the objective response rate with this combination as first-line treatment for recurrent or metastatic HNSCC was favourable. Further studies of ramucirumab and pembrolizumab in patients with recurrent or metastatic HNSCC are warranted. Lilly and the Joseph Sanchez Foundation.

Intratumoral Fc-optimized agonistic CD40 antibody induces tumor rejection and systemic antitumor immunity in patients with metastatic cancer.

While CD40 agonism is an attractive approach for activating antigen-presenting cells and initiating antitumor responses, previous attempts have encountered limited clinical efficacy coupled with toxicity. We previously demonstrated that interactions between the antibody Fc domain and the inhibitory receptor FcγRIIB are critical for enhanced antitumor activity. Here, we present the results of a phase 1 study on intratumoral administration of an anti-CD40 agonistic antibody (2141-V11) Fc-engineered to enhance FcγRIIB binding. Primary endpoints included safety, maximum tolerated dose (MTD), and recommended phase 2 dose. Secondary objectives included preliminary clinical activity and correlative studies from biospecimens. 2141-V11 was well-tolerated without dose-limiting toxicities and MTD was not reached. In ten evaluable patients with metastatic cancer, the overall response rate was 20%, with complete responses in two patients (melanoma and breast carcinoma) and stable disease in six patients. 2141-V11 induced tumor regression in injected and non-injected lesions, with increased leukocyte infiltration and tertiary lymphoid structures (TLS) formation in post-treatment biopsies. In a humanized mouse model for CD40 and FcγRs, 2141-V11 induced TLS formation in mice bearing orthotopic breast carcinoma, correlating with local and abscopal antitumor effects, systemic immune activation, and immune memory. These findings support the safety and efficacy of 2141-V11, warranting phase 2 studies and suggesting a unique mechanism of action for this Fc-enhanced immunotherapy (NCT04059588).

Pancreatic-enzyme replacement therapy with pancrelipase plus chemotherapy for patients with pancreatic adenocarcinoma with cachexia and exocrine pancreatic insufficiency (PANCAX-3).

e24059 Background: Pancreatic-enzyme replacement therapy (PERT) is the standard of care to prevent maldigestion, malnutrition, and excessive weight loss in patients with exocrine pancreatic insufficiency (EPI). The utility of this therapy for patients with EPI in the setting of pancreatic ductal adenocarcinoma (PDAC) is unclear. We report results of a single site phase 2 trial for PERT with Pancreaze® plus standard of care (SOC) chemotherapy in PDAC patients with cachexia and EPI. The primary outcome measure was to assess feasibility of completing PERT during the first 8 weeks of treatment. Secondary outcome measures included weight stability, mean change in stool frequency, stool consistency from Cycle 1 (C1) to Cycle 3 (C3) (after 8 weeks of PERT), mean change in serum levels of fat soluble vitamins (A, D, E, K) from baseline to end of study, functional activity, and safety. Methods: Feasibility was defined as adherence to therapy of ≥50% of the needed total lipase units in the first 8 weeks of treatment (84,000 IU lipase units per meal, 42,000 IU lipase units per snack). Data are presented as frequencies (%) for categorical variables and means ± standard deviation for continuous variables. Weight stability, stool frequency, fat soluble vitamin levels, walk speed, and hand grip strength compared using two-sample paired t-tests. Stool consistency (Bristol stool type) compared using Fisher’s exact test. Results: Of 36 patients enrolled, 30 were evaluable for primary endpoint. Median age was 70. 73.3% (22/30) were female. 33.3% (10/30) were borderline resectable, 33.3% (10/30) locally advanced, and 33.3% (10/30) advanced/metastatic. 30 patients completed 8 weeks of PERT and 96.7% (29/30) were compliant. Efficacy results include PR (6.7%, 2/30), SD (66.7%, 20/30) and PD (23.3%, 7/30). Imaging not available for 1 patient. 6 patients experienced grade 1/2 GI toxicities (nausea, bloating, diarrhea, abdominal pain) deemed possibly/probably related to PERT. Grade 3/4 AEs included fatigue, infection, and hematologic toxicities deemed unrelated to PERT. Among evaluable patients, weight remained stable (-0.01±0.07 kg/BMI, p = 0.511) and there was a trend toward reduced stool frequency (p = 0.052) from C1 to C3. Stool consistency from C1 to C3 showed significant association (p = 0.035). Serum fat soluble vitamins, functional activity by walk speed and hand grip strength were also explored and no statistically significant differences were observed from C1 to C3 among the evaluable patients. Conclusions: PERT plus SOC chemotherapy for PDAC patients with cachexia and EPI is feasible and well-tolerated. Patients taking PERT experienced weight stability. PERT may aid in reducing stool frequency and further analysis is warranted into how PERT affects stool consistency. Clinical trial information: NCT04098237 .

