Optimizing clinical benefit with targeted treatment in mRCC: "Tumor growth rate" as an alternative clinical endpoint

Tumor Growth Rate as a Validated Early Radiological Biomarker Able to Reflect Treatment-Induced Changes in Neuroendocrine Tumors: The GREPONET-2 Study

PURPOSE

Tumor growth rate (TGR) represents the percentage change in tumor volume per month (%/m). Previous results from the GREPONET study showed that TGR measured after 3 months (TGR_3m) of starting systemic treatment (ST) or watch and wait (WW) was an early biomarker predicting progression-free survival (PFS) in neuroendocrine tumors (NET).

EXPERIMENTAL DESIGN

Patients from 7 centers with advanced grade (G) 1/2 NETs from the pancreas (P)/small bowel (SB) initiating ST/WW were eligible. Computed tomography (CT)/MRI performed at prebaseline, baseline, and 3(±1) months of study entry were retrospectively reviewed. Aim-1: explore treatment-induced changes in TGR (ΔTGR_3m-BL; paired T test), and Aim-2: validate TGR_3m (<0.8%/m vs. ≥0.8%/m) as an early biomarker in an independent cohort (Kaplan-Meier/Cox regression).

RESULTS

Of 785 patients screened, 127 were eligible. Mean (SD) TGR₀ and TGR_3m were 5.4%/m (14.9) and -1.4%/m (11.8), respectively. Mean (SD) ΔTGR_3m-BL paired-difference was -6.8%/m (19.3; P < 0.001). Most marked ΔTGR_3m-BL [mean (SD)] were identified with targeted therapies [-11.3%/m (4.7); P = 0.0237] and chemotherapy [-7.9%/m (3.4); P = 0.0261]. Multivariable analysis confirmed the absence of previous treatment (OR = 4.65; 95% CI, 1.31-16.52; P = 0.018) and low TGR_3m (continuous variable; OR 1.09; 95% CI, 1.01-1.19; P = 0.042) to be independent predictors of radiologic objective response. When the multivariable survival analysis for PFS (Cox regression) was adjusted to grade (P = 0.004) and stage (P = 0.017), TGR_3m ≥ 0.8 (vs. <0.8) maintained its significance as a prognostic factor (P < 0.001), whereas TGR₀ and ΔTGR_3m-BL did not. TGR_3m ≥ 0.8%/m was confirmed as an independent prognostic factor for PFS [external validation; Aim-2; multivariable HR 2.21 (95% CI, 1.21-3.70; P = 0.003)].

CONCLUSIONS

TGR has a role as a biomarker for monitoring response to therapy for early identification of treatment-induced changes and for early prediction of PFS and radiologic objective response.

Change in non-small-cell lung cancer tumor size in patients treated with nintedanib plus docetaxel: analyses from the Phase III LUME-Lung 1 study

Background

Nintedanib in combination with docetaxel is approved in the European Union and other countries for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) of adenocarcinoma histology after first-line chemotherapy, based on the overall survival findings of Phase III LUME-Lung 1 study. Change in target lesion size over time as a treatment effect was assessed in patients from this study.

Methods

Tumor size was evaluated using predefined tumor measurements. Mixed-effects models were used to quantify individual relationships between time from randomization and tumor burden, measured as the sum of longest diameter (SLD) of target lesions and assessed by an independent review (Response Evaluation Criteria In Solid Tumors [RECIST] v1.0). Exploratory analyses were conducted on the overall adenocarcinoma population, adenocarcinoma patients with time from start of first-line therapy <9 months (TSFLT <9), adenocarcinoma patients who had progressive disease as best response to first-line therapy (PD-FLT), and in squamous cell carcinoma patients.

