The state of the art of EGFR exon 20 insertions in non-small cell lung cancer: Diagnosis and future perspectives

Insertions in the epidermal growth factor receptor (EGFR) exon 20 (Ex20Ins) are the third most incident mutations in non-small cell lung cancer (NSCLC). The hypervariable nature of these driver mutations hinders their identification by traditional polymerase chain reaction (PCR)-based methods, requiring a comprehensive sequencing approach to detect all possible insertions. The prognosis of patients with EGFR Ex20Ins is similar to those with wild-type NSCLC, since no targeted drugs are approved in the first-line setting, and platinum-based chemotherapy is currently the front-line treatment. However, the new generation of drugs currently being tested in first and post-platinum settings will likely change the management of this entity. Here, we summarize the latest data on EGFR Ex20Ins molecular characteristics, patient profile, identification challenges, and emerging therapies to help lung clinicians face a growing treatment landscape.

Targeting HER2-mutant metastatic cervical cancer with neratinib: Final results from the phase 2 SUMMIT basket trial

OBJECTIVE

HER2 mutations are associated with poor prognosis and are detected in 3-6% of cervical cancers. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, had activity in several HER2-mutant cancer types in the phase 2 SUMMIT basket study. We present updated and final results from the cervical cancer cohort of SUMMIT.

METHODS

Eligible patients had HER2-mutant, metastatic or recurrent cervical cancer progressing after platinum-based treatment for advanced/recurrent disease. Patients received neratinib 240 mg/day; loperamide was mandatory during cycle 1. Confirmed objective response rate (ORR) was the primary endpoint. Duration of response (DoR), clinical benefit rate (CBR), progression-free survival (PFS), and safety were secondary endpoints.

RESULTS

Twenty-two patients were enrolled; 18 (81.8%) had endocervical adenocarcinoma; median two prior systemic chemotherapy regimens (range 1-4). The most common HER2 variant was S310F/Y mutation (n = 13; 59.1%). Four patients had confirmed partial responses (ORR 18.2%; 95% CI 5.2-40.3); 6 had stable disease ≥16 weeks (CBR 45.5%; 95% CI 24.4-67.8). Median DoR was 7.6 months (95% CI 5.6-12.3). Median PFS was 5.1 months (95% CI 1.7-7.2). All-grade diarrhea (90.9%), nausea (54.5%), and constipation (54.5%) were the most common adverse events. Five patients (22.7%) reported grade 3 diarrhea. There were no grade 4 adverse events, no diarrhea-related treatment discontinuations, and two grade 5 adverse events, unrelated to neratinib: dyspnea (n = 1) and embolism (n = 1).

CONCLUSIONS

Neratinib resulted in durable responses and disease control in patients with HER2-mutant metastatic/recurrent cervical cancer in SUMMIT. These findings support next-generation sequencing and tailored therapy for select patients with advanced cervical cancer. All responses occurred in patients with endocervical adenocarcinoma. Further assessment of neratinib in this setting is warranted.

TRIAL REGISTRATION NUMBER

NCT01953926 (ClinicalTrials.gov), 2013-002872-42 (EudraCT).

Bexmarilimab-induced macrophage activation leads to treatment benefit in solid tumors: The phase I/II first-in-human MATINS trial

Macrophage Clever-1 contributes to impaired antigen presentation and suppression of anti-tumor immunity. This first-in-human trial investigates the safety and tolerability of Clever-1 blockade with bexmarilimab in patients with treatment-refractory solid tumors and assesses preliminary anti-tumor efficacy, pharmacodynamics, and immunologic correlates. Bexmarilimab shows no dose-limiting toxicities in part I (n = 30) and no additional safety signals in part II (n = 108). Disease control (DC) rates of 25%-40% are observed in cutaneous melanoma, gastric, hepatocellular, estrogen receptor-positive breast, and biliary tract cancers. DC associates with improved survival in a landmark analysis and correlates with high pre-treatment intratumoral Clever-1 positivity and increasing on-treatment serum interferon γ (IFNγ) levels. Spatial transcriptomics profiling of DC and non-DC tumors demonstrates bexmarilimab-induced macrophage activation and stimulation of IFNγ and T cell receptor signaling selectively in DC patients. These data suggest that bexmarilimab therapy is well tolerated and show that macrophage targeting can promote immune activation and tumor control in late-stage cancer.

