Trial #: NCT01018680

Research Sponsor:
Eli Lilly and Company
Drug Studied:
Duloxetine (Cymbalta®)
Nat'l Trial #:
Protocol #:
Study Date:
Nov. 2009 to Apr. 2011

Thank you!

As a clinical study volunteer, you belong to a large community of volunteers around the world. You help researchers answer important health questions and help them discover new medical treatments.

Thank you for taking part in the clinical study for the drug duloxetine, which took place between November 2009 and April 2011. Duloxetine is also known by its brand name, Cymbalta®. It is a prescription drug used in adults to treat the pain of osteoarthritis, a common disease of the joints.

Eli Lilly and Company, the sponsor of this trial, thinks it is important for you to know the results. An independent non-profit called CISCRP prepared this summary of the results for you. We hope it helps you understand and feel proud of your key role in medical research. If you have questions about the results, please speak with the doctor or staff at your study site.

Questions & Answers about the study:

1What has happened since my trial ended?

You were in the study for up to 14 weeks, but the entire study took much longer. It took 17 months for the study to finish. The study had 524 patients at 35 locations across the United States. When the study ended in April, 2011, the sponsor began reviewing the data. Then the sponsor created a report of the results. This is a summary of that report.

2Why was the research needed?

Researchers were looking for a better way to treat knee pain in people with osteoarthritis. This pain is usually treated with drugs called “NSAIDs” (Non-Steroidal Anti-Inflammatory Drugs), such as aspirin and ibuprofen. But some people who take NSAIDs for osteoarthritis still have pain. Researchers wanted to find out if a drug called duloxetine would help people who take NSAIDs, but still have pain.

Previous studies showed that duloxetine can decrease osteoarthritis knee pain and increase knee function. Now researchers wanted to know:

  • Does duloxetine help patients with osteoarthritis knee pain who are taking NSAIDs, but still have pain?
  • Is it safe to take duloxetine and NSAIDs at the same time?

To answer these questions, researchers asked for the help of men and women like you. All of the patients in your study were over 40 years old, had osteoarthritis in their knee, and were taking NSAIDs but still had knee pain.

3What kind of study was this?

This study compared two groups of patients to find out if duloxetine was safe and relieved pain for patients already taking NSAIDs. Researchers used a computer program to randomly put patients into the two groups:

  • Duloxetine Group: 264 patients took NSAIDs and duloxetine.
  • Placebo Group: 260 patients took NSAIDs and a placebo.

A “placebo” looks like medicine, but does not have any medicine in it. Using a placebo helps make study results fair and unbiased, because researchers and patients cannot tell who is taking a placebo, and who is taking the real medicine.

4What happened during the study?

In the first 2 weeks, doctors helped patients find the best dose of NSAIDs. Patients also started taking a drug called omeprazole every day to help with the stomach pain that NSAIDs can cause.

Over the next 10 weeks, patients were treated with either duloxetine and NSAIDs, or with a placebo and NSAIDs. Each duloxetine pill had 60 milligrams of the drug. The placebo pills looked like the duloxetine pills, but had no medicine in them. At first, all patients took 1 pill every day. Later, patients who still had a lot of knee pain took 2 pills every day. Patients saw their study doctor 5 times during the treatment period. During those visits, patients completed surveys that rated how much their knee pain interfered with their lives. Patients also used a telephone system to keep a daily diary of their pain, rating it from 0 (no pain) to 10 (extreme pain). Many of the study results were measured when patients had been treated for 8 weeks.

The study ended with a 2-week period, during which patients slowly stopped taking the study treatment with the doctor’s help.

5What were the study results?

In this study, patients taking 60 to 120 milligrams of duloxetine with NSAIDs had less knee pain and felt better than patients taking a placebo with NSAIDs. Below is a summary of the medical questions that were asked in this study, and the study results.

Did duloxetine help with osteoarthritis knee pain? Yes. Patients taking duloxetine had less knee pain than patients taking a placebo.

  • What was the data? On a scale from 0 ("no pain") to 10 ("extreme pain"), patients started the study with a pain rating of about 6.3. After 8 weeks of treatment, patients taking a placebo had a pain rating of about 4.8. And patients taking duloxetine had a pain rating of about 3.8.
  • What does this mean? Both groups of patients still had pain, but less than when they started treatment. And duloxetine with NSAIDs gave more pain relief than a placebo with NSAIDs.
6What side effects did patients have?

A side effect is any medical problem caused by a drug or treatment. A lot of research is needed to know whether a drug causes a medical problem. So, when new drugs are being studied, researchers keep track of all medical problems that patients have. These medical problems are called "adverse events," and may or may not be caused by the study drugs.

  • Nausea
  • Dry Mouth
  • Constipation
  • Diarrhea
  • Dizziness
  • Headache
  • Decreased Appetite
  • Somnolence
  • Vomiting

Full list can be found on the U.S. government’s clinical trial website at

7Where can I learn more about this clinical trial?

This summary of the clinical study results is available online at At that webpage, you will find a link to the full scientific report. If you have questions about the results, please speak with the doctor or staff at your study site.

Thank you

It is said that the greatest gift is one which is given anonymously, giving when you do not know whether you will get direct personal benefit.

This is the gift that you have given by taking part in a clinical trial. It is a brave and selfless act, one that advances medical knowledge and benefits public health. Thank you for the gift of your participation in clinical research.

Center for Information & Study on Clinical Research Participation

The Center for Information & Study on Clinical Research Participation (CISCRP) is a non-profit organization focused on educating and informing the public about clinical research participation. CISCRP is not involved in recruiting patients for clinical trials, nor is it involved in conducting clinical trials.