Phase 1b study of EZH1/2 inhibitor valemetostat in combination with trastuzumab deruxtecan in patients with HER2 low/ultra-low/null metastatic breast cancer.

TPS1120 Background: In the DAISY study (NCT04132960), meaningful clinical response was observed with Trastuzumab deruxtecan (T-DXd) in HER2 IHC 0 MBC. Valemetostat is an oral, selective dual inhibitor of enhancer of zeste homolog 1 and 2 (EZH1/2) methyltransferases that specifically methylate histone H3 lysine 27. EZH2-mediated PP2A inactivation confers resistance to HER2-targeted therapy. Additionally, valemetostat upregulates Schlafen11 (SLFN11), a putative DNA/RNA helicase, that regulates the sensitivity to DNA damaging agents such as topoisomerase I inhibitors. Based on these preclinical studies, this study examines the safety and anti-tumor activity of valemetostat in combination with T-DXd in subjects with HER2 low/ultra-low/null MBC. Methods: This is a single-arm, phase-1b study to evaluate the safety and clinical activity of T-DXd in combination with valemetostat in patients with HER2 low/ultra-low/null MBC (NCT05633979). The dosing for T-DXd is 5.4 mg/kg Q3W administered intravenously as indicated for current clinical use by FDA approval. Valemetostat will be evaluated at three dose levels (100 mg, 150 mg, and 200 mg orally), with a starting dose (level 1) at 100 mg QD. The dose-limiting toxicity (DLT) evaluation period will be the first 2 treatment cycles (42 days). Major eligibility criteria: Pathologically confirmed HER2 low/ultra-low/null breast cancer; ECOG performance status ≤1; Measurable disease; Received at least one line of chemo in the metastatic setting; Progressed and would no longer benefit from endocrine therapy; Normal organ and marrow function. Exclusion criteria: symptomatic brain metastases, interstitial lung disease, cord compression, prior treatment with any anti-HER2 therapy. Objectives: To evaluate the safety and determine the maximum tolerated dose (MTD)/recommended dose for expansion (RDE); To evaluate the objective response rate (ORR); To determine the duration of response (DoR), clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS); To evaluate the pharmacokinetics and pharmacodynamic markers. Statistical methods: Approximately 12 evaluable patients will be enrolled for the dose-escalation portion based on the Bayesian optimal interval design with a target DLT rate of 25%. Patients will be enrolled in cohorts of 3. The expansion will be performed at the RDE using the 2-stage Bayesian optimal dose-expansion design. In the first stage, 13 evaluable patients will be enrolled. If <5 patients respond in the first stage, the study will be stopped for futility. If ≥5 responses are observed, 13 additional evaluable patients will be enrolled. If 11 or more responses are observed among 26 patients, the treatment will be regarded as promising. This two-stage design yields 78% power under the alternative hypothesis of ORR = 50% (null ORR = 30%) while controlling the one-sided type I error at 10%. Clinical trial information: NCT05633979 .

A phase 1 dose-escalation and expansion study of CUE-101, given as monotherapy and in combination with pembrolizumab, in patients with recurrent/metastatic HPV16+ head and neck squamous cell cancer (R/M HNSCC).

6004 Background: Immuno-STATs are modular T cell engagers engineered to selectively activate tumor-antigen specific CD8+ T cells via targeted delivery of cytokines. CUE-101, the first Immuno-STAT in clinical trials, is composed of a human leukocyte antigen (HLA) complex, HLA-A*0201, a peptide epitope derived from the HPV16 E7 protein and 4 molecules of attenuated human interleukin-2 (IL-2), to bind, expand, and activate HPV16-specific CD8+ T cells for the treatment of HPV16+ HNSCC. Methods: CUE-101-01 is an ongoing first-in-human study in HLA-A*0201 patients with HPV16+ R/M HNSCC. Escalating doses of CUE-101 monotherapy (0.06 mg/kg to 8 mg/kg) were evaluated in R/M HNSCC refractory to ≥ 1 platinum or checkpoint inhibitor (CPI) based therapy, alone or combined with pembrolizumab (1 mg/kg to 4 mg/kg + 200 mg pembrolizumab) in the first line treatment of PD-L1+ R/M HNSCCs. Enrollment at the recommended phase 2 dose (RP2D) was expanded. Therapy was administered every 3 weeks (Q3W) until disease progression or intolerable toxicity. Safety, PK/PD, and antitumor activity were assessed. Results: Enrollment in both monotherapy and combination cohorts is now completed (N=80 patients, 49 in monotherapy and 31 CUE-101 plus pembrolizumab). Following dose escalation, 4 mg/kg Q3W of CUE-101 was selected for RP2D for both monotherapy and pembrolizumab combination cohorts. At data cut-off, adverse events (AEs) have been manageable and 92% grade ≤2. The most frequent grade 3 AEs reported include lymphocyte count decreased (7.6%), anemia (6.3%), decreased appetite (5.1%) and infusion-related reactions (5.1%). In combination with pembrolizumab no unanticipated significant safety concerns have emerged. Exposure-dependent PD effects of CUE-101 are consistent with IL-2 pharmacology and indicate preferential expansion of CUE-101 on E7-specific T cells. Among the 19 evaluable patients treated with the RP2D of CUE-101 plus pembrolizumab, an ORR of 47% (1 CR, 8 PRs), a Disease Control Rate (ORR + durable SDs) of 74%, and mPFS of 5.8 months [95% CI 2.56; NA] were observed. A median OS has not been reached. Of the 9 patients with confirmed objective responses, all achieved >99% reduction in HPV16 cfDNA in plasma during their treatment course. Among the 19 evaluable monotherapy RP2D patients, 1 PR and 6 durable SD (SD ≥ 12 weeks) and mOS of 20.8 months [95% CI 11.0; NA] were observed. Conclusions: An ORR of 47% and a mPFS of 5.8 months were observed in R/M HNSCC patients treated with CUE-101 4 mg/kg + pembrolizumab as 1L therapy. A median OS of 20.8 was observed in patients treated with CUE-101 monotherapy as post-platinum/CPI therapy. CUE-101 continues to demonstrate safety, tolerability and meaningful clinical benefit in patients with HPV16+ R/M HNSCC. Clinical trial information: NCT03978689 .