Single-Agent Divarasib (GDC-6036) in Solid Tumors with a KRAS G12C Mutation

BACKGROUND

Divarasib (GDC-6036) is a covalent KRAS G12C inhibitor that was designed to have high potency and selectivity.

METHODS

In a phase 1 study, we evaluated divarasib administered orally once daily (at doses ranging from 50 to 400 mg) in patients who had advanced or metastatic solid tumors that harbor a KRAS G12C mutation. The primary objective was an assessment of safety; pharmacokinetics, investigator-evaluated antitumor activity, and biomarkers of response and resistance were also assessed.

RESULTS

A total of 137 patients (60 with non-small-cell lung cancer [NSCLC], 55 with colorectal cancer, and 22 with other solid tumors) received divarasib. No dose-limiting toxic effects or treatment-related deaths were reported. Treatment-related adverse events occurred in 127 patients (93%); grade 3 events occurred in 15 patients (11%) and a grade 4 event in 1 patient (1%). Treatment-related adverse events resulted in a dose reduction in 19 patients (14%) and discontinuation of treatment in 4 patients (3%). Among patients with NSCLC, a confirmed response was observed in 53.4% of patients (95% confidence interval [CI], 39.9 to 66.7), and the median progression-free survival was 13.1 months (95% CI, 8.8 to could not be estimated). Among patients with colorectal cancer, a confirmed response was observed in 29.1% of patients (95% CI, 17.6 to 42.9), and the median progression-free survival was 5.6 months (95% CI, 4.1 to 8.2). Responses were also observed in patients with other solid tumors. Serial assessment of circulating tumor DNA showed declines in KRAS G12C variant allele frequency associated with response and identified genomic alterations that may confer resistance to divarasib.

CONCLUSIONS

Treatment with divarasib resulted in durable clinical responses across KRAS G12C-positive tumors, with mostly low-grade adverse events. (Funded by Genentech; ClinicalTrials.gov number, NCT04449874.).

Measurement of vegetations in infective endocarditis: An inaccurate method to decide the therapeutical approach

BACKGROUND

The European Society of Cardiology and American Heart Association guidelines give a central role to the maximal vegetation diameter in the indication for surgery to prevent embolism in left sided infective endocarditis. Vegetation measuring is likely to be inaccurate. The hypothesis herein, is that the vegetation diameter is not an appropriate surgical criterion given the variability of its measurement.

METHODS

Two trained echocardiographers independently measured the maximal vegetation diameter by transesophageal echocardiogram of 76 vegetations in 67 consecutive patients with definite infective endocarditis in an off-line workstation. The interobserver variability was calculated by the interclass correlation coefficient. The relationship between the strength of agreement for the cut-off points of 10 and 15 mm was also calculated. Finally, the number of patients whose surgical indication would have changed depending on which operator measured the vegetation was evaluated.

RESULTS

Interobserver interclass correlation coefficient in the measurement of the maximal longitudinal diameter of the vegetations was 0.757 (0.642-0.839). The strength of agreement of the interobserver analysis for the cut-off point of 10 mm was 0.533 (0.327-0.759). For the cut-off point of 15 mm it was 0.475 (0.270-0.679). If heart failure or uncontrolled infections had been absent, the surgical indication would have changed in a total of 33 patients (33/76; 43%) depending on which operator measured the vegetation.

CONCLUSIONS

The variability in the measurements of the maximal longitudinal diameter by transesophageal echocardiogram is high. Surgical indications based on the cut-off points recommended by the international guidelines should be revised.

New Checkpoint Inhibitors on the Road: Targeting TIM-3 in Solid Tumors

PURPOSE OF REVIEW

Even though checkpoint inhibitors have become a recent milestone for the treatment of many different tumor types, eventually, most part of patients will develop resistance mechanisms and their disease will progress. New generations of checkpoint inhibitors, as the ones directed to TIM-3, are on research.

RECENT FINDINGS

TIM-3 expression has been associated with more advanced stages and shorter survival in several tumor types, due to its association with T-cell dysfunction, and has become an interesting target to explore. Early phase clinical trials with different anti-TIM-3 monoclonal antibodies have shown a safe toxicity profile, as cobolimab, LY3321367, or sabatolimab; however, the general antitumor activity remains to be determined and further investigations are needed. TIM-3 is implicated in resistance to immunotherapy due to its role in T cell exhaustion. However, the TIM-3 pathway is highly complex in terms of non-canonical signaling, broad expression by different immune cells and multiple ligands. Different anti-TIM-3 inhibitors are currently on research, either as monotherapy or in combination with other immunotherapies or chemotherapy, aiming to overcome resistance.

