Exelixis Faces FDA Delay & Karyopharm Faces October Deadline

Exelixis faces three more months of FDA review for its colorectal cancer combination. A potential launch now hinges on a March decision.

And Karyopharm missed a loan payment, then secured a creditor standstill with an October deadline. An FDA refusal to file its myelofibrosis application could end that standstill early.

Welcome to The Pharma Closeout for Friday, September 11th. I'm Alex Mercer.

And I'm Maya Patel. We bring you the day's pharma and biotech news, with the context that makes the developments worth understanding.

In our top story today, FDA extended its review of Exelixis's zanzalintinib combination by three months, to March 3rd, 2027. The company disclosed the change in a filing today, after receiving FDA's notice yesterday. The application pairs its investigational drug with Roche's Tecentriq for previously treated metastatic colorectal cancer.

About ninety-one percent of Exelixis's second-quarter revenue came from CABOMETYX, its established cancer drug — calculated from the company's reported figures. Zanzalintinib is its potential second franchise. That makes this a decision about broadening the company's business as well as entering another indication.

The explanation is in the filing itself. Exelixis had already submitted updated efficacy and safety data that FDA asked for. The agency classified that submission as a major amendment and extended the review. There's no disclosed finding tying the extra time to a specific safety issue or trial result.

And what does the trial itself show?

The Phase 3 study, STELLAR-303, had two primary endpoints. It tested the combination against Bayer's Stivarga in patients whose metastatic colorectal cancer had already been treated, excluding MSI-high and mismatch-repair-deficient disease. In results published last year, median overall survival was 10.9 months with the combination, versus 9.4 months with Stivarga. That endpoint was met across the full randomized population.

The second primary endpoint asked the same question in patients without active liver metastases. That final analysis, reported in June, didn't reach statistical significance. Both findings come from the same trial — a positive overall result alongside an endpoint that missed.

On the money side, Exelixis's August outlook already excluded any zanzalintinib launch revenue, so the extension doesn't subtract sales management had included in that forecast. It pushes the opportunity into next year.

Approval is still an open question, along with who an approved label would cover. March 3rd is the new target for FDA's decision.

Next, our Deal and Pipeline roundup. COSCIENS acquired Nualtis from AtaiBeckley yesterday for $15 million in cash, plus contingent earn-outs. Nualtis develops and manufactures oral films for other drug companies — its manufacturing work includes RizaFilm, an FDA-approved oral film for acute migraine.

COSCIENS paid $9 million at closing, with the remaining $6 million due within six months. Separately, it closed roughly $6 million of convertible debt carrying fifteen percent annual cash interest, and only that first tranche has closed.

So the profile changes. COSCIENS picks up an operating manufacturing business with an approved product running through it, sitting alongside its own drug-development programs. The deferred payment and that interest rate are the near-term cost of getting it.

Separately, Frazier Life Sciences said yesterday it added more than $1.1 billion in commitments to its Public Fund. Frazier is a specialist biotech investment firm. It launched this dedicated fund in 2021, alongside its venture funds backing private companies.

The Public Fund focuses on small- and mid-cap listed biotechs, with room for later-stage private investments too. August SEC filings disclosed stakes in Allogene Therapeutics and Attovia Therapeutics held specifically by this fund. Those are dated disclosures, rather than a live portfolio list.

So this is an established investor attracting more capital, with the fund's cumulative commitments now around $2.8 billion. Frazier points to clinical progress, FDA approvals and commercial launches as reasons for its optimism. The raise gives it more capacity to back that strategy across public and late-stage private biotech. It hasn't disclosed an investment schedule.

To Regulatory Watch. Roche said yesterday that FDA accepted its application to expand Enspryng into MOGAD and granted Priority Review. The decision is expected January 10th, 2027. MOGAD is an antibody-associated inflammatory disease affecting the optic nerves, spinal cord or brain. Roche says relapses can leave lasting neurological injury and there are no approved treatments for it.

Enspryng is already approved in the U.S., but for a different disease — neuromyelitis optica spectrum disorder in adults who test positive for the AQP4 antibody. MOGAD is separate, and clinicians treating it rely on off-label options today.

The trial behind the filing is METEOROID. It compared Enspryng with placebo in adolescents and adults, either on its own or added on top of the immunosuppressive treatment patients were already taking. Roche reported the results at a conference in April: at forty-eight weeks, eighty-seven percent on Enspryng were relapse-free, versus sixty-seven percent on placebo. Those are sponsor-reported figures, and the comparison is with placebo — not with the various off-label regimens in use.

So Roche could add a new indication for an existing product, in a disease where treatment is currently off-label. UCB also has a Phase 3 program, cosMOG, with no results posted. Roche is further along the regulatory path, though we don't have a head-to-head comparison. January 10th is the next decision target.

Quick note before our second top story today — if The Pharma Closeout is how you close out your day, follow the show on Spotify or Apple Podcasts.

Karyopharm missed a roughly $15.8 million term-loan principal payment due yesterday. Its creditors then agreed to a temporary standstill on specified defaults, with an outside date of October 15th unless it's extended.

Karyopharm markets Xpovio for multiple myeloma, and it's seeking accelerated approval for the same drug, selinexor, combined with ruxolitinib in myelofibrosis. It submitted that application in late August — and the filing's progress is written directly into the standstill terms.

Specifically, the standstill can end early if FDA refuses to file that myelofibrosis application, or if Karyopharm withdraws it. That's a condition in the agreement, not a report that either has happened, and filing acceptance would still leave the approval decision ahead. It can also end if liquidity falls below $10 million. Karyopharm says its current operating plan is funded only through October 15th, assuming the standstill holds — so the runway and the creditor deadline land on the same date.

And the standstill wasn't cheap. Karyopharm agreed to $20 million in fees and elected to pay them in convertible preferred shares rather than cash, with issuance expected next week. Creditors haven't waived the defaults or moved the missed payment deadlines. If the standstill ends, the overdue amounts become payable, and creditors can pursue remedies, including acceleration. That leaves a limited window to fix the financing, and a filing decision could shorten it before that deadline.

What to watch: Telix's Pixclara application had an announced FDA goal date of today. The investigational PET imaging agent is proposed to distinguish recurrent or progressive glioma from changes caused by treatment, in adults and children.

As of 8:04 p.m. Pacific, we hadn't verified an outcome in the company and FDA channels checked. That leaves the watch open; the absence of an announcement doesn't establish a delay or a decision.

Thanks for spending part of your Friday with us. Wherever the rest of the evening takes you, have a good weekend.

Follow the show on Apple Podcasts, Spotify, or wherever you listen — a quick rating or share helps other listeners find us. The Week in Review lands Sunday.