Divarasib plus cetuximab in KRAS G12C-positive colorectal cancer: a phase 1b trial

KRAS G12C mutation is prevalent in ~4% of colorectal cancer (CRC) and is associated with poor prognosis. Divarasib, a KRAS G12C inhibitor, has shown modest activity as a single agent in KRAS G12C-positive CRC at 400 mg. Epidermal growth factor receptor has been recognized as a major upstream activator of RAS-MAPK signaling, a proposed key mechanism of resistance to KRAS G12C inhibition in CRC. Here, we report on divarasib plus cetuximab (epidermal growth factor receptor inhibitor) in patients with KRAS G12C-positive CRC (n = 29) from arm C of an ongoing phase 1b trial. The primary objective was to evaluate safety. Secondary objectives included preliminary antitumor activity. The safety profile of this combination was consistent with those of single-agent divarasib and cetuximab. Treatment-related adverse events led to divarasib dose reductions in four patients (13.8%); there were no treatment withdrawals. The objective response rate was 62.5% (95% confidence interval: 40.6%, 81.2%) in KRAS G12C inhibitor-naive patients (n = 24). The median duration of response was 6.9 months. The median progression-free survival was 8.1 months (95% confidence interval: 5.5, 12.3). As an exploratory objective, we observed a decline in KRAS G12C variant allele frequency associated with response and identified acquired genomic alterations at disease progression that may be associated with resistance. The manageable safety profile and encouraging antitumor activity of divarasib plus cetuximab support the further investigation of this combination in KRAS G12C-positive CRC.ClinicalTrials.gov identifier: NCT04449874.

Niraparib plus nivolumab or niraparib plus ipilimumab in patients with platinum-sensitive advanced pancreatic cancer: a randomised, phase 1b/2 trial

BACKGROUND

Establishing alternatives to lifelong chemotherapy for patients with advanced pancreatic cancer has been proposed to address chemotherapy resistance and cumulative toxicity. Poly(ADP-ribose) polymerase (PARP) inhibitors have shown efficacy in this setting, and concurrent immune checkpoint blockade could offer synergistic tumour control. The aim of this study was to test the safety and antitumour activity of maintenance with PARP inhibition combined with immune checkpoint blockade in patients with advanced pancreatic cancer who had a stable response to platinum-based chemotherapy.

METHODS

We conducted an open-label, randomised, phase 1b/2 study of niraparib plus anti-PD-1 (nivolumab) or anti-CTLA-4 (ipilimumab) therapy for patients with advanced pancreatic cancer whose cancer had not progressed after at least 16 weeks of platinum-based therapy. Patients were randomly assigned (1:1) via permuted block randomisation (block sizes 2 and 4) to niraparib 200 mg orally per day plus either nivolumab 240 mg intravenously every 2 weeks (later changed to 480 mg intravenously every 4 weeks based on manufacturer update) or ipilimumab 3 mg/kg intravenously every 4 weeks for four doses. The primary endpoints were safety and progression-free survival at 6 months. Treatment groups were not compared for activity, which was assessed in each group against a clinically meaningful progression-free survival at 6 months of 44% (null hypothesis). Superiority of a treatment regimen could be declared if 6-month progression-free survival was 60%, and inferiority if 6-month progression-free survival was 27%. All patients who received at least one dose of study treatment and had at least one post-treatment assessment of response according to Response Evaluation Criteria in Solid Tumours version 1.1 were included in the efficacy population. The safety population consisted of all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03404960, and enrolment is completed and follow-up is ongoing.

