What happened

After the company reported positive data for its lead drug in a key multiple myeloma study, shares of Karyopharm Therapeutics Inc. (NASDAQ:KPTI) are surging 15% higher at 12:15 p.m. EDT today.

So what

Karyopharm Therapeutics is developing selinexor for the treatment of hematological cancers, including multiple myeloma and diffuse large B-cell lymphoma (DLBCL).

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After the market's closing bell yesterday, the company reported an overall response rate of 25.4% in multiple myeloma patients who have seen their disease return following five prior therapies, including the billion-dollar blockbusters Revlimid, Velcade, and Darzalex.

The response rate in this heavily treated patient population is good enough for management to say it'll seek accelerated review based on this phase 2b data, with a filing for Food and Drug Administration approval anticipated by the end of 2018. 

Now what

Since most multiple myeloma patients see their disease return following treatment, there's an important need for new options for late-stage patients, but that may not be the only opportunity for selinexor's use.

A trial is also evaluating its use alongside Velcade in patients who've had one to three prior treatments. Data from that trial is anticipated in 2019, and if it pans out well, then selinexor's addressable market would expand significantly.

Also, Karyopharm Therapeutics previously reported solid phase 2b study results for selinexor in DLBCL. A phase 3 trial of it in that indication should have data available later this year. If selinexor is a success in DLBCL as well, then it has a good shot at racking up significant sales someday.

Given selinexor's potential to win approval in the U.S. next year and the need for new therapies, the company's latest data makes Karyopharm Therapeutics an intriguing stock to add to aggressive portfolios.

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