�On Monday, the US Food and Drug Administration (FDA) posted on its website, a copy of a letter from Genentech Inc, the makers of cancer
drug Avastin, to healthcare providers that warns them around a eccentric anemia seen in clinical trial patients treated with Avastin in combination with Pfizer
Inc's Sutent (sunitinib malate).
Microangiopathic hemolytic anemia, or MAHA, is a type of anemia (shortage of red stemma cells) caused by a build up of platelets and other organic
obstructions on the inner walls of very small blood vessels. These shred healthy red blood cells as they pass through, finally leading to a a whole
body shortage of them.
Avastin, which works by cutting off the blood supply that feeds tumors, is sanctioned for the treatment of colon, lung and boob cancer, and according
to Reuters, is widely considered to be Genentech's most important product, with second quarter results in the US anticipated to be around 640 million
dollars. The dose is currently undergoing a number of trials to test its safety and efficacy in combination with a range of other drugs.
The varsity letter states that a combination of Avastin and Sutent, a do drugs that is widely used for treating advanced kidney cancer, is neither recommended nor
approved and that a Phase 1 dose-escalation study looking at the safety and efficacy of the combination in 25 patients was stopped early because 5
of the 12 patients on the highest Sutent dose had symptoms consistent with MAHA.
The patients were in three groups, each taking a frozen dose of Avastin at 10 mg/kg/IV every 2 weeks, with the number one on 25, the sec on 37.5 and the
third on 50 mg day-after-day oral dot of Sutent in a 4 week on and 2 week off schedule.
Two of the five MAHA-consistent cases were classed as severe, with evidence of:
"Thrombocytopenia, anemia, reticulocytosis, reductions in serum haptoglobin, schistocytes on peripheral stain, modest increases in serum
creatinine levels, and stern hypertension, reversible posterior leukoencephalopathy syndrome (RPLS), and proteinuria."
However, in both cases, these symptoms were reversed inside three weeks of stopping the combination drugs and without whatsoever additional treatment.
According to Reuters, Kimberly O'Campo, speaking for Genentech, aforesaid that other studies on Avastin in combination with lower doses of Sutent are
still ongoing, only two other mid-stage studies of the two drugs with chemotherapy, involving patients with white meat and lung cancer, were stopped
because of fatigue, gastrointestinal complications and myelosuppression, a condition that reduces blood cell and thrombocyte production.
The alphabetic character asks wellness professionals to report cases of MAHA, or whatsoever other serious adverse event that they suspect arose from or in association with
function of Avastin.
Click here to see the Genentech alphabetic character to
healthcare providers (PDF).Sources: FDA, Reuters.
Written by: Catharine Paddock, PhD
View drug information on Avastin; Sutent.
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