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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Palladia, First Dog Cancer Drug FDA Approved But Not Great

Updated: March 14th, 2019

Palladia, the first drug officially approved for use in treating dog cancer has arrived.  This was described in the Dog Cancer Survival Guide by it’s pre-market name, SU11654. Now it’s finally ready for release.

Palladia, made by Pfizer, has been approved by the FDA. It is expected to be available next year.  This drug is approved for treating mast cell tumors in the dog.

The fact that this is the first drug approved for dog cancer may be odd for many.  What about all those chemotherapy drugs that are used? They are not FDA approved?

Well, the facts are that vets and veterinary oncologists have been using human drugs the whole time.  As a matter of fact, many of the drugs we use generally are not FDA-approved for use in the canine.



Why?

It turns out that FDA drug approval is allowed for one species at a time.  On top of that, approval is for one disease or problem.  In veterinary medicine, we have cats, dogs, birds, rabbits, monkeys, snakes, and so on…many different species, and they all need treatment.

It would take hundred of years and staggering amounts of money to get all our drugs approved for all these different species and diseases.

So vets have “off-label” drug use privileges.  Off-label drug use means we can use drugs approved for one species (including humans) freely in  other species.

Let’s take a look at some of the facts around Palladia.

Like most of the conventional treatments we use in treating dogs with cancer, the numbers for Palladia are a bit disheartening.

The median duration of objective response (meaning how long the Palladia’s effect lasted on mast cell tumors) was 12 weeks. Yes, 3 months of tumor shrinkage or disappearance  is what you can expect. This number is taken from the original study.

After 3 months the cancer came back.

On top of this, not all dogs with mast cell tumors even responded.  It turns out that roughly 40% of dog with mast cell tumors will actually respond to the drug, while the majority do not.

This means that while about 40% of the time the cancer either went away or shrank, in the remaining 60% of dogs Palladia had no effect.


Get a copy of the Dog Cancer Survival Guide for more information and tools to help your dog with cancer


Sigh.

If you would like to look at the original data for yourself, here is the link.

This highlights important points.

First, there is a big to do about Palladia.  But, the actual statistics are depressing.  Interesting contrast between hype and reality.

Second, I think most guardians of dogs afflicted with mast cell tumors would not be jumping for joy  at these numbers, in spite of the festivities at Pfizer.

Lastly, this shows how important it is to leap sideways in our efforts to really treat canine cancer.

The more I think about dog cancer, and disease in general, the more I believe early choices are key, long before old age.

I will start addressing how dog cancer does not start in old age, in future posts. Instead, it starts many, many years before hand. We need to start taking steps earlier, much earlier.

Best to all,

Dr D

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  1. Thomas on April 29, 2013 at 7:20 am

    I’d like to post a WARNING about a POSSIBLE interaction between Prilosec OTC and Zonisamide. Our little pug’s oncologist had us give her Prilosec OTC with chemotherapy with nearly disastrous side effects, and yet there are no reported interactions between Prilosec OTC and Zonisamide (seizure med).

    Our oncologist had us give her Prilosec OTC one hour before Palladia treatment (to help prevent any gastric problems caused by the Palladia). But about 15 hours after receiving the Prilosec, our little girl started exhibiting some rather disturbing side effects, which we realized were not likely associated with the Palladia (I’ll explain why shortly). She would “belch” up a load of yellow foam out her nose every few hours. Each episode caused her to be in real distress and she would furiously rub her face on whatever surface was handy. She appeared very scared and had a hard time breathing (probably from stomach acids burning her throat).

    Here is a key point: it wasn’t until the Palladia/Prilosec treatment that we made an important connection: we remembered that Lexi had once bee prescribed Prilosec alone, and the exact same symptoms appeared. Back when the vets didn’t know she had cancer, they suspected a possible ulcer and had us try the Prilosec. The symptoms appeared within about 15 hours, so the vet had us discontinue the Prilosec and bring her down for an ultrasound. That’s when they discovered her cancer. The vet said they’d never heard of this kind of thing happening to a dog on Prilosec, so everyone forgot about it and focused on the need for immediate surgery. It wasn’t until the oncologist put her on Prilosec/Palladia and the exact same symptoms appeared again that we made the connection. We immediately took Lexi off the Prilosec/Palladia and again the symptoms resolved in 24 hours. Still, the vet said they’d never heard of such severe GERD-like symptoms (at first they didn’t appear to believe us).