Phase 1/2 randomized, open-label, multicenter, Simon two-stage study of pelareorep combined with modified FOLFIRINOX +/- atezolizumab in patients with metastatic pancreatic ductal adenocarcinoma.

TPS4203 Background: Immune therapies benefit only the small subset of metastatic pancreatic ductal adenocarcinoma (mPDAC) patients who have microsatellite instability-high (MSI-H) tumors (approximately 1%). Most PDAC tumors are microsatellite stable (MSS) and have an immunologically “cold” phenotype with fewer genetic mutations, reduced immune cell infiltration, and downregulated immune checkpoint proteins. These attributes make most mPDAC tumors resistant to conventional immunotherapy including checkpoint inhibitors. Pelareorep is a naturally occurring, non-genetically modified reovirus that selectively infects cancer cells following intravenous administration. Upon infection, pelareorep’s double-stranded RNA genome stimulates a pro-inflammatory response that primes tumors for immunologic killing. This includes increased T cell infiltration into tumors, expansion of tumor-infiltrating lymphocyte clones, increased PD-L1 expression, and stimulation of tumor-directed innate and adaptive immune responses. Pelareorep combined with chemotherapy, checkpoint inhibitors, or both has shown promising efficacy in several malignancies, including mPDAC. This study is designed to evaluate pelareorep plus modified FOLFIRINOX with or without the PD-L1 inhibitor atezolizumab as first-line therapy in patients with mPDAC. Methods: This trial represents a new cohort within the ongoing GOBLET signal finding platform study in gastrointestinal cancers. This is a phase 1/2 randomized, open-label study that uses a screened selection design within a Simon two-stage approach. Eligible patients must be 18 years or older and have newly diagnosed, radiologically evaluable mPDAC with no prior chemotherapy and an ECOG performance status of 0 or 1. Patients are randomized 1:1 to receive either pelareorep + mFOLFIRINOX orpelareorep + mFOLFIRINOX + atezolizumab. The first stage enrolls 15 evaluable patients into each arm. If pre-specified efficacy criteria are met in Stage 1, one or both arms may be expanded to Stage 2 and enroll 17 additional evaluable patients per arm. The first 3-6 patients enrolled into both arms comprise a safety run-in that must be successfully concluded prior to enrolling additional patients. The treatment period consists of 4-week treatment cycles. The primary objectives are 1) safety and tolerability of pelareorep + mFOLFIRINOX with or without atezolizumab and 2) efficacy based on objective response rate per RECIST v1.1. Secondary objectives include duration of response, progression-free survival, and overall survival. In addition, tumor and blood samples are being collected to evaluate the immunological effects of treatment and to explore potential biomarkers of response. Clinical trial information: Eudra-CT: 2020-003996-16.

Induction chemotherapy effects on very advanced (T3/T4) human papillomavirus-related oropharyngeal cancer for participation in hypoxia-directed major de-escalation (30 Gy) definitive treatment trial.

