Anyone on full dose (5)Tykerb w/Herceptin?

[SoCalGal]

I was on Tykerb 5 pills a day for about 6 months but since stopping all chemo for a month and then starting Herceptin I can only seem to get up to 3 pills of Tykerb a day. If I go any higher I have such severe runs that I have to stop and that's no good.

Since there is not any data on the combo yet (comma) I wonder if anyone here is able to take the full dose or what dose you are taking?

Thanks for feedback.
Flori

[hutchibk]

Hey Flori - I just found this paragraph on this link... does this help at all?

http://www.clinicalbreastcancer.com/publication/gsk_slide_06/article2.php

...(Slide 6) Preclinical studies have suggested synergistic activity for lapatinib and trastuzumab in ErbB2-positive (ErbB2+) breast cancer cell lines.3 Based on these data, a phase I study, EGF10023, was initiated in heavily pretreated patients with ErbB2-overexpressing advanced or metastatic breast cancer.10 Patients received lapatinib 750-1500 mg/day plus trastuzumab 2 mg/kg/week (4-mg/kg loading dose). The optimal regimen was determined to be lapatinib 1000 mg/day administered with standard weekly trastuzumab. Lapatinib/trastuzumab was found to be tolerable, with the most frequent grade 3 adverse events being rash, diarrhea, fatigue, nausea, anorexia, and vomiting. Interestingly, cutaneous toxicity is typically not associated with ErbB2-directed therapies and might reflect ErbB1 inhibition. Coadministration of lapatinib and trastuzumab did not affect the pharmacokinetics of either drug.

[SoCalGal]

Thanks Brenda. You are the best. Yes - will send to my onc.

[Roz]

Hi Brenda,
I'm not sure what is meant by the cutaneous toxicity being a reflection of Erb1 inhibition as opposed to Erb2. I have still got a rash (quite pronounced) after reaching what I regard as my maximum dosage of Tykerb (4 and a half tabs [1125mg]) 7 weeks ago. What does it all mean???
Cheers, Roz

[hutchibk]

I don't really know, but one guess would be that you might have a high over-expression of HER1 (erbB1) - and your rash is a reaction to the Tykerb inhibiting the HER1... but we would be better off asking one of our resident scientific minds to sort us out on that question!

[Carolyns]

Hi Flori,

I was on 4 Tykerb and Herceptin for 7 months. I have just returned to Gemzar and Herceptin after slight progression in the bones.

I hope this helps.

Carolyn