Purpose: Here, we report results of the first phase I study of erdafitinib, a potent, oral pan-FGFR inhibitor. Patients and Methods: Patients age !18 years with advanced solid tumors for which standard antineoplastic therapy was no longer effective were enrolled (NCT01703481). Parts 2 to 4 employed molecular screening for activating FGFR genomic alterations. In patients with such alterations, two selected doses/schedules identified during part 1 doseescalation [9 mg once daily and 10 mg intermittently (7 days on/7 days off), as previously published (Tabernero JCO 2015;33:3401-8)] were tested. Results: The study included 187 patients. The most common treatment-related adverse events were hyperphosphatemia (64%), dry mouth (42%), and asthenia (28%), generally grade 1/2 severity. All cases of hyperphosphatemia were grade 1/2 except for 1 grade 3 event. Skin, nail, and eye changes were observed in 43%, 33%, and 28% of patients, respectively (mostly grade 1/2 and reversible after temporary dosing interruption). Urothelial carcinoma and cholangiocarcinoma were most responsive to erdafitinib, with objective response rates (ORR) of 46.2% (12/26) and 27.3% (3/11), respectively, in response-evaluable patients with FGFR mutations or fusions. All patients with urothelial carcinoma and cholangiocarcinoma who responded to erdafitinib carried FGFR mutations or fusions. Median response duration was 5.6 months for urothelial carcinoma and 11.4 months for cholangiocarcinoma. ORRs in other tumor types were <10%. Conclusions: Erdafitinib shows tolerability and preliminary clinical activity in advanced solid tumors with genomic changes in the FGFR pathway, at two different dosing schedules and with particularly encouraging responses in urothelial carcinoma and cholangiocarcinoma.

Expanded clinical experience with patients taking antiangiogenic compounds has come with increasing recognition of the renal adverse effects. Because renal histology is rarely sought in those patients, the renal consequences are underestimated. Antiangiogenic-treated-cancer patients, who had a renal biopsy for renal adverse effects from 2006 to 2013, were included in the current study. Clinical features and renal histologic findings were reviewed. Our cohort was 100 patients (58 women) with biopsy-proven kidney disease using anti-vascular endothelial growth factor (VEGF) therapy with a mean age of 59.8 years (range, 20–85 yr). Patients were referred for proteinuria, hypertension, and/or renal insufficiency. Kidney biopsy was performed 6.87 ± 7.18 months after the beginning of treatment. Seventy-three patients experienced renal thrombotic microangiopathy (TMA) and 27 patients had variable glomerulopathies, mainly minimal change disease and/or collapsing-like focal segmental glomerulosclerosis (MCN/cFSGS). MCN/cFSGS-like lesions developed mainly with tyrosine-kinase inhibitors, whereas TMA complicated anti-VEGF ligand. Thirty-one percent of TMA patients had proteinuria up to 1 g/24 h. Half of TMA cases are exclusively renal localized. Pathologic TMA features are intraglomerular exclusively. MCN/cFSGS glomeruli displayed a high abundance of KI-67, but synaptopodin was not detected. Conversely, TMA glomeruli exhibited a normal abundance of synaptopodin-like control, whereas KI-67 was absent. Median follow-up was 12 months (range, 1–80 mo). Fifty-four patients died due to cancer progression. Hypertension and proteinuria resolved following drug discontinuation and antihypertensive agents. No patient developed severe renal failure requiring dialysis. Drug continuation or reintroduction resulted in a more severe recurrence of TMA in 3 out of 4 patients requiring maintenance of anti-VEGF agents despite renal TMA. In conclusion, TMA and MCN/cFSGS are the most frequent forms of renal involvement under anti-VEGF therapy. Careful risk-benefit assessment for individual patients should take into account risk factors related to the host and the tumor.

Renal toxicity constitutes a dose-limiting side effect of anticancer therapies targeting vascular endothelial growth factor (VEGF). In order to study this further, we followed up 29 patients receiving this treatment, who experienced proteinuria, hypertension, and/or renal insufficiency. Eight developed minimal change nephropathy/focal segmental glomerulopathy (MCN/FSG)-like lesions and 13 developed thrombotic microangiopathy (TMA). Patients receiving receptor tyrosine kinase inhibitors (RTKIs) mainly developed MCN/FSG-like lesions, whereas TMA complicated anti-VEGF therapy. There were no mutations in factor H, factor I, or membrane cofactor protein of the complement alternative pathway, while plasma ADAMTS13 activity persisted and anti-ADAMTS13 antibodies were undetectable in patients with TMA. Glomerular VEGF expression was undetectable in TMA and decreased in MCN/FSG. Glomeruli from patients with TMA displayed a high abundance of RelA in endothelial cells and in the podocyte nuclei, but c-mip was not detected. Conversely, MCN/FSG-like lesions exhibited a high abundance of c-mip, whereas RelA was scarcely detected. RelA binds in vivo to the c-mip promoter and prevents its transcriptional activation, whereas RelA knockdown releases c-mip activation. The RTKI sorafenib inhibited RelA activity, which then promoted c-mip expression. Thus, our results suggest that c-mip and RelA define two distinct types of renal damage associated with VEGF-targeted therapies.

