Use of modified RECIST criteria to improve response assessment in targeted therapies: challenges and opportunities

Tumor Growth Rate Decline despite Progressive Disease May Predict Improved Nivolumab Treatment Outcome in mRCC: When RECIST Is Not Enough

Simple Summary

The treatment scenario of metastatic renal cell carcinoma has drastically changed in recent years, with the advent of immunotherapy. Since 2015 immune-checkpoint inhibitors, either alone or in combination with other compounds, are constantly enriching the treatment scenario, with a drastic change of patients’ outcomes. The benefit from immunotherapy is difficult to capture with the currently available assessment radiological criteria. Often, with rhe use of immunotherapy, we can observe atypical patterns of response, such as hyperprogression or pseudoprogression. Pseudoprogression consists of an initial increase in tumor burden followed by a response to therapy, while hyperprogression is defined as a tumor growth rate that was at least 2-fold greater in patients with disease progression during immunotherapy. We performed a retrospective monocentric study to explore the impact of tumor growth rate change after immunotherapy administration as second or later line of treatment in patients with metastatic renal cell carcinoma.

Abstract

Treatment response is usually assessed by the response evaluation criteria in solid tumors (RECIST). These criteria may not be adequate to evaluate the response to immunotherapy, considering the peculiar patterns of response reported with this therapy. With the advent of immunotherapy these criteria have been modified to include the evaluation of the peculiar responses seen with this type of therapy (iRECIST criteria), including pseudoprogressions and hyperprogressions. Tumor growth rate (TGR) is a dynamic evaluation that takes into account the kinetics of response to treatment and may help catch the real efficacy of an immunotherapy approach. We performed a retrospective monocentric study to explore the impact of TGR change after nivolumab administration as the second or later line of treatment in patients with metastatic renal cell carcinoma (RCC). We evaluated 27 patients, divided into three categories: Disease control (DC) if there was no PD; lower velocity PD (LvPD) if disease progressed but the TGR at second assessment (TGR2) was lower than the TGR at first assessment (TGR1); higher velocity PD (HvPD) if TGR2 was higher than TGR1. The median OS for the DC group was 11.0 months (95% CI 5.0–17.0) (reference) vs. (not reached) NR (95% CI NR-NR) for LvPD (HR 0.27; 95% CI 0.06–1.30; p 0.102) vs. NR (95% CI NR–NR) for HvPD (HR 0.23; 95% CI 0.06–0.88; p 0.032). There was no difference between LvPD and DC (HR 1.21; 95% CI 0.20–7.28; p 0.838). In patients with metastatic RCC, the second or later line of nivolumab treatment may lead to a deceleration in TGR resulting in an improved survival outcome similar to that observed in patients experiencing tumor regression. In this subgroup, especially in the presence of a clinical benefit, continuing the treatment beyond progression can be recommended.

Systemic treatment of the metastatic renal cell carcinoma: usefulness of the apparent diffusion coefficient of diffusion-weighted MRI in prediction of early therapeutic response

Accurate prediction of early treatment response to systemic therapy (ST) with tyrosine kinase inhibitors (TKI) in patients with metastatic renal cell carcinoma (mRCC) could help avoid ineffective and expensive treatment with serious side effects. Neither RECIST v.1.1 nor Choi criteria successfully discriminate between patients with mRCC who received ST having a short or long time to progression (TTP). There is no biomarker, which is able to predict early therapeutic response to TKIs application in patients with mRCC. The goal of our study was to investigate the potential of apparent diffusion coefficient (ADC) of diffusion-weighted imaging (DWI) of MRI in prediction of early therapeutic response to ST with pazopanib in patients with mRCC. The retrospective study enrolled 32 adult patients with conventional mRCC who received pazopanib (mean duration-7.5 ± 3.45). The mean duration of follow-up was 11.85 ± 4.34 months. In all patients as baseline examination and 1 month after treatment, 1.5T MRI including DWI sequence was performed followed by ADC measurement of the main renal lesion. For assessment of the therapeutic response, RECIST 1.1 is used. Partial response (PR), stable disease (SD) and progressive disease (PD) were observed in 12 (37.50%), 10 (31.25%) and 10 (31.25%) cases with mean TTP of 10.33 ± 2.06 months (95% confidence interval, CI = 9.05-11.61), 7.40 ± 2.50 months (95% CI = 5.61-9.19) and 4.20 ± 1.99 months (95% CI = 2.78-5.62) accordingly (p < 0.05). There was no difference in change of main lesions' longest size 1 month after ST in patients with PR, SD and PD. Comparison of mean ADC values before and 1 month after systemic treatment showed significant decrease by 19.11 ± 10.64% (95% CI = 12.35-25.87) and by 7.66 ± 6.72% (95% CI = 2.86-12.47) in subgroups with PR and SD, respectively (p < 0.05). There was shorter TTP in patients with mRCC if ADC of the main renal lesion 1 month after the ST increased from the baseline less than 1.73% compared to patients with ADC levels above this threshold: 5.29 ± 3.45 versus 9.50 ± 2.04 months accordingly (p < 0.001). Overall, our findings highlighted the use of ADC as a predictive biomarker for early therapeutic response assessment. Use of ADC will be effective and useful for reliable prediction of responders and non-responders to systemic treatment with pazopanib.

