Safety, Efficacy, and Pharmacokinetics of SHR-A1811, a Human Epidermal Growth Factor Receptor 2-Directed Antibody-Drug Conjugate, in Human Epidermal Growth Factor Receptor 2-Expressing or Mutated Advanced Solid Tumors: A Global Phase I Trial

PURPOSE

SHR-A1811 is an antibody-drug conjugate composed of an anti-human epidermal growth factor receptor 2 (HER2) antibody trastuzumab, a cleavable linker, and a topoisomerase I inhibitor payload. We assessed the safety, tolerability, antitumor activity, and pharmacokinetics of SHR-A1811 in heavily pretreated HER2-expressing or mutated advanced solid tumors.

METHODS

This global, multi-center, first-in-human, phase I trial was conducted at 33 centers. Patients who had HER2-expressing or mutated unresectable, advanced, or metastatic solid tumors and were refractory or intolerant to standard therapies were enrolled. SHR-A1811 was administered intravenously at doses ranging from 1.0 to 8.0 mg/kg once every 3 weeks. The primary end points were dose-limiting toxicity, safety, and the recommended phase II dose.

RESULTS

From September 7, 2020, to February 27, 2023, 307 patients who had undergone a median of three (IQR, 2-5) previous treatment regimens in the metastatic setting received SHR-A1811 treatment. As of data cutoff (February 28, 2023), one patient from the 6.4 mg/kg group experienced dose-limiting toxicities (pancytopenia and colitis). The most common grade 3 or higher adverse events (AEs) included decreased neutrophil count (119 [38.8%]) and decreased WBC count (70 [22.8%]). Interstitial lung disease occurred in only eight (2.6%) patients. Serious AEs and deaths occurred in 70 (22.8%) and 13 (4.2%) patients, respectively. SHR-A1811 led to objective responses in 59.9% (184/307) of all patients, 76.3% (90/118) of HER2-positive breast cancer, 60.4% (55/91) of HER2 low-expressing breast cancer, and 45.9% (39/85 with evaluable tumor responses) of the 98 nonbreast tumors.

CONCLUSION

SHR-A1811 exhibited acceptable tolerability, promising antitumor activity, and a favorable pharmacokinetic profile in heavily pretreated advanced solid tumors. The recommended phase II dose of 4.8 or 6.4 mg/kg was selected for various tumor types.

PKC-independent PI3K signalling diminishes PKC inhibitor sensitivity in uveal melanoma

Protein kinase C (PKC) is activated downstream of gain-of-function GNAQ or GNA11 (GNAQ/GNA11) mutations in over 90% of uveal melanoma (UM). Phase I clinical trials of PKC inhibitors have shown modest response rates with no survival benefit in metastatic UM. Although PKC inhibitors actively suppress mitogen-activated protein kinase (MAPK) signalling in UM, the effect on other UM signalling cascades is not well understood. We examined the transcriptome of UM biopsies collected pre- and post-PKC inhibitor therapy and confirmed that MAPK, but not PI3K/AKT signalling, was inhibited early during treatment with the second-generation PKC inhibitor IDE196. Similarly, in GNAQ/GNA11-mutant UM cell models, PKC inhibitor monotherapy effectively suppressed MAPK activity, but PI3K/AKT signalling remained active, and thus, concurrent inhibition of PKC and PI3K/AKT signalling was required to synergistically induce cell death in a panel of GNAQ/GNA11-mutant UM cell lines. We also show that re-activation of MAPK signalling has a dominant role in regulating PKC inhibitor responses in UM and that PI3K/AKT signalling diminishes UM cell sensitivity to PKC inhibitor monotherapy. Thus, combination therapies targeting PKC and PKC-independent signalling nodes, including PI3K/AKT activity, are required to improve responses in patients with metastatic UM.

Immune checkpoint inhibitor therapy for advanced cutaneous squamous cell carcinoma in Australia: a retrospective real world cohort study

OBJECTIVES

To review the outcomes of immune checkpoint inhibitor (ICI) treatment of advanced cutaneous squamous cell carcinoma (CSCC) outside clinical trials.

STUDY DESIGN

Retrospective observational study; review of patient records in fifteen Australian institutions.

SETTING, PARTICIPANTS

All Australian adults with locally advanced or metastatic CSCC not amenable to curative surgery or radiotherapy treated with ICIs, 5 May 2017 - 23 May 2022, through a cemiplimab compassionate access scheme (Therapeutic Goods Administration Special Access Scheme) or who personally covered the cost of pembrolizumab prior to the start of the access scheme.

MAIN OUTCOME MEASURES

Best overall response rate (ORR) according to standardised assessment criteria using the hierarchy: Response Evaluation Criteria in Solid Tumors (RECIST 1.1), the modified World Health Organization clinical response criteria, and the Positron Emission Tomography Response Criteria (PERCIST 1.0); overall and progression-free survival.

