Category Archives: Cancer

Fight Advanced Melanoma Better with Just-Approved Drug Keytruda (pembrolizumab)

Cancer
3-D image of melanoma cell structure
Photo credit: National Cancer Institute (NCI)

Will September 4, 2014 become the day melanoma was vanquished forever?

Probably not. But it is the day the FDA approved a new drug that helps your immune system fight off this deadly cancer.

Pembrolizumab (brand name Keytruda), from Merck, got fast-track approval almost two months earlier than expected. The FDA gave approval without the usual three clinical trial phases because the drug showed amazing promise in Phase 1 trials.

Many patients with advanced melanoma saw tumors shrink and lived months longer than would normally be expected. Not all patients got the same benefits, and more studies need to be done to confirm the drug really does work that well.

What is Melanoma

Melanoma is a very serious skin cancer that starts in cells called melanocytes. These are the cells that give skin color by making a pigment called melanin. You get a tan because sun exposure causes them to make more melanin.

Skin cancer is the most common cancer in the US—about 3.5 million people are diagnosed every year. Less than 5% of those are melanoma—an estimated 76,100 cases will be diagnosed in 2014.

That’s the good news.

The bad news is melanoma is the deadliest of the skin cancers. It accounts for more than half of the skin cancer deaths each year. In 2014, about 13,000 people will die of skin cancer. Around 9700 of those will be from melanoma.

Pembrolizumab Helps the Body Kill Melanoma Cells

This newly approved therapy is an antibody that helps your immune system identify and kill cancer cells.

Keytruda targets a molecule that certain white blood cells (called T cells) use to figure out which cells need to die. This molecule is called programmed cell death 1 (PD-1). Cells with PD-1 signal the immune system to put on the brakes and let cells live. Certain kinds of tumors—including melanoma—have high levels of PD-1. So the body lets them live and grow.

Blocking this molecule with the Keytruda antibody essentially releases the brakes so the body can go about identifying and stopping the tumor cells.

The PD-1 pathway is a different target from the previously approved immunotherapy drug Yervoy (ipilimumab) from Bristol-Myers. That drug blocks a protein called CTLA-4.

Approved Only for Some Melanoma Patients

For now, the FDA has approved Keytruda only for the sickest patients who have no other treatment options.

These patients must have tried the above-mentioned Yervoy without getting better.

Also, if their tumors show a mutation called BRAF V600, they must also try a BRAF inhibitor. These patients can get Keytruda only after using both Yervoy and the BRAF inhibitor.

Patients who don’t get better with Yervoy or the Yervoy/BRAF inhibitor combination were basically out of options until now. Keytruda appears to help more than half of them stay alive for at least another year.

Unfortunately, like most cancer treatments, this one is expensive. There’s concern that the $150,000 per year price tag could leave many patients unable to afford it.

Trial Showed Significant Tumor Shrinkage

The work cited in the FDA news release involved 173 patients whose melanoma did not respond to ipilimumab (Yervoy). This group was divided into 2 groups, each receiving a different dose of the drug, either 2 mg/kg (the recommended dose) or 10 mg/kg. Both groups showed similar responses, with 24% of people seeing their tumors shrink.

These results were published in the Lancet on July 15, 2014.

The overall trial involved many more patients, not all of whom had taken ipilimumab. Overall results showed as many as 72% of patients showed some tumor shrinkage (but in some it was a very small response).

More work is needed to show that the treatment can actually improve survival and/or symptoms.

What’s Next for Pembrolizumab

Merck will still have to conduct Phase 2 and 3 clinical trials to verify that the drug not only shrinks tumors but helps people live longer and/or slows progression of melanoma.

Also, there’s some evidence that anti-PD-1 drugs can work in other cancers, including lung and bladder. The company is actually testing/planning to test the drug in patients with many different tumor types.

They’re also planning studies to see how it works in combination with other drugs. One of those studies involves an immunotherapy drug from Advaxis, ADXS-PSA. This drug targets prostate cancer and will be tested alone and as a combination treatment with pembrolizumab. The two companies plan to begin this study in 2015.

 

 

 

 

Stop Measles and Cure Cancer?

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Could this finally be the holy grail of cancer cures? A single shot of a measles virus kills cancer?

It was for one woman with myeloma who had run out of treatment options. She went into complete remission for nine months.

From Tumors All Over to Complete Remission

How did this happen? She got a huge dose of an engineered measles virus that targets myeloma cells, according to a Mayo Clinic press release. That’s it. Just one dose caused her tumors to shrink and disappear.

Of course, it wasn’t really as simple as all that. The treatment came with some pretty nasty side effects. She had a headache, spiked a 105 fever and was vomiting, among other things.

But she probably considers it worth the temporary misery. It took a few weeks, but the tumors all over her body disappeared.

Reason for Hope, But No Guarantees

As amazing as this news is, it’s not time to sound the death knell for cancers everywhere just yet.

This study included only two people. And only one saw her tumors disappear. A second woman had positive initial results, but her cancer started growing again.

So is this a miracle cure? Maybe someday. But a lot more work needs to be done.

A few things to keep in mind:

  • We need more clinical trials to show it’s safe.
  • We need even more (and bigger) trials to show that it can work in more than two people. And hopefully cause remission in more than one.
  • This treatment is specific to myeloma. The measles virus was engineered to infect those specific cancer cells. For similar treatments to work on other cancers, viruses (not necessarily measles) would need to be engineered to target those cancers.

Also, the treatment may not work as well (or at all), if you have antibodies against the virus used in the treatment (in this case measles). Your body might kill them before they have a chance to kill the cancer. Researchers will have to look at this more closely, too.

What’s Next

More trials, of course. The Mayo Clinic plans to start a larger trial later this year.

If you might be interested in participating in this trial, you can contact the Mayo Clinic for more information.

Learn More

This story has been widely reported since the Mayo Clinic published its news release on April 14, 2014. If you’re interested in learning more we have some sources listed below the video.

But first, check out what the Mayo Clinic’s Stephen Russell has to say about this treatment:

Additional reading:

Could measles cure cancer? Uh, not exactly… – This is a great article from Cancer Research UK, explaining in plain language what the scientists did and why it’s nowhere near ready for prime time.

Measles virus used to treat bone marrow cancer – Another easy to understand explanation of what the researchers did and how they interpreted what happened.

Remission of Disseminated Cancer After Systemic Oncolytic Virotherapy – Warning: this is a rather technical article in Mayo Clinic Proceedings