Tumor growth velocity: A modified tumor growth rate defining tumor progression during sorafenib treatment in patients with metastatic renal cell carcinoma

OBJECTIVES

To investigate the role of tumor growth velocity in defining tumor progression in metastatic renal cell carcinoma patients treated with the vascular endothelial growth factor tyrosine kinase inhibitor, sorafenib.

METHODS

A modified calculation for tumor growth velocity was introduced to evaluate the tumor growth velocity, before and after sorafenib withdrawal. Known prognostic factors together with tumor growth velocity before drug withdrawal and tumor growth velocity after drug withdrawal were compared using a χ² -test from a contingency table, and partial likelihood test from a Cox regression model for overall survival.

RESULTS

A total of 114 patients who reached progressive disease and withdrew from sorafenib were enrolled after a median follow-up period of 107.8 months. Tumor growth velocity before drug withdrawal was 7.347 ± 4.040, and tumor growth velocity after drug withdrawal was 11.647 ± 5.937 (P < 0.001). Higher tumor growth velocity before drug withdrawal was correlated with a higher risk Memorial Sloan Kettering Cancer Center score (P = 0.022), Karnofsky Performance Status <80 (P = 0.028), non-clear cell carcinoma (P = 0.037), higher tumor nucleus grade (P < 0.001) and best treatment response (P < 0.001). Patients with tumor growth velocity before drug withdrawal >5.0 had shorter overall survival (P < 0.001). On multivariate analysis, factors associated with overall survival were high/intermediate Memorial Sloan Kettering Cancer Center risk score (hazard ratio 2.119, P = 0.006), non-clear histological subtype (hazard ratio 1.900, P = 0.031), tumor growth velocity before drug withdrawal ≥5.0 (hazard ratio 2.758, P < 0.001) and progressive disease as best response (hazard ratio 2.069, P = 0.001).

CONCLUSIONS

Significantly faster tumor growth can be observed if sorafenib is discontinued in the case of disease progression. Thus, we suggest not to withdraw targeted agents until tumor growth velocity is >5.0.

Tolerability of toceranib phosphate (Palladia) when used in conjunction with other therapies in 35 cats with feline oral squamous cell carcinoma: 2009-2013

Objectives Squamous cell carcinoma (SCC) is the most common oral tumor in cats and typically carries a poor prognosis with current treatment options. The objective of this study was to evaluate the toxicity of toceranib phosphate (Palladia; Pfizer) in cats with oral SCC in combination with other treatment modalities. Methods In this study, 35 cats were retrospectively evaluated to determine toxicity when treated with toceranib in combination with other treatment modalities. Cats received toceranib at a median dose of 2.75 mg/kg (range 1.9-4.17 mg/kg) 3 days a week. Cats also underwent additional therapies, including surgical excision, radiation therapy, chemotherapy and/or use of non-steroidal anti-inflammatory drugs. Results Toxicity was seen in six cats, with five cases of grade 1 or 2 gastrointestinal (GI) toxicity and one grade 4 metabolic toxicity. Toceranib was discontinued in one cat and two cats received dose reductions. None of the cats required treatment delays or hospitalization due to toxicity. Median toceranib treatment duration was 77 days (range 7-741 days). Conclusions and relevance This study revealed that toceranib was well tolerated by the majority of cats, with five cases of low-grade GI toxicity and one case of metabolic toxicity. Given the favorable toxicity profile, future studies further evaluating the safety and efficacy of toceranib for cats with oral SCC should be considered.

