Ranee Mehra

Ceritinib in ALK-rearranged non-small-cell lung cancer.

BACKGROUND Non-small-cell lung cancer (NSCLC) harboring the anaplastic lymphoma kinase gene (ALK) rearrangement is sensitive to the ALK inhibitor crizotinib, but resistance invariably develops. Ceritinib (LDK378) is a new ALK inhibitor that has shown greater antitumor potency than crizotinib in preclinical studies. METHODS In this phase 1 study, we administered oral ceritinib in doses of 50 to 750 mg once daily to patients with advanced cancers harboring genetic alterations in ALK. In an expansion phase of the study, patients received the maximum tolerated dose. Patients were assessed to determine the safety, pharmacokinetic properties, and antitumor activity of ceritinib. Tumor biopsies were performed before ceritinib treatment to identify resistance mutations in ALK in a group of patients with NSCLC who had had disease progression during treatment with crizotinib. RESULTS A total of 59 patients were enrolled in the dose-escalation phase. The maximum tolerated dose of ceritinib was 750 mg once daily; dose-limiting toxic events included diarrhea, vomiting, dehydration, elevated aminotransferase levels, and hypophosphatemia. This phase was followed by an expansion phase, in which an additional 71 patients were treated, for a total of 130 patients overall. Among 114 patients with NSCLC who received at least 400 mg of ceritinib per day, the overall response rate was 58% (95% confidence interval [CI], 48 to 67). Among 80 patients who had received crizotinib previously, the response rate was 56% (95% CI, 45 to 67). Responses were observed in patients with various resistance mutations in ALK and in patients without detectable mutations. Among patients with NSCLC who received at least 400 mg of ceritinib per day, the median progression-free survival was 7.0 months (95% CI, 5.6 to 9.5). CONCLUSIONS Ceritinib was highly active in patients with advanced, ALK-rearranged NSCLC, including those who had had disease progression during crizotinib treatment, regardless of the presence of resistance mutations in ALK. (Funded by Novartis Pharmaceuticals and others; ClinicalTrials.gov number, NCT01283516.).

Activity of XL184 (Cabozantinib), an Oral Tyrosine Kinase Inhibitor, in Patients With Medullary Thyroid Cancer

PURPOSE XL184 (cabozantinib) is a potent inhibitor of MET, vascular endothelial growth factor receptor 2 (VEGFR2), and RET, with robust antiangiogenic, antitumor, and anti-invasive effects in preclinical models. Early observations of clinical benefit in a phase I study of cabozantinib, which included patients with medullary thyroid cancer (MTC), led to expansion of an MTC-enriched cohort, which is the focus of this article. PATIENTS AND METHODS A phase I dose-escalation study of oral cabozantinib was conducted in patients with advanced solid tumors. Primary end points included evaluation of safety, pharmacokinetics, and maximum-tolerated dose (MTD) determination. Additional end points included RECIST (Response Evaluation Criteria in Solid Tumors) response, pharmacodynamics, RET mutational status, and biomarker analyses. RESULTS Eighty-five patients were enrolled, including 37 with MTC. The MTD was 175 mg daily. Dose-limiting toxicities were grade 3 palmar plantar erythrodysesthesia (PPE), mucositis, and AST, ALT, and lipase elevations and grade 2 mucositis that resulted in dose interruption and reduction. Ten (29%) of 35 patients with MTC with measurable disease had a confirmed partial response. Overall, 18 patients experienced tumor shrinkage of 30% or more, including 17 (49%) of 35 patients with MTC with measurable disease. Additionally, 15 (41%) of 37 patients with MTC had stable disease (SD) for at least 6 months, resulting in SD for 6 months or longer or confirmed partial response in 68% of patients with MTC. CONCLUSION Cabozantinib has an acceptable safety profile and is active in MTC. Cabozantinib may provide clinical benefit by simultaneously targeting multiple pathways of importance in MTC, including MET, VEGFR2, and RET. A global phase III pivotal study in MTC is ongoing (ClinicalTrials.gov number NCT00215605).

