ESMO 2016-ESMO BENEFIT SCALE FOR RARE TUMOURS

COPENHAGEN, Denmark — The European Society for Clinical Oncology (ESMO) Magnitude of Clinical Benefit Scale (MCBS) was found to be a helpful tool for clinical practice in rare tumors, according to findings of the first study to analyze the tool in this setting.

The authors analyzed the feasibility of using the MCBS for rare tumors and assessed data on neuroendocrine tumors (NETs); glioblastomas; sarcomas; and thyroid, pancreatic, ovarian, head/neck, and urothelial cancers.

Overall, the ESMO-MCBS was an effective adjunct for clinicians and supported treatment decisions based on the expected clinical benefit.

That said, lead author Barbara Kiesewetter, MD, from the Medical University of Vienna, Austria, noted that its practicability was also somewhat limited in cases where there was a lack of randomized trial data, such as for sarcoma and glioblastoma.

"However, the ESMO-MCBS was applicable in most situations where controlled trials were available, such as the data on salvage treatment with pazopanib for soft tissue sarcoma achieving a score of 3 based on a significant progression-free survival gain of 3 months in comparison to 1.6 months in the placebo arm," she said in a statement.

The findings were presented here at the ESMO Congress 2016.

Tool to "Stratify" Drug's Benefit 

Released last year, the ESMO-MCBS was developed to offer a rational, structured, and consistent approach to "stratify" a drug's clinically meaningful benefit.

The scale was developed and field tested on 77 cancer drugs across 10 cancer types, and it takes into account several measures of efficacy as well as the prognosis of the condition and the toxicity of the drug. These factors are taken together to assess the magnitude of clinical benefit.

The treatment is then analyzed with respect to the duration of response or survival in the control arm, and this results in a clinical benefit ranking.

Cost was not included in the assessment tool because of the variation in prices across different European countries.

In the current study, Dr Kiesewetter and colleagues note that while they have already evaluated the practicability of using the ESMO-MCBS in daily practice for treating common tumor types at their center, it has not yet been used for rare tumors.

To analyze the feasibility of using the tool for rare tumors, they developed a three-step approach.

First, data were retrospectively collected to gain an overview of which treatments were in regular use. Next, they scored the data by using the ESMO-MCBS. Third, they evaluated the results with the corresponding program directorships to assess feasibility in a real-life setting.

For NETs and thyroid cancer, the authors found that recently published trials for these cancers were similar in design and efficacy and the ESMO-MCBS scores were consistent with the clinical benefit seen in practice.

"However, the MCBS added little information on the question of optimal sequencing except for differentiated thyroid cancer where prior treatment (TKI [tyrosine kinase inhibitor] or not) suggests an algorithm," they write.

With pancreatic cancer, only two major trials evaluating first-line treatment were available, and thus making any direct comparisons was difficult.

ESMO-MCBS was useful for gastrointestinal stromal tumor (GIST) and non-GIST sarcoma, but MCBS practicability was limited for rare subtypes because of a lack of controlled trials.

"For sarcomas, practicability of ESMO-MCBS was limited due to a lack of trials in many indications," said Dr Kiesewetter. "However, the ESMO-MCBS was useful whenever randomized data were available. For example, the ESMO-MCBS score of 4 clearly underlines the clinical benefit achieved by adding dacarbazine to gemcitabine in pretreated soft tissue sarcoma."

"This is in line with our clinical experience and supports further use of the ESMO Magnitude of Clinical Benefit Scale," she noted.

The authors did find that the MCBS supported the use of bevacizumab in high-risk patients with ovarian cancer, but for the remaining cancers in their study — glioblastoma, head/neck, and urothelial cancers — only minimal data were available.

The study was funded by the Department of Medicine at the University of Vienna. Dr Kiesewetter has disclosed no relevant financial relationships; several of the coauthors report relationships with industry.

European Society for Medical Oncology (ESMO) 2016 Congress. Abstract 1364O_PR. Presented October 10, 2016.