6076 Background: De-escalation trials in human papillomavirus associated oropharyngeal carcinoma (HPV+ OPC) often exclude patients with very locally advanced disease. We previously demonstrated in a Phase II study that for patients with T1-T2 HPV+OPC that de-escalation to 30Gy of definitive chemoradiation based on lack of hypoxia on 18F-FMISO (fluoromisonidazole) PET (ROC Study) is associated with excellent outcomes (JNCI 2021; JCO 2024). Here, we hypothesized that induction chemotherapy (ICT) could be used in locally advanced (T3-T4) HPV+OPC to down-stage patients and make them eligible for de-escalation and simultaneously improve tumor hypoxia. Methods: We conducted a pilot study in HPV+ OPC patients with AJCC v7 T3-T4 and/or large volume N2b-N2c-N3 disease (i.e. pts ineligible for ROC Study (NCT03323563)). ICT – carboplatin (AUC2), paclitaxel (90 mg/m2), and cetuximab (250 mg/m2 after 400 mg/m2 loading dose) weekly for 6 weeks. To be eligible for de-escalation (ROC), after ICT, patients needed to be down-staged (<=T2). 18F-FMISO PET scan done prior to ICT, after ICT, and, if eligible for ROC study, about 2 weeks after start of radiation therapy. If an 18F-FMISO PET scan showed no hypoxia at any time point, no further scans necessary and patients received 30Gy of radiation therapy with 2 cycles of chemotherapy concurrently. Primary outcome is 2-year local control rate in 20 evaluable patients (description only in this pilot study). This abstract reports only on the outcomes of the ICT portion of the study. Results: 20 patients were accrued 3/2023-12/2023. Median age - 70 years old (46-88); Male – 95%; ECOG PS 0 – 80%. Tumor stage – T3 (70%); T4a (30%); N2b (70%); N2c (30%). All 20 patients had pretreatment hypoxia by 18F-FMISO. Of the 17 evaluable patients post ICT, 14 (82%) had no hypoxia on post ICT scan (other 3 still receiving ICT). Of 3 patients with hypoxia after ICT, 2 had resolution 2 weeks into radiotherapy, and 1 patient is still pending intra-treatment scan. All 17 evaluable patients had a significant enough of a response anatomically to allow treatment on the ROC Study. All patients to date were able to receive 2 cycles of cisplatin (100 mg/m2) without dose or treatment adjustment. Conclusions: Preliminary results suggest that ICT can allow more advanced tumors (T3/T4), that are typically excluded from de-escalation studies, to be de-escalated and may eliminate tumor hypoxia in a large proportion of cases, but a larger study is needed to confirm these results. Further followup of outcomes (2 year local control rate) is still needed. Clinical trial information: NCT05491512 .

A phase 2 study evaluating response and biomarkers in patients with microsatellite stable (MSS) advanced colorectal cancer (CRC) treated with nivolumab/relatlimab.

3554 Background: Lymphocyte-activation gene 3 (LAG-3) is an immunosuppressive signal, impairing T effector (Teff) activation. Pre-clinical studies suggest LAG-3 inhibition promotes anti-tumor immunity by enhancing Teff function. Correlative studies linked increased LAG-3 levels with reduced overall survival (OS) in CRC. These data prompted optimism that combined LAG-3/PD-1 inhibition might promote anti-tumor responses in MSS CRC. Methods: We conducted a phase 2 study of nivolumab (Nivo) (aPD1)/relatlimab (Rela) (aLAG3) in patients with previously treated advanced MSS CRC. This study enrolled patients onto 1 of 3 arms. Arms A and B used a Composite PD-L1 and acellular Mucin (CPM) score to define patients as CPM(+) in Arm A (CPM≥ 15%) and CPM(-) in Arm B (CPM< 15%). Patients in Arm A and B received Nivo 480mg/Rela 160mg IV q4 weeks. Arm C enrolled patients without biomarker selection who received Nivo 480mg/Rela 960mg or Rela 480mg/Nivo 480mg. The primary endpoint was objective response, and each arm was powered to detect an objective response rate (ORR) of ≥20%. Results: Fifty nine evaluable patients were enrolled (Arm A: 12, Arm B: 15, Arm C: 32). Patient characteristics and responses are outlined. Treatment was well tolerated with no new safety signals over aPD1 alone. Three (5%) patients achieved a partial response (PR), 6 (10%) stable disease (SD), and 50 with progression of disease (PD) as best response. The median progression-free survival was (Arm A: 2.2 mo., Arm B: 2.8 mo., Arm C: 2.6 mo.) while median OS was (Arm A: 4.3 mo., Arm B: 14.2 mo., Arm C: 12.4 mo.). In N=6 patients with lung-only metastases, 2 (33%) experienced a PR, and 1 (17%) a SD, for a clinical benefit rate of 50%. The trial incorporated translational correlates. We will report mass cytometry on PBMCs, RNAseq on baseline biopsies, and imaging mass cytometry on pre- and on-treatment biopsies. Conclusions: This combination did not meet the primary endpoint of 20% ORR for any of the 3 cohorts, but there was intriguing possible activity in patients with lung only metastases, consistent with emerging data. Clinical trial information: NCT03642067 .