Safety and clinical activity of pembrolizumab for treatment of recurrent or metastatic squamous cell carcinoma of the head and neck (KEYNOTE-012): an open-label, multicentre, phase 1b trial

BACKGROUND Patients with recurrent or metastatic squamous cell carcinoma of the head and neck have few treatment options. We aimed to assess the safety, tolerability, and antitumour activity of pembrolizumab, a humanised anti-programmed death receptor 1 (PD-1) antibody, in patients with PD-L1-positive recurrent or metastatic squamous cell carcinoma of the head and neck. METHODS This study was an open-label, multicentre, phase 1b trial of patients with recurrent or metastatic squamous cell carcinoma of the head and neck. Patients were eligible for enrolment if they were aged 18 years or older, had a confirmed diagnosis of recurrent or metastatic squamous cell carcinoma of the head and neck, and had any level of PD-L1 expression (ie, at least 1% of tumour cells or stroma that were PD-L1-positive by immunohistochemistry). Patients received pembrolizumab 10 mg/kg intravenously every 2 weeks. Primary outcomes were safety in the per-protocol population and the proportion of patients with centrally reviewed overall response per Response Evaluation Criteria In Solid Tumors (RECIST, version 1.1). Overall response was analysed in the full analysis set, which was defined as all patients who had received at least one dose of pembrolizumab, had measurable disease at baseline, and one post-baseline scan or patients without a post-baseline scan who discontinued therapy because of disease progression or a drug-related adverse event. The study is registered with ClinicalTrials.gov, number NCT01848834 and is ongoing, but no longer enrolling patients. FINDINGS Of the 104 patients screened between June 7, 2013, and Oct 3, 2013, 81 (78%) were PD-L1-positive. Of these, 60 patients with PD-L1-positive squamous cell carcinoma of the head and neck were enrolled and treated: 23 (38%) were HPV-positive and 37 (62%) were HPV-negative. Pembrolizumab was well tolerated, with 10 (17%) of 60 patients having grade 3-4 drug-related adverse events, the most common of which were increases in alanine aminotransferase and in aspartate aminotransferase, and hyponatraemia, each occurring in two of 60 patients; one patient developed a grade 3 drug-related rash. 27 (45%) of 60 patients experienced a serious adverse event. There were no drug-related deaths. The proportion of patients with an overall response by central imaging review was 18% (eight of 45 patients; 95% CI 8-32) in all patients and was 25% (four of 16 patients; 7-52) in HPV-positive patients and 14% (four of 29 patients; 4-32) in HPV-negative patients. INTERPRETATION Pembrolizumab was well tolerated and demonstrated clinically meaningful antitumour activity in recurrent or metastatic squamous cell carcinoma of the head and neck, supporting further study of pembrolizumab as anticancer therapy for advanced head and neck cancers. FUNDING Merck & Co.

Phase III Randomized Trial of Induction Chemotherapy in Patients With N2 or N3 Locally Advanced Head and Neck Cancer

PURPOSE Induction chemotherapy (IC) before radiotherapy lowers distant failure (DF) rates in locally advanced squamous cell carcinoma of the head and neck (SCCHN). The goal of this phase III trial was to determine whether IC before chemoradiotherapy (CRT) further improves survival compared with CRT alone in patients with N2 or N3 disease. PATIENTS AND METHODS Treatment-naive patients with nonmetastatic N2 or N3 SCCHN were randomly assigned to CRT alone (CRT arm; docetaxel, fluorouracil, and hydroxyurea plus radiotherapy 0.15 Gy twice per day every other week) versus two 21-day cycles of IC (docetaxel 75 mg/m(2) on day 1, cisplatin 75 mg/m(2) on day 1, and fluorouracil 750 mg/m(2) on days 1 to 5) followed by the same CRT regimen (IC + CRT arm). The primary end point was overall survival (OS). Secondary end points included DF-free survival, failure pattern, and recurrence-free survival (RFS). RESULTS A total of 285 patients were randomly assigned. The most common grade 3 to 4 toxicities during IC were febrile neutropenia (11%) and mucositis (9%); during CRT (both arms combined), they were mucositis (49%), dermatitis (21%), and leukopenia (18%). Serious adverse events were more common in the IC arm (47% v 28%; P = .002). With a minimum follow-up of 30 months, there were no statistically significant differences in OS (hazard ratio, 0.91; 95% CI, 0.59 to 1.41), RFS, or DF-free survival. CONCLUSION IC did not translate into improved OS compared with CRT alone. However, the study was underpowered because it did not meet the planned accrual target, and OS was higher than predicted in both arms. IC cannot be recommended routinely in patients with N2 or N3 locally advanced SCCHN.

