Upfront FOLFOXIRI plus bevacizumab with or without atezolizumab in the treatment of patients with metastatic colorectal cancer (AtezoTRIBE): a multicentre, open-label, randomised, controlled, phase 2 trial.

BACKGROUND: Immune checkpoint inhibitors have not shown clinical benefit to patients with metastatic colorectal cancer who had proficient mismatch repair (pMMR) or microsatellite stable (MSS) tumours in previous studies. Both an active combination chemotherapy (FOLFOXIRI; fluorouracil, leucovorin, oxaliplatin, and irinotecan) and bevacizumab seem able to increase the immunogenicity of pMMR or MSS tumours. We aimed to provide preliminary evidence of benefit from the addition of the anti-PD-L1 agent atezolizumab to first-line FOLFOXIRI plus bevacizumab in patients with metastatic colorectal cancer. METHODS: AtezoTRIBE was a multicentre, open-label, randomised, controlled, phase 2 study of patients (aged 18-70 years with an Eastern Cooperative Oncology Group [ECOG] performance status of 0-2 and aged 71-75 years with an ECOG performance status of 0) with histologically confirmed, unresectable, previously untreated metastatic colorectal cancer and adequate organ function, who were recruited from 22 oncology centres in Italy. Patients were stratified according to centre, ECOG performance status, primary tumour site, and previous adjuvant therapy. A randomisation system incorporating a minimisation algorithm randomly assigned (1:2) patients via a masked web-based allocation procedure to two groups: the control group received first-line FOLFOXIRI (intravenous 165 mg/m2 irinotecan, 85 mg/m2 oxaliplatin, 200 mg/m2 leucovorin, and 3200 mg/m2 fluorouracil as a 48 h infusion) plus bevacizumab (5 mg/kg intravenously), and the atezolizumab group received the same regimen plus atezolizumab (840 mg intravenously). Combination treatments were administered up to eight 14-day cycles followed by maintenance with fluorouracil and leucovorin plus bevacizumab with or without atezolizumab, according to randomisation group, until disease progression, unacceptable adverse events, or consent withdrawal. The primary endpoint was progression-free survival, analysed by the intention-to-treat principle. Safety was assessed in patients who received at least one dose of the study treatment. The study recruitment is completed. The trial is registered with Clinicaltrials.gov, NCT03721653. FINDINGS: Between Nov 30, 2018, and Feb 26, 2020, 218 patients were randomly assigned and received treatment (73 in the control group and 145 in the atezolizumab group). At the data cutoff (Aug 1, 2021), median follow-up was 19·9 months (IQR 17·3-23·9). Median progression-free survival was 13·1 months (80% CI 12·5-13·8) in the atezolizumab group and 11·5 months (10·0-12·6) in the control group (hazard ratio [HR] 0·69 [80% CI 0·56-0·85]; p=0·012; adjusted HR 0·70 [80% CI 0·57-0·87]; log-rank test p=0·018). The most frequent all-cause grade 3-4 adverse events were neutropenia (59 [42%] of 142 patients in the atezolizumab group vs 26 [36%] of 72 patients in the control group), diarrhoea (21 [15%] vs nine [13%]), and febrile neutropenia (14 [10%] vs seven [10%]). Serious adverse events were reported in 39 (27%) patients in the atezolizumab group and in 19 (26%) patients in the control group. Two (1%) treatment-related deaths (due to acute myocardial infarction and bronchopulmonary haemorrhage) were reported in the atezolizumab group; none were reported in the control group. INTERPRETATION: The addition of atezolizumab to first-line FOLFOXIRI plus bevacizumab is safe and improved progression-free survival in patients with previously untreated metastatic colorectal cancer. FUNDING: GONO Foundation, ARCO Foundation, F Hoffmann-La Roche, and Roche.

Variant allele frequency in baseline circulating tumour DNA to measure tumour burden and to stratify outcomes in patients with RAS wild-type metastatic colorectal cancer: a translational objective of the Valentino study.

INTRODUCTION: In patients with metastatic colorectal cancer (mCRC), baseline circulating tumour DNA (ctDNA) variant allele fraction (VAF) might serve as a surrogate of disease burden and should be evaluated in comparison with CEA and RECIST-defined sum of target lesions. METHODS: In this pre-planned analysis of the VALENTINO trial, we included patients with RAS wild-type mCRC receiving upfront FOLFOX/panitumumab with available baseline liquid biopsy. CtDNA was analysed by means of a 14-gene NGS panel. For each patient, the gene with the highest VAF in ctDNA was selected. RESULTS: The final cohort included 135 patients. The median VAF was 12.6% (IQR: 2.0-45.2%). Higher VAF was observed in patients with liver metastases and with synchronous metastases presentation. Patients with high VAF had poorer median OS compared to those with low VAF (21.8 vs 36.5 months; HR: 1.82, 95%CI: 1.20-2.76; p = 0.005). VAF outperformed baseline CEA and target lesion diameter in the prognostic stratification and remained significantly correlated with OS (p = 0.003) in a multivariate model. VAF was not significantly correlated with dimensional response and PFS. CONCLUSION: CtDNA measured by VAF is prognostic in patients with RAS wild-type mCRC. Response and PFS after an anti-EGFR-based first-line strategy are independent from initial tumour burden.

