Through the success of Revlimid and other drugs, Celgene has become a respected and powerful player in the biopharmaceutical industry in recent years.
The company decided to take a second look at a drug that others had written off for decades. Today, several myeloma patients are living longer lives, and new methods of drug delivery are making therapeutic agents more effective than ever.
Looking to a controversial drug that caused thousands of cases of birth defects in children born in the 1950s for inspiration might seem counterintuitive. Thalidomide was discovered in 1953 in Germany and administered as a sedative. Although the FDA never approved use of the drug in the United States, thalidomide has become a major part of Celgene’s success.
Revlimid, an analog of thalidomide, is being used to treat patients with relapsed or refractory multiple myeloma (MM) and myelodysplastic syndrome (MDS). When treated with Revlimid, patients are now living beyond the expected 2 to 2.5 years after diagnosis, and the drug has eliminated the need for blood transfusions—the standard of care for relapsed MM patients—in two-thirds of patients who have taken the drug.
Revlimid (lenalidomide) was formed as an analog of thalidomide, a drug used to treat MM and erythema nodosum leprosum, a type of skin disease and nerve sore disorder found in patients with leprosy. Revlimid was approved for the treatment of MDS in 2005 and for relapsed or refractory MM in 2006.
Revlimid is the first of a group of compounds at Celgene called immunomodulatory drugs (IMiDs). These oral capsules are immunomodulatory agents that have multiple mechanisms of action that may involve the microenvironment of the cancer cell and not just the cancer cell itself. Revlimid works by modifying cytokines and other growth factors, and blocks the growth of blood vessels that support tumors. In 1 study, MM patients survived for nearly 3 years, the longest median survival for phase III trials. In another phase III study, 93% of patients who took Revlimid with dexamethasone survived for at least 2 years. Patients with MDS experienced long-term responses for more than 2 years and more than a 75% reduced need for transfusion, with approximately two-thirds of patients achieving infusion independence.
type of paclitaxel injection, Abraxane is a nanoparticle-sized anticancer compound that is used to treat breast cancer patients who have been unsuccessfully treated with other drugs. The injection uses human albumin, a water-soluble protein, as a shell to house Abraxane. The shell binds to the tumor, and the therapeutic agent is released in a targeted dose, initiating cell death.
In phase III studies, Abraxane was shown to have a higher response rate (33%) compared to a normal paclitaxel injection (19%). Patients also had an increased time to tumor progression (23 weeks vs 16.9 weeks) and prolonged survival in second-line and later patients (56.4 weeks vs 46.7 weeks).
Abraxane is delivered intravenously by a doctor or nurse on either a weekly or semiweekly basis. In addition to breast cancer, Abraxane is being explored for use in patients with head and neck cancers, esophageal cancer, bladder cancer, and cervical cancer.
Vidaza is an injectable form of azacitidine, which is approved for use in patients with MDS. It is the first and only drug approved for patients falling into all 5 subtypes of MDS, as well as the first drug to achieve transfusion independence across all risk categories.
The injection is a demethylation agent that works by inhibiting hypermethylation of DNA. The drug helps bone marrow to produce normal cells and causes the death of rapidly dividing cells.
In a phase III study, patients with MDS taking Vidaza had a 2-year survival rate, nearly double the rate of other regimens approved for MDS. The median survival rate was 9.4 months, and extended survival was seen in 74% of patients.
A brand form of thalidomide, Thalomid has been approved in the United States to treat newly diagnosed cases of MM when given with dexamethasone, an immunosuppressive drug. Thalomid has also been approved in the European Union and Australia to treat new cases of MM when administered with melphalan and prednisone (MP). According to recent data, patients taking thalidomide plus MP had an overall median survival of 51.6 months versus 33.2 months for standard therapies.
Like Revlimid, Thalomid is closely associated with severe birth defects. Celgene’s STEPS program was established to minimize fetal exposure to Thalomid.