RESULTS

A total of 286 people with advanced CSCC received ICI therapy during May 2017 - May 2022 (cemiplimab, 270; pembrolizumab, 16). Their median age was 75.2 years (range, 39.3-97.5 years) and 232 were men (81%); median follow-up time was 12.2 months (interquartile range, 5.5-20.5 months). Eighty-eight people (31%) were immunocompromised, 27 had autoimmune disease, and 59 of 277 (21%) had ECOG performance scores of 2 or 3. The ORR was 60% (166 of 278 evaluable patients): complete responses were recorded for 74 (27%) and partial responses for 92 patients (33%). Twelve-month overall survival was 78% (95% confidence interval [CI], 72-83%); progression-free survival was 65% (95% CI, 58-70%). Poorer ECOG performance status was associated with poorer overall survival (per unit: adjusted hazard ratio [aHR], 3.0; 95% CI, 2.0-4.3) and progression-free survival (aHR, 2.4; 95% CI, 1.8-3.3), as was being immunocompromised (overall: aHR, 1.8; 95% CI, 1.1-3.0; progression-free: aHR, 1.8; 95% CI, 1.2-2.7). Fifty-five people (19%) reported immune-related adverse events of grade 2 or higher; there were no treatment-related deaths.

CONCLUSION

In our retrospective study, the effectiveness and toxicity of ICI therapy were similar to those determined in clinical trials. Our findings suggest that ICIs could be effective and well tolerated by people with advanced CSCC who are ineligible for clinical trials.

Coil or Plug-Assisted Ethylene Vinyl Alcohol Copolymer (EVOH) Thoracic Duct Embolization in the Treatment of Postoperative Chylothorax

Eleven patients (5 men, 6 women) with post-operative thoracic duct injuries and high output chylothorax were treated with thoracic duct embolization (TDE). Six patients underwent intraprocedural thoracic duct ligation at the time of original procedure. In all cases, the pleural fluid demonstrated high triglyceride levels (414 mg/dL; interquartile range [IQR], 345 mg/dL). Median daily (IQR) chest tube outputs before and after TDE were 900 mL (1,200 mL) and 325 mL (630 mL), respectively. Coil- or plug-assisted ethylene vinyl alcohol (EVOH) copolymer was used as embolic agent in all patients. Technical and clinical success rates were 100% and 82%, respectively. Nontarget venous embolization of EVOH copolymer was not identified on subsequent imaging.

Operator radiation exposure during radioembolisation of the liver: transfemoral versus transradial access using real-time dose monitoring

In this study, operator radiation exposure is compared utilising transradial access (TRA) versus transfemoral access (TFA) during transarterial radioembolisation (TARE) of liver tumors. Patients who underwent Y90 TARE between May 2017 and April 2018 were included. Electronic medical records and interventional data were collected and the following parameters evaluated: technical success, fluoroscopy time, operator radiation exposure and rate of operator radiation exposure per fluoroscopy time. Statistical analysis was performed with the Wilcoxon rank-sum test. A total of 22 patients (12 males, 10 females) underwent 22 procedures. A total of 12 procedures were performed via TFA and 10 via TRA. Technical success was 100% in both groups. Median fluoroscopy time (10 minutes for TRA vs 6.4 minutes for TFA, p = 0.082) was not statistically different. Both operator radiation exposure (49 vs 4.2 μSv, p = 0.00016) and rate of operator exposure (4.9 vs 0.71 μSv per min, p = 0.00021) were significantly higher in the TRA versus TFA groups, respectively.

A first-in-human phase 1 study of nofazinlimab, an anti-PD-1 antibody, in advanced solid tumors and in combination with regorafenib in metastatic colorectal cancer

BACKGROUND

We assessed nofazinlimab, an anti-PD-1 antibody, in solid tumors and combined with regorafenib in metastatic colorectal cancer (mCRC).

METHODS

This phase 1 study comprised nofazinlimab dose escalation (phase 1a) and expansion (phase 1b), and regorafenib dose escalation (80 or 120 mg QD, days 1-21 of 28-day cycles) combined with 300-mg nofazinlimab Q4W (part 2a) to determine safety, efficacy, and RP2D.

RESULTS

In phase 1a (N = 21), no dose-limiting toxicity occurred from 1 to 10 mg/kg Q3W, with 200 mg Q3W determined as the monotherapy RP2D. In phase 1b (N = 87), 400-mg Q6W and 200-mg Q3W regimens were found comparable. In part 2a (N = 14), both regimens were deemed plausible RP2Ds. Fatigue was the most frequent treatment-emergent adverse event (AE) in this study. Any-grade and grade 3/4 nofazinlimab-related AEs were 71.4% and 14.3%, 56.3% and 5.7%, and 57.1% and 21.4% in phases 1a, 1b, and part 2a, respectively. ORRs were 14.3% and 25.3% in phases 1a and 1b, respectively. In part 2a, no patients had radiological responses.