CEA increase as a marker of disease progression after first-line induction therapy in metastatic colorectal cancer patients. A pooled analysis of TRIBE and TRIBE2 studies.

BACKGROUND: In mCRC, CEA is used to monitor response to systemic therapy together with imaging. After the end of induction, no major improvement in tumour shrinkage is expected, and the availability of a marker able to predict progressive disease (PD) versus no-PD might allow avoiding CT scans. METHODS: We pooled data from patients with baseline CEA ≥ 10 ng/mL included in TRIBE and TRIBE2 studies with the aim of identifying a threshold for percent increase of CEA from nadir able to predict PD after the end of the induction therapy. RESULTS: In total, 1178 paired CEA and radiological assessments from 434 patients were included. According to the optimal cut-off determined by ROC, a CEA increase of at least 120% from nadir differentiated between PD and no-PD with a sensitivity of 74% and a specificity of 78%, excluding PD in the 92% of radiological assessments and allowing to avoid the 67% of CT scans. However, CEA cut-off of 120% was not able to detect radiological PD in 26% of cases. In order to mitigate this issue, a different clinically relevant threshold was evaluated based on the best sensitivity cut-off. Therefore, using any CEA increase from nadir as a threshold, the sensitivity grew to 93% and only in the 7% of cases the radiological PD was not detected. CONCLUSIONS: In mCRC with baseline CEA ≥ 10 ng/mL, CEA values can accurately predict PD versus no-PD after the end of the first-line induction therapy.

Systemic doxycycline for pre-emptive treatment of anti-EGFR-related skin toxicity in patients with metastatic colorectal cancer receiving first-line panitumumab-based therapy: a post hoc analysis of the Valentino study.

INTRODUCTION: The combination of anti-EGFRs and doublet chemotherapy is considered the optimal upfront option for patients with RAS/BRAF wild-type left-sided metastatic colorectal cancer (mCRC). The prophylactic or reactive treatment with tetracyclines for EGFR inhibitor-induced skin toxicity is currently clinical practice, though non-conclusive results are available. METHODS: We performed a post hoc analysis of the Valentino study that randomized RAS wild-type mCRC patients to two panitumumab-based maintenance regimens after the first-line induction, aimed at assessing the safety and efficacy of the administration of a pre-emptive doxycycline prophylaxis for anti-EGFR-related skin toxicity. We assessed the rate of treatment-related and panitumumab-related adverse events (AEs), treatment intensity, progression-free survival (PFS), and overall survival (OS). RESULTS: A total of 226 patients, out of the 229 enrolled in the Valentino study, were eligible for the analysis. Overall, 143 (63%) and 83 (37%) patients received or not the antibiotic prophylaxis for skin toxicity. Any grade and G3/4 panitumumab-related AEs were reported in 89% versus 92% (p = 0.650) and 27% versus 27% (p = 1.000) patients who received or not the pre-emptive prophylaxis, respectively. Any grade and G3/4 skin rash occurred in 81% versus 90% (p = 0.085) and 27% versus 25% (p = 0.876) patients receiving or not the prophylaxis, respectively. No significant differences in terms of treatment duration, treatment delays or dose reductions, PFS, and OS were observed in the two sub-populations. CONCLUSION: The adequate management of anti-EGFR-related skin toxicity is fundamental to optimize the outcome of mCRC patients, balancing the survival benefit with patients' quality of life, especially in the first-line setting.

BRAF + EGFR +/- MEK inhibitors after immune checkpoint inhibitors in BRAF V600E mutated and deficient mismatch repair or microsatellite instability high metastatic colorectal cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the guideline endorsed first choice for patients with deficient mismatch repair or microsatellite instability high (dMMR/MSI-H) mCRC, however a significant proportion experience primary or secondary resistance. BRAF V600E mutated (BRAFm) and dMMR/MSI-H mCRC can be treated with BRAF + EGFR inhibitors but specific data on the efficacy after progression to ICIs are missing. METHODS: We collected consecutive patients with BRAFm dMMR/MSI-H mCRC treated from 2017 to 2024 with a combination of BRAFi+EGFRi+/-MEKi, after disease progression on ICIs. A control cohort of BRAFm pMMR/MSS mCRC patients treated with encorafenib+cetuximab+/-binimetinib from 2nd line was used. RESULTS: dMMR/MSI-H (n = 50) BRAFm mCRC patients were more often > 70-year-old, with right-sided primary tumors, without liver but more lymphnode metastases than pMMR/MSS (n = 170). They were treated more frequently beyond 2nd line and 45 % were primary progressors to ICIs. Lower ORR (18 % versus 32 %, p = 0.09) and DCR (60 % versus 73 %, p = 0.11) was seen without reaching significance in dMMR/MSI-H as compared to pMMR/MSS patients. After a median follow-up of 14.04 months, no differences in PFS (median 5.13 versus 4.50 months, HR 0.83, 95 %CI: 0.57-1.20, p = 0.31) and OS (median 10.75 versus 9.11 months, HR 0.89, 95 %CI: 0.59-1.32, p = 0.55) were observed. CONCLUSIONS: Our results show that BRAFm dMMR/MSI-H mCRC patients benefit from BRAFi+EGFRi+/-MEKi after progression under ICIs. Despite lower ORR and DCR, the outcome is not different from that observed in pMMR/MSS BRAFm CRC and is in line with the results of the BEACON registration trial.