FINDINGS

91 patients were enrolled between Feb 7, 2018, and Oct 5, 2021 and were randomly assigned to niraparib plus nivolumab (n=46) or niraparib plus ipilimumab (n=45). Of these patients, 84 were evaluable for the progression-free survival endpoint (niraparib plus nivolumab=44; niraparib plus ipilimumab=40). Median follow-up was 23·0 months (IQR 15·0-31·5). 6-month progression-free survival was 20·6% (95% CI 8·3-32·9; p=0·0002 vs the null hypothesis of 44%) in the niraparib plus nivolumab group; and 59·6% (44·3-74·9; p=0·045) in the niraparib plus ipilimumab group. Ten (22%) of 46 patients in the niraparib plus nivolumab group and 23 (50%) of 45 patients in the niraparib plus ipilimumab group had a grade 3 or worse treatment-related adverse event. The most common grade 3 or worse adverse events in the niraparib plus nivolumab group were hypertension (in four [8%] patients), anaemia (two [4%]), and thrombocytopenia (two [4%]) whereas in the niraparib plus ipilimumab group these were fatigue (in six [14%]), anaemia (five [11%]), and hypertension (four [9%]). There were no treatment-related deaths.

INTERPRETATION

The primary endpoint of 6-month progression-free survival was met in the niraparib plus ipilimumab maintenance group, whereas niraparib plus nivolumab yielded inferior progression-free survival. These findings highlight the potential for non-cytotoxic maintenance therapies in patients with advanced pancreatic cancer.

FUNDING

Bristol Myers Squibb, GlaxoSmithKline, the Basser Center Young Leadership Council, The Konner Foundation, The Pearl and Philip Basser Innovation Research Award, the Anonymous Foundation, and the US National Institutes of Health.

529 Phase 1 study of INCB086550, an oral PD-L1 inhibitor, in immune-checkpoint naive patients with advanced solid tumors

Background

INCB086550 is an orally administered small molecule that binds PD-L1 and inhibits PD-1/PD-L1 interaction. Translational data demonstrating markers of immune activation in patients following INCB086550 were previously reported.1 Preliminary clinical data from this phase 1 study are presented below.

Methods

Adult patients (≥18 years) with advanced solid tumors were enrolled into this open-label study. Patients had disease progression after standard available therapy or were intolerant of or ineligible for standard treatment. Measurable disease was required. A modified 3+3 dose-escalation design was employed, followed by dose expansions. The primary endpoints were safety and tolerability of INCB086550, identification of a pharmacologically active dose and/or MTD, and confirmation of the RP2D. Secondary endpoints included PK, pharmacodynamics, and efficacy as assessed by investigator-determined ORR and DCR (CR, PR, or SD ≥12 weeks).

Results

As of 9Apr2021, 79 patients received treatment (Table 1); 57.0% were female, 62.0% had ≥2 prior lines of therapy, and 16% received prior IO treatment. Forty-six (58.2%) patients had treatment-related TEAEs; those occurring in ≥5% of patients are presented in Table 2. Ten patients (12.7%) had grade ≥3 treatment-related TEAEs. Immune-related TEAEs occurred in 15 patients (19.0%); the most common (>1 patient) included peripheral sensory neuropathy (n=5), pruritus (n=3), immune-mediated neuropathy (n=2), and peripheral motor neuropathy (n=2). In total, 10 (12.7%) patients had TEAEs of peripheral neuropathy; all were grade ≤3. All grade 2 or 3 TEAEs of peripheral neuropathy resolved or improved with either study drug continuation without dose modification, dose reduction, or drug interruption/discontinuation. Patients with TEAEs leading to treatment interruption were 21 (26.6%), dose reduction 5 (6.3%), and discontinuation 13 (16.5%). Five patients (6.3%) died of a TEAE (cerebrovascular accident, dyspnea, general physical health deterioration, intestinal obstruction, intracranial hemorrhage [each n=1]); all fatal TEAEs were considered unrelated to study drug. The efficacy-evaluable population included 68 patients; ORR was 11.8% (95%CI, 5.2%–21.9%; CR, 1.5%; PR, 10.3%), and DCR was 19.1% (95%CI, 10.6%–30.5%; Table 3). Eight objective responses were observed at doses ≥400 mg BID (Table 4); 3 of these were noted among the 5 IO treatment-naive patients with MSI-H tumors who received 400 mg BID.

Conclusions

Immune-related AEs observed in this ongoing phase 1 study are consistent with those seen with antibody immune checkpoint inhibitors, with the exception of peripheral neuropathy. Preliminary efficacy of INCB086550 in tumor types known to be responsive to anti-PD-(L)1 therapy is encouraging and warrants further investigation.