Phase I study of lurbinectedin in combination with weekly paclitaxel with or without bevacizumab in patients with advanced solid tumors

Lurbinectedin and paclitaxel showed synergism in preclinical studies and have non-completely overlapping toxicity profiles. This phase I trial evaluated a combination of paclitaxel and lurbinectedin with/without bevacizumab in advanced tumors. This trial was divided into Group A, which evaluated weekly paclitaxel (60 or 80 mg) plus lurbinectedin (3.0-5.0 mg flat dose [FD] or 2.2 mg/m²) every 3 weeks in advanced solid tumors; and Group B, which evaluated bevacizumab (BEV, 15 mg/kg) added to the recommended dose (RD) defined in Group A in advanced epithelial ovarian or non-small cell lung cancer (NSCLC). 67 patients (A, n = 55; B, n = 12) were treated. The RD was paclitaxel 80 mg/m² on Day (D)1,D8 plus lurbinectedin 2.2 mg/m² on D1. At this RD, myelotoxicity was reversible and manageable, and most non-hematological toxicities were mild/moderate. Adding BEV did not notably change tolerability. Twenty-five confirmed responses were observed: 20/51 evaluable patients in Group A (overall response rate [ORR] = 39% at all dose levels and at the RD), and 5/10 evaluable patients in Group B (ORR = 50%). Most responders had breast (n = 7/12 patients), small cell lung (SCLC) (n = 5/7), epithelial ovarian (n = 3/9) and endometrial cancer (n = 3/11) in Group A, and epithelial ovarian (n = 3/4) and NSCLC (n = 2/6) in Group B. Clinical benefit rate was 61% in Group A (58% at the RD), and 90% in Group B. No major pharmacokinetic drug-drug interactions were observed. Paclitaxel/lurbinectedin and paclitaxel/lurbinectedin/BEV are feasible combinations. Further development is warranted of paclitaxel/lurbinectedin in SCLC, breast, and endometrial cancer, and of paclitaxel/lurbinectedin/BEV in epithelial ovarian cancer.

T cell engagers in solid tumors kick the door down

Tebentafusp, a T cell-redirecting, bispecific-antibody-targeting, HLA^∗02:01-restricted gp100 peptide and CD3, induces T cells to kill glycoprotein 100 (gp100)-expressing tumor cells. Tebentafusp is the first T cell engager to show a statistically significant overall survival improvement for the treatment of patients with solid tumors, and this has been reported in the New England Journal of Medicine.

504 A phase I, first-in-human clinical trial of the GDF-15 neutralizing antibody CTL-002 in subjects with advanced stage solid tumors (Acronym: GDFATHER)

Background

Growth and differentiation factor 15 (GDF-15) is a TGF-β superfamily member physiologically expressed mainly in placenta and linked to feto-maternal tolerance. Under pathophysiologic conditions, prevention of excessive immune cell infiltration during tissue damage and cachexia induction have been ascribed to GDF-15. Recent research has though indicated a prominant role in modulation of the tumor microenvironment and the immune synapse, too1 2 indicating that GDF-15 may be a major tumor-derived immunosuppressant. Importantly, several cancer entities secrete high levels of GDF-15, correlating with poor prognosis and reduced overall survival [Front Immunol 2020 May 19;11:951]. To block this effect the GDF-15 neutralizing antibody CTL-002 was generated. In preclinical models CTL-002 demonstrated potent effector T cell shifting into tumor tissue by neutralizing GDF-15.