Results

Estimated mean baseline SLD was 82.5 mm in the adenocarcinoma (n=658), 88.3 mm in the TSFLT <9 (n=405), 98.1 mm in the PD-FLT (n=117), and 94.3 mm in the squamous cell carcinoma (n=555) populations. Treatment with nintedanib/docetaxel showed a significant reduction in tumor size over time (P<0.0001) in patients with adenocarcinoma compared with placebo/docetaxel, and in patients with squamous cell carcinoma (P=0.0049). Treatment difference at 6 months was 9.7 mm in the overall adenocarcinoma population, 16.8 mm in the TSFLT <9 population, 19.7 mm in the PD-FLT population, and 6.8 mm in the squamous cell carcinoma population. SLD at 2 months post-randomization was identified as a surrogate endpoint for overall survival, in addition to progression-free survival, for all except the PD-FLT population.

Conclusion

Treatment with nintedanib/docetaxel significantly decreased tumor burden and decelerated tumor size over time compared with placebo/docetaxel in the overall adenocar-cinoma population, including in patients with the poorest prognosis due to aggressive tumor dynamics.

A Phase II Study of Dovitinib in Patients with Recurrent or Metastatic Adenoid Cystic Carcinoma

Purpose: Genetic and preclinical studies have implicated FGFR signaling in the pathogenesis of adenoid cystic carcinoma (ACC). Dovitinib, a suppressor of FGFR activity, may be active in ACC.Experimental Design: In a two-stage phase II study, 35 patients with progressive ACC were treated with dovitinib 500 mg orally for 5 of 7 days continuously. The primary endpoints were objective response rate and change in tumor growth rate. Progression-free survival, overall survival, metabolic response, biomarker, and quality of life were secondary endpoints.Results: Of 34 evaluable patients, 2 (6%) had a partial response and 22 (65%) had stable disease >4 months. Median PFS was 8.2 months and OS was 20.6 months. The slope of the overall TGR fell from 1.95 to 0.63 on treatment (P < 0.001). Toxicity was moderate; 63% of patients developed grade 3-4 toxicity, 94% required dose modifications, and 21% stopped treatment early. An early metabolic response based on 18FDG-PET scans was seen in 3 of 15 patients but did not correlate with RECIST response. MYB gene translocation was observed and significantly correlated with overexpression of MYB but did not correlate with FGFR1 phosphorylation or clinical response to dovitinib.Conclusions: Dovitinib produced few objective responses in patients with ACC but did suppress the TGR with a PFS that compares favorably with those reported with other targeted agents. Future studies of more potent and selective FGFR inhibitors in biomarker-selected patients will be required to determine whether FGFR signaling is a valid therapeutic target in ACC. Clin Cancer Res; 23(15); 4138-45. ©2017 AACR.

Translating new data to the daily practice in second line treatment of renal cell carcinoma: The role of tumor growth rate

The therapeutic options for patients with metastatic renal cell carcinoma (mRCC) have completely changed during the last ten years. With the sequential use of targeted therapies, median overall survival has increased in daily practice and now it is not uncommon to see patients surviving kidney cancer for more than four to five years. Once treatment fails with the first line targeted therapy, head to head comparisons have shown that cabozantinib, nivolumab and the combination of lenvatinib plus everolimus are more effective than everolimus alone and that axitinib is more active than sorafenib. Unfortunately, it is very unlikely that we will ever have prospective data comparing the activity of axitinib, cabozantinib, lenvatinib or nivolumab. It is frustrating to observe the lack of biomarkers that we have in this field, thus there is no firm recommendation about the optimal sequence of treatment in the second line. In the absence of reliable biomarkers, there are several clinical endpoints that can help physicians to make decisions for an individual patient, such as the tumor burden, the expected response rate and the time to achieve the response to each agent, the prior response to the agent administered, the toxicity profile of the different compounds and patient preference. Here, we propose the introduction of the tumor-growth rate (TGR) during first-line treatment as a new tool to be used to select the second line strategy in mRCC. The rapidness of TGR before the onset of the treatment reflects the variability between patients in terms of tumor growth kinetics and it could be a surrogate marker of tumor aggressiveness that may guide treatment decisions.