1. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Omer N. Koc, MD; Charles Redfern, MD; Peter H. Wiernik, MD; Fred Rosenfelt, MD; Jane N. Winter, MD; Troy H. Guthrie, MD; Lawrence Kaplan, MD; Peter Holman, MD; John Densmore, MD, PhD; John Hainsworth, MD; Thomas Lin, MD; Rene A. Castillo, MD; Nalini Janakiraman, MD; and Richard G. Ghalie, MD Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia

2. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Mitumprotimut-T is a patient-specific and B-cell tumor-specific idiotype (Id) protein chemically conjugated to keyhole limpet hemocyanin (KLH), a potent non-specific immunogenic protein Mitumprotimut-T induces a cellular and humoral immune response to the Id-protein expressed by the patient’s own tumor, leading to active immunization against the tumor while sparing normal B-cells Background Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

3. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Mitumprotimut-T is co-administered with Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF to further enhance anti-Id immune responses The Id protein is produced by proprietary recombinant technology; ~8 weeks from biopsy to final product Background Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

5. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy To compare the progression-free survival (PFS) in patients treated with Rituximab followed by mitumprotimut-T (Specifid™, Id-KLH, FavId®) and GM-CSF to historical data with rituximab alone To evaluate the safety of this combination regimen Objectives Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

6. Key Inclusion Criteria: – Histologically confirmed Grade 1 or 2 follicular B-cell lymphoma (WHO classification) – Treatment-naïve (T-N), relapsed/refractory (R/R) to chemotherapy, or relapsed following prior ≥ 6-month response to rituximab – ≥8 weeks between completion of any prior lymphoma therapy and start of rituximab on study – Measurable disease (≥2 cm) following node biopsy – Performance status (ECOG) of 0, 1 or 2 Methods Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

7. Key Exclusion Criteria: – >3 prior chemotherapy or anti-CD20 regimens – Prior fludarabine – Concurrent immunosuppressive therapy (e.g., high-dose steroids) Methods Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

8. Methods Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia. Treatment Regimen: Rituximab: 375 mg/m2 weekly infusion x 4 weeks. Subjects with stable disease (SD) or an objective response (CR or PR) to rituximab were eligible for mitumprotimut-T Mitumprotimut-T: 1 mg sc on Day 1 of each course. Courses administered monthly x6, bimonthly x6, and then every 3 months until disease progression or significant toxicity GM-CSF: 250 mcg/day sc on Days 1-4 of each course; same injection site as mitumprotimut-T CT scans: Obtained every 3 months; read by an independent radiologist blinded to clinical data

9. Study Schema and Treatment Regimen 0 3 6 912 15 18 21 24 Months CT Scans Mitumprotimut-T + GM-CSF Rituximab Mitumprotimut-T Production Biopsy Cytoreduction Induction Maintenance Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

10. Patient Characteristics at Study Entry CharacteristicN = 89 Age Median (range)53 (30 – 85) years Gender, n (%) Male 47 (53%) Female42 (47%) Follicular Lymphoma WHO Grade, n (%) Grade 147 (53%) Grade 238 (43%) Grade 32 (2%) Not reported2 (2%) Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

11. Patient Characteristics at Study Entry CharacteristicN = 89 Treatment History, n (%) Treatment-naïve (T-N)35 (39%) Relapsed/Refractory (R/R)54 (61%) No. of Prior Systemic Therapies (n = 54 R/R) Median (range)1.5 (1 – 4) FLIPI Risk Group, n (%) Low16 (18%) Intermediate26 (29%) High20 (23%) Not evaluable27 (30%) Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

12. Disease Response Assessment 27 patients (30%) had a response improvement during treatment with mitumprotimut-T + GM-CSF: 11 SD converted to PR, 1 SD converted to CR, 15 PR converted to CR. Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia. ~3 Months After Start Rituximab (Before Start of Mitumprotimut-T) Any Time After Start of Mitumprotimut-T + GM-CSF Overall N = 89 T-N N = 35 R/R N = 54 Overall N = 89 T-N N = 35 R/R N = 54 Complete Response 2 (2.2%) 02 (3.7%) 18 (20.2%) 9 (25.7%) 9 (16.7%) Partial Response 41 (46.1%) 24 (68.6%) 17 (31.5%) 37 (41.6%) 18 (51.4%) 19 (35.2%) Objective Response 42 (48.3%) 24 (68.6%) 19 (35.2%) 55 (61.8%) 27 (77.1%) 28 (51.9%) Stable Disease 43 (48.3%) 11 (31.4%) 32 (59.2%) 31 (34.8%) 8 (22.9%) 23 (42.6%) Progressive Disease ‡ 3 (3.4%) 03 (5.6%) 3 (3.4%) 03 (5.6%)

13. Time Course for Achievement of Complete Response Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia. Months From Rituximab Start Cumulative No. of Patients in CR Confirmation by a repeat CT scan was required to meet the criteria for a CR

14. Time to Achieving a Complete Response in Study FavId-04 and in Rituximab Alone Trials in Treatment-Naive Follicular NHL Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia. Cumulative % of Pts. in CR Author/ReferenceNo. of Pts. Total No. (%) of Pts. in CRBy Mo 3 From Mo 3 - 12 From Mo 12 - 33 Study FavId-04359 (26%)0%56%100% Witzig et al, J Clin Oncol 2005;23:1103 3613 (36%)92%100%N/A Colombat et al, Blood 2001;97:101 4920 (41%)65%100%N/A  In published single-agent rituximab trials all patients had achieved a CR by Month 12.  In Study FavId-04, 44% of the CRs were achieved between Month 12 and 33, suggesting an added effect of mitumprotimut-T + GM-CSF beyond of what is achieved with rituximab alone.

15. Progression-Free Survival for All Evaluable Patients (N=89) And for Patients Who Achieved a Complete Response (N=18) Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia. Median follow-up = 51 months (range, 47 – 62 months). Six of 18 (33%) subjects with CR have progressed and one (6%) withdrew from study in CR.

16. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Overall 18 of 89 (20.2%) patients treated with rituximab followed by mitumprotimut-T achieved a complete response (CR), including 26% of treatment-naïve patients and 17% of patients with relapsed-refractory disease Of the 18 confirmed CRs, 16 have occurred during the mitumprotimut-T + GM-CSF phase of the study Summary Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

17. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy Conversion to CR has occurred as late as 33 months from start of rituximab Achieving a CR is associated with prolonged disease-free survival; 11 of 18 (61%) of CR patients remain disease-free 47 to 62 months after start of rituximab therapy Most adverse events reported in the study were of severity Grade 1-2; the most common adverse event was injection site reaction (79.6% of patients) Summary Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

18. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy The occurrence of late CRs and the durability of these responses suggest added anti-tumor effect of active immunization with mitumprotimut-T + GM-CSF after rituximab cytoreduction than would be expected with single-agent rituximab therapy Conclusions Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.

19. Continued Late Conversion to Complete Remission and Durability of Remission in Patients with B-cell Follicular Lymphoma (FL) Treated with Rituximab Followed by Mitumprotimut-T Immunotherapy These findings are relevant when considering an ongoing Phase 3 registration trial where patients with follicular lymphoma randomized to receive mitumprotimut-T or placebo, both with GM-CSF, following cytoreduction with rituximab achieved a best CR rate of 47% in a blinded interim analysis (Freedman et al, Blood 2006;108:#2756.) Analysis of time to progression, the study primary efficacy endpoint, is expected in July 2008 Conclusions Omer K et al. Abstract #3427. Presented December 10, 2007, at the 49th ASH Annual Meeting in Atlanta, Georgia.