Antitumor Activity of Pembrolizumab in Biomarker-Unselected Patients With Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma: Results From the Phase Ib KEYNOTE-012 Expansion Cohort

Purpose Treatment with pembrolizumab, an anti–programmed death-1 antibody, at 10 mg/kg administered once every 2 weeks, displayed durable antitumor activity in programmed death-ligand 1 (PD-L1) –positive recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) in the KEYNOTE-012 trial. Results from the expansion cohort, in which patients with HNSCC, irrespective of biomarker status, received a fixed dose of pembrolizumab at a less frequent dosing schedule, are reported. Patients and Methods Patients with R/M HNSCC, irrespective of PD-L1 or human papillomavirus status, received pembrolizumab 200 mg intravenously once every 3 weeks. Imaging was performed every 8 weeks. Primary end points were overall response rate (ORR) per central imaging vendor (Response Evaluation Criteria in Solid Tumors v1.1) and safety. Secondary end points included progression-free survival, overall survival, and association of response and PD-L1 expression. Patients who received one or more doses of pembrolizumab were included in analyses. Results Of 132 patients enrolled, median age was 60 years (range, 25 to 84 years), 83% were male, and 57% received two or more lines of therapy for R/M disease. ORR was 18% (95% CI, 12 to 26) by central imaging vendor and 20% (95% CI, 13 to 28) by investigator review. Median duration of response was not reached (range, ≥ 2 to ≥ 11 months). Six-month progression-free survival and overall survival rates were 23% and 59%, respectively. By using tumor and immune cells, a statistically significant increase in ORR was observed for PD-L1–positive versus –negative patients (22% v 4%; P = .021). Treatment-related adverse events of any grade and grade ≥ 3 events occurred in 62% and 9% of patients, respectively. Conclusion Fixed-dose pembrolizumab 200 mg administered once every 3 weeks was well tolerated and yielded a clinically meaningful ORR with evidence of durable responses, which supports further development of this regimen in patients with advanced HNSCC.

Activity and safety of ceritinib in patients with ALK-rearranged non-small-cell lung cancer (ASCEND-1): updated results from the multicentre, open-label, phase 1 trial