Methods

This is a phase 1, first-in-human (FIH), two-part, open-label clinical trial of intravenous (IV) administration of CTL-002 given as monotherapy and in combination with an anti-PD-1 antibody in subjects with advanced-stage, relapsed/refractory solid tumors who relapsed or were refractory to a prior anti-PD-1/PD-L1 therapy. Eligible subjects have exhausted all available approved standard treatments, including prior anti-PD1/-PD-L1 treatment, and present with a biopsy-accessible tumor for serial biopsy taking. The trial is termed GDFATHER, for ”GDF-15 Antibody-mediaTed Effector cell Relocation”.Main endpoints are safety of CTL-002 monotherapy and CTL-002 combination with an anti-PD-1 antibody, pharmacokinetics, pharmacodynamics (e.g. degree of GDF-15 neutralization achieved and change in immune-cell number and composition in the tumor tissue) as well as preliminary clinical efficacy (tumor mass reduction; anticachexia effect)In part A of the trial (dose escalation) up to 24 subjects will receive escalating doses of CTL-002 IV (0.3 – 20 mg/kg) in a ”mono-followed-by-combination”-design with CTL-002 given as monotherapy and followed by combination with an anti-PD-1 checkpoint inhibitor. In part B (expansion) up to 5 cohorts with up to 25 subjects per cohort with defined tumor entities expected to be GDF-15 dependent will be treated to determine the recommended phase 2 dose (RP2D) and further evaluate safety and preliminary efficacy of CTL-002 monotherapy and the combination.The study was initiated in December 2020 and enrolled the first patient on Dec 09, 2020. Cohort 4 is ongoing at time of submission (07/2021) and so far no DLT has occurred. Updated safety, biomarker and response assessments will be reported at the meeting. The ClinicalTrials.gov Identifier is NCT04725474. For more information please contact info@catalym.com.

Trial Registration

NCT04725474

References

Wischhusen J, Wistuba-Hamprecht K, Harter PN, Cheng P, Martens A, Gogolla F, Nonomura Y, Romer P, Koch SD, Haake M, Schuberth-Wagner C, Rudiger M, Leo E, Mittelbronn M, Levesque MP, Hackl H, Dummer R, Weide B. Identifying GDF-15 as potential novel immunotherapeutic target linked to immune cell exclusion in tumors and resistance to anti-PD-1 treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27–28 and Jun 22–24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl): Abstract nr 2161.

Hurt E, Thomas S, Mulgrew K, Blackmore S, Moynihan J, Cusdin F, Dodd R, Cariuk P, Sigurdardottir A, Brannigan E, Dobson C, Kumar R, Cobbold M. AZD8853: A novel antibody targeting GDF15 for immunotherapy refractory tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10–15 and May 17–21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl): Abstract nr 1828.

Ethics Approval

All participants gave informed consent prior to participation. EC approval by Gobierno de Navarra, Departamento de Salud, EC_2020/30, Dated: Oct 13, 2020 in Pamplona, Spain. Respective additional national lead EC approvals for Germany (Ethikkommission der Universität Würzburg, 203–20ff of Oct 26, 2020) and Switzerland (Kantonale Ethikkommission Zürich, 2020–02308 of Nov 24, 2020).

Toxicity and antitumor activity of novel agents in elderly patients with cancer included in phase 1 studies

Introduction The number of cancer cases among the elderly continue to increase as the worldwide population ages. This patient subset is underrepresented in clinical trials, partly because of unresolved uncertainties about age-associated tolerabilities and antitumor activities. We reviewed phase 1 trial data to study tolerance and efficacy of novel agents used for treatment of elderly patients with cancer. Methods Data from 773 consecutive evaluable patients in 85 phase 1 clinical trials (2008-2016) at START Madrid-CIOCC were analyzed according to age, with respect to objective response, survival, and toxicity. Results The mean age was 58.7 (range: 18-87) years; 260 (33.6%) patients were >65 y (elderly group). One hundred thirty-seven (17.8%) patients received immunotherapy drugs, 308 (39.8%) received targeted agents, and 328 (42.4%) received chemotherapy. No statistically significant differences in overall survival, objective response, or severe toxicity rates were found according to treatment type. Similar toxicities and clinical activities were found between the two age subgroups; 18.8% of the elderly and 20.7% of the younger patients experienced severe hematological toxicity (p=0.5), and 30.2% and 32.7%, respectively, experienced severe non-hematological toxicity (p=0.4). Regarding antitumor activity, 12.4% of the elderly and 15% of the younger patients achieved objective responses (p=0.41). There were no significant between-group differences in overall survival (9.7 versus 11.5 months, respectively, p=0.1) or progression-free survival (2.3 versus 2.2 months, respectively, p=0.7). Conclusions This retrospective study found that elderly and younger populations had comparable antitumor activities and toxicity profiles. These results support including elderly patients with cancer in early-phase trials.

