Lack of efficacy

Recent reports have identified a specific oncogenic mutation L265P of the MYD88 gene in approximately 90% of the patients with Waldenström's macroglobulinemia. MYD88 is a key linker protein in the signaling pathway of Toll Like Receptors (TLRs) 7, 8, and 9, and IMO-8400 is an oligonucleotide specifically designed to inhibit TLRs 7,8, and 9. The scientific hypothesis for use of IMO-8400 to treat patients with Waldenström's macroglobulinemia depends on the inhibition of mutant MYD88 signaling in the TLR pathway, thereby interrupting the proliferation of cell populations responsible for the propagation of the disease.

Eligible subjects will be enrolled and assigned to escalating dose cohorts. Treatment will be administered by subcutaneous injection.

Inclusion Criteria:

Patients must have a diagnosis of relapsed Waldenstrom's Macroglobulinemia.

In addition to the above, key inclusion and exclusion criteria are listed below.

Inclusion Criteria:

1. At least 18 years of age.
2. Agree to use contraception
3. Hemoglobin ≥ 7.5 g/dL, - Absolute neutrophil count ≥ 1.0 x 109/L (1000/mm3), - Platelets ≥ 50,000/μL

Exclusion Criteria:

1. Is nursing or pregnant
2. Has BMI > 34.9 kg/m2.
3. Has a positive test for human immunodeficiency virus (HIV-1 or -2) hepatitis C virus (HCV) or hepatitis B surface antigen (HBsAg).
4. Receiving chronic systemic corticosteroid therapy > 20 mg of prednisone daily.
5. Being treated with other anti-cancer therapies (approved or investigational).
6. Has, at the initiation of study drug, received cytotoxic chemotherapy or a Bruton's tyrosine kinase (BTK)-inhibitor (e.g. ibrutinib) within the past 3 weeks or rituximab within the past 2 months
7. Has an active infection requiring systemic antibiotics.
8. Has had surgery requiring general anesthesia within 4 weeks of starting the study.
9. Has autoimmune cytopenia (anemia, thrombocytopenia, leukopenia).
10. Has heart failure of Class III or IV.
11. Has sensory or motor neuropathy limiting daily activities.

The Idera staff in collaboration with the Investigator will be responsible for writing presentations and manuscripts for publication. Investigators will not be allowed to publish or present the data from this study without prior agreement with Idera.