This study is investigating a new administration schedule of Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (R-CHOP) chemotherapy for participants with Diffuse Large B-Cell Lymphoma (DLBCL), focusing on an underserved elderly population (aged 75 and up; certain participants 70-74 may be eligible) that is often excluded from clinical trials. Participants can expect to be on study for 2.5 years (treatment for 6 months and 2 years of post treatment follow-up).

This study will test the efficacy of split-dose R-CHOP for the treatment of elderly patients with de novo diagnosis of DLBCL or transformed DLBCL. Split-dose R-CHOP involves giving Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP) chemotherapy at 14 days' interval with Rituximab given once/month. The safety for every 14-day CHOP administration was studied in a large prospective randomized control trial of patients up to the age of 80 years. In this study, R-CHOP given every 14 days for up to 6 cycles was felt to be the best method of delivery of chemotherapy. Receiving greater than 6 cycles of R-CHOP chemotherapy was not found to be beneficial compared to participants receiving 6 cycles of R-CHOP. Additionally, an interim response adapted approach by combining imaging and MRD testing will be used to identify participants who will receive an abbreviated chemotherapy course if they are both Positron Emission Tomography/Computed Tomography (PET/CT) and Minimum Residual Dose (MRD) negative.

In the proposed study, participants will receive a 50% dose reduction of CHOP chemotherapy on Day 1 and Day 15 of each cycle with full dose Rituximab on Day 1 for up to a total of 6 months of chemotherapy. Participants who are MRD and PET/CT negative after 2 months will be placed on an abbreviated regimen with R-CHOP x 4 additional doses with full dose Rituximab and a 50% dose reduction in CHOP chemotherapy. The hypothesis is that this method of administration of R-CHOP will be a safe and effective form of chemotherapy for older patients with DLBCL and will allow older patients to receive curative intent treatment.

Inclusion Criteria:

• Signed and dated informed consent document indicating that the participant (or legally acceptable representative) has been informed of all pertinent aspects of the trial

• All patients age ≥75 years and participants aged 70-74 years who are determined to be unfit or frail by Cumulative Illness Rating Score-Geriatrics (CIRS-G) scale

  • For participants aged 70-74 years: CIRS-G score with 5-8 comorbid conditions scored 2 or ≥1 comorbidity scored 3-4. CIRS-G score is to be reviewed by the study PI prior to enrollment.

• Newly diagnosed, untreated, biopsy proven CD20 positive DLBCL (including high grade B-cell lymphoma & T-cell/histiocytic rich large B-cell lymphoma). Participants with discordant bone marrow (i.e. involved by low-grade/indolent NHL) are eligible. Participants with transformed DLBCL from underlying low-grade disease are eligible. Participants with composite DLBCL and concurrent low-grade lymphoma are eligible.

  • Copy of pathology report must be sent to coordinating site to confirm diagnosis for eligibility
  • Participants with prior treatment for low grade NHL with non-anthracycline based regimens are eligible

• Measurable disease by PET/CT or Bone Marrow (BM) biopsy prior to enrollment

• Left ventricular ejection fraction ≥50% by resting echocardiography or resting Multi-gated acquisition (MUGA) scan

• Karnofsky Performance Score ≥50

• Ann Arbor Stage II bulky, III, or IV disease

• Minimum life expectancy greater than 3 months

• Negative HIV test

• For participants with hepatitis B virus antigen (HbsAg) or core antibody (HbcAb) seropositivity, participants must have a negative Hep B viral load and an appropriate prophylaxis plan must be in place during chemotherapy therapy treatment. For all participants that have Hep B core antibody positive, they should take entecavir prophylaxis (0.5 mg PO daily) until 1 year from completion of chemotherapy. Hep B viral load should be checked on these participants prior to starting chemotherapy and every 3 months thereafter if initial Hep B viral load is negative (+/- 1 week if chemotherapy cycle is delayed). If Hep B viral load is positive, Hepatology or Identification (ID) referral is recommended, and hepatitis B virus (HBV) viral load should be checked monthly

• For participants with hepatitis C Ab (HbcAb) positivity, a viral load must be checked and be negative for enrollment

• Intrathecal chemotherapy for central nervous system prophylaxis only can be given at the discretion of the primary oncologist

Exclusion Criteria:

• History of previous anthracycline exposure
• Central Nervous System (CNS) or meningeal involvement at diagnosis
• Creatinine Clearance <25 mL/min by body surface area (BSA)-adjusted Cockroft-Gault
• Poor hepatic function, defined as total bilirubin concentration greater than 3.0 mg/dL or transaminases over 4 times the maximum normal concentration, unless these abnormalities are felt to be related to the lymphoma.
• Pulmonary dysfunction defined as >2 L of oxygen required by nasal cannula to maintain peripheral capillary oxygen saturation (SpO2) ≥90% unless felt to be related to underlying lymphoma.
• Myocardial Infarction within 6 months of enrollment
• Active, uncontrolled infectious disease
• Known concurrent bone marrow malignancies (e.g. myelodysplastic syndrome) or poor bone-marrow reserve, defined as neutrophil count less than 1.5×10⁹/L or platelet count less than 100×10⁹/L, unless caused by bone-marrow infiltration with lymphoma
• History of a second concurrent active malignancy or prior malignancy which required chemotherapy treatment within the preceding 2 years
• Treatment with any investigational drug within 30 days before the planned first cycle of chemotherapy
• Unable or unwilling to sign consent

Data collected up to approximately 6 months

All-cause mortality is reported for all participants enrolled (N=27).

Per protocol section 7.4.4: The incidence of serious adverse events will be reported for all subjects who received at least one dose of the study treatment (N=26).

Per protocol section 8.3: Adverse events will be recorded from the beginning of informed consent until 2 weeks after completion of the last cycle of chemotherapy (N=27).