Defining the Pharmacodynamic Profile and Therapeutic Index of NHS-IL12 Immunocytokine in Dogs with Malignant Melanoma

Background

Interleukin (IL)-12 is a pro-inflammatory cytokine that mediates T-helper type 1 responses and cytotoxic T-cell activation, contributing to its utility as anti-cancer agent. Systemic administration of IL-12 often results in unacceptable toxicity; therefore, strategies to direct delivery of IL-12 to tumors are under investigation. The objective of this study was to assist the preclinical development of NHS-IL12, an immunocytokine consisting of an antibody, which targets necrotic tumor regions, linked to IL-12. Specifically this study sought to evaluate the safety, serum pharmacokinetics, anti-tumor activity, and immune modulation of NHS-IL12 in dogs with naturally occurring cancers.

Methodology/Principal Findings

A rapid dose-escalation study of NHS-IL12 administered subcutaneously to dogs with melanoma was conducted through the Comparative Oncology Trials Consortium (COTC). Eleven dogs were enrolled in four dose-escalation cohorts; thereafter, an additional seven dogs were treated at the defined tolerable dose of 0.8 mg/m². The expanded cohort at this fixed dose (ten dogs in total) was accrued for further pharmacokinetics and pharmacodynamics assessment. NHS-IL12 levels, serum cytokine concentrations, and peripheral blood mononuclear cell characterization (post-treatment) and draining lymph node immune profiling, and tumor biopsies (pre- and post-treatment) were collected. Adverse events included thrombocytopenia, liver enzymopathies, fever, and vasculitis. Correlation between interferon (IFN)-γ induction, adverse events, and NHS-IL12 exposure (maximum concentration and area under the concentration-time curve) were dose-dependent. Serum IL-10 levels and intratumoral CD8⁺ populations increased after treatment. Partial responses, according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, were observed in two dogs treated with NHS-IL12 0.8 mg/m² and 1.6 mg/m².

Conclusions/Significance

NHS-IL12 was administered safely to dogs with melanoma and both immunologic and clinical activity was observed. This study successfully defined a narrow therapeutic window for systemic delivery of NHS-IL12 via the subcutaneous route. Results will inform the design and implementation of first-in-human clinical trials of NHS-IL12 in cancer patients.

Treatment Response Evaluation and Follow-up in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality and healthcare expenditure in patients with chronic liver disease. The management of HCC is evolving because of recently introduced novel therapeutic approaches. Optimal outcome requires an early and accurate assessment of tumor response to therapy. Current imaging modalities, such as computed tomography (CT) and magnetic resonance (MR) imaging; provide reliable and reproducible anatomical data in order to demonstrate tumor burden changes. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. There has been a growing interest to monitor the therapeutic response, at an early phase of treatment, by measuring tumor viability and/or perfusion. Therefore the importance of tumor viability assessment is increasingly being recognized. The tumor viability measurement guidelines have recently been amended to include the measurement of only the longest diameter of the enhancing tumors to formally amend RECIST to modified RECIST (mRECIST). Viable tumor should be defined as uptake of contrast agent in the arterial phase. In this review, we discuss criteria of response evaluation in HCC and further follow-up of patients receiving curative and palliative treatment.

Retreatment with bevacizumab in patients with gynecologic malignancy is associated with clinical response and does not increase morbidity

Purpose

Bevacizumab (Bev) is associated with improved progression-free survival in advanced epithelial ovarian cancer. The use of Bev in patients with gynecologic malignancy is increasing; however, little is known about cumulative toxicity and response in patients retreated with Bev. Our goal was to determine cumulative side effects and response in patients retreated with Bev.

Patients and methods

Women with recurrent gynecologic malignancy treated with Bev between January 2007 and March 2012 at a single institution were identified, including a subset who received Bev in a subsequent regimen. The primary outcome was Bev-associated toxicity, and the secondary outcome was response.

Results

Of 83 patients that received Bev for recurrent disease, 23 were retreated with Bev and four received Bev maintenance. Three patients (13%) developed grade 3 or 4 hypertension; all had a history of chronic hypertension. One (4.3%) patient developed grade 3 proteinuria, and one (4.3%) developed an enterovaginal fistula. Four patients discontinued Bev secondary to toxicity. Toxicity was not related to the cumulative number of cycles. Twenty-six percent of patients responded to Bev retreatment. On univariate analysis, there was a significant (P=0.003) overall survival advantage when the Bev-free interval was >9 months (95% confidence interval [CI] 4.9–43.7) compared to ≤9 months (95% CI 2.1–11.5), 24.3 months, and 6.8 months.

