Entrectinib, a potent oral inhibitor of the tyrosine kinases TRKA/B/C, ROS1, and ALK, was evaluated in two phase I studies in patients with advanced or metastatic solid tumors, including patients ...with active central nervous system (CNS) disease. Here, we summarize the overall safety and report the antitumor activity of entrectinib in a cohort of patients with tumors harboring
, or
gene fusions, naïve to prior TKI treatment targeting the specific gene, and who were treated at doses that achieved therapeutic exposures consistent with the recommended phase II dose. Entrectinib was well tolerated, with predominantly Grades 1/2 adverse events that were reversible with dose modification. Responses were observed in non-small cell lung cancer, colorectal cancer, mammary analogue secretory carcinoma, melanoma, and renal cell carcinoma, as early as 4 weeks after starting treatment and lasting as long as >2 years. Notably, a complete CNS response was achieved in a patient with
-rearranged lung cancer.
Gene fusions of
, and
(encoding TRKA/B/C, ROS1, and ALK, respectively) lead to constitutive activation of oncogenic pathways. Entrectinib was shown to be well tolerated and active against those gene fusions in solid tumors, including in patients with primary or secondary CNS disease.
.
This phase Ib study (NCT00960960) evaluated pictilisib (GDC-0941; pan-phosphatidylinositol 3-kinase inhibitor) plus paclitaxel, with and without bevacizumab or trastuzumab, or in combination with ...letrozole, in patients with locally recurrent or metastatic breast cancer.
This was a three-part multischedule study. Patients in parts 1 and 2, which comprised 3 + 3 dose escalation and cohort expansion stages, received pictilisib (60-330 mg) plus paclitaxel (90 mg/m
) with and without bevacizumab (10 mg/kg) or trastuzumab (2-4 mg/kg). In part 3, patients received pictilisib (260 mg) plus letrozole (2.5 mg). Primary objectives were evaluation of safety and tolerability, identification of dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of pictilisib, and recommendation of a phase II dosing regimen. Secondary endpoints included pharmacokinetics and preliminary antitumor activity.
Sixty-nine patients were enrolled; all experienced at least one adverse event (AE). Grade ≥ 3 AEs, serious AEs, and AEs leading to death were reported in 50 (72.5%), 21 (30.4%), and 2 (2.9%) patients, respectively. Six (8.7%) patients reported a DLT, and the MTD and recommended phase II pictilisib doses were established where possible. There was no pictilisib-paclitaxel drug-drug interaction. Two (3.4%) patients experienced complete responses, and 17 (29.3%) patients had partial responses.
Combining pictilisib with paclitaxel, with and without bevacizumab or trastuzumab, or letrozole, had a manageable safety profile in patients with locally recurrent or metastatic breast cancer. The combination had antitumor activity, and the additive effect of pictilisib supported further investigation in a randomized study.
ClinicalTrials.gov, NCT00960960 . Registered on August 13, 2009.
In patients with advanced triple-negative breast cancer (TNBC), translational research efforts are needed to improve the clinical efficacy of immunotherapy with checkpoint inhibitors. Here, we report ...on the immunological characterization of an exceptional, long-lasting, tumor complete response in a patient with metastatic TNBC treated with dual PD-1 and LAG-3 blockade within the phase I/II study CLAG525X2101C (NCT02460224) The pre-treatment tumor biopsy revealed the presence of a CD3
and CD8
cell infiltrate, with few PD1
cells, rare CD4
cells, and an absence of both NK cells and LAG3 expression. Conversely, tumor cells exhibited positive staining for the three primary LAG-3 ligands (HLA-DR, FGL-1, and galectin-3), while being negative for PD-L1. In peripheral blood, baseline expression of LAG-3 and PD-1 was observed in circulating immune cells. Following treatment initiation, there was a rapid increase in proliferating granzyme-B
NK and T cells, including CD4
T cells, alongside a reduction in myeloid-derived suppressor cells. The role of LAG-3 expression on circulating NK cells, as well as the expression of LAG-3 ligands on tumor cells and the early modulation of circulating cytotoxic CD4
T cells warrant further investigation as exploitable predictive biomarkers for dual PD-1 and LAG-3 blockade.Trial registration: NCT02460224. Registered 02/06/2015.