The Prognostic Nutritional Index in patients with microsatellite instability-high metastatic gastric or gastroesophageal cancers receiving immune checkpoint inhibitors.

BACKGROUND: Microsatellite instability high (MSI-H) and/or mismatch repair deficient (dMMR) status is the strongest predictive factor for immune checkpoint inhibitors (ICIs) benefit in patients with metastatic gastroesophageal cancer (mGC). Primary resistance to ICIs is a relevant issue, but prognostic and predictive factors are lacking. MATERIALS AND METHODS: In this multinational, retrospective cohort of patients with MSI-H/dMMR mGC treated with ICIs without chemotherapy we collected baseline laboratory values to establish the prognostic nutritional index (PNI). We evaluated the association between baseline PNI with the activity and efficacy of ICIs. RESULTS: At a median follow-up of 31.6 months, median progression-free survival (PFS) and 2-year PFS rate were not reached and 73.6 % in the PNI-high subgroup versus 6.3 months and 38.3 % in the PNI-low one (HR 0.32, 95 % CI: 0.16-0.61, p < .001). Median overall survival (OS) and 2-year OS rate were not reached and 81.9 % in the PNI-high subgroup versus 24.4 months and 50.5 % in the PNI-low one (HR 0.26, 95 % CI: 0.12-0.56, p < .001). In multivariable models, high PNI was associated with longer PFS and OS (HR 0.30, 95 % CI: 0.15-0.61, p <0.001 and 0.37, 95 % CI: 0.15-0.91, p = .031). CONCLUSIONS: High PNI is associated with longer PFS and OS, in patients with MSI-H mGC receiving ICIs. Patients with low baseline PNI may benefit from intensive therapeutic approaches.

Association of immune-related adverse events with the outcomes of immune checkpoint inhibitors in patients with dMMR/MSI-H metastatic colorectal cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) show a tremendous activity in microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC), but a consistent fraction of patients does not respond. Prognostic/predictive markers are needed. Despite previous investigations in other tumor types, immune-related adverse events (irAEs) have not been well evaluated in patients with MSI-H cancers treated with ICIs. METHODS: We conducted an international cohort study at tertiary cancer centers collecting clinic-pathological features from 331 patients with MSI-H mCRC treated with ICIs. Of note, the irAEs were summarized using a 'burden score' constructed in a way that the same score value could be obtained by cumulating many low-grade irAEs or few high-grade irAEs; as a result, the lower the burden the better. Clearly, the irAE burden is not a baseline information, thus it was modeled as a time-dependent variable in univariable and multivariable Cox models. RESULTS: Among 331 patients, irAEs were reported in 144 (43.5%) patients. After a median follow-up time of 29.7 months, patients with higher burden of skin, endocrine and musculoskeletal irAEs (the latter two's effect was confirmed at multivariable analysis) had longer overall survival (OS), as opposed to gastrointestinal, pneumonitis, neurological, liver, renal and other irAEs, which showed an harmful effect. Similar results were observed for progression-free survival (PFS). Based on the results retrieved from organ-specific irAEs, 'aggregated' burden scores were developed to distinguish 'protective' (endocrine and musculoskeletal) and 'harmful' (gastrointestinal, pneumonitis, neurological, hepatic) irAEs showing prognostic effects on OS and PFS. CONCLUSIONS: Our results demonstrate that not all irAEs could exert a protective effect on oncologic outcome. An easy-to-use model for ICIs toxicity (burden score of protective and harmful irAEs) may be used as surrogate marker of response.

