Sitting motionless on the ocean floor gently filtering water for nutrients, the sea sponge Halichondria okadai may seem like an unlikely hero in the fight against metastatic breast cancer. But contained within their porous bodies lies a compound that is uniquely effective at destroying cancer cells: halichondrin B.1 This discovery inspired intensive investigations that, after decades of research, yielded a breakthrough in the form of a refined compound similar to halichondrin B called eribulin mesylate that would go on to be known as HALAVEN.2,3
Cancer cells reproduce and grow in an uncontrolled manner due to mutations in the genes.4 This growth process occurs by cell division, called mitosis.4 Microtubules are tiny structures that are essential to mitosis as well as other cellular processes.5 What does any of this have to do with sea sponges? The naturally occurring compound, halichondrin B, and its pharmaceutical counterpart, eribulin mesylate, have distinct structures that bind with the microtubules, interrupting mitosis and ultimately killing the cancerous cells.6 The video below explores the journey of this fascinating compound from the sea to patients.
You can think of a microtubule as a tiny spring that tightly coils up to form a tube. These tubes have a “minus end” that attaches to the core of the cell and a “plus end” where its growth occurs.5 Eribulin mesylate binds with these growing plus ends, thus inhibiting or disrupting the microtubules from completing their job in mitosis. Not only does this inhibition prevent the cancerous cells from dividing and reproducing, it also causes the cell to trigger its self-destruct mechanism, called apoptosis.7
Apoptosis is a natural process that many cells undergo as a normal part of the body’s growth and development.8 In this case, the cancerous cells detect that something is awry, and they are hardwired to undergo apoptosis rather than divide improperly. Eribulin mesylate essentially tricks the cancerous cells into killing themselves.6 And that’s not all.
Eribulin mesylate is also thought to work in another surprising way: by helping the tumor breathe.9,10 While that may sound counterintuitive, the science behind it is fascinating.
In simple terms, tumors are clusters of cancerous cells growing rapidly out of control. They aren’t just getting larger: they’re a big, jumbled mess lacking the sophisticated infrastructure that our bodies have in place for healthy organs.10 This means that cancer cells are not getting enough oxygen, a condition a known as hypoxia.11 Cancer cells not getting enough oxygen—that should be a good thing, right? Not so fast. Tenacious little things that they are, cancer cells desperate for oxygen change their behavior in order to acquire it, including spreading to other regions.10 And that can be very problematic.
Laboratory research suggests that eribulin mesylate changes the structure of blood vessels, increasing blood flow to the parts of the tumor that lack oxygen.9 Further evidence indicates that eribulin mesylate may change the way the cancer cells move and spread throughout the body.10
Inspired by a naturally occurring compound found in sea sponges, HALAVEN is the first agent in the halichondrin class. Its dual action of destroying cancer cells and changing the internal environment around the tumor makes it a potent compound in the fight against cancer.
HALAVEN is a prescription medicine used to treat adults with breast cancer that has spread to other parts of the body, and who have already received other types of anticancer medicines after the cancer has spread.
HALAVEN can cause serious side effects, including
Before you receive HALAVEN, tell your health care provider about all of your medical conditions, including if you
Tell your health care provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
What are the possible side effects of HALAVEN?
HALAVEN can cause changes in your heartbeat (called QT prolongation). This can cause irregular heartbeats. Your health care provider may do heart monitoring (electrocardiogram or ECG) or blood tests during your treatment with HALAVEN to check for heart problems.
The most common side effects of HALAVEN in adults with breast cancer include low white blood cell count (neutropenia), low red blood cell count (anemia), weakness or tiredness, hair loss (alopecia), nausea, and constipation.
Your health care provider will do blood tests before and during treatment while you are taking HALAVEN.
For more information about HALAVEN, please see full Prescribing Information.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.