Durvalumab and consolidation SBRT following chemoradiation for stage III non-small cell lung cancer: A single institution pilot study.

e20085 Background: Definitive chemoradiation (CRT) followed by consolidative immunotherapy with durvalumab (IO) demonstrated survival benefit and is now standard of care for Stage III Non-small Cell Lung Cancer (NSCLC). However, local-regional control (LRC) remains a concern with intrathoracic progression representing the most common site of failure. Adding stereotactic body radiotherapy (SBRT) boost may enhance the immunogenicity and antigenicity of tumor cells by regulating cell surface receptors and augmenting T-lymphocyte infiltration into tumor. SBRT boost also allows escalated dose to the primary tumor while minimizing dose to critical structures. Methods: Patients with Stage III NSCLC planned for definitive concurrent CRT with 1 year of consolidative IO were prospectively enrolled on a single institutional pilot trial. IO started 6-8 weeks after completion of CRT. SBRT was delivered between cycle 1 and 2 of IO to the residual, primary tumor (20 Gy in 2 fractions for peripheral, 19.5 Gy in 3 fractions for central tumors). Residual tumors needed to be < 120 cc. Lymph nodes were not boosted. Primary endpoints were grade (gr) ≥3 toxicities (CTCAE V4.03) and progression free survival (PFS). Secondary endpoints were Overall Survival (OS), LRC, and distant metastasis (DM). A sample size of 25 patients was proposed to determine safety and efficacy. Results: Accrual was slower than anticipated, and the study closed with 11 patients enrolled over 54 months. Slow accrual was due to a low rate of eligibility based on post CRT clinical status and SBRT target limitations. 1 patient withdrew consent before receiving treatment leaving 10 evaluable patients. Median age was 73 years and median CRT dose was 60 Gy (range 60-66 Gy). 6/10 of patient were adenocarcinoma. 5/10 pts had central tumor location. Median follow-up for evaluable patients is 2.2 years. OS was 90%, 70%, and 70% at 1-year, 2-years, and 3 years, respectively. PFS was 90%, 47%, and 47% at 1 year, 2 years, and 3 years, respectively. LRC was 100%, 83%, and 63% at 1 year, 2 years, and 3 years, respectively. Rates of DM were 0%, 12%, and 34% at 1 year, 2 years, and 3 years, respectively. 1 patient developed gr 3 pneumonitis requiring discontinuation of IO. 1 additional patient developed gr 2 pneumonitis requiring a brief pause in IO therapy and resumed IO without any further complications. One patient developed gr 5 myocarditis 29 days after the first dose of IO and 18 days after SBRT, on investigation deemed to be myocarditis secondary to IO. There was no other gr 3 toxicity attributable to IO or SBRT. Conclusions: The addition of SBRT to consolidative IO in stage III NSCLC patients treated with CRT was feasible. The single gr 5 toxicity was attributed to IO. SBRT boost demonstrated encouraging efficacy and manageable toxicity and merits further study. Our data adds to the growing evidence of harnessing tumor immunogenicity in enhancing IO responses. Clinical trial information: NCT03589547 .

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 .

A multi-centre, single arm, phase 2 trial of pembrolizumab in treatment-naïve patients with carcinoma of unknown primary site.

2659 Background: Cancer of unknown primary (CUP) represents a heterogeneous group of cancers that present with metastatic epithelial disease with no identifiable primary lesion at the time of diagnosis. Patients with poor prognostic features have limited effective systemic therapy options. Researchers hypothesize that these primary lesions are occult, in part, due to anti-cancer immune surveillance. We hypothesize, pembrolizumab will have activity in this setting. Methods: This single arm phase 2 study evaluated the use of pembrolizumab in treatment naïve patients with poor prognosis CUP. Patients ≥18 years of age with ECOG PS 0-1 and histologically proven, measurable metastatic carcinoma with no primary site identified were eligible. Pembrolizumab was administered at 200 mg intravenously every 3-weeks for up to 24 months. The primary endpoint was safety and objective response rate (ORR) per RECIST 1.1. Secondary objectives included progression free survival (PFS) and overall survival (OS). The study used a Simon’s two stage design based on a one-sided test with a type 1 error rate of 0.1, null hypothesis for ORR ≤ 20% yielding a power of 0.8 with an alternate hypothesis of ≥40%. The null hypothesis will be rejected if 8 or more responses are observed in 25 patients. Mismatch repair (MMR) and microsatellite instability (MSI) testing was not mandatory for patients. Results: There were 27 evaluable and 6 unevaluable (no response assessment, included in adverse event analysis) patients. The median age was 64 (range 21-80) and the majority were male (57.6%) and ECOG 1 (84.8%). Four patients experienced grade 3 treatment related adverse events (pain, anorexia, fatigue, confusion, and anemia). There were no treatment related deaths or new signals of toxicity. Of the evaluable patients, the ORR was 18.5% (4 partial responses and 1 complete response), disease control rate was 51.9% (9 stable disease) and thus the null hypothesis could not be rejected. For evaluable patients, the median PFS and OS were 2.56 (95% CI 2.10 – 7.46) and 9.79 (95% CI 3.84 – 16.03) months respectively. The one patient who developed a CR had MMR deficiency and has completed 2 years of therapy. Of the 4 patients with a partial response, one had an MMR proficient tumour, while the remaining 3 had unknown MMR status. Conclusions: Although not meeting the primary endpoint, pembrolizumab has some activity in CUP patients. Patients with CUP should be screened for MMR or MSI. Future studies should evaluate combination therapies with the addition of pembrolizumab. Clinical trial information: NCT03391973 .