Tumour mutational burden as a biomarker in patients with mismatch repair deficient/microsatellite instability-high metastatic colorectal cancer treated with immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the standard treatment in patients with mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). Tumour mutational burden (TMB) is a promising biomarker for the prediction of treatment outcomes. PATIENTS AND METHODS: We screened 203 patients with dMMR/MSI-H mCRC treated with an anti-PD-(L)1 (anti-Programmed-Death-(Ligand)1) plus or minus an anti-Cytotoxic T-Lymphocyte Antigen 4 (anti-CTLA-4) agent at three Italian Academic Centers. TMB was tested by Foundation One Next Generation Sequencing assay and correlated with clinical outcomes, in the overall population and according to ICI regimen. RESULTS: We included 110 patients with dMMR/MSI-H mCRC. Eighty patients received anti-PD-(L)1 monotherapy and 30 received anti-CTLA-4 combinations. Median TMB was 49 mut/Mb (range: 8-251 mut/Mb). The optimal prognostic cut-off for progression-free survival (PFS) stratification was 23 mut/Mb. Patients with TMB ≤23 mut/Mb had significantly worse PFS (adjusted Hazard Ratio [aHR] = 4.26, 95% confidence interval [CI]:1.85-9.82, p = 0.001) and overall survival (OS) (aHR = 5.14, 95% CI: 1.76-14.98, p = 0.003). Using a cut-off optimised for predicting treatment outcome, anti-CTLA-4 combination was associated with a significant PFS/OS benefit versus anti-PD-(L)1 monotherapy in patients with TMB>40 mut/Mb (2-year PFS: 100.0% versus 70.7%, p = 0.002; 2-year OS: 100.0% versus 76.0%, p = 0.025), but not in those with TMB ≤40 mut/Mb (2-year PFS: 59.7% versus 68.6%, p = 0.888; 2-year OS: 80.0% versus 81.0%, p = 0.949). CONCLUSION: Patients with dMMR/MSI-H mCRC and relatively lower TMB value displayed early disease progression when receiving ICIs, whereas patients with the highest TMB values may obtain the maximal benefit from intensified anti-CTLA-4/PD-1 combination.

Negative hyperselection of elderly patients with RAS and BRAF wild-type metastatic colorectal cancer receiving initial panitumumab plus FOLFOX or 5-FU/LV.

BACKGROUND: Upfront anti-EGFR therapy represents the standard of care for patients with left-sided, MSS/pMMR, RAS and BRAF wild-type mCRC. Molecular 'hyperselection' may optimize EGFR inhibition by detecting additional resistance alterations. MATERIALS AND METHODS: We used comprehensive genomic profiling on archival samples of elderly patients enrolled in the PANDA trial to detect: HER2 amplification/mutations; MET amplification; NTRK/ROS1/ALK/RET rearrangements; PIK3CA exon 20 mutations; PTEN alterations; AKT1 mutations; MAP2K1 mutations. We defined 'Gene Altered' (GA) patients whose tumour harboured at least one alteration, and 'Hyperselected' (HS) those without. Survival and tumour response outcomes were correlated to hyperselection status alone or combined with primary tumour sidedness or treatment arm. RESULTS: Genomic alterations were detected in 41/147 patients (27.9%). PFS, OS and ORR were inferior in GA versus HS (median PFS: 7.6 versus 12.8 months, HR = 2.08, 95% CI: 1.43-3.03, p < 0.001; median OS: 20.0 versus 29.5 months, HR = 1.82, 95% CI:1.23-2.69, p = 0.002; ORR: 51% versus 71%; OR = 0.43, 95% CI: 0.21-0.91, p = 0.02). In the multivariable models, the impact of hyperselection on PFS and OS was confirmed. Lower ORR was observed with 5-FU/LV/panitumumab in GA (40% versus 62%), but not in HS (70% versus 72%). GA was associated with worse survival and response regardless of primary tumour sidedness, whereas in the HS subgroup, right-and left sided tumours had similar outcomes. CONCLUSIONS: Molecular hyperselection and comprehensive genomic profiling have a potential usefulness in elderly patients with RAS/BRAF wild-type, pMMR/MSS mCRC, eligible for upfront EGFR inhibition.

Outcomes and a prognostic classifier in patients with microsatellite instability-high metastatic gastric cancer receiving PD-1 blockade.

BACKGROUND: Subgroup analyses of randomized trials suggest the superiority of immune checkpoint inhibitor-based therapy over chemotherapy in patients with mismatch-repair deficient (dMMR) and/or microsatellite instability-high (MSI-high) advanced gastric or gastroesophageal junction adenocarcinoma. However, these subgroups are small and studies examining prognostic features within dMMR/MSI-high patients are lacking. METHODS: We conducted an international cohort study at tertiary cancer centers and collected baseline clinicopathologic features of patients with dMMR/MSI-high metastatic or unresectable gastric cancer treated with anti-programmed cell death protein-1 (PD-1)-based therapies. The adjusted HRs of variables significantly associated with overall survival (OS) were used to develop a prognostic score. RESULTS: One hundred and thirty patients were included. At a median follow-up of 25.1 months, the median progression-free survival (PFS) was 30.3 months (95% CI: 20.4 to NA) and 2-year PFS rate was 56% (95% CI: 48% to 66%). Median OS was of 62.5 months (95% CI: 28.4 to NA) and 2-year OS rate was 63% (95% CI: 55% to 73%). Among the 103 Response Evaluation Criteria in Solid Tumors-evaluable patients, objective response rate was 66% and disease control rate 87% across lines of therapy. In the multivariable models, Eastern Cooperative Oncology Group Performance Status of 1 or 2, non-resected primary tumor, presence of bone metastases and malignant ascites were independently associated with poorer PFS and OS. These four clinical variables were used to build a three-category (ie, good, intermediate, and poor risk) prognostic score. Compared with patients with good risk, patients with intermediate risk score had numerically inferior PFS and OS (2-year PFS rate: 54.3% versus 74.5%, HR 1.90, 95% CI: 0.99 to 3.66; 2-year OS rate: 66.8% versus 81.2%, HR 1.86, 95% CI: 0.87 to 3.98), whereas patients with poor risk score had significantly inferior PFS and OS (2-year PFS rate: 10.6%, HR 9.65, 95% CI: 4.67 to 19.92; 2-year OS rate: 13.3%, HR 11.93, 95% CI: 5.42 to 26.23). CONCLUSIONS: Overall outcomes with anti-PD-1-based therapies are favorable in MSI-high gastroesophageal adenocarcinomas. However, within this overall favorable subgroup a more accurate prognostication using baseline clinical characteristics might identify patients at higher risk of rapid disease progression who may deserve intensified immunotherapy combination strategies.

