Real-World Experience Using Tafasitamab Plus Lenalidomide and/or Loncastuximab Tesirine in a Predominately Hispanic Population with Relapsed or Refractory Diffuse Large B-Cell Lymphoma
Authors: Latiolais Heidi , Horowitz Justin , Michalek Joel , Diaz Duque Adolfo Enrique 
Published: December 2024

Background:

Diffuse large B-cell lymphoma (DLBCL), the most common type of non-Hodgkin lymphoma, has had improved progression free survival (PFS) in the first-line setting; however, prognosis remains poor for those with relapsed or refractory diffuse large B-cell lymphoma (RR DLBCL). Further analysis of SCHOLAR-1 demonstrated that those with refractory DLBCL, defined as progressive disease (PD) or stable disease (SD) as best response after four cycles of first-line therapy or following salvage therapy for relapsed disease or relapse ≤12 months following autologous stem cell transplantation had a median overall survival (OS) of 6.3 months (Blood PMID 28774879). Furthermore, at two years, 20% of patients were alive. This analysis emphasized the need for effective treatments in the setting of RR DLBCL. Since 2017, multiple phase 2 trials have led to accelerated FDA approvals including the L-MIND and LOTIS-2 studies that evaluated tafasitamab plus lenalidomide (TL) and loncastuximab tesirine (LT), respectively. However, Hispanics (HI) were an underrepresented group in these clinical trials, which is of concern due to healthcare disparities. L-MIND reported race (88.9% white, 2.5% Asian, and 8.6% unknown or not reported), but not ethnicity (Lancet Oncol PMID 32511983). Moreover, only 9.0% of patients identified as HI in the LOTUS-2 trial (Lancet Oncol PMID 33989558). This retrospective study was conducted at the only National Cancer Institute (NCI) Designated Cancer Center of South Texas, and aimed to highlight the demographics, treatment patterns, and real-world outcomes in a predominately HI population with RR DLBCL with TL, LT, or both.

Methods:

Baseline and treatment characteristics were collected and analyzed amongst patients with RR DLBCL treated with TL and/or LT at the University of Texas Health San Antonio MD Anderson Cancer Center from October 26, 2020 to July 1, 2024. Kaplan-Meier method was used to estimate PFS and OS in patients treated with TL and/or LT.

Results:

As of July 1, 2024, 22 patients with RR DLBCL were treated with TL, LT, or both. Of which, 77% identified as HI. Median age was 59 years old (range 24-81 years) and 59% were males. All patients were insured, including 64% with government sponsored insurance and the remaining with private insurance.

Patients predominately presented with stage IV disease (59%) and International Prognostic Index score 2-3 (41%) at time of initial diagnosis. Of all patients, 45% had bulky disease. Germinal center B-cell like DLBCL accounted for 64% of all diagnoses.

Of all patients, 32% received only TL and 46% received only LT; the remaining patients received TL with LT as a subsequent line of therapy. TL was given as a second line of therapy in 47% treated with TL; the remaining patients had two or more prior lines of therapy. All patients treated with LT had two or more prior lines of therapy. Refractory disease to the prior line of therapy was identified in 67% treated with TL and 67% treated with LT.

In those treated with TL, 27% achieved complete response (CR), 7% had partial response (PR), 7% had SD, 33% had PD, and 27% died prior to restaging imaging.

In all patients treated with LT, 50% achieved CR, 25% had PD, 17% were lost to follow, and 8% died prior to restaging imaging. Among those who received TL prior to LT, 60% achieved CR, 20% had PD, and 20% died prior to restaging imaging.

PFS at 12 months and 24 months was 40% and 13%, respectively, in those treated with TL. Median PFS was 4.1 months. OS in those treated with TL at 12 months was 59% and at 24 months was 59%. Median OS was 40 months.

PFS in patients treated with LT at 12 months was 17% and at 24 months was 0%. Median PFS was 7.0 months. OS in those treated with LT at 12 months and 24 months was 67% and 51%, respectively. Median OS was not determined due to small sample size. Among those treated with TL prior to LT, median PFS was 4.0 months and median OS was 4.9 months.

Conclusion:

Real-world outcomes with TL in a predominately HI population with RR DLBCL showed worse PFS, but better OS compared to patients in the L-MIND study. A better PFS was shown in those receiving LT than patients in the LOTIS-2 study. This analysis highlights the unmet need of diversity and inclusion of patients with distinctive ethnic backgrounds to ensure generalizability. Further studies with a larger sample size, including an increased number of minorities and longer follow-up time, are needed to better understand the treatment pattern and survival outcome differences.