Spectrum, Oncopeptides' oncology drugs have much to overcome heading into FDA adcomm

After scoring a long-awaited FDA approval earlier this month for Rolvedon, Spectrum Pharmaceuticals was hoping to double down with another FDA endorsement for a different drug.

But that now appears unlikely as the regulator has panned lung cancer hopeful Pozenveo ahead of Thursday’s oncologic drugs advisory committee meeting.

In a briefing document for the session, the FDA said (PDF) Pozenveo may not “provide a meaningful advantage over available therapies.”

In another advance document for a different cancer hopeful also up for review Thursday, the FDA threw cold water on Oncopeptides’ multiple myeloma drug Pepaxto.

Results from a trial “failed to confirm clinical benefit” the FDA wrote (PDF). The agency added that the medicine's benefit-risk profile was “unfavorable.”

While Spectrum’s stock dropped by 38% from open to close on Tuesday, Oncopeptides’ fell by 46%.

With Pozenveo, Spectrum is seeking an FDA approval to treat patients with previously treated locally advanced or metastatic non-small cell lung cancer harboring the human epidermal growth factor receptor exon 20 insertion mutation.

In the FDA staff review, the agency pointed to the drug's objective response rate (ORR) of 28% and median duration of response (mDOR) of 5.1 months in a confirmatory trial. These figures pale in comparison to Daiichi Sankyo’s Enhertu, which was approved in the indication last month and showed a 58% ORR and 8.7-month mDOR.

The FDA also cited Pozenveo’s “poorly tolerated safety profile,” as 57% of patients had to undergo dose reductions and 85% experienced severe or life threatening side effects. Spectrum has proposed studying different dosing regimens to address this concern, but those results are in the distant future as trials have yet not begun enrolling.

As for Oncopeptides, the news is a blow after the company appeared on the verge of collapse early this year before rallying and then gaining an approval recommendation in Europe. Its drug is known as Pepaxti in Europe.

The FDA cited the drug for a variety of concerns. In a trial comparing Pepaxto to the steroid dexamethasone, Pepaxto produced a higher rate of death (48% to 43%) and a shorter median duration of overall survival (19.7 months to 25 months).

In February of 2021, the FDA approved Pepaxto, but eight months later the company took the infused drug off the market for safety concerns raised by the U.S. regulator. The company said it would not only pull the plug on its business units in the U.S. but would do the same in Europe and return the biotech to its R&D roots, before it had a change of heart.

Thursday morning, Spectrum will get its chance to sway the expert committee. Oncopeptides will get its chance later that afternoon.