Transcriptomic Signatures of MSI-High Metastatic Colorectal Cancer Predict Efficacy of Immune Checkpoint Inhibitors.

PURPOSE: Microsatellite instability (MSI) is currently the only predictive biomarker of efficacy of immune checkpoint inhibitors (ICI) in metastatic colorectal cancers (mCRC). However, 10% to 40% of patients with MSI mCRC will experience a primary resistance to ICI. EXPERIMENTAL DESIGN: In two cohorts of patients with MSI mCRC treated with ICI (exploratory, N = 103; validation, N = 35), 3' RNA sequencing was performed from primary tumors. Previously described single-cell transcriptomic signatures of tumor microenvironment (TME) were analyzed. RESULTS: In the exploratory cohort, the unsupervised clustering allowed the identification of three clusters of tumors with distinct transcriptional profiles: cluster A ("stromalHIGH-proliferationLOW"), cluster B ("stromalHIGH-proliferationMED"), and cluster C ("stromalLOW-proliferationHIGH"), with an enrichment of patients progressing at first disease assessment under ICI in cluster A (30% vs. 12% in cluster B and 8.1% in cluster C; P = 0.074). Progression-free survival (PFS) was also significantly shorter in patients belonging to cluster A, compared with clusters B or C (P < 0.001) with 2-year PFS rates of 33.5%, 80.5%, and 78.3%, respectively. In multivariate analysis, PFS was still significantly longer in patients belonging to cluster B [HR, 0.19; 95% confidence interval (CI), 0.08-0.45; P < 0.001] and cluster C (HR, 0.25; 95% CI, 0.10-0.59; P = 0.02), compared with patients belonging to cluster A. The association of this clustering with PFS under ICI was confirmed in the validation cohort. PFS related to non-ICI-based regimens was not significantly different according to cluster. CONCLUSIONS: This unsupervised transcriptomic classification identified three groups of MSI mCRCs with different compositions of TME cells and proliferative capacities of TME/tumor cells. The "stromalHIGH-proliferationLOW" cluster is associated with a poorer prognosis with ICI treatment.

Long-term outcomes and persistent toxicities following BRAF/MEK inhibitor therapy for advanced melanoma.

BACKGROUND: Recent studies have shown that approximately 20% of patients have 4-5 year progression free survival (PFS) on BRAF/MEK inhibitors. The long-term safety and efficacy in these patients with more durable responses have not been studied. METHODS: This retrospective multicenter cohort study assessed response, progression, and adverse events in patients from eight institutions in four countries with >4-year PFS following BRAF/MEK inhibitors. RESULTS: Among 146 patients, 112 (76.7%) remained progression-free at median follow-up of 7.8 years from treatment start; 131 (89.7%) were alive. Among progressors (n = 34), 21 (62%) were on treatment at progression. Among those who discontinued treatment for reasons other than progression (toxicity, preference, etc.) (n = 68, with median 49 months treatment duration), 13 (19%) progressed (median 15.3 months from treatment cessation to progression). Surgery or radiation for single-organ progression resulted in durable benefit in 11 of 22 patients (50%). Subsequent systemic therapy included immune therapy (24% responded) and BRAF/MEK rechallenge (56% responded). Thirteen (8.9%) patients had ongoing toxicities at last follow-up, 10 (77%) of which remained on active treatment; all cardiac adverse events had resolved (n = 9). Twenty-four (16.4%) patients developed any new primary cancer, and 28 (19%) patients experienced other major health events. CONCLUSIONS: Over 75% of patients with 4-year PFS from BRAF/MEK inhibitors had continued durable antitumor responses after nearly 8-year median follow-up, with similar results in patients who discontinued therapy for reasons other than progression. Long-term toxicities were uncommon and low-grade. These findings highlight the often-favourable outcomes in patients with extended benefit from BRAF/MEK inhibitors.

Targeted protein degraders from an oncologist point of view: The Holy Grail of cancer therapy?

