[Ron Harvot]

Xpovio (selinexor) approved by the FDA

by Ron Harvot on Sat Jul 06, 2019 2:41 pm

The U.S. Food and Drug Administration (FDA) has approved Xpovio (selinexor) for use with highly pre-treated multiple myeloma patients who are refractory to at least 2 immunodulatory agents (thalidomide, Revlimid, or Pomalyst), 2 proteasome Inhibitors (Velcade, Ninlaro, or Kyprolis), and a CD38 targeted monoclonal antibody (such as Darzalex or the investigational drug isatuximab).

Earlier this year, an FDA advisory committee voted 8-5 against recommending selinexor for approval, and the FDA then delayed its decision about whether to approve the drug. The advisory committee raised concerns about both the efficacy of the drug and the serious side effects that can occur in patients treated with it. Nearly 1 out of 10 patients treated with Xpovio have died from side effects, and others have had to be taken off of the drug.

Xpovio's approval was based mainly on results of a trial carried out with heavily pretreated myeloma patients who were administered 80 mg of Xpovio and 20 mg of dexamethasone twice per week (so 160 mg of Xpovio and 40 mg of dex per week). Among the 83 patients in the trial who previously were treated with at least 2 immunodulatory agents, 2 proteasome inhibitors, and Darzalex, 16 had a partial response, 4 had a very good partial response, and 1 had a stringent complete response, for an overall response rate of 25 percent. The median duration of response to treatment was 3.8 months.

Here is a press release from the FDA about the Xpovio approval:

"FDA Approves New Treatment For Refractory Multiple Myeloma," FDA press release, July 3, 2019

[Nancy Shamanna]

Re: Xpovio (selinexor) approved by the FDA

by Nancy Shamanna on Thu Jul 11, 2019 8:59 am

Thanks for posting this, Ron!

Selinexor (Xpovio) is a new type of drug, a nuclear export inhibitor. It is given in tablet form and may help patients who have exhausted all other forms of therapy, including monoclonal antibodies. Clinical trials have been ongoing in several countries to test this new drug.

[Melpen]

Re: Xpovio (selinexor) approved by the FDA

by Melpen on Thu Jul 11, 2019 9:44 pm

My oncologist said they will probably begin using Xpovio (selinexor) in their Boston practice as soon as the end of July for patients who have relapsed on other available drugs and want to try selinexor. I read that the side effects of nausea and vomiting are rather likely, but my doctor said there are dose adjustments that can be made.

[Ron Harvot]

Re: Xpovio (selinexor) approved by the FDA

by Ron Harvot on Fri Jul 12, 2019 5:15 pm

The side effects are an issue. I am troubled be the nearly 1 in 10 dying from its use. However, patients that become refractive to all of the other novel agents have no real alternatives.

[Mike F]

Re: Xpovio (selinexor) approved by the FDA

by Mike F on Mon Jul 15, 2019 4:14 pm

From what I've read, the side effects of Xpovio can be severe and require careful management. Xpovio was up for approval earlier, but the FDA delayed that approval, potentially so that it could wait until a Phase III study was complete because of concerns over its toxicity [moderator's note: the FDA eventually made its decision without waiting for the publication of data from a comparative trial]. I seem to remember reading something by a doctor who's using Xpovio who believes it to be an important drug for myeloma patients but that its use requires a lot of attention to the side effects.