Conclusion

Retreatment of patients with recurrent gynecologic malignancy with Bev did not increase morbidity and was associated with treatment response. Physicians treating women with recurrent disease may consider a Bev-containing regimen even if prior regimen(s) included Bev. Future studies should prospectively evaluate the efficacy of this treatment strategy.

Novel functional magnetic resonance imaging biomarkers for assessing response to therapy in hepatocellular carcinoma

The established and adapted image biomarkers based on size for tumor burden measurement continue to be applied to hepatocellular carcinoma (HCC) as size measurement can easily be used in clinical practice. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. Functional magnetic resonance imaging (MRI) has a potential to be a promising technique for assessment of HCC response to therapy. In this review, we discuss various functional MRI biomarkers that play an increasingly important role in evaluation of HCC response after treatment.

Tumor growth rate provides useful information to evaluate sorafenib and everolimus treatment in metastatic renal cell carcinoma patients: an integrated analysis of the TARGET and RECORD phase 3 trial data

BACKGROUND

Response Evaluation Criteria in Solid Tumors (RECIST) criteria may not be sufficient to evaluate the response of targeted therapies in metastatic renal cell carcinoma (mRCC). The tumor growth rate (TGR) incorporates the time between evaluations and may be adequate.

OBJECTIVE

To determine how TGR is modified along the treatment sequence and is associated with outcome in mRCC patients.

DESIGN, SETTING, AND PARTICIPANTS

Medical records from all patients prospectively treated at Gustave Roussy (IGR) in the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET) (sorafenib vs placebo, n=84) and the RECORD (everolimus vs placebo, n=43) phase 3 trials were analyzed. TGR was computed across clinically relevant periods: BEFORE treatment introduction (wash-out), UNDER (first cycle), at PROGRESSION (last cycle) and AFTER treatment discontinuation (washout). The association between TGR and outcome (overall survival [OS] and progression-free survival [PFS]) was computed in the entire TARGET cohort (n=903).

INTERVENTION

Sorafenib, everolimus, or placebo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

TGR, RECIST, OS, and PFS rates.

RESULTS AND LIMITATIONS

Although nearly all the patients (IGR) were classified as stable disease (RECIST) after the first cycle, the great majority of the patients exhibited a decrease in TGR UNDER compared with BEFORE (sorafenib: p<0.00001; everolimus: p<0.00001). In sorafenib-treated but not in everolimus-treated patients (IGR), TGR at PROGRESSION (last cycle) was still lower than TGR BEFORE (washout) (p=0.012), while TGR AFTER progression (washout) was higher than TGR at PROGRESSION (last cycle) (p=0.0012). Higher TGR (first cycle) was associated with worse PFS (hazard ratio [HR]: 3.61; 95% confidence interval [CI], 2.45-5.34) and worse OS (HR: 4.69; 95% CI, 1.54-14.39), independently from the Motzer score and from the treatment arm in the entire TARGET cohort.

CONCLUSIONS

Computing TGR in mRCC patients is simple and provides clinically useful information for mRCC patients: (1) TGR is independently associated with prognosis (PFS, OS), (2) TGR allows for a subtle and quantitative characterization of drug activity at the first evaluation, and (3) TGR reveals clear drug-specific profiles at progression.

Gastrointestinal stromal tumors: diagnosis, therapy and follow-up care in Austria

Optimal treatment for patients suffering from gastrointestinal stromal tumors (GIST) is based on an interdisciplinary treatment approach. Austrian representatives of Medical and Surgical Oncology, Pathology, Radiology, Nuclear Medicine, Gastroenterology, and Laboratory Medicine issued this manuscript on a consensual base within the context of currently available and published literature. This paper contains guidelines and recommendations for diagnosis, therapy, and follow-up of GIST patients in Austria.

Established and novel imaging biomarkers for assessing response to therapy in hepatocellular carcinoma

The management of hepatocellular carcinoma (HCC) is evolving because of recently introduced novel therapeutic approaches. There is growing recognition that optimal outcome requires choosing treatment tailored to suit each individual patient, necessitating an early and accurate assessment of tumor response to therapy. The established and adapted image biomarkers based on size for tumor burden measurement continues to be applied to HCC as size measurement can easily be used in any clinical practice. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. Therefore the importance of image biomarkers such as tumor viability measurement, functional perfusion and diffusion imaging for response assessment is increasingly being recognized. Although promising, these imaging biomarkers have not gone through all the required steps of standardization and validation. In this review, we discuss various established, evolving and emerging imaging biomarkers and the criteria of response evaluation and their challenges in HCC.

