"Palbociclib a new oral drug whose efficacy in combating breast cancer has been demonstrated alone and in combination with endocrine therapy also has potential to combat other types of cancer according to a literature review and additional original research httponcology.jamanetwork.comarticle.aspxarticleid conducted by experts at the Abramson Cancer Center ACC in the University of Pennsylvania published this month in JAMA Oncology. Palbociclib targets the rapid division of tumor cells by inhibiting the activity of the enzymes CDK and CDK which propel cell division and increase in number in most cancers. It is the first CDK inhibitor to be approved for the treatment of breast cancer. All living cells undergo cell division and palbociclibs unique capacity to halt the cell division process also known as the cell cycle therefore has potentially broad applicability said the studys lead author Amy S. Clark MD MSCE an assistant professor of HematologyOncology at Penns Perelman School of Medicine and ACC. Pairing palbociclib with other anticancer therapies such as endocrine therapy chemotherapy and targeted therapy can create a powerful combinatorial effect with real promise for addressing a variety of cancers. For example amplification of CDK is reported in a high percentage of melanomas and esophageal cancers.  Targeted therapy uses medication and other interventions to more accurately identify and attack cancer cells usually while doing no or little damage to normal cells.  This drug has minor effects on normal cells other than neutrophils white blood cells said the studys senior author Peter J. ODwyer MD a professor of HematologyOncology at Penn and director of the Developmental Therapeutics Program at the ACC. In tumors it can cause shrinkage or more commonly arrest of growth. As we discover new functions for the CDK target of this medicine we are likely to use it in combinations to make other anticancer agents work better. In addition to inhibiting the cell cycle palbociclib has been shown for example to alter several recently described noncell cycle functions of CDK a finding expected to expand its therapeutic role ODwyer added. Assessing  relevant publications in the literature as well as interpreting their own continuing studies the allPenn team found that in addition to its safety and effectiveness in fighting certain types of breast cancer early trials of palbociclib have shown promise of effectiveness in cases of lymphoma sarcoma and teratoma tumors that while rare often afflict younger patients.  A phase  trial showed that among  patients with previously treated mantlecell lymphoma palbociclib resulted in one complete response and two partial responses. Although median progressionfree survival was four months five patients had progressionfree survival greater than one year. Another phase  trial with  sarcoma patients treated with palbociclib showed a progressionfree survival of  percent at  weeks. Also combining palbociclib with other anticancer agents is feasible and early results in myeloma and some solid tumors have led to more definitive studies.  In both breast and other cancer trials palbociclib has been shown to be safe with oncedaily dosing and its main adverse effect is reversible neutropenia an abnormally low count of neutrophils a type of white blood cell that helps fight infections. The lower their neutrophil count the more vulnerable patients are to infectious diseases. In such cases the drug is temporarily discontinued and reintroduced at a lower dose. Other side effects included fatigue  percent nausea  percent diarrhea  percent constipation  percent and rash  percent.  At the recommended doses evidence of the desired drug effect in tumors has been obtained using novel PET imaging at Penn. These tools can help to individualize patient therapy going forward.  Other Penn coauthors are Thomas B. Karasic MD Angela DeMichele MD MSCE David J.Vaughn MD Mark OHara MD Rodolfo Perini MD Paul Zhang MD Priti Lal MD Michael Feldman MD PhD and Maryann Gallagher RN. The study was funded by Pfizer Inc and the National Institutes of Health P CA."