    It could be that the Prilosec alone didn’t agree with Lexi, but the vets began to wonder if there could be some unreported interaction between the Prilosec OTC and Zonisamide, which Lexi was taking on a daily basis for her seizures. Lexi was NOT on Apocaps the first time the Prilosec alone caused the problem.

    I hope this post helps anyone else out there experiencing this kind of problem while using Prilosec OTC, because the vets seem entirely unaware of this kind of side effect and they tend to use it with some of the chemotherapies. Sadly, our little girl lost her battle with cancer only 10 weeks after the surgeon removed an adenocarcinoma from her small intestine. The cancer had just metastasized for too long and she was too weak to fight.

  2. Michael on April 24, 2013 at 12:41 pm

    This is a follow-up to my message of April 18, in which I forgot to tell you that our Portuguese Water Dog has not wanted to eat anything even after being given
    Mirtazapine pills. What to do?

    P.S. Your book is on the way from Amazon.com and will arrive in 3 or 4 days’ time.

  3. Suttinan Chattong on January 30, 2013 at 7:01 pm

    Dear Dr Dressler/Ettinger,

    I have a dog named Gege (12 years old) who developed a big lump on her leg. The lump was removed on 14 Dec 2012 and was identified to be Mast Cell Tumor grade 3. Gege is doing fine after that with Prednisolone medication and doesn’t seem sick – although our vet say her life expectancy could be around 6 months.

    Our vet did mention Palladia as a choice, but I’m wondering if we should start it since Gege seems to be doing fine right now. She doesn’t seem like a sick dog.

    What is your opinion?

    Best Regards,
    Suttinan…

  4. Glen Park on January 18, 2013 at 12:06 pm

    Hello Dr. Dressler/Ettinger,

    I have a 12 year old pekingese named Sumo that was originally diagnosed with small intestine adenocarcinoma near the jejunum. He had it resected back in July ’12 followed by carboplatin treatments (once every couple weeks) for a few months. Unfortunately it had already returned so we switched over to Palladia for several weeks (three times a week). Follow up ultrasound indicated that the adenocarcinoma had grown from 1.5cm to 3 cm since last check. The oncologist suggested stopping Palladia at that point since it looked like the cancer just wasn’t responding to it (this was about 3 weeks ago). I started him on Apocaps and K-9 Immunity about 2 weeks ago to hopefully help him. The oncologist was resolutely opposed to allowing Sumo have the supplements while on any of the chemotherapy despite my willingness to do so.

    Next logical course was to do another resection of the small intestine which was done today. The surgery went well and my little guy is recovering but the surgeon said that he noticed nodules on Sumo’s omentum which he obtained a sample to include with the rest of the tissue to be examined by the pathologist. While he mentions that everywhere else looks ok (nothing he can see on the liver, spleen, inner cavity walls, etc), I’m extremely concerned that the cancer has spread to his omentum.

    Since Sumo’s cancer has seemed to be unresponsive to two of the bigger chemo drugs available, do you know of any other options (chemo or otherwise) that could help in his case? I plan on resuming his Apocaps and K9-Immunity as soon as he’s healed from surgery and he’s already had most of his diet changed to a high-protein/veggie diet per your book’s recommendations (although he still gets occasional dog biscuits or canned food). Replaced his plastic bowls with ceramic and he exercises twice a day with 20-30 minute walks.

    I apologize for the long post, just needed to get his history out there and find out what else I need to be doing as despite all my efforts I’m getting increasingly concerned for my little guy.