SUMMARY Background ALK-rearranged non-small-cell lung cancer (NSCLC) is sensitive to ALK tyrosine kinase inhibitors (ALKi) such as crizotinib, but resistance invariably develops, often with progression in the brain. Ceritinib is a more potent ALKi than crizotinib in vitro, crosses the blood-brain barrier in vivo and shows clinical responses in crizotinib-resistant disease. Here, we assessed whole-body and intracranial activity of ceritinib in both ALK-pretreated and ALKi-naïve patients with ALK-rearranged NSCLC. Methods The primary objective (to determine the maximum tolerated dose of ceritinib) of this first-in-human, phase I, open-label ASCEND-1 trial has been reported previously. In the analysis reported here, antitumour efficacy of ceritinib was evaluated in all patients with ALK-rearranged NSCLC (n=246) treated with ceritinib at the recommended dose of 750 mg/day. Additionally, as patients with untreated or locally treated neurologically stable brain metastases at baseline were permitted in this study, intracranial efficacy was retrospectively confirmed by independent neuroradiologists for 94 patients with baseline brain metastases and at least one post-baseline MRI/CT tumour assessment. This study is no longer recruiting patients; however, treatment and follow-up are ongoing. This study is registered with ClinicalTrials.gov, number NCT01283516. Findings Median follow-up at the time of this report was 11 1 months (interquartile range 6·7–15·2). Patients were mainly heavily pretreated (105/246 [42·7%] at least three prior regimens). The overall response rate was 72·3% (60/83; 95% confidence interval [CI] 61·4–81·6) for ALKi-naïve (n=83) and 56·4% (92/163; 95% CI 48·5–64·2) for ALKi-pretreated (n=163) patients. Median progression-free survival in ALKi-naïve and ALKi-pretreated patients was 18·4 (95% CI 11·1-non-estimable) and 6·9 (95% CI 5·6–8·7) months, respectively. Brain metastases by investigator assessment were reported at study entry in 124 patients. Of these, 94 (n=19 ALKi-naïve and n=75 ALKi-pretreated) were included in the retrospective analysis; intracranial disease control rate was 78·9% (15/19; 95% CI 54·4– 93·9) in ALKi-naïve patients and 65·3% (49/75; 95% CI 53·5–76·0) in ALKi-pretreated patients. Of the 94 patients included in the retrospective analysis, 11 had measurable brain lesions and no prior radiotherapy to the brain: 6 of these achieved a partial intracranial response. Safety was evaluated for all 246 patients with ALK-rearranged NSCLC. Serious adverse events were recorded for 117 (47·6%) patients. The most common grade 3/4 laboratory abnormalities were increased alanine aminotransferase and increased aspartate aminotransferase, occurring in 73 (29·7%) and 25 (10·2%) patients, respectively. The most common grade 3/4 non-laboratory adverse events were diarrhoea and nausea, both of which occurred in 15 (6.1%) patients. Two on-treatment deaths in the study were considered to be related to study drug by the investigators, one due to interstitial lung disease and one as a result of multi-organ failure that occurred in the context of infection and ischaemic hepatitis. Interpretation This study demonstrated clinically meaningful and durable responses in mainly heavily pretreated patients with ALK-rearranged NSCLC (ALKi-naïve and ALKi-pretreated) receiving ceritinib 750 mg/day. Treatment with ceritinib also achieved both whole-body and intracranial efficacy in patients with brain metastases at baseline, a common site of disease progression in patients with NSCLC. The durable whole-body responses reported, together with the intracranial efficacy, support a clinical benefit for treatment with ceritinib in patients post-crizotinib, or as an alternative to crizotinib in patients with ALK-rearranged NSCLC. Funding Sponsored by Novartis Pharmaceuticals Corporation.BACKGROUND ALK-rearranged non-small-cell lung cancer (NSCLC) is sensitive to ALK tyrosine kinase inhibitors (ALK inhibitors) such as crizotinib, but resistance invariably develops, often with progression in the brain. Ceritinib is a more potent ALK inhibitor than crizotinib in vitro, crosses the blood-brain barrier in vivo, and shows clinical responses in patients with crizotinib-resistant disease. We aimed to assess whole-body activity of ceritinib in both ALK inhibitor-pretreated and ALK inhibitor-naive patients with ALK-rearranged NSCLC. METHODS ASCEND-1 was an open-label, phase 1 trial that recruited patients from 20 academic hospitals or cancer centres in 11 countries in Europe, North America, and Asia-Pacific. Eligible patients were aged 18 years or older with ALK-rearranged locally advanced or metastatic cancer that had progressed despite standard therapy (or for which no effective standard therapy existed), who had at least one measurable lesion at baseline. The primary objective (to determine the maximum tolerated dose) has been reported previously. This updated analysis includes all patients with ALK-rearranged NSCLC given oral ceritinib at the recommended dose of 750 mg/day in the dose-escalation and expansion phases. Here we report the secondary outcomes of overall response, duration of response, and progression-free survival, analysed in all patients who received at least one 750 mg dose of ceritinib. Exploratory analyses included retrospective analysis of intracranial activity by independent neuroradiologists, in patients with untreated or locally treated neurologically stable brain metastases at baseline. Safety was assessed in all patients who received at least one dose of ceritinib. This study is no longer recruiting patients; however, treatment and follow-up are ongoing. This study is registered with ClinicalTrials.gov, number NCT01283516. FINDINGS Between Jan 24, 2011, and July 31, 2013, 255 patients were enrolled and received at least one dose of ceritinib 750 mg/day, of whom 246 had ALK-rearranged NSCLC. At data cutoff (April 14, 2014), median follow-up was 11·1 months (IQR 6·7-15·2) and 147 (60%) patients had discontinued treatment, 98 (40%) as a result of disease progression. An overall response was reported in 60 (72% [95% CI 61-82]) of 83 ALK inhibitor-naive patients and 92 (56% [49-64]) of 163 ALK inhibitor-pretreated patients. Median duration of response was 17·0 months (95% CI 11·3-non-estimable [NE]) in ALK inhibitor-naive patients and 8·3 months (6·8-9·7) in ALK inhibitor-pretreated patients. Median progression-free survival was 18·4 months (95% CI 11·1-NE) in ALK inhibitor-naive patients and 6·9 months (5·6-8·7) in ALK inhibitor-pretreated patients. Of 94 patients with retrospectively confirmed brain metastases and at least one post-baseline MRI or CT tumour assessment, intracranial disease control was reported in 15 (79% [95% CI 54-94]) of 19 ALK inhibitor-naive patients and in 49 (65% [54-76]) of 75 ALK inhibitor-pretreated patients. Of these 94 patients, 11 had measurable brain lesions and no previous radiotherapy to the brain, six of whom achieved a partial intracranial response. Serious adverse events were recorded in 117 (48%) of 246 patients. The most common grade 3-4 laboratory abnormalities were increased alanine aminotransferase (73 [30%] patients) and increased aspartate aminotransferase (25 [10%]). The most common grade 3-4 non-laboratory adverse events were diarrhoea and nausea, both of which occurred in 15 (6%) patients. Two on-treatment deaths during the study were deemed to be related to study drug by the investigators, one due to interstitial lung disease and one as a result of multiorgan failure that occurred in the context of infection and ischaemic hepatitis. INTERPRETATION The durable whole-body responses reported, together with the intracranial activity, support a clinical benefit for treatment with ceritinib in patients with ALK-rearranged NSCLC who have received crizotinib, or as an alternative to crizotinib. A confirmatory phase 2 clinical trial is ongoing to assess ceritinib activity in patients with ALK-rearranged NSCLC and brain or leptomeningeal metastases. FUNDING Novartis Pharmaceuticals Corporation.

