Enhertu side effect: pneumonitis (lung inflammation)

[LDR1]

Hi all,

After 3 years on oral meds I had to switch to IV chemo in December and started with Enhertu. After my 2nd infusion I developed pneumonitis (lung inflammation), which is a known risk with Enhertu and can be dangerous if left untreated. The main intial symptom is a persistent dry cough, indicating irritation from the lung inflammation. Unfortunately this means I have to abandon Enhertu and wait to start any new chemo until the lungs are stabilized through a course of high-dose steroids (60 mg Prednisone/day) that will gradually taper off over several weeks. This is all rather disappointing as I had high hopes for Enhertu, and frustrating as I am eager to get back on treatment asap (latest scan showed liver lesions were encroaching on some vital areas, so we need to shrink those!).

I'm wondering if anyone else on here developed pneumonitis from Enhertu, how long you had to pause treatment, and what your next steps were?

Thanks and best wishes ...

[HelenWi]

I’m sorry that Enhertu caused you to get pneumonitis but it’s good that you caught it early. I understand your disappointment because I got pneumonitis from Ibrance, which felt like a real bummer because so many people get multiple years on it. I had the same dose of Prednisone as you and it cleared up sufficiently in a few weeks. I’ve been on Piqray for a year now. Enhertu is also a possibility for me and I’ve actually been concerned about pneumonitis.

I'm wondering.. . do you know if a lower dose is an option?

Sorry not to be more helpful and wishing you a speedy recovery from the pneumonitis and good results on your next drug.

[LDR1 in reply to HelenWi]

Hi HelenWi , sorry to hear you experienced pneumonitis on Ibrance. In the Enhertu trial, 12% of patients developed it which is fairly substantial so it's a known risk that I hope your oncologist will evaluate and be extra-vigilant for if you do try it. Also in the trial, 40% of patients had a dose reduction for one reason or another so those are possible. The treatment guidelines for Enhertu patients who have _asymptomatic_ pneumonitis allow for a re-starting of Enhertu at a reduced dose (see link below). However if you're symptomatic you have to abandon Enhertu. Looking at the Facebook group for Enhertu patients it seems not all oncologists are clear on / following those guidelines, as there were a number of people who were symptomatic but their doctors plowed ahead with treatment. Scary!

enhertuhcp.com/en/managing-...

[HelenWi in reply to LDR1]

Thanks for the link! I’m actually getting a second opinion at UCSF regarding my treatment plan next week . I like my current onco but I’m starting to think that I would prefer working with a breast oncologist, who is on top of new drugs and their side effects.

[TammyCross in reply to LDR1]

I think the cdk4/6 inhibitors all carry the risk of pneumonitis, but perhaps not as much as enhertu? I just started Kisqali, and coincidentally, got a cold, or so I thought. Had a sore throat one day, and since then a persistent cough that is driving me crazy. I still think it is a cold that settled in my chest, but I wonder if that is obviously different from pneumonitis.

[PJBinMI]

I'm sorry that your developed pneumonitis.....so disappointing when a promising new drug doesn't work! I developed ILD from Ibrance after just a few doses in 2016 and the lung damage is permanent but well controlled. I hope you do well with whatever is next!

[LDR1 in reply to PJBinMI]

Hi PJBinMI I'm sorry to hear this. I'm curious about the lasting lung damage you experienced, is it visible in scans and do you feel any impacts from it? Are you doing any long-term treatment for it - just wondering what you mean by well-controlled. Thank you!

[PJBinMI in reply to LDR1]

The interstitial lung disease is only in my right lower lungand I really don't feel any differently than before it happpened. It shows up on scans. My pulmonologist says it looks like goo between the air sacs. He sees me just once a year now. And prescribes two inhalers, albuterol and Trilegy.

[13plus]

I'm so sorry this happened to you and can imagine your total frustration, with both the Enhurtu not working out for you because of this, and also having to delay another treatment significantly. I hope your lungs heal well, and with speed!

I've also had a dry, occasional but not-going-away cough since between Thanksgiving and Christmas which has been bothering me why it won't go away. I had been on Afinitor at that time, which actually has an even higher incidence of pneumonitis (after just looking it up), and now I'm a little concerned too! Plus I keep having night sweats for much of this month (although an oncologist told me yesterday that. there is such a thing as tumor sweats/fever?).

Anyway, I had a thorax to pelvis CT end of December, so that would have shown if there were any pneumonitis-related issues in my lungs, wouldn't it? I certainly have many new little lung lesions Because of the progression in my liver and other places I've been off Afinitor now since the first week of January. I just started with Xeloda last night.

[DianaTrapani in reply to 13plus]

Ask for a referral to a pulmonologist, as they are the specialists who can verify the diagnosis, when it is gone and other possible treatments besides steroids. My understanding it that it can take a few months to fully clear up. I’ve had it on and off, from Kisqali and Ibrance, have taken antibiotics and prednisone only to have the cough return within five days of resuming the drug. Now I’m off the drugs since late Dec. and on second round of prednisone. Once I’m off it for three weeks and the cough doesn’t return, then I’m going to try Versenio (hoping I do better o it). Also, Getting referred to pulmonologist to learn what he says or what tests he may recommend. If V does give me the pneumonitis then I skip Afinitor and go right to oral chemo - which I’d rather not do as that will run me through the first four options in eight months. Bummer!

[13plus in reply to DianaTrapani]

Thanks, I think I might be ok actually as my cough has been gradually diminishing just very recently. You've certainly been having a bit of a yo-yo reaction with your treatments though! It seems like there is always something new for us to contend with on this journey, doesn't it? I really hope for you that that all settles down properly soon, and that you have good luck with Verzenio! Sending you best wishes,

[Andersl]

Hi

I haven't had pneumonitis but I do suffer from green phlegm daily.

Did the clinicians consider lowering/halving the dose?

I had horrendous nausea in the first 2 cycles of Enhertu. My oncologist halved the dose. I'm now on my 11th cycle and managing much better.

Lx

[LDR1 in reply to Andersl]

Hi Andersl , the treatment guidelines from Enhertu's own manufacturer are very explicit that if you become symptomatic for pneumonitis, you have to discontinue Enhertu permanently. Doing a dose reduction and continuing Enhertu treatment would put the patient at risk of permanent or even fatal lung damage :-0

[Chamisa]

Starting my second week of hospitalization (with continuous high IV doses of steroids) due to Enhertu pneumonitis. 🤞 things get better. Onc suggested maybe I could go back low-dose Enhertu (I had four infusions and it was working VERY well) …but, NO. THIS IS NO JOKE. ☹️

(That onc kept messing around giving me 60mg prednisone then tapering off, messing around with this for 2-3 weeks. Not enough to stop my serious lung inflammation. 🙁)

BTW, I was relatively *healthy* before this pneumonitis.

[LDR1 in reply to Chamisa]

I’m so sorry to hear this! Being hospitalized for pneumonitis sounds serious & I hope you’ll get better soon. It’s a bit concerning to hear about your oncologist’s too-fast tapering and thoughts of restarting Enhertu. My doctors at Dana Farber in Boston tapered me off the steroids very gradually over 5 weeks, explaining that if they went too fast the pneumonitis could reappear … and they were very clear that I could never go back to Enhertu at any dose due to the risk of lung damage. I wonder if you could get a 2nd opinion from another oncologist or a lung specialist? Wishing you healing…🙏🏼

[Chamisa in reply to LDR1]

I am also a patient at MD Anderson and will ultimately do what they say. I was just in no shape to travel there, so I’m at UTSW in Dallas. 🤞🤞🤞