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Breakthrough Pharmaceuticals
Checkpoint Inhibitors
Cancer immunotherapy received the lion’s share of attention for pharma- ceutical breakthroughs in 2014; most notably, programmed death 1 (PD-1)/programmed death ligand
1 (PD-L1) checkpoint inhibitors. These oncology pharmaceuticals work at the cellular level to unmask cancer cells and allow the body’s immune system to attack cancer tumors.1
Although Bristol-Myers Squibb’s cytotoxic T lymphocyte antigen-4 (CTLA-4) inhibitor Yervoy (ipili- mumab) received FDA approval in 2011 for unresectable or metastatic melanoma, its track record of pro- longing lives began drawing media
attention in October 2013. Additional attention on checkpoint inhibitors ramped up when the FDA granted accelerated approval to Merck’s PD-1 blocker, Keytruda® (pembroli- zumab), in September 2014.
Checkpoint inhibitors are considered to be in the early stage of development and study, yet many researchers remain cautiously optimistic. Checkpoint inhibitors are not cur- rently considered “the cure” for all cancers — let alone for individuals with similar cancer types, but for many patients, the successes of Yervoy and Keytruda are remarkable. “Cancer’s Super-Survivors,” a Wall Street Journal article, eloquently
describes the long-term survival — meaning more than three years—of patients whose tumors disappeared or stopped grow-ing after checkpoint inhibitor treatment. Some of these patients were diagnosed with Stage 3 lung cancer, Stage 4 melanoma, and other advanced melanomas prior to treatment.2
CAR T-cell therapy re-engineers a patient’s immune cells to recognize and attack a tumor. —National Cancer Institute
CARs
Yet another cancer immunotherapy making 2014 headlines involves re- engineering a patient’s immune cells to recognize and attack a tumor. Using a process called adoptive cell transfer (ACT), this cancer immu- notherapy genetically engineers a patient’s T-cells to produce special receptors — called chimeric antigen receptors (CARs) — on their surface. CARs are proteins that allow T cells to recognize a specific protein (anti- gen) on tumor cells. After removing T cells from patients, the engineered CAR T-cells are grown in a lab by re- searchers; once billions have formed, the CAR T-cells are then infused into the patient to further multiply in the patient’s body. Working off guid- ance from their engineered receptor, the CAR T-cells can then recognize and kill cancer cells that harbor the antigen on their surfaces.3
Patients with advanced acute lymphoblastic leukemia (ALL), many of whom had few if any remaining
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