CONCLUSIONS

Nofazinlimab monotherapy was well tolerated and demonstrated preliminary anti-tumor activity in multiple tumor types. Regorafenib plus nofazinlimab had a manageable safety profile but was not associated with any response in mCRC.

CLINICAL TRIAL REGISTR ATION

Clinicaltrials.gov (NCT03475251).

A phase I trial of LXS196, a protein kinase C (PKC) inhibitor, for metastatic uveal melanoma

BACKGROUND

Up to 50% of patients with uveal melanoma develop metastases (MUM) with a poor prognosis and median overall survival of approximately 1 year.

METHODS

This phase I study evaluated the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of the oral protein kinase C inhibitor LXS196 in 68 patients with MUM (NCT02601378). Patients received LXS196 doses ranging from 100-1000 mg once daily (QD; n = 38) and 200-400 mg twice daily (BID; n = 30).

RESULTS

First cycle dose-limiting toxicities (DLTs) were observed in 7/38 (18.4%) QD and 2/17 (11.8%) BID patients. Hypotension was the most common DLT, occurring at doses ≥500 mg/day, and manageable with LXS196 interruption and dose reduction. Median duration of exposure to LXS196 was 3.71 months (range: 1.81-15.28) for QD and 4.6 months (range: 0.33-58.32) for BID dosing. Clinical activity was observed in 6/66 (9.1%) evaluable patients achieving response (CR/PR), with a median duration of response of 10.15 months (range: 2.99-41.95); 45/66 had stable disease (SD) per RECIST v1.1. At 300 mg BID, the recommended dose for expansion, 2/18 (11.1%) evaluable patients achieved PR and 12/18 (66.7%) had SD.

CONCLUSION

These results suggest manageable toxicity and encouraging clinical activity of single-agent LXS196 in patients with MUM.

Use of Botulinum Toxin Injections for the Treatment of Chronic Anal Fissure: Results From an American Society of Colon and Rectal Surgeons Survey

BACKGROUND

Chronic anal fissure (CAF) is commonly treated by colorectal surgeons. Pharmacological treatment is considered first-line therapy. An alternative treatment modality is chemical sphincterotomy with injection of botulinum toxin (BT). However, there is a lack of a consensus on the BT administration procedure among colorectal surgeons.

METHODS

A national survey approved by the American Society of Colon and Rectal Surgeons (ASCRS) Executive Council was sent to all members. An eight-question survey was sent via ASCRS email correspondence between December 2019 and February 2020. Questions were derived from available meta-analyses and expert opinions on BT use in CAF patients and included topics such as BT dose, injection technique, and concomitant therapies. The survey was voluntary and anonymous, and all ASCRS members were eligible to complete it. Responses were recorded and analyzed via an online survey platform.

RESULTS

216 ASCRS members responded to the survey and 90% inject 50-100U of BT. Most procedures are performed under MAC anesthesia (56%). A majority of respondents (64%) inject into the internal sphincter and a majority (53%) inject into 4 quadrants in the anal canal circumference. Some respondents perform concomitant manual dilatation (34%) or fissurectomy (38%). Concomitant topical muscle relaxing agents are not used uniformly among respondents.

DISCUSSION

Injection of BT for CAF is used commonly by colorectal surgeons. There is consensus on BT dosage, administration site, technique, and the use of monitored anesthesia care.

Temporary Vascular Occlusion with Retrievable Microvascular Plugs to Protect Normal Liver during Yttrium-90 Radioembolization

This case series describes a technique to protect nondiseased liver parenchyma during transarterial radioembolization (TARE) using microvascular plugs to occlude nontarget vessels temporarily and protect normal liver. This technique, defined as temporary vascular occlusion, was performed in 6 patients, with complete vessel occlusion obtained in 5 of the 6 patients and partial occlusion with flow reduction in 1 of the 6 patients. A statistically significant (P = .001) dose decrease of 5.7 ± 3.1 times was measured using postadministration yttrium-90 positron emission tomography/computed tomography in the protected zone compared with that in the treated zone.

Case Series: "Silent" Spinal Epidural Metastases in Metastatic Castrate-Resistant Prostate Cancer

Introduction

Spinal epidural metastases (SEM) are an uncommon phenomenon and traditionally occur as a preterminal event in heavily pre-treated patients. The introduction of novel anti-androgen therapies, such as enzalutamide and abiraterone acetate, has greatly improved the survival of patients with metastatic prostate cancer but may be changing the pattern of disease.