    Thank You,
    Glen

    • Dr. Demian Dressler on January 29, 2013 at 7:05 pm

      Dear Glen,
      if chemo is out, I might consider low dose oral neoplasene along with mirtazapine under veterinary supervision. I hope this helps,
      Best
      Dr D

    • Dr. Susan Ettinger on February 3, 2013 at 11:57 am

      Glen,
      Sorry about all you’ve been through with Sumo. For GI ACA and chemo, I would consider doxorubicin. Talk to your oncologist about this option. I hope Sumo does well, and glad you have found the support of the Guide!
      All my best, Dr Sue

  5. dan on January 12, 2013 at 6:50 pm

    my cat is is 15 year old..and has been diagnosed with Multiple Myeloma.. Past treaments have not been sucessful in lowering her Globulin levels.. (Vincristine/Vinblastine) .. so instead of treating it like a lymphoma a NYC Vet oncologist is treating it with Palladia.. Have you had an experience with cat on Palladia . in terms of Multiple Myeloma or lymphoma? Overall Toxicity? What other treatments have you seen for Cats suffering from multiple Myeloma?

    Thanks in Advance

  6. Jonathan on January 12, 2013 at 8:09 am

    A follow up: She is now drinking water from a bowl and lets me give her veg soup stock with a turkey baster. She is still very weak, we can’t get her out because of the lameness, so we have her lying down. She is also very alert.

  7. Jonathan on January 11, 2013 at 7:42 am

    We have a female standard poodle with anal sac cancer who has been on Palladia for almost a year. She started out fine and had tumor shrinkage. Later on she developed diarrhea so we did several breaks and added Flagyl and Prilosec. This helped a little, but eventually it go worse. We recently did a two week break and she seemed much better, but had constipation. We put her back on Palladia last week and gave it to her Friday, Monday and Wednesday (Jan. 4, 7 and 9th 2013) On Wednesday she developed black stools with a little blood and very bad lameness. We took her off the Palladia since then but still has black diarrhea and bad lameness this Friday. She won’t eat and we have to almost force her to drink water, which she has been doing. Our vet is in the dark and won’t even discuss Palladia side effects as the cause. She just wants to do all kinds of testing and xrays. We just want to know if there is anything else we can be doing right now while we wait to see if stopping the drug will resolve things, as it had in the past.

  8. Erin H. on December 12, 2012 at 4:53 am

    Hello! I have a 14.5 year old beagle who was just diagnosed with 2 liposarcomas and peripheral nerve sheath tumor. All three of them just sort of popped up. She’s had the nerve sheath tumor and one of the liposarcomas removed…both with dirty margins. The surgeon wasn’t even willing to try and remove the third liposarcoma due to location (on the back of her paw) and her inability to remove the other LS. Apparently both were low grade but locally very invasive. I had a consult with an oncologist and we started on Palladia this past Monday. The plan is to start Cytotoxan in two weeks as well. I’ve been doing research and am having a hard time finding info on whether or not Palladia and Cytoxan are effective on either tumor type. We’ve had scans of her belly and lungs and both were clear. Bloodwork came back great as well. My old girl has a host of other issues. Addison’s disease, hypertension, hypothyroidism, has had dual TPLO’s on her rear legs, arthritis and canine cognitive disorder. Is a combo of Palladia and Cytoxan appropriate? I’m not looking to make my old girl live forever, I just can’t stand the thought of her being uncomfortable and hurting because of cancer. The lump on the back of her paw appears to be growing very quickly and it seems like the other liposarcoma is growing back as well (it’s only been about a week and a half since it was removed). Am I doing the right thing?

  9. Angel on September 6, 2012 at 8:44 am

    Dr. Dressler,
    I continue to read about “early prevention” being key. I come from a family of holistic vets. My dog has eaten nothing but home-cooked grass-fed and whole foods since he was weaned. He has always been treated with herbs, homeopathy and energetic arts.

    He had a tumor on his leg, was treated with mushroom complexes, artemisinin etc., etc., etc. Resection finally was necessary. 8 weeks later, amputation. My dog is living with grade 3 Mast Cell Cancer and I have to decide if using cytotoxic drugs, and immunosuppressants is my only option.

    For my emotional health, I cannot believe that his diet and upbringing led to this awful diagnosis. I have done almost everything possible to provide him with a truly healthy lifestyle. I understand your concept, but the guilt pet parents such as myself might feel, that they did something wrong has to be accounted for. Sometimes cells just go rougue…and that’s just that. Now, at 9 years old, my best friend may finally have to process and deal with those nasty chemicals to no fault of my own, or anyone’s. Just wanted to share the feelings of someone who thought they were always “doing it right”.