In the era of precision medicine, monoclonal antibodies and small molecule inhibitors are the mainstays of the biological therapy in patients with solid tumors. However, resistance to treatment and the "undruggability" of certain key oncogenic proteins emerged as major limitations and jeopardize the clinical benefit of modern therapeutic approaches. Targeted protein degraders are novel molecules entering the early phase of clinical development that exploit the intracellular ubiquitine-proteasome system to promote a specific degradation of target proteins. Since the peculiar mechanism of action, targeted protein degraders have the potential to limit and overcome resistance to treatment and to allow a full actionability of certain cancer drivers that are actually elusive targets. Here, we discuss the state-of-the-art and the open issues in the development of these emerging biological agents from a clinical perspective and with a focus on solid tumors.

Prognostic impact of performance status on the outcomes of immune checkpoint inhibition strategies in patients with dMMR/MSI-H metastatic colorectal cancer.

BACKGROUND: Immune checkpoint inhibitors yielded unprecedented outcomes in patients with mismatch repair deficient/ microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer (mCRC), but clinical decision-making in this rapidly evolving treatment landscape is challenging. Since performance status (PS) represents a well-established prognostic factor in clinical practice, we investigated whether worse PS, overall or related to either patients' frailty or high tumour burden, could affect the outcomes in this whole patients' population and according to immune checkpoint inhibitor treatment type. METHODS: We conducted a global study at Tertiary Cancer Centres and collected data of patients with dMMR/MSI-H mCRC treated with anti- programmed-death (ligand)-1 (PD(L)-1) monotherapy or anti-PD-1/anti- cytotoxic T-lymphocyte antigen 4 combination. RESULTS: The cohort included 502 patients. At a median follow-up of 31.2 months, worse PFS and OS were reported in patients with patient-related PS ≥ 1 (adjusted-HRs: 1.73, 95%CI: 1.06-2.83, p = 0.004 and 2.06, 95%CI: 1.13-3.74, p = 0.001, respectively) and cancer-related PS ≥ 1 (adjusted-HRs: 1.61, 95%CI: 1.19-2.17, p = 0.004 and 1.87, 95%CI: 1.32-2.66, p = 0.001, respectively). Anti-PD-1/anti- cytotoxic T-lymphocyte antigen 4 combination did not provide significantly better survival compared to anti-PD(L)-1 monotherapy in PS 0 subgroup (PFS HR = 0.62, 95%CI: 0.37-1.02, p = 0.059; OS HR = 0.59, 95%CI: 0.32-1.11, p = 0.100) and in patient-related PS ≥ 1 (PFS HR 0.93, 95%CI: 0.31-2.83, p = 0.899; OS HR 1.22, 95%CI: 0.34-4.37, p = 0.760), but the difference was significant and clinically meaningful in the subgroup with cancer-related PS ≥ 1 (PFS HR = 0.32, 95%CI: 0.19-0.53, p < 0.001; OS HR = 0.26, 95%CI: 0.14-0.48, p < 0.001). CONCLUSIONS: In patients with dMMR/MSI-H mCRC, an extensive evaluation of clinical variables including PS may be implemented in the therapy decision-making.

Negative Ultraselection of Patients With RAS/BRAF Wild-Type, Microsatellite-Stable Metastatic Colorectal Cancer Receiving Anti-EGFR-Based Therapy.

PURPOSE: Several uncommon genomic alterations beyond RAS and BRAFV600E mutations drive primary resistance to anti-epidermal growth factor receptors (EGFRs) in metastatic colorectal cancer (mCRC). Our PRESSING panel (including PIK3CA exon 20/AKT1/PTEN mutations, ERBB2/MET amplifications, gene fusions, and microsatellite instability-high status) represented a paradigm of negative hyperselection with more precise tailoring of EGFR blockade. However, a modest proportion of hyperselected mCRC has intrinsic resistance potentially driven by even rarer genomic alterations. MATERIALS AND METHODS: A prospective data set at three Italian Academic Hospitals included 650 patients with mCRC with comprehensive genomic profiling by FoundationOne CDx and treated with anti-EGFRs. PRESSING2 panel alterations were selected on the basis of previous clinico-biologic studies and included NTRKs, ERBB3, NF1, MAP2K1/2/4, AKT2 pathogenic mutations; PTEN/NF1 loss; ERBB3, FGFR2, IGF1R, KRAS, ARAF, and AKT1-2 amplification; and EGFR rearrangements. These were collectively associated with outcomes in patients with hyperselected disease, ie, RAS/BRAF wild-type, PRESSING-negative, and microsatellite stable. RESULTS: Among 162 hyperselected patients, 24 (15%) had PRESSING2 alterations, which were mutually exclusive except in two samples and were numerically higher in right-sided versus left-sided cancers (28% v 13%; P = .149). Independently of sidedness and other factors, patients with PRESSING2-positive status had significantly worse progression-free survival and overall survival compared with PRESSING2-negative ones (median progression-free survival 6.4 v 12.8 months, adjusted hazard ratio 4.19 [95% CI, 2.58 to 6.79]; median overall survival: 22.6 v 49.9 months, adjusted hazard ratio 2.98 [95% CI, 1.49 to 5.96]). The combined analysis of primary tumor sidedness and PRESSING2 status allowed us to better stratify outcomes. CONCLUSION: Negative ultraselection warrants further investigation with the aim of maximizing the benefit of EGFR blockade strategies in patients with RAS and BRAF wild-type, microsatellite stable mCRC.