Case Presentation

Four patients diagnosed with metastatic castrate-resistant prostate cancer (CRPC) were commenced on enzalutamide prior to chemotherapy. Baseline scans in all patients demonstrated extensive bony disease and lymph node involvement. All patients experienced a moderate initial PSA response to treatment (median PSA at baseline 53.5 ng/mL to median nadir 24.5 ng/mL). In all four cases, clinical presentation of spinal cord compression was unexpected with no prodromal neurological symptoms, PSA levels either stable or slowly rising, and CT scans and whole-body bone scans showing stable disease at other metastatic sites. Whole-spine MRI on presentation of neurological deficits showed epidural and dural metastases on the background of stable bone disease. Spinal cord compression occurred at a median of 11.4 months after starting enzalutamide.

Conclusion

Clinicians should be aware of this change in the pattern of CRPC in patients treated with novel anti-androgen therapy. Onset of "silent" spinal cord compression due to SEM rather than bone metastases, can occur relatively early with minimal warning despite stable disease on PSA and standard imaging. Differential progression in nontraditional sites suggests that research into the androgen microenvironment in a wide range of tissue sites should be undertaken, and may explain why prostate cancer metastasizes preferentially to bone and lymph nodes.

Protein kinase inhibitor responses in uveal melanoma reflects a diminished dependency on PKC-MAPK signaling

Uveal melanoma (UM) is a rare cancer arising from melanocytes in the uveal tract of the eye. Despite effective primary treatment, there is no approved therapy for metastatic UM and prognosis and survival remain poor. Over 90% of UM are driven by mutations affecting the Gα subunits encoded by the GNAQ and GNA11 genes. These mutations activate downstream and targetable signaling pathways, including the protein kinase C (PKC) cascade. PKC inhibitors have been used in clinical trials for metastatic UM but have shown limited efficacy. In this study, we examined the signaling and functional effects of two PKC inhibitors (AEB071 and IDE196) in a panel of UM cell models. In response to PKC inhibition, all UM cell lines showed potent suppression of PKC activity, but this was not sufficient to predict PKC inhibitor sensitivity and only two UM cell lines showed substantial PKC inhibitor-induced cell death. The differences in UM cell responses to PKC inhibition were not attributable to the degree or timing of PKC suppression or inhibition of the downstream mitogen-activated protein kinase (MAPK) or phosphatidylinositol-3-kinase (PI3K) pathways. Instead, UM cell show complex, PKC-independent signaling pathways that contribute to their survival and resistance to targeted therapies.

Importance of catecholamine signaling in the development of platelet exhaustion after traumatic injury

BACKGROUND

Impaired ex vivo platelet aggregation is common in trauma patients. The mechanisms driving these impairments remain incompletely understood, but functional platelet exhaustion due to excessive in vivo activation is implicated. Given platelet adrenoreceptors and known catecholamine surges after injury, impaired ex vivo platelet aggregation in trauma patients may be linked to catecholamine-induced functional platelet exhaustion.

OBJECTIVE

To determine the relationship of catecholamines with platelet-dependent hemostasis after injury and to model catecholamine-induced functional platelet exhaustion in healthy donor platelets.

PATIENTS/METHODS

Whole blood was collected from 67 trauma patients as part of a prospective cohort study. Platelet aggregometry and rotational thromboelastometry were performed, and plasma epinephrine (EPI) and norepinephrine (NE) concentrations were measured. The effect of catecholamines on healthy donor platelets was examined in a microfluidic model, with platelet aggregometry, and by flow cytometry examining surface markers of platelet activation.

RESULTS

In trauma patients, EPI and NE were associated with impaired platelet aggregation (both p < 0.05), and EPI was additionally associated with decreased viscoelastic clot strength, increased fibrinolysis, and mortality (all p < 0.05). In healthy donors, short duration incubation with EPI enhanced platelet aggregation, platelet adhesion under flow, and increased glycoprotein IIb/IIIa activation, while weaker effects were observed with NE. Compared with short incubation, longer incubation with EPI resulted in decreased platelet adhesion, platelet aggregation, and surface expression of glycoprotein IIb/IIIa.

CONCLUSIONS

These findings suggest sympathoadrenal activation in trauma patients contributes to impaired ex vivo platelet aggregation, which mechanistically may be explained by a functionally exhausted platelet phenotype under prolonged exposure to high plasma catecholamine levels.

Leveraging metabolic modeling to identify functional metabolic alterations associated with COVID-19 disease severity

OBJECTIVE

Since the COVID-19 pandemic began in early 2020, SARS-CoV2 has claimed more than six million lives world-wide, with over 510 million cases to date. To reduce healthcare burden, we must investigate how to prevent non-acute disease from progressing to severe infection requiring hospitalization.

METHODS

To achieve this goal, we investigated metabolic signatures of both non-acute (out-patient) and severe (requiring hospitalization) COVID-19 samples by profiling the associated plasma metabolomes of 84 COVID-19 positive University of Virginia hospital patients. We utilized supervised and unsupervised machine learning and metabolic modeling approaches to identify key metabolic drivers that are predictive of COVID-19 disease severity. Using metabolic pathway enrichment analysis, we explored potential metabolic mechanisms that link these markers to disease progression.

