Fight Against Melanoma Q&A
What can this do for patients with metastatic melanoma that couldn’t be done before?
Dr. Rubin: Proleukin is now available for patients with metastatic melanoma. It was available to patients with other forms of cancer previously. What we now know and what the FDA has accepted is patients with metastatic melanoma often manifest significant clinical responses to this drug. By that I mean their tumors either shrink significantly or go away completely. The unique quality of Proleukin appears to be the duration of the response. For people whose tumors go away significantly, they often remain in remission for very long periods of time. I think this is one of the few treatments that is able to accomplish that. By approving this drug, it should be much more readily available to large numbers of patients who have metastatic melanoma.
Is this a widespread disease?
Dr. Rubin: Melanoma is becoming increasingly common. Our being enamored of the sun is to blame in part. It’s a cancer that, if found early, can be easily cured, and that’s why people are urged as part of their routine health screening to examine their skin on a regular basis. Someone should look at the scalp because you can get melanoma under the hair as well. Melanoma is a disease that starts as something as harmless as a mole. When it’s at a very early stage, simple removal of the mole is curative. When we ignore a mole, that allows the disease to then spread, and we end up with what we call metastatic melanoma. That’s where little seeds of the tumor leave the mole and go to various parts of the body. Once the tumor has distributed itself throughout the body, you can no longer cure it by surgery. You need a treatment that literally is distributed throughout the body — something that’s given either intravenously or orally. Proleukin is a drug that’s administered through the veins then brought to every part of the body. Where ever melanoma would reside, Proleukin can have an affect on that. As we’ve seen in a large number of clinical trials now, there’s a small subset of patients, perhaps 20 percent, who have a very, very significant clinical benefit as a result of treatment with Proleukin.
What about the others?
Dr. Rubin: Unfortunately there are patients who do not respond to treatment with Proleukin. I think if we could answer the question — why don’t they respond? — we would make a significant contribution to the treatment of this disease. We’ve always suspected that the mechanism by which Proleukin works is immune. In other words, somehow we know it’s a very potent stimulator of the immune system. It’s very different from chemotherapy, which is toxic and has a direct toxic affect on the tumor as well as the patient. Fortunately for chemotherapy, the toxicity against the tumor usually far exceeds the toxicity of the person, which is why there’s clearly a benefit to chemotherapy in a variety of diseases. Proleukin doesn’t have significant direct toxicity to the tumor. It does stimulate the immune system, and we know that melanoma is a cancer that can be recognized as foreign by the immune system and can be destroyed by it. So we’ve suspected that Proleukin stimulates the immune system in patients who have melanoma. In some of those patients, the melanoma is susceptible to recognition by the immune system, which can then destroy it. Perhaps that’s why the response lasts so long — because your immune system just doesn’t go away. The immunity often is very durable. So this represents yet another approach to treating cancer. It’s not chemotherapy. It’s an immunotherapy. Its mechanism of action is very different. I think the major question is why are some melanomas resistant to this immune-mediated killing?
Is it too early to tell how well it’s working?
Dr. Rubin: As you suggested, this is not a new medication. Its indications have been expanded for Proleukin. Proleukin has been evaluated now for a number of years. There’s extensive clinical experience with its use. Which is good now because people with melanoma who are now receiving this drug aren’t getting it from someone who never heard of it or never used it before. The drug has been available for a long period of time for other types of cancer for which it’s equally or even more effective.
What are some of the common side effects?
Dr. Rubin: Side effects are unfortunately numerous. It can affect most every organ system in the body. Obviously patients differ. Some patients have little in the way of side effects. Other patients have multiple side effects. It clearly affects the heart, lung, kidneys and liver. Some people can feel ill on treatment. Some people don’t feel ill until the end of treatment. I think the two important things from my perspective as a clinician who took care of many patients and who received this medication and who had also been treated with other conventional forms of anti-cancer therapy are number one: when properly given, the risk of dying as a result of treatment is exceedingly low. It should be a very, very safe drug to administer. The other remarkable thing to me was the rapidity with which people recovered from treatment. People who felt very, very ill towards the end of their therapy often would bounce back within days of stopping. So there seems to be a lot less down time as a result of therapy. Say you got treated for a week, and then rather than being sick for one to two months, you might get treated for a week, but within three, five, maybe seven days you’re back to where you were before. Obviously there are exceptions to that generalization, but that’s what struck me while taking care of many patients with Proleukin.
Who is the best candidate for this treatment?
Dr. Rubin: Because it affects a variety of organ systems, people have to generally be fairly healthy. In other words, if you had very bad heart disease, I would not recommend this treatment. The drug can put a significant amount of stress on the heart. Same goes for the lungs and kidneys. In patients whose organ function is normal or relatively normal, the risk of permanent organ damage is exceedingly low. For people who don’t have that ability to bounce back, people whose health is not that good to begin with, this does not represent a reasonable option for them.
Does melanoma occur in a broad age range?
Dr. Rubin: Melanoma is generally a disease of the adult population, but adulthood starts at a relatively young age from my perspective. So sure, people in their 20s and 30s can get this disease. The tragedy again is that it is so easily cured if detected early. I think that’s why people are urged to have any mole or skin blemish that seems to change in any way evaluated by a physician. At its very early stage, simple excision under local anesthesia cures the disease. It will not come back.