Zometa vs Pamidronate

[Faith in Him]

Hi,

I haven't posted in awhile since I feel a little guilty doing so after I crossed over to the triple negative side. I lurk because I like to see how you all are doing. So, I hope you don't mind if I post this.

Is Zometa better than Pamidronate? I know they are both used to heal and strengthen bones. However, there has been a lot of press about Zometa possibly slowing the progression of the disease. Is the same true for all bone strenghten drugs or just Zometa?

Thanks, Tonya

[Debbie L.]

Tonya, you are "of this group" in ways much stronger than HER2 status. Please continue to be a part of this community. (you made me laugh with your comment of "crossing over", it sounded like a Star Wars quote).

On that topic, I am hearing some oncs questioning whether they should treat based on biopsies of mets, vs. on pathology details of the primary cancer. Some are saying things like (somewhat paraphrased) "if there ever was a positive ERPR (or HER2), it's worth treating that target and watching for response, even if the mets biopsy now tests negative."

But back to your question. There are many studies trying to figure out the question you asked about bone strengtheners (bisphosphonates). The answer, thus, is that we don't really know yet for sure, but it seems that they should all behave the same although perhaps some are stronger than others.

Zometa is more-commonly used nowadays, for those with bone mets -- and those with bone mets are more likely to be ERPR+, thus it is more-studied in that population. I think that part of the reason for the switch to Zometa (from Aredia/pamidronate) was that it could be administered over a shorter time period? Please correct me if I'm wrong, those of you in the know.

The few studies that have looked at prevention of recurrence have been with Zometa, I believe. But that doesn't mean that other drugs in the same class would not have the same effect (or not). The studies have been done in those with ERPR+ disease but again, that does not mean there may not be the same effect in ERPR- disease. It's just not known. Not much help, I know, to tell you there are no answers.

Is your onc promoting one over the other, for you?

Debbie Laxague

[Rich66]

Amazing how a slight change in google terms brings up totally new issues to consider. I was not aware of the level of danger from hypercalcemia..especially in those without bone mets. This may not specifically apply to your situation..but it suggests there are some differences in how they work:

Oncologist. 2002;7(6):481-91.
The use of zoledronic acid, a novel, highly potent bisphosphonate, for the treatment of hypercalcemia of malignancy.

Major P.
Department of Medicine, McMaster University, 699 Concession Street, Hamilton, Ontario, Canada L8V 5C2. Pierre.major@hrcc.on.ca


FREE TEXT

Abstract

BACKGROUND: Hypercalcemia of malignancy is a serious complication of cancer that affects patients with and without bone metastases. A single infusion of pamidronate disodium, a nitrogen-containing bisphosphonate, effectively normalizes serum calcium in the majority of patients treated for up to 1 month. Zoledronic acid is a new-generation, heterocyclic nitrogen-containing bisphosphonate and the most potent inhibitor of bone resorption identified to date.
METHODS: The natural history, clinical presentation, and treatment of hypercalcemia of malignancy are reviewed, with a focus on the mechanisms of action and relative efficacy and safety of bisphosphonate therapies.
RESULTS: The improved efficacy of zoledronic acid compared with pamidronate disodium has been demonstrated in a pooled analysis of two randomized clinical trials in patients with hypercalcemia of malignancy. In these trials, both zoledronic acid and pamidronate disodium were safe and well tolerated; however, zoledronic acid treatment resulted in a significantly higher number of complete responses, more rapid calcium normalization, and more durable responses compared with pamidronate disodium.
CONCLUSIONS: Given the superior efficacy and comparable safety profile of zoledronic acid compared with pamidronate disodium, zoledronic acid is likely to become the treatment of choice for hypercalcemia of malignancy.

PMID: 12490736 [PubMed - indexed for MEDLINE]Free Article





More on Zoledronic acid/Zometa HERE




From an earlier comparison of Zometa vs Pam, a bit on hypercalcemia:


FREE TEXT

INTRODUCTION


HYPERCALCEMIA OF malignancy (HCM) is the most common life-threatening metabolic complication of malignancy, affecting approximately 10% to 20% of patients with advanced cancer.1 The incidence of HCM varies widely by cancer type but occurs most frequently in patients with multiple myeloma and carcinomas of the lung, breast, kidney, and head and neck.2-4 A retrospective study of cancer-associated hypercalcemia reported that median survival was 30 days in patients treated with antihypercalcemic therapy.5 Clinical symptoms of HCM such as nausea, vomiting, and altered mental status are distressing and diminish quality of life in the later stages of cancer progression. HCM can also lead to renal failure.
Patients with or without bone metastases can develop HCM. Hypercalcemia is mediated by soluble factors secreted by tumor cells and the immune system, such as parathyroid hormone–related protein (PTHrP), prostaglandins, and cytokines. These factors stimulate excess bone resorption and release of calcium from the bone matrix. As a result, patients experience bone loss, weakened bone structure, and elevated circulating calcium levels.1,6-8 PTHrP also stimulates increased renal reabsorption of calcium, resulting in further increases in serum calcium levels.