RESULTS

Enriched metabolites associated with tryptophan in non-acute COVID-19 samples suggest mitigated innate immune system inflammatory response and immunopathology related lung damage prevention. Increased prevalence of histidine- and ketone-related metabolism in severe COVID-19 samples offers potential mechanistic insight to musculoskeletal degeneration-induced muscular weakness and host metabolism that has been hijacked by SARS-CoV2 infection to increase viral replication and invasion.

CONCLUSIONS

Our findings highlight the metabolic transition from an innate immune response coupled with inflammatory pathway inhibition in non-acute infection to rampant inflammation and associated metabolic systemic dysfunction in severe COVID-19.

A phase I dose-escalation and expansion study of HBM4003, an anti-CTLA-4 heavy chain only monoclonal antibody, in patients with advanced solid tumors

2641

Background: HBM4003 is a fully human heavy chain only monoclonal antibody (HCAb) to CTLA-4, which has been engineered to deplete Treg cells by enhanced antibody-dependent cellular cytotoxicity (ADCC) activity. In the Phase 1 dose escalation part, HBM4003 showed favorable safety and efficacy profile in patients (pts) with advanced solid tumors. Here, we present the updated data from the dose escalation part and most recent safety and clinical activity data from three expansion cohorts of pts with advanced hepatocellular carcinoma (HCC), melanoma, and renal cell carcinoma (RCC). Methods: In the dose-escalation part, pts were enrolled into 3 dose levels (DL): 0.3mg/kg QW (28-day cycle), 0.45mg/kg Q3W (21-day cycle), and 0.6mg/kg Q3W (21-day cycle). In the dose-expansion part, pts with advanced HCC, melanoma, and RCC received 0.45 mg/kg Q3W (21-day cycle). Tumor measurements were performed every 6 weeks for up to 12 months and subsequently every 12 weeks per RECIST v1.1. Results: In total 60 pts were included for this analysis, including 24 pts with advanced solid tumors in the dose escalation part and 36 pts in the dose expansion part: 18 pts with HCC, 4 pts with melanoma, and 14 pts with RCC, from 12 sites in mainland China, 5 sites in Australia, and 1 site in Hong Kong. 46 pts (77%) received ≥ 2 lines of previous systemic therapies and 37 pts (62%) received previous PD-1/PD-L1 treatment. For the HCC cohort, 19 pts were treated in dose-escalation (1 pt, 0.45 mg/kg Q3W) and dose-expansion parts. All 19 pts received previous PD-1/PD-L1 therapy. 12 pts were evaluable for efficacy. Two had stable disease (SD), 2 pts had partial response (PR) as best response. For 12 evaluable pts, ORR was 16.7% and disease control rate (DCR) was 33.3%. For the RCC cohort, 19 pts were treated in dose-escalation and dose-expansion parts; 18 pts were evaluable for efficacy. Eight had SD as best response; the DCR was 44.4%. Overall, the most common treatment-related adverse event (TRAE) (incidence ≥ 10%) of all grades was rash (16 [26.7%] pts). At the 0.45 mg/kg Q3W DL, the most common TRAE of all grades was hepatic function abnormalities (12 [27.9%] pts) and rash (12 [27.9%] pts). 30 (69.8%) pts reported Gr 1 or 2 TRAEs. Gr ≥3 TRAEs occurred in 4 (9.3%) pts. 1 pt reported Gr 4 TRAE: blood creatine phosphokinase increased. No Gr 5 TRAE was reported. TRAE leading to discontinuation occurred in 4 pts. In mouse model, only tumor infiltrating lymphocytes Treg was depleted upon HBM4003 treatment while no Treg change in blood and spleen. In pts, Treg depletion was observed only in tumor tissue on day 21 post dosing. Overall, HBM4003 demonstrated dose proportional pharmacokinetics and low immunogenicity. Conclusions: HBM4003 showed a favorable safety profile, promising antitumor activity and intratumoral Treg depletion in pts with advanced solid tumors at the 0.45 mg/kg Q3W DL. Clinical trial information: NCT04135261.