To determine the clinical efficacy of imatinib in patients with advanced aggressive fibromatosis (AF) and to identify the molecular basis of response/nonresponse to this agent.
Nineteen patients with ...AF were treated with imatinib (800 mg/d) as part of a phase II clinical study. Tumor specimens were analyzed for mutations of KIT, PDGFRA, PDGFRB, and CTNNB1 (beta-catenin). Tumor expression of total and activated KIT, PDGFRA, and PDGFRB were assessed using immunohistochemistry and immunoblotting techniques. We also measured plasma levels of PDGF-AA and PDGF-BB in patients and normal patient controls.
Three of 19 patients (15.7%) had a partial response to treatment, with four additional patients having stable disease that lasted more than 1 year (overall 1 year tumor control rate of 36.8%). No mutations of KIT, PDGFRA, or PDGFRB were found. Sixteen of 19 patients (84%) had mutations involving the WNT pathway (APC or CTNNB1). However, there was no correlation between WNT pathway mutations and clinical response to imatinib. AF tumors expressed minimal to null levels of KIT and PDGFRA but expressed levels of PDGFRB that are comparable with normal fibroblasts. However, PDGFRB phosphorylation was not detected, suggesting that PDGFRB is only weakly activated. AF patients had elevated levels of PDGF-AA and PDGF-BB compared with normal patient controls. Notably, the plasma level of PDGF-BB was inversely correlated with time to treatment failure.
Imatinib is an active agent in the treatment of advanced AF. Imatinib response in AF patients may be mediated by inhibition of PDGFRB kinase activity.
Predictive biomarkers of response to immune-checkpoint inhibitors (ICIs) are an urgent clinical need. The aim of this study is to identify manageable parameters to use in clinical practice to select ...patients with higher probability of response to ICIs. Two-hundred-and-seventy-one consecutive metastatic solid tumor patients, treated from 2013 until 2017 with anti- Programmed death-ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) ICIs, were evaluated for baseline lactate dehydrogenase (LDH) serum level, performance status (PS), age, neutrophil-lymphocyte ratio, type of immunotherapy, number of metastatic sites, histology, and sex. A training and validation set were used to build and test models, respectively. The variables' effects were assessed through odds ratio estimates (OR) and area under the receive operating characteristic curves (AUC), from univariate and multivariate logistic regression models. A final multivariate model with LDH, age and PS showed significant ORs and an AUC of 0.771. Results were statistically validated and used to devise an Excel algorithm to calculate the patient's response probabilities. We implemented an interactive Excel algorithm based on three variables (baseline LDH serum level, age and PS) which is able to provide a higher performance in response prediction to ICIs compared with LDH alone. This tool could be used in a real-life setting to identify ICIs in responding patients.
Synergistic/additive cytotoxicity in tumor models and widespread applicability of fluoropyrimidines in solid tumors prompted the study of the combination of the mammalian target of rapamycin (mTOR) ...inhibitor, non-prodrug rapamycin analog ridaforolimus, with capecitabine.
Thirty-two adult patients were treated. Intravenous ridaforolimus was given once weekly for 3 weeks and capecitabine was given from days 1 to 14 every 4 weeks. Ridaforolimus was given at 25, 37.5, 50, or 75 mg with capecitabine at 1,650 mg/m(2) or 1,800 mg/m(2) divided into two daily doses. Pharmacokinetics of both drugs were determined during cycles 1 and 2. Pharmacodynamic studies in peripheral blood mononuclear cells (PBMCs) and wound tissue of the skin characterized pathways associated with the metabolism or disposition of fluoropyrimidines and mTOR and ERK signaling.
Two recommended doses (RDs) were defined: 75 mg ridaforolimus/1,650 mg/m(2) capecitabine and 50 mg ridaforolimus/1,800 mg/m(2) capecitabine. Dose-limiting toxicities were stomatitis and skin rash. One patient achieved a partial response lasting 10 months and 10 of 29 evaluable patients had stable disease for ≥ 6 months. The only pharmacokinetic interaction was a ridaforolimus-induced increase in plasma exposure to fluorouracil. PBMC data suggested that prolonged exposure to capecitabine reduced the ridaforolimus inhibition of mTOR. Ridaforolimus influenced the metabolism of fluoropyrimidines and inhibited dihydropyrimidine dehydrogenase, behavior similar to that of rapamycin. Inhibition of the target thymidylate synthase by capecitabine was unaffected. mTOR and ERK signaling was inhibited in proliferating endothelial cells and was more pronounced at the RD with the larger amount of ridaforolimus.