Trial Registration

Clinicaltrials.

gov identifier NCT03762447

References

Piha-Paul S, et al. J Immunother Cancer. 2020;8(suppl 3):A255.

Ethics Approval

The study protocol was approved by institutional review boards (IRB) or independent ethics committees at participating centers. All study participants gave informed consent before taking part. The approval numbers were: Integ Review IRB (Austin, TX), RM 598; MD Anderson Cancer Center Office of Human Subject Protection (Houston, TX), IRB ID 2018-0765; ADVARRA (Columbia, MD), IRB# 00000971; Ethisch Comité/Comité d’ Ethique Hospital (Brussels, Belgium), A2021/085; Hôpital Saint-Louis (Paris, France), Prof Le Tourneau – 2020-118/Ref. of the Promoter 0.09.22.72214; NHS Health Research Authority London - City & East Research Ethics Committee (Bristol, UK), IRAS project ID:282291/REC reference: 20/LO/1001; Comitato Etico IRCCS Pascale (Milan, Italy), ISS Validation Protocol Number 29111(2020)-PRE21-1835; Comitato Etico Della Fondazione IRCCS ”Istituto Nazionale Dei Tumori”- Milano CE150053 (Milan, Italy), INT 230/20; Comitato Etico Regione Toscana - Area Vasta Sud Est CE150047, 18064; Comitato Etico Indipendente Istituto Clinico Humanitas CE150081, 940/20; Regulatory Pharma Net (Pisa, Italy), IEC 1393.

Abstract 529 Table 1

Number of patients per dose level

BID, twice daily; QD, once daily.

The tumor types in the study included breast, cervical, colorectal, endometrial, esophageal, gastric, hepatocellular, melanoma, mesothelioma, ovarian, small cell lung cancer, squamous cell carcinoma of the head and neck, renal cell, urothelial, adrenal, anal, cholangiocarcinoma, gall bladder, pancreatic, penile, salivary gland, sarcoma, vaginal, prostate, basal cell, pleomorphic sarcoma, fallopian, carcinoma of parotid gland, well-differentiated liposarcoma, myoepithelial, castrate-resistant prostate cancer, cancer of unknown primary, neuroendocrine, prostate adenocarcinoma with neuroendocrine differentiation, glioblastoma, anal canal, angiosarcoma, and gastroesophageal junction.

Abstract 529 Table 2

Treatment-related TEAEs reported by ≥5% of patients (N=79)

TEAE, treatment-emergent adverse event.

Abstract 529 Table 3

Summary of best overall response by RECIST v1.1 or RANO*

CR, complete response; DCR, disease control rate; GBM, glioblastoma; ORR, objective response rate; PR, partial response; RANO, Response Assessment of Neuro-Oncology; RECIST, Response Evaluation Criteria in Solid Tumors; SD, stable disease.

* 1 patient with GBM was assessed by RANO and had best overall response of progressive disease.

† The efficacy-evaluable population included all solid tumor participants enrolled in the study who received at least 1 dose of INCB086550, completed a baseline scan, and met at least 1 of the following criteria: ≥1 postbaseline scan, participant had been on the study for a minimum of 63 days of follow-up, or participant had discontinued from treatment.

‡ ”Not evaluable” indicates participants in the efficacy-evaluable population that did not have valid postbaseline overall response assessments by RECIST or RANO.

§ ”Not assessed” indicates participants in the efficacy-evaluable population that did not have any postbaseline overall response assessments by RECIST or RANO.

Abstract 529 Table 4

Tumor types with investigator-assessed objective response per RECIST v1.1 (n=8)

BID, twice daily; dMMR, deficient mismatch repair; IO, immuno-oncology; MSI-H, high microsatellite instability; RECIST, Response Evaluation Criteria in Solid Tumors.

+Ongoing response.

Impact of the Cholangiocarcinoma Component of Combined Hepatocellular/Hepatocholangiocarcinoma on Patient Survival

Introduction/Objective

The radiopathologic correlation, overall prognosis, and best management of combined hepatocellular carcinoma/cholangiocarcinoma (HCC/CC) remains uncharted territory.