Monitoring response to antiangiogenic treatment and predicting outcomes in advanced hepatocellular carcinoma using image biomarkers, CT perfusion, tumor density, and tumor size (RECIST)

PURPOSE

Our aim was to investigate the hypothesis that the CT perfusion (CTP) is a more sensitive image biomarker when compared with tumor burden (Response Evaluation Criteria in Solid Tumors [RECIST]) and tumor density (HU) for monitoring treatment changes and for predicting long-term outcome in advanced hepatocellular carcinoma (HCC) treated with a combination of antiangiogenic treatment and chemotherapy.

MATERIAL AND METHODS

In this phase II clinical trial, 33 patients with advanced HCC were enrolled and 23 were included in the current study. A diagnostic dual-phase contrast-enhanced CT and perfusion CT was performed at baseline and days 10 to 12 after initiation of antiangiogenic treatment (Bevacizumab). The patients subsequently received bevacizumab in combination with gemcitabine and oxaliplatin (GEMOX-B) and contrast-enhanced CT was performed at the end of treatment (after completing 3 cycles of GEMOX-B chemotherapy) and after every 8 week until there was evidence of disease progression or intolerable toxicity. The CTP protocol included a targeted dynamic cine acquisition for 25 to 30 seconds after 50 to 70 mL of iodinated contrast media injection at 5 to 7 mL/s. The CTP parameters were compared with tumor size (according to Response Evaluation Criteria in Solid Tumors, RECIST 1.1) and density measurements (HU) before and after treatment and correlated with patient's outcome in groups with and without tumor thrombus. A one-sided P value was calculated and the Bonferroni correction was used to address the issue of multiple comparisons.

RESULTS

On days 10 to 12 after initiation of bevacizumab, significant decrease in CTP parameters was noted (P < 0.005). There was a mild reduction in mean tumor density (P = 0.016) without any significant change in mean tumor size. Tumors with higher baseline mean transit time values on CTP correlated with favorable clinical outcome (partial response and stable disease) and had better 6 months progression-free survival (P = 0.002 and P = 0.005, respectively). The baseline transfer constant (Ktrans) of responders (1425.19 ± 609.47 mL/1000 mL/min) was significantly higher than that of nonresponders (935.96 ± 189.47 mL/1000 mL/min). The tumor thrombus in the portal vein demonstrated baseline perfusion values and post-treatment change values similar to the HCC.

CONCLUSION

In advanced HCC, CTP is a more sensitive image biomarker for monitoring early antiangiogenic treatment effects as well as in predicting outcome at the end of treatment and progression-free survival as compared with RECIST and tumor density.

Morphological and functional MDCT: problem-solving tool and surrogate biomarker for hepatic disease clinical care and drug discovery in the era of personalized medicine

This article explains the significant role of morphological and functional multidetector computer tomography (MDCT) in combination with imaging postprocessing algorithms served as a problem-solving tool and noninvasive surrogate biomarker to effectively improve hepatic diseases characterization, detection, tumor staging and prognosis, therapy response assessment, and novel drug discovery programs, partial liver resection and transplantation, and MDCT-guided interventions in the era of personalized medicine. State-of-the-art MDCT depicts and quantifies hepatic disease over conventional CT for not only depicting lesion location, size, and extent but also detecting changes in tumor biologic behavior caused by therapy or tumor progression before morphologic changes. Color-encoded parameter display provides important functional information on blood flow, permeability, leakage space, and blood volume. Together with other relevant biomarkers and genomics, the imaging modality is being developed and validated as a biomarker to early response to novel, targeted anti-VEGF(R)/PDGFR or antivascular/angiogenesis agents as its parameters correlate with immunohistochemical surrogates of tumor angiogenesis and molecular features of malignancies. MDCT holds incremental value to World Health Organization response criteria and Response Evaluation Criteria in Solid Tumors in liver disease management. MDCT volumetric measurement of future remnant liver is the most important factor influencing the outcome of patients who underwent partial liver resection and transplantation. MDCT-guided interventional methods deliver personalized therapies locally in the human body. MDCT will hold more scientific impact when it is fused with other imaging probes to yield comprehensive information regarding changes in liver disease at different levels (anatomic, metabolic, molecular, histologic, and other levels).