Circulating tumor DNA to guide rechallenge with panitumumab in metastatic colorectal cancer: the phase 2 CHRONOS trial.

Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies are approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC), but the emergence of resistance mutations restricts their efficacy. We previously showed that RAS, BRAF and EGFR mutant alleles, which appear in circulating tumor DNA (ctDNA) during EGFR blockade, decline upon therapy withdrawal. We hypothesized that monitoring resistance mutations in blood could rationally guide subsequent therapy with anti-EGFR antibodies. We report here the results of CHRONOS, an open-label, single-arm phase 2 clinical trial exploiting blood-based identification of RAS/BRAF/EGFR mutations levels to tailor a chemotherapy-free anti-EGFR rechallenge with panitumumab (ClinicalTrials.gov: NCT03227926 ; EudraCT 2016-002597-12). The primary endpoint was objective response rate. Secondary endpoints were progression-free survival, overall survival, safety and tolerability of this strategy. In CHRONOS, patients with tissue-RAS WT tumors after a previous treatment with anti-EGFR-based regimens underwent an interventional ctDNA-based screening. Of 52 patients, 16 (31%) carried at least one mutation conferring resistance to anti-EGFR therapy and were excluded. The primary endpoint of the trial was met; and, of 27 enrolled patients, eight (30%) achieved partial response and 17 (63%) disease control, including two unconfirmed responses. These clinical results favorably compare with standard third-line treatments and show that interventional liquid biopsies can be effectively and safely exploited in a timely manner to guide anti-EGFR rechallenge therapy with panitumumab in patients with mCRC. Further larger and randomized trials are warranted to formally compare panitumumab rechallenge with standard-of-care therapies in this patient setting.

ALK Inhibitors in Patients With ALK Fusion-Positive GI Cancers: An International Data Set and a Molecular Case Series.

PURPOSE: In GI cancers, anaplastic lymphoma kinase (ALK) rearrangements are extremely less frequent than in non-small-cell lung cancer but may be important to offer personalized strategies of treatment in selected patients. Data about the activity and efficacy of ALK inhibitors (ALKi) in GI cancers are scarce. MATERIALS AND METHODS: We assembled a clinical and molecular international data set of pretreated patients with metastatic or nonresectable cancers of GI primary tumor origin with documented ALK rearrangement treated with at least one line of ALKi. Measurable disease as per RECIST 1.1 was required for response analysis. RESULTS: Primary tumor sites were distributed as follows: 5 (38%) pancreas, 3 (23%) right colon, and 1 (8%) for each one of gastric, duodenal, rectal, left colon, and biliary tract sites. Seven patients (54%) were treated with alectinib, 5 (38%) with crizotinib, and 1 (8%) with entrectinib. After disease progression, five patients (38%) received a subsequent ALKi treatment line, and at the time of data cutoff date, treatment was still ongoing in two patients. Five of 12 evaluable patients (41%) achieved a partial response to first-line ALKi, five patients (41%) had stable disease, and 2 (17%) had progressive disease. No complete responses were registered. At a median follow-up of 39.6 months (interquartile range: 19.8-59.5), the median progression-free survival was 5.0 months (95% CI, 3.68 to no response) and the median overall survival was 9.3 months (95% CI, 5.46 to no response). CONCLUSION: Treatment with ALKi provides remarkable responses and clinical benefit in pretreated patients with ALK fusion-positive GI malignancies. Despite the rarity, ALK rearrangements represent an important therapeutic target in individual pretreated patients with GI solid tumors. Further work providing prospective clinical validation of this target is needed.

Ascites and resistance to immune checkpoint inhibition in dMMR/MSI-H metastatic colorectal and gastric cancers.

BACKGROUND: Despite unprecedented benefit from immune checkpoint inhibitors (ICIs) in patients with mismatch repair deficient (dMMR)/microsatellite instability high (MSI-H) advanced gastrointestinal cancers, a relevant proportion of patients shows primary resistance or short-term disease control. Since malignant effusions represent an immune-suppressed niche, we investigated whether peritoneal involvement with or without ascites is a poor prognostic factor in patients with dMMR/MSI-H metastatic colorectal cancer (mCRC) and gastric cancer (mGC) receiving ICIs. METHODS: We conducted a global multicohort study at Tertiary Cancer Centers and collected clinic-pathological data from a cohort of patients with dMMR/MSI-H mCRC treated with anti-PD-(L)1 ±anti-CTLA-4 agents at 12 institutions (developing set). A cohort of patients with dMMR/MSI-high mGC treated with anti-PD-1 agents±chemotherapy at five institutions was used as validating dataset. RESULTS: The mCRC cohort included 502 patients. After a median follow-up of 31.2 months, patients without peritoneal metastases and those with peritoneal metastases and no ascites had similar outcomes (adjusted HR (aHR) 1.15, 95% CI 0.85 to 1.56 for progression-free survival (PFS); aHR 0.96, 95% CI 0.65 to 1.42 for overall survival (OS)), whereas inferior outcomes were observed in patients with peritoneal metastases and ascites (aHR 2.90, 95% CI 1.70 to 4.94; aHR 3.33, 95% CI 1.88 to 5.91) compared with patients without peritoneal involvement. The mGC cohort included 59 patients. After a median follow-up of 17.4 months, inferior PFS and OS were reported in patients with peritoneal metastases and ascites (aHR 3.83, 95% CI 1.68 to 8.72; aHR 3.44, 95% CI 1.39 to 8.53, respectively), but not in patients with only peritoneal metastases (aHR 1.87, 95% CI 0.64 to 5.46; aHR 2.15, 95% CI 0.64 to 7.27) when compared with patients without peritoneal involvement. CONCLUSIONS: Patients with dMMR/MSI-H gastrointestinal cancers with peritoneal metastases and ascites should be considered as a peculiar subgroup with highly unfavorable outcomes to current ICI-based therapies. Novel strategies to target the immune-suppressive niche in malignant effusions should be investigated, as well as next-generation ICIs or intraperitoneal approaches.