IMPRINTER: An open label, multicenter, dose escalation/expansion, phase 1 study of imu-201 (PD1-Vaxx), a B-cell immunotherapy as monotherapy or in combination with atezolizumab, in adults with non-small cell lung cancer (IMU.201.101)

e21134

Background: Therapies with monoclonal antibodies targeting PD-1 and its ligands are associated with remarkable outcomes and have revolutionized cancer treatment (Honey 2017). However, patients treated with PD-1/PD-L1 blockade may develop “a primary or secondary resistance” to therapy (Sharma, Hu-Lieskovan et al. 2017). Contrary to monoclonal antibodies, chimeric B-cell cancer vaccines have the advantage of producing polyclonal B-cell antibodies that can potentially induce memory B- and T-cell responses, while reducing immune evasion and suppression. The hypothesis is that a polyclonal induced B-cell antibody response will be more effective or as effective with improved safety over current monoclonal antibody therapy. IMU-201 (PD1-Vaxx) is being developed using an active immunization approach to treat cancers that overexpress PD-L1 by inducing the production of anti-PD-1 antibodies with a peptide epitope designed to stimulate polyclonal antibodies against PD-1 (Kaumaya et al. 2020). Methods: The IMPRINTER study is an ongoing open-label dose escalation study of IMU-201 as monotherapy (Phase 1) or in combination with atezolizumab (Phase 1b) for patients with PD-L1 expressing non-small cell lung cancer (NSCLC). All patients enrolled in Phase 1 of the study must have previously received an immune checkpoint inhibitor and experienced disease progression. The primary objective is to evaluate the safety and tolerability of IMU-201 and identify the optimal biological dose (OBD). The secondary objective is to evaluate the efficacy of IMU-201 as monotherapy and in combination with atezolizumab. Humoral and cellular immunogenicity data will be evaluated, including IMU-201 and PD-1 specific antibodies (IgG, IgM), vaccine-specific cytokine levels, and regulatory and effector T and B cells. IMU-201 is administered by intramuscular (IM) injection on Day 1, Day 15, and Day 29. Dose-limiting toxicity (DLT) assessment is completed after 29 days on treatment. Tumor progression is evaluated according to RECIST 1.1 at Day 43 then every 42 days until progression or withdrawal. Results: In Phase 1, four patients were enrolled into each of the three cohorts at 10 μg/dose, 50 μg/dose and 100 μg/dose IMU-201 with no DLTs observed. In the 10 μg/dose cohort, one patient achieved CR and one patient SD; in the 50 μg/dose cohort, four patients achieved SD; and in the 100 μg/dose cohort, one patient achieved PR and two patients achieved SD. Within the 100 μg/dose cohort, one patient experienced an immune related pneumonitis after two IMU-201 administrations and discontinued from study treatment. Conclusions: IMU-201 had no observed DLT and demonstrated preliminary signs of efficacy. The study will therefore move into Phase 1b with IMU-201 being assessed in combination with atezolizumab. Clinical trial information: NCT04432207.

Safety and efficacy of YBL-006, an anti-PD-1 monoclonal antibody in advanced solid tumors: A phase I study

e14557

Background: YBL-006 is a fully human anti-programmed death-1 (PD-1) antibody under evaluating its safety and efficacy in phase I clinical trial. We have reported interim analysis of dose escalation cohort which showed a tolerable safety profile. Here, we present the updated clinical activity of YBL-006 in dose escalation and expansion cohorts. Methods: Dose escalation (0.5, 2, 5, 10 mg/kg) and dose expansion (flat doses of 200 mg every 2 weeks [Q2W] and 300 mg every 3 weeks [Q3W]) cohorts explored the safety, pharmacokinetics (PK) and objective response rate (ORR) in the patients with advanced solid tumors who failed or were ineligible to the standard of care. Adverse events (AEs) were graded using the CTCAE v5. ORR was assessed using the RECIST (v1.1). Lunit SCOPE IO, an H&E analysis tool, was applied as an exploratory biomarker, and samples with “Immune inflamed phenotype” were defined as those with high intratumoral TIL density in ≥ 20% of the tumor microenvironment. The cut-off date for analysis was Jan 4th, 2022. Results: A total of 67 patients (safety set) with advanced solid tumors were enrolled in the study. Median follow-up duration of the safety set was 1.6 months (range 0.2-16.8). There was no dose-limiting toxicity during dose escalation phase. Most frequent AEs were grade 1 or 2; fatigue (19.4%), pruritus (10.4%), and fever (7.5%), and two hypothyroidism (3.0%), one pneumonitis (1.5%), and one cytokine-releasing syndrome (1.5%) were observed. One subject experienced grade 3 diarrhea in the safety set. PK study showed that half-life was 8.0 days, and mean Cmax and AUC0-inf were 4.15 x 104 ng/ml and 1.12 x 107 ng/ml*h for 200 mg dose, and 6.26 x 104 ng/ml and 1.53 x 107 ng/ml*h for 300 mg dose, respectively. A total of 52 patients were evaluable for efficacy. ORR was 15.4%, including 1 complete response (penile squamous cell carcinoma [SqCC]), and 7 partial responses (two gastric adenocarcinomas, anal SqCC, paranasal sinus SqCC, nasopharyngeal carcinoma, neuroendocrine carcinoma, and thyroid Hurthle cell carcinoma). Durable responses were seen in 2 patients for over 12 months. Median duration of response was 4.9 weeks (range 1-65). Among efficacy set, 32 samples were available for Lunit SCOPE IO. ORR was significantly higher in inflamed immune phenotype compared to non-inflamed samples (62.5% vs 8.3% p = 0.005). Conclusions: Interim analysis of phase I trial of YBL-006 shows a tolerable safety profile and clinical activity. Notable anti-tumor efficacy was observed in inflamed immune phenotype. Clinical trial information: NCT04450901.