Istodax (romidepsin), an injectable drug, is approved for previously treated cases of cutaneous T-cell lymphoma (CTCL) and is being explored for use in patients with peripheral T-cell lymphoma. The drug is a histone deacetylase inhibitor, which removes acetyl groups from proteins. Genes without acetyl groups that are supposed to regulate cell growth cannot function. However, this group of inhibitors reverses the process so that the gene can function and resume its normal life cycle.
In a National Cancer Institute trial, the overall response rate among patients with CTCL was 35% versus 34% in a company trial. The company trial showed a median response of 15 months, while the NCI trial showed an 11-month median response.
Istodax is delivered intravenously by a doctor or nurse over 4-hour periods on specific days within a 28-day cycle. The cycle repeats itself as long as the drug is still proving effective in the patient.
Through the success of Revlimid and other drugs, Celgene, based in Switzerland and New Jersey, has become a respected and powerful player in the biopharmaceutical industry in recent years. The company has pursued new sciences and technologies in the development of therapies for cancer and hematologic diseases, with 25 phase III or late-stage trials currently underway exploring new drugs or new indications for their existing line of drugs.
The discovery of thalidomide was made decades ago, yet its effectiveness in the form of Revlimid is a result of how it’s delivered into the body. Brian P. Gill, vice president of corporate communications at Celgene, said the company’s immunomodulatory compounds work by using multiple mechanisms to modify the genetic environment of a cancerous cell and by blocking the growth of blood vessels that tumors need to thrive, while at the same time triggering a boosted immune response in the body.
Abraxane, another Celgene product, showcases one of the company’s new methods for drug delivery, called nab Technology. Nab stands for nanoparticle albumin bound. Albumin is a water-soluble protein used to create a protective shell around the drug. Cancerous cells secrete a protein called SPARC (secreted protein acidic and rich in cysteine) that attracts the albumin, and once there is a link, the drug is fed directly into the tumor.
Gill said the company’s success with this targeted method of drug delivery will hopefully pave the way for similarly successful new technologies.
“Right now, we’re concentrating on blood cancers,” Gill said, “but more of our time and energy is being devoted to eventually moving into the treatment of solid tumors.”
Revlimid has proved life-changing to thousands of MM patients, but the drug’s history of birth defects is still a concern even decades after its discovery.
“It’s a powerful drug,” said Gill. “Along with that power comes some serious side effects.”
One of the major challenges for Celgene in terms of growing its presence in the biopharmaceutical industry was not only making a drug that worked, but also avoiding a repeat of a well-documented pharmaceutical disaster. After demonstrating the effectiveness of Revlimid in clinical trials, the FDA approved the drug with the provision that Celgene be required to establish a subsequent program to ensure that female patients of childbearing age are not taking the drug. According to Gill, this led to one of the first FDA-approved drug management programs.
Celegene first created the STEPS program (System for Thalidomide Education and Prescribing Safety) to educate physicians and patients about the risks associated with Thalomid (thalidomide). The company later established RevAssist for patients taking Revlimid and has established similar drug management programs in other countries where these drugs are available. RevAssist helps physicians to closely monitor their patients and ensure they do not become pregnant while taking the drug.
“This is not something that’s contracted out to another company,” Gill said. “These are our programs with patented designs that involve a closely monitored relationship between the patient, the physician, and the pharmacist.”
Since the programs began, more than 145,000 women have enrolled, and no incidents of birth defects have been reported in association with Thalomid or Revlimid use.
Celgene’s pipeline shows that the company is looking to expand the applications of its existing drugs into other forms of cancer. Abraxane is currently approved for patients with relapsed or refractory metastatic breast cancer, but clinical trials are underway to see if the drug could be approved for advanced lung cancer, malignant melanoma, advanced pancreatic cancer, bladder cancer, and ovarian cancer.
“There are a number of phase III trials that we should have completely enrolled by the end of 2011,” Gill said. “We also hope to be filing with the FDA for the approval of some of our drugs by the end of 2011.”