Janssen Phase 1 Trial

[Eugmn]

A Phase 1 Study of JNJ-87189401 (PSMA-CD28 Bispecific

Antibody) Combined with JNJ-78278343 (KLK2-CD3 Bispecific

Antibody) for Advanced Prostate Cancer

PROTOCOLb

Hello, I am hoping to get opinions or possibly find other information on this trial. My doctors have been applying these treatments and working in the trial for the past 10 months or so. They have only offered good verbal information and results, I have not been able to find any other published data. If Tall Allen or any others have input regarding this I would appreciate it.

[GP24]

This is a link to the trial: clinicaltrials.gov/study/NC... The side effects the patients are experiencing will be published when the trial is done.

[Eugmn in reply to GP24]

Thank you for your reply. Yes I have already looked at this link and I know that official results will not be published until future completion. Just thought I would take a stab out there to see if anybody in this trial or has any additional information that’s not published

[Tall_Allen]

It's interesting because it hunts down cells with both PSMA on the cell surface (some cancer cells don't have PSMA) and PSA on the cancer cell surface. So it gives the medicine two different ways of attracting T-cells to the cell surface.

As with all BiTEs, the biggest danger is runaway immune reactions.

[podsart in reply to Tall_Allen]

So we are talking about cytokine release syndrome I assume. Dr morris video described for AMG509 doing 3 priming doses to help mitigate this problem. Don’t know how effective this is. What’s not clear how effective are the interventions if this cytokine issue arises.

[Tall_Allen in reply to podsart]

They give a lot of steroids to stop it, but people have died. Phase I trials can be particularly dangerous.

[Eugmn]

thank you for your reply. I hope you’re doing well.

I like your explanation more so than what I have heard so I do appreciate it. I’m supposed to start on Jan 14th and they will be watching me very closely with a 5 day hospital stay.

I will be posting anything informative once I get involved. Thanks again.

[KocoPr in reply to Eugmn]

You could always ask them what are the risks and see if they mention runaway immune reaction and what is their plan is if it happens to you.

[God_Loves_Me]

Hello

I did participated in ARX517 in phase 1 trials. Mostly important thing to remember that Phase 1 trial is design for High dosage + understand side effects. So whatever side effect they are telling you may be never happen and you will come up with new side effects.

My suggestion is

- Work closely with Cardiologist

- Work Closely with Kidney doctors for all the reports.

Many times Phase 1 clinic run by Nurse and they do not monitors everything.

[TeleGuy]

I’m on this trial and will post about it soon.

[Eugmn in reply to TeleGuy]

Perfect, I was hoping to find somebody that was participated in this trial that we could compare notes. Thanks for the reply.

[TeleGuy]

Sorry for the delay, I dropped out of the trial due to disease progression and have been dealing with pain that keeps me from my computer. I know that the treatment has done something, as I have pretty significant salivary gland impairment beyond the damage I've done through seven PSMA radioligand treatments.

The idea with the trial is that two BiTEs are better than one They give you a couple of ramp-up doses of the KLK2xCD3 antibody, and on the third week you get a full dose of that combined with the PSMAxCD28 antibody. The idea is that these two flags should stimulate more of a response from the immune system.

I felt increased fatigue with each infusion, but was mostly just bored during the four-day hospitalization for the first combined dose. A couple of days after I was discharged, I started to feel REALLY tired, like I had the flu, and when I started having fevers they admitted me for grade 1 cytokine release syndrome. They kept me overnight to observe my vital signs and they explained that the risk is that if you develop full-on CRS your blood pressure can drop, you can get hypoxic, and you need fast response. I began to feel pretty reasonable the next morning and they released me. They said that if you do develop real CRS, they give you a monoclonal antibody that works against one of your inflammation responses. They seem to avoid steroids on this trial. They seem to be really diligent in watching for these responses.

This treatment has the potential to help people, I'm sorry that it didn't help me!

[Eugmn]

I appreciate your comments and feedback. I start on the 14th, Thank you.

[TeleGuy]

All the best to you. What didn’t work for me may work for you, it’s all part of the exploration!

[Eugmn]

just a bit of information as I have started the trial. I am scheduled to check into the hospital on January 26. I will be having the double infusion on the morning of the 27th and then I will be staying in the hospital for three days for observation

Jan 8 2025, PSA 160

Jan 14 2025, PSA 141, Received 1st infusion JNJ-78278343 (KLK2-CD3 3.5 mg today, I felt great after. No side effects. for a couple days. Had more bone pain Jan 18, 19. Slight bit of nausea

Jan 21 2025, PSA 164, Received 2nd infusion of JNJ-78278343 (KLK2-CD3 18 mg today. I felt great all day. No side effects yet.