Provenge Compared to Xtandi for Treating Prostate Cancer

Provenge compared to Xtandi is just one exercise in decision-making facing men who have been diagnosed with advanced prostate cancer that has not responded to hormone therapy. Xtandi (enzalutamide) was approved by the Food and Drug Administration on August 31, 2012. Whenever a new drug hits the market, one of the first questions to ask is, “How does it compare with other drug treatments?” Here we look at Provenge compared to Xtandi and answer the question, “What is the difference?”

How do Provenge and Xtandi work?

The biggest difference between Provenge (sipuleucel-T) and Xtandi is in how they work. Provenge is a form of immunotherapy, which means it is designed to work with the immune system to fight prostate cancer. Immunotherapy is considered a positive therapy, in that it does not involve destroying or otherwise harming cells in the body, whether they are prostate cancer cells or healthy prostate cells.

Xtandi is a new type of hormone therapy, and is in fact the first member of a new class of drugs called androgen inhibitors. This means that Xtandi was designed to interfere with the activity of testosterone when it tries to attach to prostate cancer cells. Prostate cancer cells need testosterone to reproduce and grow, and Xtandi helps prevent the hormone from assisting these functions.

Provenge compared to Xtandi: Who is eligible?

Generally, men who have metastatic prostate cancer that has resisted hormone therapy are eligible for both Provenge and Xtandi. However, there are a few differences.

To be a candidate for Provenge, men must have asymptomatic or minimally symptomatic prostate cancer, which means if cancer pain is present, it must not be severe enough to require treatment with narcotics. Men who qualify for Xtandi treatment must have failed not only hormone therapy but chemotherapy with docetaxel as well.

Provenge compared to Xtandi: How are they used?

Provenge is unique in that each dose of the medication is made from the patient’s own cells. Part of how men prepare for treatment with Provenge includes a process called leukapheresis. This involves collecting a patient’s blood, harvesting certain cells, and then returning the remaining blood to the patient. The harvested cells are modified and then given to the patient a few days later via an infusion. This is the procedure necessary for one dose of Provenge, and men who follow the Provenge treatment program need three doses. The entire treatment course takes about 5 weeks.

Xtandi is an oral medication that is taken daily at home. Men who participated in the clinical trials took Xtandi for an average of 8 months.

Provenge compared to Xtandi: Side effects

Among men who take Provenge, the most common side effects–those that affect at least 15% of patients–include back pain, chills, fatigue, fever, headache, joint aches, and nausea. Serious side effects are rare, but can include stroke or severe reactions to the infusion. About 3.5% of patients experience infusion reactions, which can include breathing problems, chills, dizziness, fatigue, fever, headache, high blood pressure, muscle ache, nausea, vomiting, and weakness.

The side effects associated with Xtandi include anxiety, back pain, blood in urine, diarrhea, dizziness, fatigue, headache, hot flashes, joint pain, lower respiratory infections, muscle weakness, musculoskeletal pain, sleep difficulties, spinal cord compression, tingling sensation, tissue swelling, and upper respiratory infections. Approximately 1% of patients experienced seizures.

Provenge compared to Xtandi: Cost

Currently the cost of the treatment course of Provenge is $93,000, not including doctor visits and other additional charges. Some men may qualify for assistance in paying for treatment, and the drug’s manufacturer, Dendreon, offers information about reimbursement possibilities. Medicare and many insurance companies have agreed to cover treatment.

Xtandi costs $7,450 per month, and the average treatment course is 8 months. It is expected Xtandi will be covered by Medicare and by most insurance companies. However, men need to check with their insurance provider.

Provenge compared to Xtandi: Effectiveness

Based on the results of clinical trials, Provenge improved overall survival a mean of 4.1 months. More specifically, a phase III trial involving 512 men showed that those who took Provenge survived a median of 25.8 months compared with 21.7 months for men who took placebo, for an advantage of 4.1 months.

In a clinical trial that included 1,199 men, those who receied Xtandi achieved a median overall survival of 18.4 months compared with 13.6 months for men who took placebo, for an advantage of 4.8 months.

Provenge compared to Xtandi: Which one for you?

Choosing a prostate cancer treatment is a major decision that should be made only after carefully considering all the options, their benefits and risks, and consulting with healthcare professionals and loved ones. Ultimately, whether you choose Provenge, Xtandi, or one of the other available medications is up to you.