    With respect,
    Angel

    • Dr. Susan Ettinger on September 7, 2012 at 5:06 pm

      Hi Angel,
      I agree. It is not fair or easy to explain why some dogs (and people) get cancer. You clearly made good choices for your dog’s environment, and sometimes it is not enough. As you said, cells can still become cancerous, and in some cancers like Mast cell tumors, we are figuring out the genes involved.
      I personally think dogs tolerate chemo well, and am glad you are considering it for the grade 3 tumor. Chemo is not for every family, but you are educating yourself about the options and being open-minded. Your dog could not ask for more from a a Guardain. Good luck!
      Al my best, Dr Sue

  10. Sibyl K and 'Angel' on August 16, 2012 at 8:29 am

    Dr D: My 9 yr old spayed female Jack Russell mix has been diagnosed with stage HSA and underwent a spenectomy and mass removal 3 weeks ago. Surgery went well with no rupture. No spread was observed but 3 small liver nodules were noted, and one of those was biopsied, however the liver lobe or nodules were not removed. The spleen tumor and liver biopsy came back as stage 3 Hemangiosarcoma. My girl has recovered from surgery quickly, has high energy level, 35 hemocrat 2 days ago, and is doing excellent so far on just your cancer diet, augmented with a senior stress vitamin/antioxidants, liver support tablet, and pre-biotics/probiotic powder. I have also ordered Apopcaps and K-9 Immunity PLUS – which should be here today or tomorrorow. We have a well-respected oncologist (Dr Olgivie) who has discussed the various treatment options, and in addition he also recommended your K9 Immunity and Transfer Factor. I am very reluctant to put her on Palladia OR standard intervenous Doxirubicin chemo, so I am currently considering the oral Metronomic therapy option (without the addition of Palladia). I would like to combine that therapy with the diet, Apocaps and K9 Immunity-Plus. My main question is do you see any problem with adding the Apocaps in conjunction with the Metronomic drugs?? I am hesitant about Palladia because of the small margin of safety and other unknowns, plus in her case of stage 3 HSA I am concerned that any meaningful life extension or actual remission on Palladia would be slight if any, and would be outweighed by the risk of side-effects and the degradation of her current well-being/energy level, comfort and immune system. Dr Olgivie has not voiced an opinion regarding the benefit of Apocaps, but he speaks highly of you – and he did suggest the added benefits of IP6, Milk Thistle, K9 Immunity and Transfer Factor. Your thoughts about using the Apocaps with Metronomic therapy, as well as your own personal opinion regarding Palladia (concerns or praise) would be very much appreciated. Thank you. Sibyl
    PS: Does the K9 Immunity PLUS have the same strength, absorption rate and dosage of IP6 and other transfer factor ingredients as the original individual versions. Also, do I need to add any addtional Omega 3 or DHA source? Thanks!

    • Christine on October 9, 2012 at 4:37 pm

      Dear Drs. Ettinger & Dressler,
      My 6 yr. old Yellow Lab had his 2nd MCT surgically removed from behind his left ear (neck area) 2 weeks ago. This one came back as a grade 3. His first tumor was removed from his left ear flap early July – that was graded as “low 2”. What is the connection, if any, of these happening so close together in the same area? We have also consulted with a well known oncologist in NYC regarding treatment. Ultra sound of the abdomen was negative. Lymph node aspriate has not been done yet. The recommendation was Vinblastine, then Palladia – we decided against radiation therapy. Your thoughts on treatment for an otherwise healthy, smart Lab….

      • Dr. Susan Ettinger on October 23, 2012 at 3:52 pm

        Hi Christine,
        About 15to 20% of dogs develop more than 1 MCT – they can occur close together or over years. Also about 1/3 of dogs have the c-kit genetic mutation. I recommended chemotherapy for grade 3 MCT. I may start with vinblastine and Lomustine if the MCT is c-kit negative, and save Palladia. No right or wrong protocol, but some options to consider.
        Also I am just north of NYC if you would like a 2nd opinion in person. I don’t get to offer that to the majority of our readers. =) I am at Animal Specialty Center in Yonkers. Either way, good luck with therapy.
        All my best, Dr Sue

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