Phase II Efficacy and Pharmacogenomic Study of Selumetinib (AZD6244; ARRY-142886) in Iodine-131 Refractory Papillary Thyroid Carcinoma with or without Follicular Elements

Purpose: A multicenter, open-label, phase II trial was conducted to evaluate the efficacy, safety, and tolerability of selumetinib in iodine-refractory papillary thyroid cancer (IRPTC). Experimental Design: Patients with advanced IRPTC with or without follicular elements and documented disease progression within the preceding 12 months were eligible to receive selumetinib at a dose of 100 mg twice daily. The primary endpoint was objective response rate using Response Evaluation Criteria in Solid Tumors. Secondary endpoints were safety, overall survival, and progression-free survival (PFS). Tumor genotype including mutations in BRAF, NRAS, and HRAS was assessed. Results: Best responses in 32 evaluable patients out of 39 enrolled were 1 partial response (3%), 21 stable disease (54%), and 11 progressive disease (28%). Disease stability maintenance occurred for 16 weeks in 49%, 24 weeks in 36%. Median PFS was 32 weeks. BRAF V600E mutants (12 of 26 evaluated, 46%) had a longer median PFS compared with patients with BRAF wild-type (WT) tumors (33 versus 11 weeks, respectively, HR = 0.6, not significant, P = 0.3). The most common adverse events and grades 3 to 4 toxicities included rash, fatigue, diarrhea, and peripheral edema. Two pulmonary deaths occurred in the study and were judged unlikely to be related to the study drug. Conclusions: Selumetinib was well tolerated but the study was negative with regard to the primary outcome. Secondary analyses suggest that future studies of selumetinib and other mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK; MEK) inhibitors in IRPTC should consider BRAF V600E mutation status in the trial design based on differential trends in outcome. Clin Cancer Res; 18(7); 2056–65. ©2012 AACR.

Antitumor activity and safety of pembrolizumab in patients (pts) with advanced squamous cell carcinoma of the head and neck (SCCHN): Preliminary results from KEYNOTE-012 expansion cohort.

LBA6008 Background: Pembrolizumab (MK-3475) is a humanized monoclonal antibody that blocks interaction of PD-1 with its ligands, PD-L1 and PD-L2, thereby promoting activity of tumor-specific effector T cells. KEYNOTE 012 (NCT01848834) had previously demonstrated clinical activity of pembrolizumab 10 mg/kg every 2 weeks in patients (pts) with recurrent/metastatic SCCHN enriched for PD-L1-positive tumors with a response rate of 20%. We now report on the larger SCCHN expansion cohort of KEYNOTE 012, irrespective of biomarker status using a 3-weekly fixed dose. METHODS Pts with advanced SCCHN irrespective of PD-L1 expression or HPV status received a fixed dose of 200 mg pembrolizumab, intravenously, every 3 weeks. Pts were evaluated every 8 weeks with radiographic imaging. The primary end point was overall response rate (ORR) per investigator assessment (RECIST 1.1). Secondary objectives included progression-free survival (PFS) and overall survival (OS). Adverse events (AEs) were assessed according to CTCAE v4. PD-L1 was assessed retrospectively by immunohistochemistry. RESULTS 132 pts with recurrent/metastatic SCCHN were enrolled. Mean (SD) age was 58.9 (9.7) years; 83.3% were male; 56.8% had ≥ 2 lines of therapy for recurrent disease. 73/132 pts (55.3%) remain on treatment. Out of 132 treated pts, 99 pts were available for this preliminary efficacy analysis with a post-baseline scan or discontinued therapy prior to the scan due to clinical progression or AE. ORR (confirmed and unconfirmed) per RECIST 1.1 was 18.2% (95% CI, 11.1-27.2) with 18 partial responses and 31.3% with stable disease. Biomarker analysis is ongoing and results will be presented. Drug-related AEs of any grade occurred in 47% of all enrolled pts, and drug-related grade ≥ 3 AEs occurred in 7.6%. The most common drug-related AEs ( ≥ 5%) of any grade were fatigue (12.1%), decreased appetite (6.8%), pyrexia (6.1%), and rash (5.3%). CONCLUSIONS Pembrolizumab given at a fixed dose of 200 mg every 3 weeks was well tolerated and demonstrated a clinically meaningful ORR of 18.2% in pts with recurrent/metastatic SCCHN. CLINICAL TRIAL INFORMATION NCT01848834.

