ASH Conference: Radioimmunotherapy as Part of First Line Therapy for Low Grade Lymphoma

By Rebecca Elstrom, MD

Update: this study is closed to enrollment. 

Radioimmunotherapy (RIT), or radiation targeted to lymphoma cells through conjugation to a monoclonal antibody, has long been known to be effective therapy in patients with relapsed indolent non-Hodgkin’s lymphomas.  Its use as first line therapy has been limited, however. This weekend at the American Society of Hematology (ASH) meeting, several studies exploring the use of RIT in initial therapy of low grade lymphomas, either alone or following chemotherapy, were reported.

Two studies explored the use of 90Y-ibritumomab tiuxetan (Zevalin) alone;  one presented by Dr. Pica of Genova on behalf of an Italian cooperative group exploring a single dose, and one presented by Dr. Illidge from the University of Manchester with fractionated dosing (multiple doses of the RIT, in this case 2). Both studies showed high response rates with this brief and simple strategy, and durations of remission comparable to front line chemotherapy with no excessive toxicity.

Two other studies explored the use of RIT as consolidation following initial chemotherapy. The first, presented by Dr. Press of the University of Washington, was a large multicenter study comparing Rituximab plus CHOP chemotherapy (R-CHOP) to CHOP followed by 131I-tositumomab (Bexxar). There was no difference between the two groups in response rate or duration of response. A caveat to this study is the fact that, at the time it was designed, there was concern that giving the anti-CD20 antibody rituximab prior to RIT would inhibit radiation dose delivery, as 131I-tositumomab also requires binding to CD20 in order to deliver the radiation dose to lymphoma cells. This concern does have support in laboratory studies, but it has become clear in the years since this study was designed that anti-CD20 antibody therapy with rituximab is a critical contributor to response and survival in follicular lymphoma. The second study of chemotherapy followed by RIT was presented by Dr. Fowler of MD Anderson Cancer Center. This group evaluated an induction chemotherapy regimen containing rituximab, fludarabine, mitoxantrone and dexamethasone (R-FND) followed by 90Y-ibritumomab tiuxetan. This study showed high response rates and long time to progression, but toxicity of the regimen was of some concern, possibly due to the fact that fludarabine has significant bone marrow suppressive effects, which is also the main side effect of RIT.

Overall, these presentations confirmed the impressive activity of RIT in low grade lymphoma, and extended the experience using RIT as part of first line therapy, demonstrating feasibility, safety and efficacy of this simple and very well tolerated therapeutic approach.

At Weill Cornell Medical College we are exploring radioimmunotherapy as first treatment of follicular lymphoma using a combined strategy of non-radiation tagged antibody to CD20 in combination with radio-labeled antibody against an alternative protein, CD22. This study is designed to maximize the benefit of anti-CD20 directed therapy in addition to radiation dose delivery by targeting the radio-labeled antibody to an alternative target. Click here to read more about this study.

Clinical Trial: Bruton’s Tyrosine Kinase (Btk) Inhibitor PCI-32765 in Relapsed/Refractory Mantle Cell Lymphoma

Update: this study is closed to enrollment. 

Bruton tyrosine kinase (Btk) is an enzyme that plays a crucial role in the development of the normal immune system. Recent studies indicate that Btk may also play a role in many B-cell lymphomas.

PCI-32765 is an investigational drug that irreversibly inhibits Btk. A phase 1 trials performed at several sites, including Weill Cornell Medical Center, demonstrated that PCI-32765 was well tolerated with minimal side effects.

In this phase 2 study, we are evaluating the efficacy of PCI-32765 (four pills take once daily) in patients with previously treated mantle cell lymphoma. We hope to learn how well PCI-32765 works and more about its side-effect profile.

To learn more about this study, please contact June Greenberg, RN at (212) 746-2651 or email June at jdg2002@med.cornell.edu.

Click here to view the clinical and research profile of Peter Martin, MD, the physician leading the study at Weill Cornell Medical Center.

Weill Cornell Investigational Drug Shuts Down Aggressive Form Of Leukemia That Affects Children

In a significant breakthrough published recently in Nature, researchers at Weill Cornell Medical College and the University of California, San Francisco, have been able to overcome resistance of a form of leukemia to targeted therapy, demonstrating complete eradication of the cancer in cell and animal studies.

The study shows that an investigational drug, RI-BPI, developed at Weill Cornell, in combination with the drug Gleevec shut down stem cells responsi ble for about one-third of acute lymphoblastic leukemia (ALL), a cancer of white blood cells that affects young children as well as older adults. This form of ALL has the so-called Philadelphia chromosome, which is also found in chronic myelogenous leukemia (CML). But while Gleevec has greatly improved survival in CML, it has had a less dramatic effect in ALL, and most patients still die within a relatively short time frame.

That prognosis may change given these results, says co-senior investigator Dr. Ari Melnick, associate professor of medicine and director of the Raymond and Beverly Sackler Center for Biomedical and Physical Sciences at Weill Cornell Medical College, and a hematologist-oncologist at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. Dr. Melnick and his colleagues developed RI-BPI, and they have shown its potent effects in non-Hodgkin’s lymphoma (NHL) with no toxicity to normal cells. The drug targets the transcription factor BCL6, a master regulator of hundreds of genes that provides strong growth signals to NHL cells.

“I am surprised, and extremely glad, to see that RI-BPI has such strong activity in a leukemia. This opens up the possibility that the agent will have similar beneficial effects in other tumor types,” says Dr. Melnick.

Click here to read the press article describing the study results. Click here to read the published research paper.

Background on the development of RI-BPI at Weill Cornell Medical Center: Diffuse Large B ell lymphoma (DLBCL) is a common and aggressive subtype of lymphoma that is frequently associated with deregulation of the oncogene BCL6 (oncogene is a genetic material that carries the ability to induce cancer). Deregulated BCL6 activity keeps B cells in a rapidly proliferating (reproducing) state. The high levels of BCL6 expression in DLBCL coupled with the low or nil expression of BCL6 in normal cells have made BCL6 an attractive candidate for anti-cancer drug development.

Personalized lymphoma medicine offers the hope that by identifying lymphoma-causing mutations in critical regulatory genes, we can target these mutant proteins to cure lymphoma while limiting the side effects. Continue reading “Weill Cornell Investigational Drug Shuts Down Aggressive Form Of Leukemia That Affects Children”