ALK research related vocabulary

AE – Adverse Events – side effects observed during a clinical trial. Generally the more of them there are and the worse they are, the worse off the drug is perceived to have done. They are usually graded on a scale from 1 to 5, where 1 is a minor adverse event and 5 is a very serious adverse event.

BM – at least one brain metastis.

CNS – central nervous system, includes brain and spinal cord.

CR – Complete Response – 100% shrinkage of all measured tumors.

DCR – disease control rate = CR+ PR + stable (stable or better).

DOR – duration of response – time from documentation of tumor response until disease progression.

Median PFS – how long it takes until half of a pool of patients has PFS.

MTD – maximum tolerated dose – the maximum amount of drug that causes a reasonable amount and degree of AEs. As an aside, the MTD for a less serious illness like a cold or allergies is likly to have far fewer and less significant AEs than for a much more serious illness like cancer or a stroke.

Mesurable disease – at least one tumor in the body (sometimes not in the brain) that is at least 1 centimeter long on its longest measurable dimension.

ORR – Objective Response Rate – complete response plus partial response (or 30% shrinkage or better)

OS – overall survival – time from randomization or receiving first dose until death from any cause.

PFS – progression free survival – time from randomization or receiving first dose until disease progression or death.

PR – Partial Response – 30% plus shrinkage of the average of the measured tumors along each of their longest dimension (so it’s not 30% shrinkage in 2 or 3 dimensions). As an interesting aside, 30% shrinkage in all three dimensions is approximately 65.7% total shrinkage by volume (assuming a perfect sphere).

Phase 1 trial –  a clinical trial focused on safty and discovering the safe MTD and to a lessor extent the effectivness of the drug. These trials start with a low dose of the drug (often so low there is no effect on the illness a) and then increasing the dose of the drug until a significant percentage of the tested patients start to experience serious AEs. The MTD is usually the highest dose that causes few serious side effects. These trials have the fewest patients.

Phase 2 trial – focused on tesing if there is some indication of the drug being effective at the MTD. Usually there is no control group. These trials are larger than phase 1 trials and are sometimes combined with a phase 1 trial.

Phase 3 trials – usually have the most patients and half the patients act as a control group who get the best currently available alternative treatment while half the patients get the drug being tested. Often these trials are double blind to minimize the possibility of bias or the placebo effect changing the results. The hope is that a material benefit will be found from the new drug. Benefits can include patients 1) living longer, 2) having a longer time till the disease progresses, 3) fewer or reduced AEs with the same efficacy, and 4) other benchmarks.

PFS – progression free survival – how long it takes from when a patient first receives the medicine until the cancer clearly starts growing again.

P value – this is a statistical term and I found a great page that explains all about statistics much better than I can. It can be found at

Power of a study – this is a statistical term and I found a great page that explains all about statistics much better than I can. It can be found at

SD – Stable Disease – tumor shrinkage from 0% to 29%.

SRS – stereo static radiosurgery that targets a limited number of tumors (Usually in the brain)

Survival Curves – are a type of graph that shows how long patients in a trial survived. For a more detailed explanation see

TTP – time to progression – time from randomization or receiving first dose until objective tumor progression, does not include deaths.

12 month OS rate – the % of patients surviving after 12 months of treatment.

Waterfall Chart – a chart showing the shrinkage of tumors for several patients where the patients with the least shrinkage (or most growth) is on the left and the patient with the most shrinkage is on the right. Growth is shown above the line and shrinkage is shown below the line.

WB – whole body

WBR – whole brain radiation

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