Mechanisms of action, indications, and dosing strategies are stated explicitly in the product labels in the provided sources. Mechanisms: EPKINLY and COLUMVI are described as CD20‑directed CD3 T‑cell engagers (bispecific) that redirect T cells to CD20‑expressing B cells ^[1][3]. ELREXFIO and LYNOZYFIC are described as bispecific BCMA‑directed CD3 T‑cell engagers for multiple myeloma ^[4][5]. RYBREVANT is described as a bispecific antibody directed against the EGF receptor and the MET receptor ^[2]. Indications: EPKINLY is indicated for relapsed or refractory DLBCL and high‑grade B‑cell lymphoma after two or more lines of systemic therapy and for relapsed or refractory FL as monotherapy or in combination with lenalidomide and rituximab in specified settings ^[1]. COLUMVI is indicated for relapsed or refractory DLBCL, NOS, or LBCL arising from FL after two or more systemic therapy lines ^[3]. ELREXFIO and LYNOZYFIC are indicated for relapsed or refractory multiple myeloma following at least four prior lines including specified agents, with accelerated approvals based on response rate and durability of response ^[4][5]. RYBREVANT’s indications cover multiple regimens in EGFR‑mutant NSCLC, including first‑line combination with lazertinib for EGFR exon 19 deletions or exon 21 L858R substitution mutations, combination with carboplatin and pemetrexed in certain settings, and single‑agent use in EGFR exon 20 insertion mutations in previously treated patients, with selection based on FDA‑approved testing ^[2].

Dosing and administration details are explicit in the labels and differ by agent and indication. EPKINLY is for subcutaneous injection and uses a step‑up dosing schedule with specified step doses and a full dose of 48 mg on defined Cycle days for DLBCL/high‑grade B‑cell lymphoma and for FL monotherapy or in combination; details include step‑up doses of 0.16 mg and 0.8 mg in Cycle 1 and a first full dose of 48 mg on Cycle 1 Day 15 for DLBCL and Day 22 for FL, with ongoing 48 mg dosing on specified cycle days and schedules ^[1]. Clinicians should consult current prescribing information for full dosing guidance. COLUMVI is administered intravenously after pretreatment with a single 1,000 mg obinutuzumab infusion 7 days before initiation; the COLUMVI step‑up schedule is 2.5 mg on Cycle 1 Day 8, 10 mg on Cycle 1 Day 15, then 30 mg on Day 1 of Cycles 2 to 12 with cycle length 21 days and hospitalization requirements around step‑up dosing ^[3]. ELREXFIO dosing is subcutaneous with a step‑up schedule of 12 mg Day 1, 32 mg Day 4, and first treatment dose 76 mg Day 8, then weekly 76 mg through week 24 followed by transition to every‑2‑week and then every‑4‑week schedules in responders, with specified hospitalization recommendations for the first step‑up doses ^[4]. LYNOZYFIC is given as intravenous infusions with a step‑up schedule of 5 mg Day 1, 25 mg Day 8, and 200 mg Day 15 followed by weekly 200 mg dosing, then biweekly and every‑4‑week options for responders, with hospitalization after early step‑up doses ^[5]. RYBREVANT dosing is weight‑based and intravenous, with weekly dosing in early weeks followed by every‑2‑week or every‑3‑week schedules depending on combination, and avec split infusions for initial doses in certain regimens; the label specifies exact mg doses by baseline weight and regimen ^[2].

Regulatory context and approval basis: multiple labels explicitly state accelerated approval for hematologic malignancy indications based on response rate and durability of response and note that continued approval may be contingent on confirmatory trials ^[1][3][4][5]. Several labels emphasize that administration should be performed by qualified healthcare professionals with immediate access to appropriate medical support due to risks such as CRS and neurologic toxicity ^{[1][3][4][5][2]}.