Abstract LB179: Oncolytic virus TG6002 locates to tumors after intravenous infusion and induces tumor-specific expression of a functional pro-drug activating enzyme in patients with advanced gastrointestinal carcinomas

Objective: TG6002 is a vaccinia virus deleted for Thymidine Kinase/Ribonucleotide Reductase and encoding the FCU1 enzyme that converts 5-Fluorocytosine (5-FC) to 5-Fluorouracil (5-FU). In a dose-escalation phase I study combining intravenous TG6002 and oral 5-FC in patients with advanced gastrointestinal carcinomas, exploratory analyses were performed to document TG6002 pharmacokinetic (PK) and biodistribution, and FCU1 function.

Methodology: A total of 10 patients, median age 60 years (range 50-69), received TG6002 infusions on days 1, 8 and 15 at the dose of 3x108 pfu (n=3) (low dose, LD) or 1x109 pfu (high dose, HD) (n=7) combined with 5-FC (4 times 50 mg/kg/day) on days 5 to 7, 12 to 14, and 19 to 28 for colorectal (n=6), esophagus (n=1), gastric (n=1), pancreatic (n=1) and ampulla of Vater (n=1) carcinomas. Blood was sampled 30 min, 3h and 24h after TG6002 infusion on day 1 and 15 for plasma TG6002 PK and one hour after intake of 5-FC at screening (single dose of 50 mg/kg) and on days 5, 7, 14 and 28 for serum 5-FC and 5-FU measurements. A metastasis biopsy was performed on day 5 along with synchronous blood sampling. Virus presence was assessed by qPCR and plaque assay, and 5-FC and 5-FU quantified using HPLC-MS. Neutralizing antibodies (NAb) titers were assessed using a plaque inhibition assay at baseline, days 28 and 43.

Results: TG6002 was detected by qPCR in plasma and was rapidly cleared with no patients showing trace of the virus beyond 3 hours after administration. On day 5, despite very scarce availability of biomaterial, the virus was detected in tumoral tissue in 1/3 and 2/7 patients of the LD and HD cohorts, respectively. 5-FC to 5-FU conversion was detected in tumor of all patients and the highest tumor concentrations of 5-FU (65 and 227 pg/mg of tissue, respectively) were found in 2 of the 3 patients in which virus was detected in the tumor. The other patients had tumor 5-FU concentrations ranging from 0.8 to 8.7 pg/mg. Those patients with highest tumor 5-FU levels had the highest level of serum 5-FU on day 5 (352 and 417 ng/mL, respectively). All other patients had levels of 5-FU ranging from 2 to 42 ng/mL, reflecting FCU1 activity. No 5-FU was detected after the intake of 5-FC during the screening period, excluding endogenous 5-FC to 5-FU conversion. Overall, blood 5-FU concentrations were 89±144, 50±96, 7±9 and 1±0.6 ng/ml on days 5, 7, 14 and 28, respectively, with no apparent differences between LD and HD cohorts. NAbs were developed by all patients on day 28 and could explain the decrease in blood 5-FU over the study course.

In conclusion, despite the sensitivity challenges associated with direct detection of viral particles in patient tumor tissue, our data suggest that TG6002 locates to tumors after intravenous administration, remains active and effectively express an active recombinant payload selectively in tumor tissue. The study is continuing with escalating doses of virus.

Citation Format: Kaidre Bendjama, Philippe Cassier, Victor Moreno, Bernard Doger, Emiliano Calvo, Maria de Miguel, Christiane Jungels, Philippe Erbs, Damien Carpentier, Alain Sadoun. Oncolytic virus TG6002 locates to tumors after intravenous infusion and induces tumor-specific expression of a functional pro-drug activating enzyme in patients with advanced gastrointestinal carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB179.

Adoptive cell therapy for solid tumors: Chimeric antigen receptor T cells and beyond

Adoptive cell therapy with chimeric antigen receptor T cells has caused a significant revolution in the treatment of hematological malignancies. Unfortunately, for solid tumors, this treatment modality has been proven insufficient to achieve significant antitumor activity. The use of modified T cell receptors towards tumor-associated antigens (NY-ESO, MAGE-A4) has recently shown antitumor activity in synovial sarcoma. Also, treatment with tumor-infiltrating lymphocytes shows clinical activity in metastatic cervical cancer and melanoma resistant to checkpoint inhibitors. Strategies to improve results and broaden the applicability of therapeutic lymphocytes for solid tumors include local delivery, fourth generation chimeric antigen receptor T cells, off-the-shelf T lymphocytes and private neoantigen-directed cells, among others. In this review, we summarize the status of adoptive cell therapy using T cells for solid tumors and the investigational strategies being tested in this field.