Methods

We studied whether the percentage (%) of the cholangiocarcinoma (CC) component of HCC/CC impacted patient survival. A retrospective analysis was performed including all cases (18) of HCC/CC in the pathology archives from 2011–2019. Tumor beds were submitted entirely in all but 2 specimens, which were representatively sampled.

Slides from these cases were reviewed to assess % of CC. Survival was calculated from the date of diagnosis to the date of demise and censored as the date last known alive at the time of the study.

Results

13 cases were liver explants, 2 were resections, and 3 were biopsies. 13 cases were from clinical stage II patients, 2 were clinical stage IVA, and 2 were clinical stage IVB. All but one patient in the study group were males. There was no predilection for any specific tumor site. The cases were divided into three groups related to CC percentage: 0–20 (n=5), 21–40 (n=6), and >40% (n=7). AFP was variably elevated in select cases, with the highest values found in the medium and high % groups. Though there was no significant difference in overall survival among the three groups, mean and median survival trended in a downward fashion with increased % CC. Interestingly, radiology read 12 cases as HCC, 1 as intrahepatic CC, and only 1 as cholangiocarcinoma/hepatoma, atypical for HCC.

Conclusion

We conclude that there is a trend for decreased survival as % CC increases in combined HCC/CC patients, with patients with >20% CC tending to have lower survival rates. Furthermore, incongruity exists between radiologic and pathologic diagnoses of combined HCC/CC. Additional study with a larger sample size will yield more information to understand better prognosis as well as guide more accurate diagnosis of these patients.

Segmentation and Grade Prediction of Colon Cancer Digital Pathology Images Across Multiple Institutions

Distinguishing benign from malignant disease is a primary challenge for colon histopathologists. Current clinical methods rely on qualitative visual analysis of features such as glandular architecture and size that exist on a continuum from benign to malignant. Consequently, discordance between histopathologists is common. To provide more reliable analysis of colon specimens, we propose an end-to-end computational pathology pipeline that encompasses gland segmentation, cancer detection, and then further breaking down the malignant samples into different cancer grades. We propose a multi-step gland segmentation method, which models tissue components as ellipsoids. For cancer detection/grading, we encode cellular morphology, spatial architectural patterns of glands, and texture by extracting multi-scale features: (i) Gland-based: extracted from individual glands, (ii) local-patch-based: computed from randomly-selected image patches, and (iii) image-based: extracted from images, and employ a hierarchical ensemble-classification method. Using two datasets (Rawalpindi Medical College (RMC), n = 174 and gland segmentation (GlaS), n = 165) with three cancer grades, our method reliably delineated gland regions (RMC = 87.5%, GlaS = 88.4%), detected the presence of malignancy (RMC = 97.6%, GlaS = 98.3%), and predicted tumor grade (RMC = 98.6%, GlaS = 98.6%). Training the model using one dataset and testing it on the other showed strong concordance in cancer detection (Train RMC – Test GlaS = 94.5%, Train GlaS – Test RMC = 93.7%) and grading (Train RMC – Test GlaS = 95%, Train GlaS – Test RMC = 95%) suggesting that the model will be applicable across institutions. With further prospective validation, the techniques demonstrated here may provide a reproducible and easily accessible method to standardize analysis of colon cancer specimens.

Abstract CT234: A Phase II, single arm study of maintenance rucaparib in patients with platinum-sensitive advanced pancreatic cancer and a pathogenic germline or somatic mutation in BRCA1, BRCA2 or PALB2

Background: PARP inhibitors have activity in multiple BRCA-related malignancies and have recently demonstrated dramatic efficacy as a maintenance strategy for platinum-sensitive ovarian cancer. Between 5-8% of patients with pancreatic cancer (PC) have a pathogenic mutation in BRCA1, BRCA2 or PALB2. Therefore, we initiated a single arm phase II clinical trial of maintenance monotherapy rucaparib in patients with advanced PC and a pathogenic germline or somatic BRCA or PALB2 mutation, whose cancer had not progressed following at least four months of platinum-based chemotherapy (NCT 03140670).

