(PA-030) Health Care Contact Days After Standard of Care (SOC) B-Cell Maturation Antigen (BCMA)-Directed Chimeric Antigen Receptor T-Cell Therapy (CAR T) for Relapsed/Refractory Multiple Myeloma (RRMM).

CAR T offers deep responses along with a maintenance free treatment option for patients with RRMM. Due to these reasons, CAR T is often considered a “one-and-done” regimen for RRMM. Nevertheless, CAR T administration can be associated with significant time burden both pre-infusion (apheresis, bridging, lymphodepletion) and post-infusion (close clinical follow up, infections, monitoring CAR T related toxicities).

Methods:

We retrospectively reviewed consecutive patients with RRMM treated with standard of care (SOC) BCMA-directed CAR T at our institution between August 1, 2021, and January 31, 2024. Our primary endpoint was the number of Days Alive and Outside of physical Health care contact through the first 100 days from CAR T infusion (DAOH₁₀₀). All patients received CAR T in the inpatient setting.

We categorized days with physical health care contact as inpatient days (index hospitalization for CAR T infusion and readmissions), clinic visits, radiologic study visits (X-ray, CT, MRI, PET, ultrasound scans), invasive procedures (biopsy, lumbar puncture, bronchoscopy, endoscopy), and infusions (blood transfusions, IVIG, G-CSF, other supportive care). We then compared the impact of patient, disease, and treatment characteristics on DAOH₁₀₀ using the Wilcoxon rank sum test.

Results:

A total of 101 patients with a median of 5 (range 4-14) prior lines of therapy were included. Overall, 44 (44%) received idecabtagene vicleucel (ide-cel) and 57 (56%) received clitacabtagene autoleucel (cilta-cel). The 100-day progression free survival was 87% (95% CI: 81-94%) and overall survival was 93% (95% CI: 88-98%). Overall, 76% patients had cytokine release syndrome (CRS, 28% ≥ grade 2, 7% ≥ grade 3), 26% had immune effector cell associated neurotoxicity syndrome (ICANS, 9% ≥ grade 2, 5% ≥ grade 3). There was no significant difference in the CRS (70% vs 81%, p=0.33) and ICANS (30% vs 21%, p=0.45) rates between ide-cel and cilta-cel.

The median DAOH₁₀₀ was 79 days (range 0-87). Days with physical health care contact were predominantly driven by the index hospitalization for CAR T infusion (median 11 contact days, range 7-61), followed by post CAR T clinic visits (median 6 contact days, range 0-26). An ECOG performance status of ≥ 2 (vs 0-1, median 72 vs 79.5 days) and occurrence of ICANS (median 75.5 vs 79 days) were significantly associated with inferior DAOH₁₀₀, with occurrence of ≥ grade 2 CRS (76 vs 79 days) demonstrating a trend towards inferior DAOH₁₀₀. The median DAOH₁₀₀ did not differ based on the CAR T product administered (77 vs 79 days for ide-cel vs cilta-cel, p=0.28), age ≥ 75 years (vs < 75 years, 77 vs 79 days, p=0.92), and number of prior lines (4 vs ≥ 5, 80 vs 76.5 days, p=0.32).

Conclusions:

During the first 100 days after CAR T infusion, patients spent around 20 days with physical health care contact. These data are helpful in counseling patients about post CAR T care and follow up.