High-risk myeloma: extended quadruplet therapy kept its survival edge at five years against an external control

Design

Multicentre single-arm phase 2 trial (Bayesian design) with molecularly matched external control, 5-year follow-up

Population

107 patients with newly diagnosed high-risk multiple myeloma or plasma cell leukaemia vs 120 matched controls

Primary outcome

Progression-free survival, progression-free survival 2 and overall survival at 5 years

Effect

PFS median not reached vs 24.4 months (HR 0.32, 95% CI 0.22 to 0.45); OS HR 0.43 (95% CI 0.28 to 0.65)

OPTIMUM was a UK phase 2 trial in newly diagnosed high-risk multiple myeloma, defined by two or more high-risk cytogenetic abnormalities, high-risk gene expression profile or plasma cell leukaemia. Patients received daratumumab, cyclophosphamide, bortezomib, lenalidomide and dexamethasone induction, autologous stem-cell transplant, two parts of consolidation, then lenalidomide and daratumumab maintenance. There was no randomised arm: results were compared with 120 genetically matched patients from the Myeloma XI trial.

Of 108 recruited, 107 were analysed, with median follow-up of 71.1 months. Median progression-free survival was not reached (lower bound 70.6) against 24.4 months in controls (HR 0.32, 95% CI 0.22 to 0.45), and overall survival hazard ratio was 0.43 (0.28 to 0.65). Second progression-free survival also favoured the trial (HR 0.26). The benefit was consistent across subgroups except patients with three or more high-risk abnormalities. Subgroups were chosen after the fact.

The external control was treated in an earlier era with less effective therapy and followed for longer, so some of the gap reflects time and supportive care. Daratumumab-based regimens are costly and access in India varies. The results support risk-stratified testing at diagnosis but do not replace randomised comparisons.

• Send cytogenetics (FISH) at diagnosis in every myeloma patient so risk status is known before treatment is chosen.
• Discuss quadruplet induction, transplant and extended maintenance with the myeloma team for fit high-risk patients where available.
• Note that patients with three or more high-risk abnormalities did not show the same benefit; plan trials or closer follow-up.
• Check access and cost of daratumumab-based regimens early in planning.
• Do not treat this as a randomised result; the comparison was with an external control.

Why it matters

It suggests molecular risk testing can guide more intensive treatment in the group that does worst on standard therapy.

Don't overread it

A single-arm phase 2 trial against an external control cannot prove that the regimen caused the survival gain, and subgroups were chosen after the fact.

The statistics, in plain English

A hazard ratio of 0.32 for progression-free survival means about two-thirds lower risk of progression or death at any time, but it compares different patient cohorts from different eras. A median 'not reached' means more than half of patients had not progressed at the time of analysis.

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