A Predictive Score of Antitumour Activity of Novel Agents in Cancer Patients Treated in Early Phase Studies

INTRODUCTION

Phase I trials aim to determine the maximum-tolerated dose of a particular drug while minimizing the number of patients exposed to either sub-therapeutic doses or severe toxicity. Thus, patient selection for phase I trials is a key component of any clinical trial design. Though several studies have been made to address this issue, patient selection still represents a major clinical challenge that needs further investigation.

METHODS

Twenty-nine baseline clinical and analytical characteristics of 773 consecutive patients treated in phase I trials between 2008 and 2016 in START Madrid-CIOCC were analysed and correlated to objective response (OR), progression-free survival, median overall survival, toxicity, and treatment type. The ones associated to OR in the univariate analysis were included in the stepwise logistic regression multivariate and Cox analysis. The statistically significant ones were included in a predictive score (named here as the Madrid score) of antitumour activity.

RESULTS

Body mass index (BMI) >25 (p = 0.027), two or less previous lines of treatment (p = 0.007), and normal levels of alkaline phosphatase (ALP) (p = 0.007) were found to positively correlate to radiological response. A Madrid score was generated using these three factors as predictive parameters: compared to a score of 2-3 (where 2 or 3 of these variables are altered), a score of 0-1 is associated with longer survival time (11.6 vs. 8.6 months; p = 0.005) and overall response (17 vs. 7.6%; p = 0.003).

CONCLUSION

The predictive Madrid score, based on the BMI, number of prior lines of treatment, and ALP levels, might be helpful to accurately select patients who would benefit from oncology phase I clinical trials.

T-cell-engaging Therapy for Solid Tumors

T-cell engagers (TCE) are a rapidly evolving novel group of treatments that have in common the concurrent engagement of a T-cell surface molecule and a tumoral cell antigen. Bispecific antibodies and genetically engineered adoptive cell therapies, as chimeric antigen receptors or T-cell receptors, have similarities and differences among their mechanisms of action, toxicity profiles, and resistance pathways. Nevertheless, the success observed in the hematologic field has not been obtained with solid tumors yet, as they are biologically more complex and have few truly tumor-specific cell surface antigens that can be targeted with high avidity T cells. Different strategies are under study to improve their short-term perspective, such as new generations of more active TCEs, multi-target or combination of different treatments approaches, or to improve the manufacturing processes. A comprehensive review of TCEs as a grouped treatment class, their current status, and research directions in their application to solid tumors therapeutics are discussed here.

Intermittent schedules of the oral RAF-MEK inhibitor CH5126766/VS-6766 in patients with RAS/RAF-mutant solid tumours and multiple myeloma: a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study

BACKGROUND

CH5126766 (also known as VS-6766, and previously named RO5126766), a novel MEK-pan-RAF inhibitor, has shown antitumour activity across various solid tumours; however, its initial development was limited by toxicity. We aimed to investigate the safety and toxicity profile of intermittent dosing schedules of CH5126766, and the antitumour activity of this drug in patients with solid tumours and multiple myeloma harbouring RAS-RAF-MEK pathway mutations.

METHODS

We did a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study at the Royal Marsden National Health Service Foundation Trust (London, UK). Patients were eligible for the study if they were aged 18 years or older, had cancers that were refractory to conventional treatment or for which no conventional therapy existed, and if they had a WHO performance status score of 0 or 1. For the dose-escalation phase, eligible patients had histologically or cytologically confirmed advanced or metastatic solid tumours. For the basket dose-expansion phase, eligible patients had advanced or metastatic solid tumours or multiple myeloma harbouring RAS-RAF-MEK pathway mutations. During the dose-escalation phase, we evaluated three intermittent oral schedules (28-day cycles) in patients with solid tumours: (1) 4·0 mg or 3·2 mg CH5126766 three times per week; (2) 4·0 mg CH5126766 twice per week; and (3) toxicity-guided dose interruption schedule, in which treatment at the recommended phase 2 dose (4·0 mg CH5126766 twice per week) was de-escalated to 3 weeks on followed by 1 week off if patients had prespecified toxic effects (grade 2 or worse diarrhoea, rash, or creatinine phosphokinase elevation). In the basket dose-expansion phase, we evaluated antitumour activity at the recommended phase 2 dose, determined from the dose-escalation phase, in biomarker-selected patients. The primary endpoints were the recommended phase 2 dose at which no more than one out of six patients had a treatment-related dose-limiting toxicity, and the safety and toxicity profile of each dosing schedule. The key secondary endpoint was investigator-assessed response rate in the dose-expansion phase. Patients who received at least one dose of the study drug were evaluable for safety and patients who received one cycle of the study drug and underwent baseline disease assessment were evaluable for response. This trial is registered with ClinicalTrials.gov, NCT02407509.

