Glad she got her second loading dose! I’ve heard similar things from my vets and friends who work for the company that manufactures Oncept, BI. They’ve said you should notice results within the first month, give or take a week or two. Keep sharing your progress!
On my end, I finally have found a vet willing to work with me on getting the vaccine, woohoo!
That is such great news! It may sound expensive but really it is not if you compare to surgery ! which can run into thousands!!! Please also keep updating your progress 
oh WOW! you know people that work for the company that manufacture the vaccine ! please feel free to share any info you can!
My vet also said this type of tumour my mare has is often a death sentence as it is aggressive and can not be operated on due to the location. When it begins to grow too big and interfer with functions the horse is put to sleep. Having something like Oncept to halt further growth means my horse gets to live. This is the reality.
Agreed, to agree to regular surgeries to remove melanoma over the course of a lifetime, the vaccine is a far superior option. People pay thousands of dollars to inject joints, why not to try to fix cancer? Luckily my horse’s masses are not in his throat like your horse’s, his are under his tail and in his sheath. Those cause their own types of problems, however, I feel lucky they’re not in an even worse location. So excited to see how this turns out for your girl! I’ll keep posting on this thread and on my blog, I hope we can be good resources for others going through similar battles with melanoma.
In terms of my friend working for BI, there’s not too much else to share that we haven’t already learned! She’s the one who reached out to me about the vaccine in the first place when I posted my first blog about his first melanoma mass removal. She called me up and told me I need to get my hands on this. Four months later, here I am hopefully starting his loading doses soon. She’s sent me a few studies and good contacts to help me source the vaccine which has been amazing. The equine world is full of good people, you just have to learn how to network!
I want to say how grateful I am for what it is I have learned in these posts & links dating back to 2014. My 14 year old gray mare, Ruby, was diagnosed yesterday with melanoma under her tail & OnCept treatments have been recommended. I am just beginning my education on this subject and am truly thankful for the experiences and information shared here. Please continue.
One of my great concerns is long-term side effects of OnCept treatments? Yesterday our vet referred to OnCept as a chemotherapeutic agent and most of my reading so far references it as a vaccine. Now that cumulative information appears to be evolving on horses since at least 2013, I wonder what side effects of OnCept treatments others have come to learn about. We live at 6,200 feet and trail ride upwards of 9,500 feet. So for example, when I think of chemo therapeutic agents, I am concerned about impact on lung function. Then if she takes this medication over 15 years are we going to run into complications with impact on liver, kidney, thyroid, heart, issues with diabetes, and so on? Like I said, I am just beginning my education on this subject.
My heartfelt thanks for the information and experience you are about to share. Thank you. And Happy Spring, Happy Trails to all.
So pleased to hear the posts of mine and others are helpful. I have bought a number of research papers so feel happier what my horse is receiving. This is some information; The Oncept vaccine does not contain chemicals (chemo). It is a protein bound to human DNA which is delivered into the horse by an injector. It initiates an immune response in the horse to target the melanomas. It is considered a therapeutic vaccine as it is working with the immune system. There are reported no side effects in any of the studies, other than slight elevated temperature (in some horses) but returning to normal soon after, some horses may have slight swelling at injector site, this too only temporarily. No other side effects with long term use. Oncept is stimulating an immune response in the horse, therefore the horse can still be ridden and life carries on as normal! My horse Holly above is in full work! she has no idea what is happening! she is bright and happy and still producing great work. Although i am careful not too over exert her and ensure she is rugged at night, well fed and has rest days, as i want to ensure her immune system is kept strong throughout.
The way Oncept works is fascinating. If you’ve got a scientific bent at all, or even just want to understand its effect in detail, I highly recommend that you purchase this article:
http://www.vetequine.theclinics.com/…13)00058-8/pdf
Yes, it’s $31.50, but it discusses ALL therapeutic approaches for equine melanoma in detail. Well worth it, especially if you are contemplating using Oncept.
The researchers very cleverly found that one chemical needed by the horse’s body to produce melanomas was not part of any other function in the horse. Oncept causes the horse’s immune system to attack that one substance, and poof! No more melanomas, or at least no more growth.
My horse has been on Oncept since 2014 and he is in fine shape. Probably even better shape than he was in 2014 as we have no way of knowing what was growing inside him. He maintains his weight better and certainly has no shortage of energy. I am careful not to give him any supplements that would interfere with his immune system. I time his yearly immunizations and his spring Oncept injection about a month apart so that his system can recover from the immunizations before he gets his Oncept. There is no written protocol about this - I’m just trying to apply some common sense to his management.
He’s just an ordinary horse - no big time show winner but I do like him a lot and could not imagine him losing his eye or otherwise suffering when a good solution appeared to be available. Kind of scary to be patient #1, but I am so, so, so SO glad that I went ahead with it.
Good luck to all of you - Mr Ay-rab sends his best!
Some insight from my research so far:
An interesting fact: grey horses are not supposed to be grey ! infact grey is a genetic mutation. Grey is defined as having black skin and brown eyes and often born black/bay/chestnut but on aging develop white hairs becoming grey (never called white/even though the coat can look/become white). A true white horse has pink skin. The process of becoming grey is called “greying out”. This is in fact a genetic mutation and it is this process which triggers melanoma in grey horses. It is thought 80% of grey horses will develop melanoma in their lifetime. This mutation can be traced back thousands of years thought to originate from an arabian ancestor and as arab blood has influenced many breeds the grey gene is now wide spread. Research shows the arab breed also has a higher incidence of melanoma when compared to grey horses of other breeds.
The Oncept vaccine contains “Tyrosinase”. This is an enzyme protein and the first step required for melanin synthesis and thus important for the formation of melanin (and melanoma cells). Tryosinase is required in high levels for melanoma cells. Oncept contains human DNA/Tryosinase, this being similar but different to horse DNA.
