FDA Requests Melphalan Flufenamide be Withdrawn From US Market

The FDA has requested that melphalanflufenamide (Pepaxto) be withdrawn from the U.S. market following confirmatory results from the Phase 3 OCEAN trial (NCT03151811), according to a press release from Oncopeptides AB.¹

Data from the OCEAN 3 study showed that the hazard ratio for overall survival by independent reviewer in the intent-to-treat population was 1.104 (95% CI, 0.846-1.441), with notable differences in survival outcomes for both melphalanflufenamides IM Experimental arm and pomalidomide (Pomalyst) in the comparator arm in a range of patient subgroups.

“We respect the FDA’s accelerated approval requirements,” Jakob Lindberg, CEO of Oncopeptides, said in a press release. “Multiple myeloma remains an incurable disease, and treatment options for patients with triple-class refractory disease will eventually be exhausted. The OCEAN study demonstrated clinical benefit for patients with multiple myeloma, particularly elderly patients who have not been transplanted and for whom unmet medical needs remain very high.”

That The FDA has granted accelerated approval to melphalanflufenamide for the treatment of adults with relapsed/refractory multiple myeloma after at least 4 lines of therapy.²

The February 2021 decision was based on data from the phase 2 HORIZON study (NCT02963493) evaluating melphalanflufenamide in combination with dexamethasone in relapsed/refractory multiple myeloma. At that time, investigators reported an overall response rate (ORR) of 23.7% (95% CI, 15.7% – 33.4%) with a median duration of response of 4.2 months (95% CI, 3.2 – 7.6 ) in a subpopulation of 97 patients who received 4 or more prior lines of therapy.

However, in September 2022, the FDA’s Oncologic Drugs Advisory Committee gave one 14 votes to 2 against retaining expedited approval for melphalan flufenamide after it was found to have an unfavorable risk-benefit profile.³

Oncopeptides AB made the decision Withdraw melphalanflufenamide from the United States market following the release of confirmatory results from the OCEAN study with the intent to work with the FDA to continue making the compound available to those still on treatment.⁴

However, in March 2022, Oncopeptides retracted the letter voluntarily withdrawing the compound from the market after a further review of OS data from the OCEAN study caused the company to reconsider its decision.⁵ Notably, marketing efforts were still on hold while the company worked with the FDA to interpret the data.

Other results from the OCEAN study showed that melphalan flufenamide resulted in 42% greater progression-free survival than pomalidomide as per investigator and IRC assessment (HR, 0.817; 95% CI, 0.659-1.012; P = 0.064; heart rate 0.790; 95% CI, 0.639-0.976).

In addition, the overall response rate was 32.1% versus 26.5% in the melphalan flufenamide and pomalidomide arms, respectively.

references

1. Oncopeptides announces US market approval of Pepaxto. press release. Oncopeptides AB. December 7, 2022. Accessed December 9, 2022. https://bit.ly/3YcSMuG
2. FDA Grants Accelerated Approval to Melphalanflufenamide for Relapsed or Refractory Multiple Myeloma. press release. FDA. February 26, 2022. Accessed December 9, 2022. https://bit.ly/3SeTdl1
3. Oncology Drugs Advisory Committee (ODAC) Meeting, May 22-23 September 2022 (Day 1). Live stream September 22, 2022. Accessed December 9, 2022. https://bit.ly/3LNcW9a
4. Oncopeptides withdraws Pepaxto® in the US, downsizes organization and focuses on research and development. press release. Oncopeptides AB. October 22, 2021. Accessed December 9, 2022. https://bit.ly/3B5OCIC
5. Important information about PEPAXTO® in the United States. press release. oncopeptides. March 1, 2022. Accessed December 16, 2022. https://bit.ly/3hq2VUE