Treatment and Management of Multiple Myeloma

Osteonecrosis

Dr. Ascensão. Do you require dental clearance prior to first dose?

Dr. Cosgriff. Bisphosphonates have a warning for 2% incidence of osteonecrosis of the jaw. Risk factors for the development of osteonecrosis of the jaw include poor dentition or major dental work, like extractions and illfitting dentures but not necessarily root canals. Ill-fitting dentures tend to rub on the gums and irritate the bone layer underneath. It’s the irritation of the bone that’s the biggest risk factor for osteonecrosis of the jaw.

We require that patients see the dentist because we’ve had individuals develop osteonecrosis eventhough we thought they had good dentition. If a patient is seeing a dentist outside of the VA system, we ask them to notify their dentist that they’re receiving bisphosphonates. Because of the risk and because we’ve had some individuals with good dentition develop it, VAPORHCS requires all patients, particularly those who are receiving zoledronic acid, to have dental evaluations. Denosumab also has a listed 2% incidence of osteonecrosis of the jaw, so those individuals also need to be evaluated by our dental service.

Dr. Ascensão. The DCVAMC has the same problem. I have a patient that presented primarily with a plasmacytoma, and we tried to get him to see the dentist. The dentist said, ‘You’ve got to get your teeth pulled.’ The patient has tried to see outside dentists and is finding all kinds of excuses because he would like to have implants.

Dr. Cosgriff. Anytime that you somehow damage or irritate that bone, that becomes a risk factor for the development of osteonecrosis. And for those individuals, we delay the bisphosphonate. If they’re having pain syndrome, we try to support them with opiates. We would love to be able to use nonsteroidal anti-inflammatory drugs—they have really good efficacy against bone pain—but renal function and renal failures prevent the use of those in a majority of patients. We start bisphosphonates as soon as dental clears them.

Dr. Mehta. Isn’t there a contraindication for denosumab and some evidence that it may worsen MM outcomes?

Dr. Cosgriff. When the drug first came on the market, it specifically stated in the package insert that it is not to be used in MM (it doesn’t state it specifically anymore). There is a thought that maybe some underlying mechanism exists that might stimulate some of the myeloma problems, which is why I get a little concerned when people say, “Well, I’m using it for hypercalcemia, I’m not using it to treat or to prevent a skeletal-related event in patients with myeloma.” That becomes a gray area and in that type of situation, I would recommend treating the hypercalcemia with a single dose and then switching the
patient to a bisphosphonate.

Dr. Mehta. And of course, bisphosphonates also lower calcium. They can be used to treat hypercalcemia.

Dr. Cosgriff. Yes. Zoledronic acid does have limitations in renal failure, though pamidronate doesn’t have quite the same limitations. The VAPORHCS tries to
use exclusively for hypercalcemia as well. The data show that when using zoledronic acid compared with pamidronate, you end up with the same outcomes as far as hypercalcemia. The zoledronic acid onset of action is a little faster, around 12 to 24 hours vs 48 to 72 hours with pamidronate, but you can get around that by using calcitonin over a short period; 48 hours is typically the maximum efficacy for calcitonin in treating hypercalcemia. So we use pamidronate in place of that, supplementing with calcitonin.

The result is that at 7 days, pamidronate and zoledronic acid show the same efficacy rates for treating hypercalcemia. But the renal function sometimes prevents us from doing that. Denosumab does become an option for hypercalcemia, but again, I caution against its use for treating hypercalcemia in patients with myeloma due to the risk of advancing the myeloma.