Impact of an objective scoring system on initiation of therapy in patients with International Neuroblastoma Risk Group Staging System (INRGSS) stage MS neuroblastoma: A report from the Children’s Oncology Group.

10003 Background: A subset of children with INRGSS Stage MS neuroblastoma (NBL) may be observed without treatment, while others have rapidly evolving symptoms that can be life-threatening. ANBL1232 adapted a previously developed semi-quantitative objective scoring system (OSS) to assign a numeric value to symptoms and laboratory abnormalities. The goal was to standardize monitoring, therapy initiation, and treatment duration in this cohort. Methods: Patients with newly diagnosed Stage MS NBL were eligible for this prospective trial. An OSS score (OSSS) was assigned at enrollment; the total number was based on scoring in 5 systems: gastrointestinal (GI), respiratory, circulatory, renal, and hepatic. Within the 5 systems, individual clinical and laboratory parameters were scored as not present = 0, mild/moderate = 1 [Grade 2 CTCAEv4.0 adverse event (AE)] or severe = 2 (Grade ≥3 AE). The OSSS was the sum of highest score within each organ system (maximum score: 2 per system, 10 total). Asymptomatic MS patients with an OSSS < 2 who were either < 3 months (mo) of age without hepatomegaly or 3-18 mo of age with favorable biology tumors were eligible for observation without initial treatment. Observed patients underwent monthly physical examinations and laboratory assessments for the first 6 mo following diagnosis. Tumor imaging was performed every 3 mo for 1 year, then every 6-12 mo through 36 mo. An OSSS ≥2 or a protocol-defined increase in primary tumor size prompted initiation of therapy. Results: From July 2014 to February 2021, 89 eligible and evaluable patients with newly diagnosed stage MS NBL enrolled. Among these, 18 (20.2%; 5 male and 13 female) were eligible for observation. Observed patients were older at diagnosis (median age: 2.87 vs. 1.81 mo, p = 0.23) and more likely to have primary tumors without image-defined risk factors (62.5% vs. 30.0%, p = 0.0166) than those assigned to therapy up front. Nearly all observed patients (17/18) had abdominal/adrenal primaries. The initial OSSS was 0 in all observed patients. Median reported observation time was 36 mo (range: 1-36 mo); 13 patients completed all required monthly assessments for the first 6 mo. No patients in the observation cohort required initiation of therapy for an increase in OSSS. One patient with OSSS = 1 at mo 3 had complete GI symptom resolution by mo 5. Conclusions: An OSSS of 0 at diagnosis can aid in identifying a favorable group of patients with stage MS NBL who can be safely observed. No patients in the observation cohort developed evidence of organ dysfunction or OSSS > 1 despite frequent physical examination and comprehensive laboratory testing, suggesting that follow up may be safely liberalized in this population over time. Clinical and laboratory criteria implemented at diagnosis could be used to identify patients requiring prompt treatment. Clinical trial information: NCT02176967 .

Anlotinib plus chemotherapy as first-line therapy for patients with gastrointestinal tumor with unresectable liver metastasis: Updated results from a multi-cohort, multi-center phase II trial, ALTER-G-001-cohort C.

