1. Androgen Deprivation Therapy - Prostap 3 DCS
I restarted Prostap 3 DCS injections in February 2018 and as usual I updated myself with the manufacturers information on the use and side effects of Prostap 3. This note is based on my understanding of the information in leaflets provided about Prostap 3 and after speaking with Takeda UK Ltd, who produce Prostap 3 DCS, to clarify some of the points in the leaflet to use in this note.
The note covers two important issues relevant to Prostap 3 injections. First, Oncology Teams and presumably GPs’ surgeries should know about the clinical information for Prostap 3 injections but I think it is also worthwhile for men having Prostap 3 to understand the product information. Second, I think it is important that all men having ADT, including Prostap, should be aware of the side effects of ADT and the preventative strategies to deal with those side effects, as shown in Section 6.
2. Information leaflets
There are two information leaflets for Prostap 3 DCS one is for the Users and the other is for Health Professionals The leaflet for the user is at Link 1 below:
“PACKAGE LEAFLET: INFORMATION FOR THE USER”
Link 1: https://www.medicines.org.uk/emc/product/4651/pil
You can see the “HEALTH PROFESSIONALS’ USER LEAFLET” either by clicking on “SMpc” in green on the front page of the User leaflet at Link 1 above, or see it at the Link 2
below:
Link 2: https://www.medicines.org.uk/emc/product/4651/smpc
The information leaflet for health professionals obviously contains much more information than the leaflet for the users. “Section 4.8 Undesirable effects” lists adverse reactions and the information for “Men” is at the beginning of that section.
If you are on Prostap 3 and you have not seen the leaflet for health professionals when you have your next injection ask your doctor or nurse to let you have the two information leaflets which are in the Prostap 3 pack – one for the patient and one for the professional.
In the leaflet for the User at Link 1 you will see from “Section 2, What you need to know before you use Prostap 3”, first bullet point, that an abscess occurring on the site of the injection on the abdomen is a rare event. I have mentioned abscesses because someone reported recently that two Prostap 3 injections in the abdomen resulted in an abscess the size of hen’s egg on each occasion but there was no reaction following an injection in the arm. An abscess on the injection site could reduce the amount of leuprorelin being absorbed into the body. Such a reduction of leuprorelin could result in a man’s PSA level not being reduced as much as may be expected and the PSA level could go up. On the other hand it could be OK.
You will see from Section 3, ”How to take Prostap” that “The injection will normally be given in your arm, thigh or abdomen.” If Prostap 3 is injected into a muscle the increased blood flow in the muscle will disperse the leuprorelin into the blood stream quickly.
3. Contact with Takeda UK Limited
I spoke to the Medical Information Team at Takeda UK Ltd about the occurrence of two large abscesses occurring at the site of the injection from separate injections. They had not heard of anyone having two abscesses each the size of an egg from two Prostap 3 injections and said this could usefully be reported higher within Takeda. Obviously, I did not comment further and things were left at that
4. Yellow Card Scheme
When talking to Takeda the Yellow Card Scheme was mentioned. This scheme helps health professionals and patients to report suspected adverse reactions which occur since the authorization of a medicine - in this case Prostap 3 for use with prostate cancer. This allows the benefits and risks to be monitored. The scheme is mentioned in the Prostap 3 DCS information for health professionals as shown on page 6 in Link 2.
The section “Reporting of adverse reactions” asks professionals to report suspected adverse reactions via the Yellow Card Scheme. Information about this scheme is in the Link 3 below.
Link 3: www.mhra.gov.uk/yellowcard
5. Continuity of Prostap 3 injections
In 2010 I asked Takeda about the “clinical life” of Prostap 3 and I was told that Prostap 3 was prepared for use every 3 calendar months (ie average 92 days) and the 3 month injection actually had a clinical life of 105 days. The marketing authorization was not mentioned. This provided some flexibility if for some reason a man could not make it on his specified injection day. I posted this information on The Prostate Cancer Charity’s Message Board, pre PCUK, and I suppose it is still there somewhere but that information about the clinical life of the injection or the life of the continuous plasma levels is now out of date.
In the current Prostap 3 leaflet for the patient “Section 3, How to take Prostap 3 CDS” shows that Prostap injections should be given “ … as precisely as possible in regular 3-monthly periods. An exceptional delay of the injection date for a few days (90 ± 2 days) does not influence the result of the therapy.” I understand that this is linked to the marketing authorization (or product licence) for Prostap 3 DCS.
If a man misses the 90 ± 2 day target for his Prostap 3 injection it will be outside the marketing authorization period. It is then up to the clinician/doctor/nurse who will give the injection to decide on its use. It seems to me that Prostap 3 injections will continue regardless of any relatively short delay exceeding 90 ± 2 days between injections.
If you look at the information for health professionals in Section 5.2 “Pharmacokinetic properties”, you will see that, amongst other things, “PROSTAP 3 provides continuous plasma levels for up to 117 days resulting in suppression of testosterone to below castrate level within 4 weeks of the first injection in the majority of patients.”
I was told by Takeda that the continuous plasma levels for up to 117 days for the majority of patients applies to all ongoing Prostap 3 injections not only the first injection although this is not clear in the text above. This is clinical information for the doctor or nurse who gives the injection. This will again be outside of the marketing authorization.
It looks as if Prostap 3 injections will continue in most situations whether or not they are outside of the marketing authorization. No doubt an injection will be given within the 117 days period of continuous plasma levels, but this question is for an individual’s Oncologist/doctor to decide. I don’t know what happens when an injection is delayed beyond 117 days other than the injection will, no doubt, be given and treatment will be “restarted”.
6. Side effects from having Prostap 3 and other ADT treatments.
The leaflet for Health Professionals contains a list of side effects from Prostap 3. There are other publications on the same subject and one of the best and most comprehensive information guides I have seen over many years is a guide by Brad Guess PA-C, Former Executive Director of the US Prostate Cancer Research Institute. The guide was set up in 2006 and was published in PCRI Insights November, 2007 vol.no.4.
The guide has been published over the years on the US Prostate Cancer Research Institute’s website. I think this shows it is still regarded as a sound clinical guide to the side effects of Androgen Deprivation Therapy. In addition to highlighting the side effects there is a section “Prevention / Treatment Strategies” for each side effect. The guide is currently on the home page of PCRI’s website at the link below.
http://pcri.org/preventing-and-treating-the-side-effects-of-testosterone-deprivation-therapy-in-men-with-prostate-cancer-a-guide-for-patients-and-physicians
I must say that this is an informal view of certain aspects of the Prostap 3 DCS injections. Although this note contains information from Takeda you need to speak to your oncology team for further clinical information and guidance.
You can also find information about side effects from ADT on the websites of PCUK and Macmillan Cancer Support.
7. Prostap SR DCS
Information about Prostap SR CDS which is the 3.75 mg monthly injection is in Link 3. Clink on “smPC” or “Patient” to see the professional and the patients leaflets.
Link 3: https://www.medicines.org.uk/emc/product/4650/smpc
I hope this is helpful.
Alan
Edited by moderator 06 Jul 2023 at 13:20
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