Assessing the “value” of treatment with specific drugs (here in the USA)

Last Friday, the National Comprehensive Cancer Cancer Network (NCCN) introduced a new way for doctors and patients to be able to consider the clinical “value” of treatment with specific drugs in specific forms of cancer. How useful this method is will take a while to work out.

We should be clear immediately, for the prostate cancer community, that this methodology, known as the NCCN Evidence Blocks™ has not yet been implemented for prostate cancer. In fact it has only been implemented, so far, for two forms of cancer: multiple myeloma and chronic myelogenous leukemia (CML). However, the methodology will be introduced for all the forms of cancer on which the NCCN offers treatment guidelines over the next 12 months, and we would expect this to be included in the next revision of the NCCN guidelines for the treatment of prostate cancer some time next year.

At this point in time, the NCCN has provided widespread access to information about how this system will work through:

  • A basic statement about the NCCN Evidence Blocks on the NCCN web site that includes additional information addressing
    • How the NCCN Evidence Blocks are developed
    • How it is suggested that the NCCN Evidence Blocks be used in clinical practice
    • The five categories of evidence included in the NCCN Evidence Blocks (see below)
  • A range of information released at the time of the press conference about the new system (which your sitemaster was able to listen to in full)

We should be clear that the evidence blocks will only be available to those who register to view the actual NCCN clinical guidelines for the treatment of specific disorders — but such registration is free. At present, even if you do register, you can only see the evidence blocks in use for the two cancers above-mentioned  (multiple myeloma and chronic myelogenous leukemia). However, each set of evidence blocks is going to have the same general structure for each category of cancer and for each specific drug evaluated by the NCCN as being an appropriate form of therapy available for the treatment of that type of cancer.

Example showing a possible evidence block for a drug that is considered to have high efficacy, a good safety record, strong and consistent evidence of its efficacy and safety in practice and reasonably affordable.

Example showing a possible evidence block for a drug that is considered to have high efficacy, a good safety record, strong and consistent evidence of its efficacy and safety in practice and reasonably affordable.

So … here is an example what each evidence block can be expected to look like and an explanation of what this evidence block means.

Each evidence block will contain five columns (labeled E, S, Q, C, and A) and five rows (labeled 1 through 5), as shown in the example.

  • E stands for “Efficacy” … i.e., how well the drug has been shown to actually work in doing things like extending life or slowing down (or stopping) disease progression.
  • S stands for “Safety” … i.e., the probability that a patient will have side effects as a consequence of treatment with the drug, and the relative severity of those side effects.
  • Q stands for “Quality and Quantity” … i.e., the quality and quantity of the evidence that the drug works well to do what it is said to be able to do. As an example, a drug that has shown it works well to significantly extend survival in (say) three large, randomized, double-blind, controlled clinical trials will have a much higher Q value than a drug that has only been shown to delay progression in a single, smaller, non-randomized trial (or worse still, just in case reports).
  • C stands for “Consistency” … i.e., the level to which all of the published evidence about a specific use of a specific drug is consistent and gives us compelling repetition of the data supporting utility of that drug in a specific form and type of cancer.
  • A stands for “Affordability” … i.e., an indication of what it actually costs to give a specific drug to a specific patient along will all related costs such as supportive care, infusions, toxicity monitoring, management of toxicity, probability of care being delivered in the hospital, etc.

The numbers from 1 through 5 refer consistently to the degree to which evidence favors the use of the drug. Thus, the higher the number, the better the supporting evidence. So, if all the Evidence Blocks for a particular drug are at level 5, this means that a drug is highly effective, has a relatively low level of side effects, has a high level of data to support its use in specific indications, has been shown to provide the expected outcomes with a high level of consistency, and is “very inexpensive” (which may or may not mean “cheap” depending on the specific drug but is likely to suggest that it is available as a generic drug). If all the evidence blocks are at level 1, this is probably not a drug that one wants to be given if one can avoid it — especially if it is really expensive.

More detailed explanations of the A, S Q, C, A coding and the 1 through 5 rating system can be found on the NCCN web site on this page under the subhead “NCCN™ Evidence Blocks Categories”.

Since every drug will come with such an evidence block related to its value in management of a particular type of cancer, it will be possible to compare the evidence blocks for each drug in the treatment of each type of cancer. An an example, the evidence block for use of docetaxel (Taxotere) in the treatment of metastatic, castration-resistant prostate cancer is likely to look somewhat different from the evidence block for the use of abiraterone acetate (Zytiga) or enzalutamide (Xtandi) in the same indication. This should help physicians and their patients to talk together better about the relative value of one drug compared to another. However, we are going to have to wait for a while to see exactly how this plays out in prostate cancer when the NCCN Evidence Blocks for drugs used in the treatment of prostate cancer become available.


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