e16304 Background: Advanced gastrointestinal (GI) tumors, such as colorectal, gastric and pancreatic cancers (CRC, GC, and PC), and esophageal squamous cell carcinoma (ESCC), 20%-50% with liver metastases (LMs) have a poor prognosis. Previous trials showed that anlotinib plus chemotherapy has promising clinical activity and a tolerable safety profile for advanced CRC and ESCC, especially with LMs. In this phase II trial, we assessed the efficacy and safety of anlotinib plus chemotherapy as first-line treatment for LMs GI tumors. Methods: Patients with unresectable LMs GI tumors and without previous systemic treatment would be divided into cohort A (CRC), cohort B (ESCC), and cohort C (other GI tumors, such as PC, GC, biliary tract cancer (BTC), etc.). In cohort C, patients received induction therapy: anlotinib plus standard chemotherapy. Patients without progressive disease (PD) and radical resection received anlotinib and metronomic capecitabine (500 mg, PO, BID, days 1-21, q3w) maintenance until PD or unacceptable toxicity. The primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints were duration of response (DoR), progression-free survival (PFS), overall survival (OS), disease control rate (DCR), time to response (TTR), depth of response (DpR), radical resection rate for LMs, and safety. Results: As of November 30, 2023, 44 patients were enrolled in cohort C (32 PC, 6 GC, 5 BTC, and others), the median age was 63.5 years (34-74), 65.9% male, 93.2% ECOG-PS 1 and 56.8% had LMs only. The majority of the pancreatic cancer patients (90.6%) received gemcitabine plus nab-paclitaxel chemotherapy combination with anlotinib as induction therapy. After induction therapy, 4 patients (1 PC, 2 GC, 1 BTC) received surgical resection. Of 37 evaluable patients in cohort C, 14 had partial response (PR), 18 had stable disease (SD) and 15 SD with reduced tumor size. The confirmed ORR was 37.8%, DCR was 86.5%. Of 25 evaluable pancreatic cancer patients, confirmed ORR and DCR were 36% (9/25) and 88% (22/25) respectively. In patients with pancreatic cancer, all PRs with DpR ≥30% and DpR ≥50% were 6 (66.7%). According to the Kaplan-Meier method, the median DoR was 4.6 (95%CI, 2.89-NE) months and PFS was 5.8 (95%CI, 4.1-6.0) months. The median TTR was 1.6 (range, 1.2-3.5) months. 36 patients in cohort C had TRAEs and ≥ grade 3 TRAEs (45.5%) mainly included hypertension (11.4%), neutropenia (9.1%), and blood platelet decreased (9.1%). Conclusions: Anlotinib plus chemotherapy as first-line treatment has shown promising efficacy and acceptable safety and maybe a favorable option for advanced LMs GI tumors, especially for pancreatic cancer. Clinical trial information: NCT05262335 .

Efficacy and safety of sitagliptin, in combination with gemcitabine plus nab-paclitaxel (GnP) in patients with previously untreated advanced pancreatic ductal adenocarcinoma (PDAC).

e16329 Background: Chemoresistance is the main reason for the poor prognosis of pancreatic ductal adenocarcinoma (PDAC). Thus, there is an urgent need to identify new targets and compounds to overcome chemotherapeutic resistance. Methods: The high-throughput virtual drug screening, molecular docking analysis and organoid biobank-based drug screening were performed to identify the candidates to efficiently overcome chemotherapy resistance. In vitro and in vivo PDOs, PDXs and KPC GEMM models were used to evaluate the effects of the compounds. Spatial single cell RNA-sequence, spatial metabolomics and proteomics were employed to elucidate the mechanism. Additionally, an ongoing open-label, randomized, single-arm, single-center phase 2 investigator-initiated clinical trial (NCT05947825) is investigating the efficacy and safety of the candidate in sensitizing gemcitabine plus nab-paclitaxel (GnP) in previously untreated advanced PDAC patients. Objective tumor responses were assessed according to RECIST1.1 criteria and any adverse events were graded using CTCAE 5.0. The primary endpoint was progression-free survival (PFS), and secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and treatment-emergent adverse events (TEAEs). Results: High-throughput drug screening of chemotherapy-resistant PDOs identified Sitagliptin that could significantly induce the degradation of RRM1/RRM2 in a ubiquitin proteasome-dependent manner and further result in unrestrained pyrimidine biosynthesis and alleviation of replication stress. In vitro and in vivo assays confirmed that Sitagliptin could synergistically enhance the ability of GnP regimen to suppress PDAC progression. In the phase 2 study (NCT05947825), previously untreated advanced PDAC received Sitagliptin, 100mg/qd and gemcitabine (G, 1000mg/m2 )plus nab-paclitaxel (nP, 125 mg/m2 )on Days 1 and 8 in a 21-day cycle. Till February 1, 2024, 12 patients with ECOG 0 to 2 have been enrolled in the study. The primary endpoint has not been reached. Among the 8 evaluable patients, 3 showed partial responses and 5 had stable diseases. The objective response rate (ORR) and disease control rate (DCR) were 37.5% and 100% respectively. There were no instances of treatment-related death in this study. The most common treatment-emergent adverse events (TEAEs) were decreased white blood cells and fatigue. One patient experience skin rash. Conclusions: Sitagliptin could effectively improve efficacy of GnP regimen by suppressing RRM1/RRM2-mediated pyrimidine metabolism. Sitagliptin plus GnP regimen is a feasible regimen with a manageable safety profile. Sitagliptin in combination with GnP regimen shows encouraging antitumor activity in PDAC, meriting continued development. Clinical trial information: NCT05947825 .