TACTI-003: A randomized phase IIb study of eftilagimod alpha (soluble LAG-3 protein) and pembrolizumab as first-line treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma

TPS6099

Background: Eftilagimod alpha (efti) is a soluble LAG-3 protein targeting a subset of MHC class II molecules that mediate antigen presenting cell (APC) and CD8 T-cell activation. Data from a non-randomized, phase II trial of efti plus pembrolizumab (TACTI-002) showed encouraging antitumor activity and manageable safety when given as second-line treatment of patients with recurrent or metastatic head and neck squamous-cell carcinoma (RM-HNSCC). TACTI-003 (NCT04811027) is a multicenter, open label, randomized phase IIb trial to investigate efti plus pembrolizumab in the first-line setting for RM-HNSCC. Methods: A total of 154 patients (pts) are currently being recruited into two cohorts (A+B). In cohort A, pts with tumors that are CPS≥1 will be randomly assigned 1:1 to receive either efti (30 mg subcutaneously Q2W for initial 6 months, thereafter Q3W) plus pembrolizumab (400 mg intravenously Q6W) for up to two years or pembrolizumab alone. Randomization will be stratified by CPS (1-19 vs. ≥ 20) and ECOG PS (0 vs. 1). Pts with tumors that are CPS < 1 will receive efti plus pembrolizumab (cohort B). Imaging will be performed every 9 weeks. The primary endpoint (EP) is objective response rate (ORR) by RECIST1.1. Secondary EPs include overall survival, ORR according to iRECIST, time to and duration of response, disease control rate, progression-free survival, occurrence of anti-efti -specific antibodies, safety, and quality of life. Exploratory endpoints comprise biomarkers. The study has been approved by relevant competent authorities, ethic committees and IRBs. Clinical trial information: NCT04811027.

Disparities in Screening for Colorectal Cancer Based on Limited Language Proficiency

BACKGROUND

This study analyzes the association between limited language proficiency and screening for colorectal cancer.

METHODS

This is a retrospective cohort study from the 2015 sample of the National Health Interview Survey database utilizing univariate and multivariate regression analysis. The study population includes subjects between 50 and 75 years of age. The main outcome analyzed was rates of screening colonoscopies between limited English-language proficiency (LEP) subjects and those fluent in English. Secondary outcomes included analysis of baseline, socioeconomic, access to health care variables, and other modalities for colorectal cancer screening between the groups.

RESULTS

Incidence of limited language proficiency was 4.8% (n = 1978, count = 4 453 599). They reported lower rates of screening colonoscopies (61% vs 34%, P < .001), less physician recommendation for a colonoscopy (87 vs 60%, P < .001), fewer polyps removed in the previous 3 years (24% vs 9.1%; P < .001), and fewer fecal occult blood samples overall (P < .001). Additionally, Hispanic non-LEP subjects have higher rates of colonoscopies compared to those with language barriers (50% vs 33%, P < .001). On multivariate analysis, LEP was associated with a lower likelihood to have a screening colonoscopy (OR .67 95% CI .49-.91). A second regression model with "Spanish language" and "other language" variables included, associated Spanish speakers with a lower likelihood for a screening colonoscopy (OR .71 95% CI .52-.97) when controlling for baseline, socioeconomic, and access to health care covariates.

DISCUSSION

Patients with limited English-language proficiency are associated with lower rates of screening for colorectal cancer, in particular the Spanish speaking subgroup.

Correlation of Tumor Response Between Flexible Sigmoidoscopy and Magnetic Resonance Imaging in Patients Undergoing Neoadjuvant Therapy for Locally Advanced Rectal Cancer: A Retrospective Review

BACKGROUND

The National Accreditation Program for Rectal Cancer recommends a pelvic MRI to assess the response to neoadjuvant therapy for advanced rectal cancers. However, there is no single restaging modality that can identify all patients with complete tumor response. At our institution, we perform both a pelvic MRI and a flexible sigmoidoscopy (FS) after neoadjuvant therapy prior to surgical resection.

OBJECTIVE

The objective is to elucidate the correlation of tumor response between FS and MRI in patients undergoing neoadjuvant therapy for locally advanced rectal cancer.

DESIGN

Single institution from 2010 to 2019. Retrospective cohort study comparing local tumor response on FS to MRI utilizing final pathology as the gold standard for comparison.