FINDINGS

Between June 5, 2013, and Jan 10, 2019, 58 eligible patients were enrolled to the study: 29 patients with solid tumours were included in the dose-escalation cohort and 29 patients with solid tumours or multiple myeloma were included in the basket dose-expansion cohort (12 non-small-cell lung cancer, five gynaecological malignancy, four colorectal cancer, one melanoma, and seven multiple myeloma). Median follow-up at the time of data cutoff was 2·3 months (IQR 1·6-3·5). Dose-limiting toxicities included grade 3 bilateral retinal pigment epithelial detachment in one patient who received 4·0 mg CH5126766 three times per week, and grade 3 rash (in two patients) and grade 3 creatinine phosphokinase elevation (in one patient) in those who received 3·2 mg CH5126766 three times per week. 4·0 mg CH5126766 twice per week (on Monday and Thursday or Tuesday and Friday) was established as the recommended phase 2 dose. The most common grade 3-4 treatment-related adverse events were rash (11 [19%] patients), creatinine phosphokinase elevation (six [11%]), hypoalbuminaemia (six [11%]), and fatigue (four [7%]). Five (9%) patients had serious treatment-related adverse events. There were no treatment-related deaths. Eight (14%) of 57 patients died during the trial due to disease progression. Seven (27% [95% CI 11·6-47·8]) of 26 response-evaluable patients in the basket expansion achieved objective responses.

INTERPRETATION

To our knowledge, this is the first study to show that highly intermittent schedules of a RAF-MEK inhibitor has antitumour activity across various cancers with RAF-RAS-MEK pathway mutations, and that this inhibitor is tolerable. CH5126766 used as a monotherapy and in combination regimens warrants further evaluation.

FUNDING

Chugai Pharmaceutical.

Clinical Challenges of Immune Checkpoint Inhibitors

Even though the immuno-oncology (IO) era has achieved many successes, some signs of research development deceleration are arising. Recently, the number of FDA immunotherapy approvals has decreased concurrently with a decline in the relative number of patients recruited to these trials. Identifying the unique features of IO treatments and taking them into consideration on clinical research will lead to a better evaluation of these agents and patient outcomes. In this review, we discuss current challenges and new potential approaches to implement rationally designed clinical trials of IO drugs, particularly those targeting immune checkpoints.

Abstract CT034: Phase I study of WNT974 + spartalizumab in patients (pts) with advanced solid tumors