Upon inserting this human DNA/Tryosinase into the horse (Oncept) the immune system is alerted to something foreign, therefore switching on an immune response.
This immune response is further primed with a series of vaccine shots (Oncept at two week intervals), creating a stronger immune response against the foreign protein. The immune response therefore is trained to target and block where it sees this in the body, as melanoma requires a high level of tryosinase, the immune response blocks the process required for melanoma, causing melanoma growth to halt. Studies show 100% of horses showed an immune response to Oncept, therefore all horses have the same probability of a potential positive outcome.
The results so far with Oncept show halting of the tumour, regressing, in some cases dramatic and others tumours have disappeared ! but for the most part it appears a halting of the tumour is most likely.
I am unsure why the results vary with Oncept, but would assume there are many factors why this is.
As it is an immune response i guess a healthy functioning immune system is also paramount.
New observation the lymph nodes on either side of throat lash ( by throat area) are raised. Looking fairly prominant when compared to my other three horses. I’ve not noticed this before on her. When comparing to my other horses; theirs are barely seen whereas Holly’s look like lumps. Upon a bit more investigation suggests the immune system is active. Hoping this means that the body is responding to the vaccine! It’s early days but I am monitoring very closely. I will also discuss this observation with the vet next week and let you know.
Had a good look at Holly’s parotid tumour last night. I am finding as she is getting fluffy with change of season it is hard to see size of the tumour clearly, so found wetting the area helpful. It doesn’t appear any bigger the last four weeks. I notice the first measurement I took was exactly 4 weeks ago. I will measure tonight with the calipers and post measurements. Holly’s lymph nodes were also not as apparent, infact also hard to see, so not sure why they looked up the other day. It maybe also possible as we are transitioning into cooler weather (autumn). Holly’s third vaccination is next week.
At what point should you notice a difference if it is going to work? I read somewhere where 60% of horses don’t change but don’t develop new tumors, 20% the tumors get smaller and 20% it doesn’t help.
The immune response is generally seen from the third week onwards. So I guess anytime after this you would want to monitor the tumor size very closely. Research statistics show mostly halting of tumor growth. However, in some cases there has been dramatic shrinkage of the tumor and in some cases disappearing completely. I am not sure about the 20% of cases that it doesn’t appear to work, it would be interesting to know the profile of these horses ie: age, type of tumor, size, health etc. A friend recently said to me “a car can’t go in reverse without halting first” so i guess a tumor cannot regress without halting first ! There is also another immune type vaccination available called "Immune FX "although it appears even more difficult to source than Oncept. Apparantely even better results are seen with this although our vet clinic can not yet get this. I am going down the Oncept path and doing all possible to save my horse. If we can keep it halted then maybe in the near future there may be another option for us that will get rid of it completely or make it shrink further. I am certainly hoping Oncept is going to help and would recommend to others even if it is just halting a tumor growth. I will certainly keep you posted how we are going !
Some very good news to share!
I have just measured Holly’s partoid tumor and it has shrunk by 1cm in length! I am very excited as it is still very early days but I think this is a rather significant result in just 3 weeks!
The width and length measurements I am doing by calipers so it is very accurate. I am measuring very carefully (my technical side) a number of times to ensure i am doing exactly to the margin of the tumor. The measurements 25 th Feb 91.5 mm length x 64.0 mm width and today’s measurement March reads 81.00 mm length x 64.0 mm width.
The difference is a reduction by 10 mm or 1 cm in length. The width is exactly the same. I am so excited to share this. I have not done a depth measurement but will look at doing so. In the meantime a reduction by 10 mm has made me very happy. This is a 10.5% reduction in length!!!
Oh yay! yay! Yippee!!!
This is great news and we’re crossing hooves and fingers that it continues!
(I described the experience of using Oncept to someone once as being similar to what the first users of antibiotics must have felt - incredible amazement that the darn stuff actually works! And a huge sigh of relief!)
Mr Ay-rab has his next injection in 2 weeks. Will add results to this discussion and my thread.
All the best Holly!
The results definitely seem to vary by horse. I noticed a change after less than a week, and a significant one as several of my horse’s internal masses just disappeared. They have never shown up again. His ocular melanoma decreased by more than 80% after the first 6 injections. OSU has had some horses that showed no effect. Clearly there’s lots more to learn about which horses will benefit, but for my little corner of the world - I couldn’t be happier!
Thank you for your support I am actually really surprised with the result! 1 cm is actually a lot! I noticed at week 2 it appeared smaller but hadn’t measured at that stage. So it must have begun reducing after the first week. I am very hopeful as following your thread your horse had the same initial response and continued to shrink so am very excited! Yes please let me know how your next vaccination goes and also the discussion with your vet. The more information shared the better!
Coming up to our third vaccination in just a few days! All looks good for now, stabilized and a slight reduction in length. Looks promising. It will be very interesting to monitor next spring also as apparantly hormone fluctuations can cause rapid growth. I will be interested to see if Oncept prevents this. But for now it’s one week at a time.
Had a good look tonight at Holly’s parotid tumor. It looks like it has shrunk further in length going by my sharp eye! Yet to be confirmed with calipers. Is this even possible? I only measured 5 days ago! the width looks the same, but the length again slightly shorter. I think the curiosity is going to kill me! I will measure again tomorrow and post.
Yes, possible! How do the masses on her neck look? I know you are most concerned with the parotid mass, but are the others changing too? My horse had a large mass on his rib cage that looked a lot like the ones on Holly’s neck. It was one of the first to completely disappear, never to return.
very exciting, in any case!
Best of luck. I know the helpless feeling as I have had a string of grey horses. Are there a lot of different melanoma
cancers making the results hit and miss?
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