PATIENTS

Patients with confirmed locally advanced rectal adenocarcinoma (stage II or III) who underwent neoadjuvant therapy prior to surgical intervention and underwent flexible endoscopy and a standardized rectal cancer protocol MRI to evaluate tumor response.

RESULTS

A total of 48 patients were evaluated. Seven (14%) patients had a complete pathological response. MRI adequately reported 1 (14%), while FS found 4 (57.14%) out of the 7 complete responders. Nevertheless, this did not reach statistical significance (P = .06). On logistic regression analysis, flexible sigmoidoscopy had a 5.5 higher likelihood to report an accurate complete response (OR 5.5, 95% CI: 1.02-29.64; P = .047).

CONCLUSIONS

Flexible sigmoidoscopy should be used in conjunction with MRI in the work up of patients who have received neoadjuvant therapy for advanced rectal cancer prior to surgical resection.

Clinical Models to Define Response and Survival With Anti-PD-1 Antibodies Alone or Combined With Ipilimumab in Metastatic Melanoma

PURPOSE

Currently, there are no robust biomarkers that predict immunotherapy outcomes in metastatic melanoma. We sought to build multivariable predictive models for response and survival to anti-programmed cell death protein 1 (anti-PD-1) monotherapy or in combination with anticytotoxic T-cell lymphocyte-4 (ipilimumab [IPI]; anti-PD-1 ± IPI) by including routine clinical data available at the point of treatment initiation.

METHODS

One thousand six hundred forty-four patients with metastatic melanoma treated with anti-PD-1 ± IPI at 16 centers from Australia, the United States, and Europe were included. Demographics, disease characteristics, and baseline blood parameters were analyzed. The end points of this study were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The final predictive models for ORR, PFS, and OS were determined through penalized regression methodology (least absolute shrinkage and selection operator method) to select the most significant predictors for all three outcomes (discovery cohort, N = 633). Each model was validated internally and externally in two independent cohorts (validation-1 [N = 419] and validation-2 [N = 592]) and nomograms were created.

RESULTS

The final model for predicting ORR (area under the curve [AUC] = 0.71) in immunotherapy-treated patients included the following clinical parameters: Eastern Cooperative Oncology Group Performance Status, presence/absence of liver and lung metastases, serum lactate dehydrogenase, blood neutrophil-lymphocyte ratio, therapy (monotherapy/combination), and line of treatment. The final predictive models for PFS (AUC = 0.68) and OS (AUC = 0.77) included the same variables as those in the ORR model (except for presence/absence of lung metastases), and included presence/absence of brain metastases and blood hemoglobin. Nomogram calculators were developed from the clinical models to predict outcomes for patients with metastatic melanoma treated with anti-PD-1 ± IPI.

CONCLUSION

Newly developed combinations of routinely collected baseline clinical factors predict the response and survival outcomes of patients with metastatic melanoma treated with immunotherapy and may serve as valuable tools for clinical decision making.

Therapeutic Anticoagulation with Heparin in Critically Ill Patients with Covid-19

BACKGROUND

Thrombosis and inflammation may contribute to morbidity and mortality among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation would improve outcomes in critically ill patients with Covid-19.

METHODS

In an open-label, adaptive, multiplatform, randomized clinical trial, critically ill patients with severe Covid-19 were randomly assigned to a pragmatically defined regimen of either therapeutic-dose anticoagulation with heparin or pharmacologic thromboprophylaxis in accordance with local usual care. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge.

RESULTS

The trial was stopped when the prespecified criterion for futility was met for therapeutic-dose anticoagulation. Data on the primary outcome were available for 1098 patients (534 assigned to therapeutic-dose anticoagulation and 564 assigned to usual-care thromboprophylaxis). The median value for organ support-free days was 1 (interquartile range, -1 to 16) among the patients assigned to therapeutic-dose anticoagulation and was 4 (interquartile range, -1 to 16) among the patients assigned to usual-care thromboprophylaxis (adjusted proportional odds ratio, 0.83; 95% credible interval, 0.67 to 1.03; posterior probability of futility [defined as an odds ratio <1.2], 99.9%). The percentage of patients who survived to hospital discharge was similar in the two groups (62.7% and 64.5%, respectively; adjusted odds ratio, 0.84; 95% credible interval, 0.64 to 1.11). Major bleeding occurred in 3.8% of the patients assigned to therapeutic-dose anticoagulation and in 2.3% of those assigned to usual-care pharmacologic thromboprophylaxis.

CONCLUSIONS

In critically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin did not result in a greater probability of survival to hospital discharge or a greater number of days free of cardiovascular or respiratory organ support than did usual-care pharmacologic thromboprophylaxis. (REMAP-CAP, ACTIV-4a, and ATTACC ClinicalTrials.gov numbers, NCT02735707, NCT04505774, NCT04359277, and NCT04372589.).