Smart Patients Get Smart Care™

The World’s Leading Authority for Chronic Lymphocytic Leukemia Patients

August 2021 CLL Bloodline

In science and medicine, information is constantly changing and may become out-of-date as new data emerge. All articles and interviews are informational only, should never be considered medical advice, and should never be acted on without review with your health care team.

MONTHLY QUIZ: Concerning the reason we got CLL:

  1. CLL can be familial, but that is rare.
  2. CLL incidence is increased in those exposed to Agent Orange in Vietnam and elsewhere.
  3. CLL incidence is increased in those exposed to radiation from Chernobyl.
  4. CLL is linked to benzene exposure.
  5. All of the above.
  6. 1, 2, and 3 are correct.

The correct answer is #6. CLL mostly occurs episodically with no known cause but occasionally CLL runs in families. Agent Orange is a recognized risk for CLL and exposed veterans who develop CLL may be entitled to compensation. For a long time, radiation was not considered a risk due to the lack of increase of CLL after Hiroshima, but we now know from the Chernobyl experience, that Hiroshima was the exception due to the very low baseline incidence of CLL in ethnic Japanese. Benzenes and other solvents may increase the risk of other blood cancers, but there has been no link found with CLL. Usually, we just don’t know why we got CLL.


BASICS:  Clinical Trials Phases – This applies to all trials, including those for CLL and COVID-19

Phase 1:  Is the drug safe and what’s the best dose?  There is no placebo arm. These are small trials. While there are officially designed to check for safety, clearly efficacy is also looked for.

Phase 2:  Does the drug work? Is it effective? Medium size trials where there is no placebo or control arm. There can be different arms with different combinations or sequencing of the drugs.

Phase 3:  Is it better than the standard of care? These are large trials where there is a randomization to either a control arm of standard care or the new therapy. Only when there is no “standard of care,” there might be a placebo arm.  This is never the case in CLL. Ask if the trial allows “crossover” so that if one progresses on one arm, one can transfer to the other. That’s important because it allows patients to get the benefit of the best treatment, no matter to which arm they were randomized.

Phase 4:  What else do we need to know about this approved drug or vaccine or treatment?

WORD OF THE MONTH:  Heterogeneity

Heterogeneity is the quality of being diverse in character or content. CLL is a heterogeneous disease as we are all different in how our disease progresses and is managed. In clinical trials and in statistics, the concept of heterogeneous populations is critical. Trials must compare “apples to apples.” One easy example is that you can’t compare relapsed CLL patients to frontline CLL patients from different trials.


The CLL Society is invested in your long life. Please invest in the long life of the CLL Society