Phase II study to evaluate safety and efficacy of neratinib, an irreversible pan-HER tyrosine kinase inhibitor, and trastuzumab biosimilar in patients with HER2 mutated advanced solid tumors (KCSG AL20-17).

3134 Background: Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has single agent clinical activity in HER2 mutated cancer. This open-label single arm phase 2 trial investigated the efficacy and safety of the dual anti-HER2 therapy, neratinib plus trastuzumab in heavily pretreated patients with HER2 mutated solid tumors excluding HER2 amplifications. Methods: Neratinib was administered 240mg p.o. daily with trastuzumab biosimilar (Herzuma) every 3 weeks. The primary endpoint was objective response rate (ORR) by RECIST v1.1. Secondary endpoints were duration of response (DoR), progression free survival (PFS), and safety. An exploratory biomarker study was also conducted. Results: Forty patients were enrolled with a median follow-up of 11.08 months (range, 0.39-21.63 months) and a median of 3 (range 1-9) lines of prior systemic therapy. Tumor types included lung (42.5%), colorectal (20%) biliary (12.5%), and breast (7.5%). Sixty percent (60%) of patients (n=24) had HER2 mutation in the kinase domain. Among evaluable patients (n=39), the ORR was 23.1% (CR=0, PR=9) with a median DoR of 11.18 months (95% CI 0-22.63). Median PFS was 3.42 months (95% CI 1.57-5.27) and median overall survival was 9.47 months (95% CI 2.93-16.01). Grade ≥3 adverse events (AEs) occurred in 47.5% of patients (n=19) and diarrhea was the most frequently reported AE (n=10; 25%) followed by bilirubin elevation (n=2; 5%), and anemia (n=2; 5%). Conclusions: In heavily pretreated patients with HER2 mutated solid tumors, neratinib plus trastuzumab showed a moderate response rate, with a durable duration of response. Most AEs were manageable, highlighting the need for prophylactic diarrhea management. Exploratory biomarker results will be presented at the upcoming meeting. Clinical trial information: NCT06083662 .

Weekly BH009 in patients with squamous cell carcinoma of the head and neck (SCCHN) and ovarian cancer: Interim phase I results.

e17545 Background: BH009 is a novel polysorbate 80-free formulation of docetaxel that will eliminate hypersensitivity reactions associated with polysorbate 80. BH009 has completed a bioavailability study compared to Taxotere and was found to have a better safety profile to Taxotere with the potential for higher doses. As a result, we conducted a phase I dose escalation study to determine the maximum tolerated dose (MTD), and the safety profile of a weekly BH009 regimen in the treatment of patients with advanced SCCHN and Ovarian cancer. Methods: This phase I study assessed safety of BH009 in patients with advanced SCCHN and Ovarian cancer. BH009 was administered at escalating doses (starting dose 40 mg/m2) as a 1-h i.v. infusion for three consecutive weeks every 28 days without dexamethasone premedication. Results: Up to January 2024, 11 patients were treated with BH009 (4 at 40 mg/m2, 7 at 50 mg/m2). 2 patients with SCCHN, and 9 patients with ovarian cancer. 100% of ovarian cancer patients were recurrent platinum-resistant ovarian cancer (PROC) patients. 82% (9/11) of patients had received prior taxanes, of whom 33% (3/9) had received prior docetaxel. There were no DLT observed in 40 mg/m2 dose groups, and one DLT was observed in the 50 mg/m2 group (grade 3 febrile neutropenia). The MTD for BH009 is expected to exceed 50 mg/m2, which would be higher than that of Taxotere under the same dosing regimen (≥50mg/m2 vs 42mg/m2*), and the overall tolerability was better than Taxotere. In this study, treatment-related adverse events (TRAEs) occurred in 100% (11/11) patients. The most common grade 3/4 TRAEs were Leukopenia (36%, n=4), Anaemia (36%, n=4), and Neutropenia (55%, n=6). Non-hematologic toxicities were generally mild with no grade 4 toxicity observed. No AEs that led to death were related to BH009. Up to January 2024, the DCR is 50% (3/6) after 2 courses of treatment. The ORR in 6 evaluable patients was 33% (2/6, 1 patient with SCCHN at 40 mg/m2, 1 patient with ovarian cancer at 50 mg/m2). One patient (17%, 1/6) with ovarian cancer at 50 mg/m2 dose group received a complete response to the target lesion and the non-target lesion was partially responded after 2 courses of BH009, and this patient had been previously treated with docetaxel, carboplatin, and bevacizumab. Conclusions: The weekly BH009 for three consecutive weeks every 28 days is a feasible schedule with a favorable toxicity profile, and the overall tolerability is better than Taxotere. BH009 has the potential to increase the dose of administration and improve the clinical efficacy. Dose escalation is ongoing. Clinical trial information: NCT06232863 . [Table: see text]