Background: WNT974, a Porcupine inhibitor, has shown evidence of Wnt pathway inhibition in clinical trials. Dysregulated Wnt signaling has been linked to immunotherapy resistance, suggesting WNT974 may act synergistically with checkpoint inhibitors. Spartalizumab is an αPD-1 mAb with demonstrated clinical activity in solid tumors. Methods: In this Phase I, open-label trial (NCT01351103) adult pts received WNT974 ± spartalizumab; here we report on the dose escalation of the combination. Eligible pts had melanoma (including uveal), lung SCC, HNSCC, esophageal SCC, cervical SCC, or TNBC. Pts with melanoma, lung SCC, or HNSCC must have had a best response of progressive disease (primary refractory) to prior αPD-1 therapy; other pts were naïve or primary refractory to prior αPD-1. WNT974 was dosed orally QD in 28-day cycles (2.5-10 mg, Days 1-8 or 1-15 of Cycles 1 or 1-4); spartalizumab was dosed IV at 400 mg Q4W. Objectives were to determine the maximum tolerated dose (MTD)/recommended dose for expansion (RDE), safety, pharmacokinetics (PK), pharmacodynamics, and activity of WNT974 + spartalizumab. Pre- and on-treatment pt samples were collected: skin samples for RT-PCR analysis of AXIN2, a marker of Wnt pathway activity; tumor samples for RNAseq of AXIN2 and immune cell markers. Results: As of Sept 2, 2019, 27 pts were enrolled: 24 discontinued (18 due to disease progression; 67%), 3 were ongoing. Most common tumor types were non-uveal melanoma (n=8), TNBC (n=7), and uveal melanoma (n=5); 63% had received prior αPD-1. PK parameters for WNT974 + spartalizumab were consistent with prior single agent data. Dose-limiting toxicities were reported in 2 pts: Grade (G) 2 spinal compression fracture that occurred in the setting of trauma and G3 arthralgia. 78% of pts experienced a treatment-related AE, the most common being hypothyroidism (19%); 4 pts (15%) had 7 suspected-related G3/4 AEs (arthralgia, atrial fibrillation, diabetes mellitus, diabetic ketoacidosis, hyperglycemia, hyponatremia, and maculopapular rash). One pt (4%) with TNBC had a partial response, 11 pts (41%) had stable disease (SD), 13 pts (48%) had progressive disease; response was unknown in 2 pts. SD was reported in 9/17 pts (53%) who were primary refractory to prior αPD-1; 4 remained on study >24 wks. All pts with uveal melanoma (n=5) had SD. Evidence of Porcupine inhibition, assessed by skin AXIN2 suppression, was detected at all dose levels studied. Pts with the largest reductions in tumor size had on-treatment increases in immune marker mRNA in tumor samples, including a pt with αPD-1 primary refractory melanoma with high baseline AXIN2 expression and 42% reduction in the sum of target lesion diameters; this pt remained on study at 48 wks at the cutoff date. Conclusions: WNT974 + spartalizumab was well tolerated; MTD/RDE have not been determined. Preliminary data suggest blocking Wnt signaling may enable response to checkpoint inhibition in some pts.

Citation Format: Filip Janku, Filip de Vos, Maria de Miguel, Patrick Forde, Antoni Ribas, Misako Nagasaka, Guillem Argiles, Ana Maria Arance, Aitano Calvo, Marios Giannakis, Maritza Melendez, Jiachang Gong, Sebastian Szpakowski, Rebecca Kan, Susan E. Moody, Maja De Jonge. Phase I study of WNT974 + spartalizumab in patients (pts) with advanced solid tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT034.

Increased vulnerability of clinical research units during the COVID-19 crisis and their protection

Currently, the complexity of clinical trial development in oncology is being further complicated by the coronavirus disease 2019 (COVID‐19) pandemic, which is reducing the resources needed to comply with protocol‐specific procedures while putting patients in units, who are already vulnerable, at increased general risk not only for COVID‐19 infection but also with respect to their baseline disease.

Individualizing the management of patients while ensuring their safety and adherence to the study protocol, establishing specific staff contingency plans, and maintaining sponsor and contract research organization (CRO) alignment are some of the key issues for maintaining the continuity of cancer patients’ investigational treatment and minimizing their infection risk as well as the risk to staff members of the unit, sponsors, and CROs while maintaining the integrity of data quality and compliance with good clinical practice.

This commentary describes the potentially deep, specific, and rapid impact of the coronavirus disease 2019 pandemic on clinical research units in oncology, and it establishes different processes and action plans in order to allow the performance of clinical research activities during this challenging period.

The presence of Microlobius foetidus cause changes in the antioxidant defense of Urochloa decumbens?

Urochloa decumbens (Stapf) R. D. Webster (Poaceae) is an exotic species with has spread rapidly through the Cerrado area of Pantanal, Mato Grosso do Sul, Brazil. It has covered the soil aggressively turning it into cultivated pastures. Thus, it has become a challenge to protect native areas due its capacity of exclusion of native species. It has been observed that Microlobius foetidus (Jacq.) M.Sousa & G.Andrade species (Fabaceae) shows a dominant pattern over the development of U. decumbens. This work shows that M. foetidus interfere on the natural growth of U. decumbens within 10 m ratio. Between 15 and 20 m, it was observed an increase of Importance Value index (IVI) and Relative cover (RC) values. It was also observed a variation on the antioxidant defense system of U. decumbens within 10m ratio from M. foetidus. The enzymes superoxide dismutase, catalase and peroxidase present higher levels of activity then those found for glutathione reductase. This data indicates that M. foetidus may have an effect on U. decumbens, increase the activity of antioxidant enzymes. This effect probably happens as means to neutralize the toxic effects of the oxygen generated due to the presence of allelochemicals, which increases oxidative stress.