◥Purpose: Lorlatinib is a third-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor with proven efficacy in patients with ALK-rearranged lung cancer previously treated with firstand second-generation ALK inhibitors. Beside compound mutations in the ALK kinase domain, other resistance mechanisms driving lorlatinib resistance remain unknown. We aimed to characterize the mechanisms of resistance to lorlatinib occurring in patients with ALK-rearranged lung cancer and design new therapeutic strategies in this setting.Experimental Design: Resistance mechanisms were investigated in 5 patients resistant to lorlatinib. Longitudinal tumor biopsies were studied using high-throughput next-generation sequencing. Patient-derived models were developed to characterize the acquired resistance mechanisms, and Ba/F3 cell mutants were generated to study the effect of novel ALK compound mutations. Drug combi-natory strategies were evaluated in vitro and in vivo to overcome lorlatinib resistance.Results: Diverse biological mechanisms leading to lorlatinib resistance were identified. Epithelial-mesenchymal transition (EMT) mediated resistance in two patient-derived cell lines and was susceptible to dual SRC and ALK inhibition. We characterized three ALK kinase domain compound mutations occurring in patients, L1196M/D1203N, F1174L/G1202R, and C1156Y/ G1269A, with differential susceptibility to ALK inhibition by lorlatinib. We identified a novel bypass mechanism of resistance caused by NF2 loss-of-function mutations, conferring sensitivity to treatment with mTOR inhibitors.Conclusions: This study shows that mechanisms of resistance to lorlatinib are diverse and complex, requiring new therapeutic strategies to tailor treatment upon disease progression.

Purpose: This phase I study assessed the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), safety, pharmacokinetics, pharmacodynamics, and clinical activity of the first-in-class dual MEK/RAF inhibitor, RO5126766.Experimental Design: Initial dose-escalation was conducted using once daily dosing over 28 consecutive days in 4-week cycles. Further escalation was completed using 2 intermittent dosing schedules [7 days on treatment followed by 7 days off (7on/7off); 4 days on treatment followed by 3 days off (4on/3off)].Results: Fifty-two patients received RO5126766 at doses of 0.1 to 2.7 mg once daily, 2.7 to 4.0 mg (4 on/3 off), or 2.7 to 5.0 mg (7 on/7 off). The most common DLTs were elevated creatine phosphokinase (CPK) and blurred vision. The MTD for each dosing schedule was 2.25 mg once daily, 4.0 mg (4 on/3 off), and 2.7 mg (7 on/7 off). The dose/schedule recommended for phase II (RP2D) investigation was 2.7 mg (4 on/3 off). Frequent adverse events included rash-related disorders (94.2%), elevated CPK (55.8%), and diarrhea (51.9%). C max occurred 1 to 2 hours after dosing and mean terminal half-life was approximately 60 hours. Pharmacodynamic changes included reduced ERK phosphorylation, an increase in apoptosis in tumor tissue, and a reduction in fluorodeoxyglucose (FDG) uptake after 15 days of dosing. Three partial responses were seen: two in BRAF-mutant melanoma tumors and one in an NRAS-mutant melanoma.Conclusion: This first-in-human study shows that oral RO5126766 has manageable toxicity, a favorable pharmacokinetic/pharmacodynamic profile, and encouraging preliminary antitumor activity in this population of heavily pretreated patients, achieving tumor shrinkage in around 40% of patients across all dose levels and all tumor types.

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Purpose: Anti-PD-(L)1 can provide overall survival (OS) benefits over conventional treatments for patients with many different cancer types. However, the long-term outcome of cancer patients responding to these therapies remains unknown. This study is an exploratory study that aimed to describe the long-term survival of patients responding to anti-PD-(L)1 monotherapy across multiple cancer types.Patients and Methods: Data from patients treated with an anti-PD-(L)1 monotherapy in a phase I trial at Gustave Roussy were retrospectively analyzed over a period of 5 years. All cancer types (n ¼ 19) were included. Clinical and biological factors associated with response, long-term survival, and secondary refractory disease were studied.Results: Among 262 eligible patients, the overall objective response rate was 29%. The median progression-free survival of responder patients (RP) at 3 months was 30 months, and the median OS of RP was not reached after a median follow-up of 34 months. In RPs, 3-and 5-year OS percentages were 84% and 64%, respectively. No death occurred in the 21 complete responders (CR) during the overall follow-up. However, many partial responders (PR) showed subsequent tumor relapses to treatment. Long responders (response 2 years) represented 11.8% of the overall population. These findings should be validated in further prospective studies.Conclusions: There are currently no differences in therapeutic strategies between CRs and PRs to anti-PD-(L)1. We found a striking difference in OS between these two types of responses. Our results are in favor of evaluating patient stratification strategies and intensification of treatments when tumor lesions of a partial responder to immunotherapy stop improving.

In tumours that harbour wild-type p53, p53 protein function is frequently disabled by the mouse double minute 2 protein (MDM2, or HDM2 in humans). Multiple HDM2 antagonists are currently in clinical development. Preclinical data indicate that TP53 mutations are a possible mechanism of acquired resistance to HDM2 inhibition; however, this resistance mechanism has not been reported in patients. Utilizing liquid biopsies, here we demonstrate that TP53 mutations appear in circulating cell-free DNA obtained from patients with de-differentiated liposarcoma being treated with an inhibitor of the HDM2–p53 interaction (SAR405838). TP53 mutation burden increases over time and correlates with change in tumour size, likely representing selection of TP53 mutant clones resistant to HDM2 inhibition. These results provide the first clinical demonstration of the emergence of TP53 mutations in response to an HDM2 antagonist and have significant implications for the clinical development of this class of molecules.