New Drugs 2012 Part 2
Ted Rosen, MD & Neal Bhatia, MD
Imiquimod for Actinic Keratosis
There are three doses of imiquimod: 5%. 3.75% and the new 2.5% (which is approved, but not commercially available at this point). What are their uses? Where does the 2.5% fit in? According to Dr Bhatia:
- 5% for solid tumors or more aggressive fields?
- 3.75% cycle therapies for routine or initial courses? It can also probably still be used for solid tumors
- 2.5% for low-grade maintenance, weaning down from 6 week cycle, or routine for high-responders
- Alternate among them?
- Don’t expect any new trials or indications for awhile, so use your own experience
Icatibant
Icatibant is a SQ injected bradykinin B2 receptor antagonist, i.e., has a receptor affinity similar to bradykinin. Icatibant inhibits bradykinin, binding the B2 receptor; therefore, resulting in symptomatic relief and modulation of episodic flares of hereditary angioedema (HAE).
The injection is 10 mg per mL and comes as a 3 ml syringe, 25-gauge needle. Icatibant is indicated for the treatment of acute attacks of hereditary angioedema (HAE) in adults 18 years of age and older. Pediatric studies are currently underway. Icatibant is dosed at 30 mg injected subcutaneously in the abdomen. If the response is inadequate or symptoms recur, additional injections of 30 mg may be administered at intervals of at least 6 hours. It is important that healthcare providers and patients know not to administer more than 3 injections in 24 hours. Patients may self-administer upon recognition of an HAE attack.
The pivotal FAST-1 and FAST-2 trials studied icatibant and showed that it had a median time to 50% reduction from baseline symptoms ranging from 2.0 to 2.3 hours. Icatibant was approved in 2011 in the US.
Belimumab
The FDA approved Belimumab (BenlystaTM) for the treatment of autoantibody positive systemic lupus erythematosus (SLE) in March 2011. Belimumab is a human monoclonal antibody that is delivered via IV infusion and targets the soluble B lymphocyte stimulator (BLyS) protein.
BLyS was discovered by the Human Genome Sciences program in 1996 and plays a pivotal role in B-cell survival and B-cell proliferation by preventing normally occurring apoptosis. During a normal immune response to infection, BLyS facilitates more B-cells to survive, proliferate and produce antibodies to fight infection. In many patients with SLE, higher concentrations of BLyS promote increased B-cell survival including the survival of autoreactive B-cells that in turn can mature into autoantibody-producing B-cells. Belimumab does not bind directly to B cells and does not directly deplete B-cell populations but instead binds BLyS. In doing so belimumab inhibits the survival of autoreactive B-cells and reduces their differentiation into immunoglobulin-producing plasma cells. Belimumab has demonstrated proven efficacy in reducing SLE disease activity.
Azficel-T
Azficel-T is indicated for the improvement of the appearance of moderate to severe nasolabial fold wrinkles in adults. It is an autologous cellular product; in that, it is made especially for patients from their own skin cells which are harvested via punch biopsy which is then shipped to a specialized lab for harvesting and growth of the patient’s fibroblasts. It is best used for acne scarring and nasolabial folds. It is important that dermatologists screen for any hypersensitivity and allergies. It is also important to recognize that this product is not meant for the “impatient” patient, as one cannot see instant results.
In reality, dermatologists should keep in mind that azficel-T is not inexpensive, i.e., $1000-$2000 to create a personalized bank of fibroblasts and each injection session costs between $700 and $1,000; therefore, the total cost may range from $3,100 to $5,000. There have been isolated cases of vasculitis, collagen vascular diseases, and keloids. There is lots of potential for good outcomes as well as mistakes with the use of azficel-T.