Incidence and management of bevacizumab-related toxicities in colorectal cancer

Bevacizumab, a recombinant, humanised monoclonal antibody against vascular endothelial growth factor, when used in combination with intravenous 5-fluorouracil (5-FU)-based chemotherapy as first-line treatment of metastatic colorectal cancer (CRC) improves survival. In a randomised, placebo-controlled Phase III study, the addition of bevacizumab to irinotecan/5-FU/leucovorin (IFL) resulted in significant improvement in survival compared with IFL alone, which led to its approval for first-line use in CRC. Bevacizumab also demonstrates improved efficacy in combination with 5-FU/LV over chemotherapy alone when data were pooled from two randomised Phase II studies utilising bevacizumab with 5-FU/leucovorin, and also in a third treatment arm of bevacizumab/5-FU/LV of a randomised Phase III study. More recently, in the second-line setting, bevacizumab in combination with FOLFOX improved survival from 10.8 to 12.9 months in the ECOG 3200 trial. Clinical activity with the addition of bevacizumab to oxaliplatin and either 5-FU or capecitabine-based regimens has also been shown in TREE-2, and activity with the combination of bevacizumab and the EGFR inhibitor cetuximab has been documented in BOND-2. In this study, bevacizumab was generally well-tolerated with no unexpected toxicities when combined with cetuximab. A few toxicities were uniformly encountered in all of the above studies, in particular grade 3 medically-manageable hypertension (3 – 16%). In addition, other toxicities were haemorrhage (2 – 9.3%), gastrointestinal perforation (1.5%), arterial thromboembolism (3.8%), wound healing (1 – 2%) and proteinuria (1 – 2%). As bevacizumab is becoming widely used in general oncology practice, it is important to understand the toxicities which can arise and to develop practice guidelines for their management. This review addresses the toxicities noted in trials using bevacizumab for the treatment of CRC and provides recommendations for toxicity management.

Survival Impact of Increasing Time to Treatment Initiation for Patients With Head and Neck Cancer in the United States

PURPOSE To estimate the overall survival (OS) impact from increasing time to treatment initiation (TTI) for patients with head and neck squamous cell carcinoma (HNSCC). METHODS Using the National Cancer Data Base (NCDB), we examined patients who received curative therapy for the following sites: oral tongue, oropharynx, larynx, and hypopharynx. TTI was the number of days from diagnosis to initiation of curative treatment. The effect of TTI on OS was determined by using Cox regression models (MVA). Recursive partitioning analysis (RPA) identified TTI thresholds via conditional inference trees to estimate the greatest differences in OS on the basis of randomly selected training and validation sets, and repeated this 1,000 times to ensure robustness of TTI thresholds. RESULTS A total of 51,655 patients were included. On MVA, TTI of 61 to 90 days versus less than 30 days (hazard ratio [HR], 1.13; 95% CI, 1.08 to 1.19) independently increased mortality risk. TTI of 67 days appeared as the optimal threshold on the training RPA, statistical significance was confirmed in the validation set (P < .001), and the 67-day TTI was the optimal threshold in 54% of repeated simulations. Overall, 96% of simulations validated two optimal TTI thresholds, with ranges of 46 to 52 days and 62 to 67 days. The median OS for TTI of 46 to 52 days or fewer versus 53 to 67 days versus greater than 67 days was 71.9 months (95% CI, 70.3 to 73.5 months) versus 61 months (95% CI, 57 to 66.1 months) versus 46.6 months (95% CI, 42.8 to 50.7 months), respectively (P < .001). In the most recent year with available data (2011), 25% of patients had TTI of greater than 46 days. CONCLUSION TTI independently affects survival. One in four patients experienced treatment delay. TTI of greater than 46 to 52 days introduced an increased risk of death that was most consistently detrimental beyond 60 days. Prolonged TTI is currently affecting survival.