Good tolerability, feasibility of prolonged treatment, antitumor activity, and favorable pharmacologic profile support further investigation of this combination.
This phase 1 trial (NCT01938846) determined the maximum tolerated dose (MTD) of the mTOR serine/threonine kinase inhibitor, BI 860585, as monotherapy and with exemestane or paclitaxel in patients ...with advanced solid tumors. This 3+3 dose-escalation study assessed BI 860585 monotherapy (5–300 mg/day; Arm A), BI 860585 (40–220 mg/day; Arm B) with 25 mg/day exemestane, and BI 860585 (80–220 mg/day; Arm C) with 60–80 mg/m2/week paclitaxel, in 28-day cycles. Primary endpoints were the number of patients with dose-limiting toxicities (DLTs) in cycle 1 and the MTD. Forty-one, 25, and 24 patients were treated (Arms A, B, and C). DLTs were observed in four (rash (n = 2), elevated alanine aminotransferase/aspartate aminotransferase, diarrhea), four (rash (n = 3), stomatitis, and increased gamma-glutamyl transferase), and two (diarrhea, increased blood creatine phosphokinase) patients in cycle 1. The BI 860585 MTD was 220 mg/day (Arm A) and 160 mg/day (Arms B and C). Nine patients achieved an objective response (Arm B: Four partial responses (PRs); Arm C: Four PRs; one complete response). The disease control rate was 20%, 28%, and 58% (Arms A, B, and C). The most frequent treatment-related adverse events (AEs) were hyperglycemia (54%) and diarrhea (39%) (Arm A); diarrhea (40%) and stomatitis (40%) (Arm B); fatigue (58%) and diarrhea (58%) (Arm C). The MTD was determined in all arms. Antitumor activity was observed with BI 860585 monotherapy and in combination with exemestane or paclitaxel.
Data are sparse for oral selective estrogen receptor (ER) degraders (SERD) in cancer treatment. The investigational oral SERD LSZ102 was assessed in monotherapy and combination use in a phase I ...study.
A phase I, multicenter, open-label dose-escalation study (NCT02734615) of LSZ102 alone (arm A;
= 77) or with ribociclib (arm B;
= 78) or alpelisib (arm C;
= 43) in heavily pretreated adults with histologically confirmed ER-positive breast cancer and prior disease progression. Arm A received LSZ102 200-900 mg/day; arm B, LSZ102 200-600 mg/day plus ribociclib 300-600 mg/day; arm C, LSZ102 300-450 mg/day plus alpelisib 200-300 mg/day. Key outcomes were dose-limiting toxicities (DLT) in the first 28-day treatment cycle, adverse events (AE), laboratory parameters, pharmacokinetics, biopsy ER protein, and investigator-assessed clinical response (RECIST v1.1).
The most common AEs were gastrointestinal. Treatment-related serious AEs occurred in 10% of participants (19/198), mostly in arm C 10/43 (23%). DLTs occurred in: arm A, 5% (4/77); arm B, 3% (2/78); and arm C, 19% (8/43). LSZ102 exposure was slightly greater than dose proportional. On-treatment biopsy ER reductions were observed, with a trend toward an LSZ102 dose response. Objective response rates (95% confidence interval) were: arm A, 1.3% (0.0-7.0); arm B, 16.9% (9.3-27.1); and arm C, 7.0% (1.5-19.1), and clinical benefit rates 7.8% (2.9-16.2), 35.1% (24.5-46.8), and 20.9% (10.0-36.0), respectively.
LSZ102 was well tolerated alone and with ribociclib and had a manageable safety profile with alpelisib. Preliminary clinical activity was observed in combination use.
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•Protein degraders selectively degrade and deplete specific intracellular proteins.•Protein degraders represent a promising strategy to enable the targeting of so far elusive cancer ...drivers.•Protein degraders may prevent/overcome resistance to other targeted agents.•The safety and target specificity are open issues in the clinical development of protein degraders.
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.
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