Fifteen-year follow-up of relapsed indolent non-Hodgkin lymphoma patients vaccinated with tumor-loaded dendritic cells.

We previously published the results of a pilot study showing that vaccination with tumor-loaded dendritic cells (DCs) induced both T and B cell response and produced clinical benefit in the absence of toxicity in patients with relapsed, indolent non-Hodgkin lymphoma (iNHL). The purpose of the present short report is to provide a 15-year follow-up of our study and to expand the biomarker analysis previously performed. The long-term follow-up highlighted the absence of particular or delayed toxicity and the benefit of active immunization with DCs loaded with autologous, heat-shocked and UV-C treated tumor cells in relapsed iNHL (5-year and 10-year progression-free survival (PFS) rates: 55.6% and 33.3%, respectively; 10-year overall survival (OS) rate: 83.3%). Female patients experienced a better PFS (p=0.016) and a trend towards a better OS (p=0.185) compared with male patients. Of note, we observed a non-negligible fraction of patients (22%) who experienced a long-lasting complete response. In a targeted gene expression profiling of pre-treatment tumor biopsies in 11 patients with available formalin-fixed, paraffin-embedded tissue, we observed that KIT, ATG12, TNFRSF10C, PBK, ITGA2, GATA3, CLU, NCAM1, SYT17 and LTK were differentially expressed in patients with responder versus non-responder tumors. The characterization of peripheral monocytic cells in a subgroup of 14 patients with available baseline blood samples showed a higher frequency of the subset of CD14++CD16+ cells (intermediate monocytes) in patients with responding tumors. Since in patients with relapsed iNHL the available therapeutic options are often incapable of inducing a long-lasting complete remission and can be sometimes characterized by intolerable toxicity, we think that the encouraging results of our long-term follow-up analysis represent a stimulus to further investigate the role of active vaccination in this specific setting and in earlier lines of therapy and to explore novel combinatorial strategies encompassing other innovative immunotherapy agents, such as immune-checkpoint inhibitors.

Rationale and Study Design of the PARERE Trial: Randomized phase II Study of Panitumumab Re-Treatment Followed by Regorafenib Versus the Reverse Sequence in RAS and BRAF Wild-Type Chemo-Refractory Metastatic Colorectal Cancer Patients.

BACKGROUND: A recent phase II randomized Japanese study reported better survival with regorafenib followed at progression by cetuximab ± irinotecan compared with the reverse standard sequence in chemo-refractory and anti-EGFR-naïve, RAS wild-type (wt) mCRC patients. Nowadays the use of anti-EGFR antibodies is more frequently anticipated to the first-line of therapy especially in patients with left-sided RAS/BRAF wt tumours. However, retrospective analyses and phase II single-arm trials showed promising activity of re-using anti-EGFRs in metastatic colorectal cancer (mCRC) patients who previously achieved benefit from a first-line anti-EGFR-based treatment. Post-hoc analyses of these trials revealed that the detection of RAS mutations in circulating tumour DNA (ct-DNA) at the time of re-treatment may be useful to identify resistant patients. PATIENTS AND METHODS: PARERE (NCT04787341) is a prospective, open label, multicentre phase II study in which 214 RAS/BRAF wt chemo-refractory mCRC patients with previous benefit from first-line anti-EGFR-based treatment and RAS/BRAF wt ct-DNA in the liquid biopsy collected at the time of inclusion will be randomized in a 1:1 ratio to receive panitumumab followed after progression by regorafenib versus the reverse sequence. Primary endpoint is overall survival. Secondary endpoints are 1st-progression free-survival (PFS), 2nd-PFS, time to failure strategy, objective response rate, and safety. AIM OF THE STUDY: The aim of this study is to validate the role of anti-EGFR retreatment and its proper placement in the therapeutic route of mCRC patients selected according to the analysis of ct-DNA in liquid biopsy. Results are expected at the end of 2023.