Methods: Patients were enrolled and treated with rucaparib 600mg PO BID until disease progression or unacceptable toxicity. The primary endpoint is progression free survival (PFS). Patients have previously received >4 months of platinum-based chemotherapy without evidence of disease progression. However, patients with a medical contraindication to receiving the full four months of platinum have been permitted to enroll at the discretion of the primary investigator. Responses were determined using RECIST v1.1.

Results: As of December 31st, 2018, we have enrolled 24 of the planned 42 patients, of which 19 are evaluable for PFS at the time of this interim analysis. For these patients, the mutational distribution includes: 13 germline BRCA2, 3 germline BRCA1, 2 germline PALB2, 1 somatic BRCA2. Patients were predominantly female (84.2%) with a median age of 61 years (range: 35-81). Patients had received a median of four months (range 0.5-32 months) of prior platinum therapy for advanced disease. All patients were evaluable for toxicity. Overall, treatment with rucaparib was well tolerated without dose limiting toxicities. The most common adverse events that were at least possibly related to treatment included nausea (grade 1, 41.6%; grade 2, 4.2%), dysgeusia (grade 1, 33.3%) and fatigue (grade 1, 25%). One patient required dose reduction for nausea. The median PFS was 9.1 months from the start of rucaparib therapy with an ORR of 36.8% (six PRs; one CR). Disease control rate (CR + PR + SD) was 89.5% for at least eight weeks. Two patients (10.5%) had progressive disease at first follow-up scan two months after beginning treatment. Eight patients have been on rucaparib for >6 months and two patients remain on treatment for >1 year (13 months and 15 months). The seven responding patients include those with germline BRCA2 mutations (4 patients), germline PALB2 mutations (2 patients) and somatic BRCA2 mutation (1 patient).

Conclusions: Based on these early data, maintenance rucaparib following induction with platinum-based chemotherapy shows encouraging disease control with minimal toxicity in patients with platinum-sensitive advanced PC and a pathogenic mutation in BRCA1, BRCA2 or PALB2.

Citation Format: Kim A. Reiss Binder, Rosemarie Mick, Mark O'Hara, Ursina Teitelbaum, Thomas Karasic, Charles Schneider, Peter J. O'Dwyer, Erica Carpenter, Austin Pantel, Mehran Makvandi, David Mankoff, Katherine Nathanson, Kara Maxwell, Stacy Cowden, Mary Jane Fuhrer, Janae Romeo, Gregory L. Beatty, Susan Domchek. A Phase II, single arm study of maintenance rucaparib in patients with platinum-sensitive advanced pancreatic cancer and a pathogenic germline or somatic mutation in BRCA1, BRCA2 or PALB2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT234.

Interleukin-17A induces bicarbonate secretion in normal human bronchial epithelial cells

The innate immune functions of human airways include mucociliary clearance and antimicrobial peptide activity. Both functions may be affected by changes in epithelial ion transport. Interleukin-17A (IL-17A), which has a receptor at the basolateral membrane of airway epithelia, is a T cell cytokine that has been shown to increase mucus secretion and antimicrobial peptide production by human bronchial epithelial (HBE) cells. Furthermore, IL-17A levels are increased in sputum from patients during pulmonary exacerbations of cystic fibrosis. Therefore, we investigated the effects of IL-17A on basal, amiloride-sensitive, and forskolin-stimulated ion transport in mature, well-differentiated HBE cells. Exposure of HBE monolayers to IL-17A for 48 h induced a novel forskolin-stimulated bicarbonate secretion in addition to forskolin-stimulated chloride secretion and resulted in alkalinization of liquid on the mucosal surface of polarized cells. IL-17A-induced bicarbonate secretion was cystic fibrosis transmembrane conductance regulator (CFTR)-dependent, mucosal chloride-dependent, partially Na(+)-dependent, and sensitive to serosal, but not mucosal, stilbene inhibition. These data suggest that IL-17A modulates epithelial bicarbonate secretion and implicate a mechanism by which airway surface liquid pH changes may be abnormal in cystic fibrosis.