A Phase 1b/2 Study of CAR T Cell Therapy Targeting CD19 and BCMA in Participants With Relapsed or Refractory AL Amyloidosis.

Inclusion Criteria:

* Confirmed histopathological diagnosis of AL amyloidosis
* One or more organs currently or historically impacted by AL amyloidosis according to consensus guidelines
* Measurable hematologic disease: dFLC \> 20 mg/L or serum M-protein \> 5g/L
* Relapsed or refractory disease with a need for additional therapy after at least 1 line of anti-plasma cell-directed therapy.
* ECOG performance status of 0 to 2
* Must be able and willing to adhere to the study visit schedule and other protocol requirements
* Women of child-bearing potential (WCBP) must have a negative serum and/or urine pregnancy test result prior to treatment. All sexually active WCBP and all sexually active male subjects must agree to use highly effective methods of birth control throughout the study.

Exclusion Criteria:

* Have any other form of amyloidosis other than AL amyloidosis
* Mayo Stage IIIb AL amyloidosis
* Oxygen saturation \< 95% on room air
* Systolic blood pressure \<100mmHg
* NYHA class III or IV
* Extensive GI involvement with evidence of active GI bleeding/risk of bleeding as determined by Investigator
* Prior therapies:

  1. CAR T cell therapy directed at any target
  2. Prior BCMA-targeting therapy
  3. Prior treatment with any FDA approved or investigational T cell engaging therapies (including T cell-directed bispecific or trispecific therapies) at any target within the last 6 months.
* Toxicity from previous anti-cancer or anti-PC-directed therapy did not resolve to baseline levels or to Grade 1 or less except for alopecia or peripheral neuropathy.
* Active plasma cell leukemia at the time of screening
* Symptomatic multiple myeloma (defined as clonal bone marrow plasma cells ≥10% plus at least one myeloma-defining event per IMWG 2014)