Delays in Myeloma Oral Therapy Linked to Race, Age

Potential reasons for delayed treatment initiation of guideline-directed oral medications to treat multiple myeloma (MM), and that demonstrate significant disparities to work at overcoming, include being of an older age and Black race, according to study results in Blood Cancer Journal.¹

Using retrospective data for January 1, 2017, to December 31, 2021, for patients with newly diagnosed symptomatic MM who were treated at Taussig Cancer Center, part of Cleveland Clinic, the investigators had a primary and a secondary outcome of interest in mind: time to treatment initiation (TTI) of FDA-approved oral antimyeloma medications (primary) and TTI for any FDA-approved facility-administered or oral antimyeloma medication (secondary).

Previous research on potential disparities in treatment initiation for MM show influences from different demographic characteristics, the study authors noted regarding autologous stem cell transplantation or any systemic antimyeloma treatment,^2,3 but there are few data on TTI for expensive oral antimyeloma medications. Prices for these oral medications can range from the double digits to millions.⁴

Seventy-five percent of the overall patient population (n = 543) filled a prescription (excluding corticosteroids) over the study follow up, which averaged 765 days. Lenalidomide was the most filled prescription (93.7%), followed by cyclophosphamide (2.6%), pomalidomide (1.7%), ixazomib (1.5%), and thalidomide (0.6%). The overall treatment rate for the study was 93% (excluding corticosteroids), and the authors saw that for triplet or quadruplet regimens did not differ between non-White and White patients. Their median (IQR) TTI was 15 (7-28) days; by 14 days, 45% had received treatment (excluding corticosteroids).

For 25% of patients, if took 2 or more months to get that first fill following their initial diagnosis. However, 52% of patients who received oral and facility-administered antimyeloma medication (excluding corticosteroids) were able to fill their oral prescription before or on the day they initiated facility treatment.

Outcomes of interest in this study were time from diagnosis to initial prescription fill for an oral multiple myeloma medication and time from initial diagnosis to receipt of any treatment for MM. | Image Credit: © Colored Lights - stock.adobe.com

By 30 days after initial diagnosis, the overall fill rate for an oral medication was 40% of patients—but this also is when fill disparities became apparent, with the investigators seeing their results vary with statistical significance by race and age:

• Race: 43% (95% CI, 39%-47%) for White patients vs 28% (95% CI, 21%-36%) for Black patients
• Age:
  • 44 years or younger: 65% (95% CI, 41%-85%)
  • 45 to 54 years: 43% (95% CI, 32%-55%)
  • 55 to 64 years: 42% (95% CI, 35%-49%)
  • 65 to 74 years: 46% (95% CI, 40%-52%)
  • 75 years or older: 24% (95% CI, 17%-31%)

There were also differences in insurance coverage, but these did not ready statistical significance.

Using a multivariable Cox regression model, the authors then saw that Black race, older age at diagnosis, inpatient diagnosis, and eGFR influenced the prescription fill rate:

• Black race (vs White): aHR, 0.61 (95% CI, 0.42-0.87)
• Older age: aHR per 1 year, 0.97 (95% CI, 0.95-0.98)
• Inpatient diagnosis: aHR, 0.63 (95% CI, 0.43-0.92)
• eGFR (≤ 29 vs ≥ 60 mL/min/1.73 m²): aHR, 0.46 (95% CI, 0.29-0.73)

There were 720 patients included in this study, 45% of whom were female patients. Twenty-two percent reported a Black race, and approximately 77%, a White race. The mean (SD) age at diagnosis was 67 (11) years, the most common ECOG performance status was 1 (41%) or 0 (30%), baseline estimated glomerular filtration rate (eGFR) was 60 or more mL/min/1.73 m² in 61% of patients, 83% lived in a metropolitan area, and 70% lived in the third (33%) or fourth (37%) Area Deprivation Index quartile, for which higher scores equate to greater disadvantage—meaning these patients lived in the most disadvantaged areas. Primary insurance types were typically private (36%), Traditional Medicare (29%), or Medicare Advantage (25%).

Speaking to their results, the investigators highlighted how when they adjusted for sociodemographic and clinical variables, the difference in results for their Black patients only changed by 5% in the relative risk, which “suggests an outstanding research gap related to the barriers affecting these populations that could be further examined via qualitative research approaches.” They also noted that quality metrics within Cleveland Clinic’s myeloma program require TTI to be 10 or fewer days for newly diagnosed patients.

“Our findings highlight the need to focus on the barriers to simultaneous initiation of all components of guideline-recommended multidrug induction regimens for multiple myeloma,” they concluded, “and identify patient populations who might be at higher risk of delayed treatment initiation with oral antimyeloma medications.”

References

1. Gasoyan H, Anwer F, Kovach JD, et al. Disparities in time to treatment with oral antimyeloma medications. Blood Cancer J. 2024;14(1):142. doi:10.1038/s41408-024-01128-1

2. Bhatnagar V, Wu Y, Goloubeva OG, , et al. Disparities in black and white patients with multiple myeloma referred for autologous hematopoietic transplantation: a single center study. Cancer. 2015;121(7):1064-1670. doi:10.1002/cncr.29160

3. Kumar V, Alhaj-Moustafa M, Bojanini L, et al. Timeliness of initial therapy in multiple myeloma: trends and factors affecting patient care. JCO Oncol Pract. 2020;16(4):e341-e349. doi:10.1200/JOP.19.00309

4. Multiple myeloma medications. Good Rx. Accessed October 11, 2024. https://www.goodrx.com/conditions/multiple-myeloma/drugs?label_override=undefined