What are the considerations for using Razumab (generic name not specified) in treatment?

Razumab Use in Clinical Practice

Primary Indication and Drug Identity

Razumab is a biosimilar ranibizumab approved for intravitreal use in ophthalmologic conditions, NOT to be confused with bevacizumab (which has oncology indications). 1 The FDA label confirms Razumab is indicated for metastatic colorectal cancer, non-squamous non-small cell lung cancer, recurrent glioblastoma, metastatic renal cell carcinoma, cervical cancer, and ovarian cancer when administered intravenously. 1 However, the research evidence demonstrates Razumab is primarily used as an intravitreal biosimilar ranibizumab for retinal disorders. 2, 3

Approved Ophthalmologic Indications

Wet Age-Related Macular Degeneration (AMD)

• Razumab demonstrates significant improvements in visual acuity with mean BCVA improvement of 8.8-9.2 letters at 24 weeks. 3
• Central retinal thickness reduces by approximately 125 μm from baseline. 3
• 97.6% of patients lose fewer than 15 letters at 24 weeks, with 31-32% gaining ≥15 letters. 3
• Long-term data shows sustained BCVA improvement from baseline (0.92 ± 0.6) to week 48 (0.51 ± 0.4, P = 0.0014). 2
• Central subfield thickness decreases significantly from 430.83 ± 14.4 μm to 301.26 ± 11.6 μm at 48 weeks (P < 0.0001). 2

Retinal Vein Occlusion (RVO)

• For both branch RVO and central RVO, Razumab produces significant BCVA improvements starting at week 8 (0.55 ± 0.02) through week 12 (0.47 ± 0.02, P < 0.0001). 4
• Central macular thickness decreases from 447.60 ± 10.91 μm at baseline to 298.23 ± 6.68 μm at week 12 (P < 0.0001). 4
• Long-term effectiveness maintained through 48 weeks with BCVA improving from 0.89 ± 0.06 to 0.41 ± 0.08. 5
• Intraretinal fluid resolves in 70% of patients by week 12, and subretinal fluid resolves in 75% by week 12. 4

Retinopathy of Prematurity (ROP)

• Razumab (0.25 mg/0.025 ml intravitreal) is effective for stage 3+ ROP in zone 1, zone 2 posterior, or aggressive posterior ROP. 6
• Complete resolution with full vascularization occurs in 19% of eyes at median 55 days post-injection. 6
• Recurrent neovascularization peaks at 7 weeks (21% cumulative incidence), significantly higher in APROP eyes (43%) versus non-APROP (13.4%, P < 0.001). 6
• Critical monitoring point: Re-evaluate at 7 weeks post-injection for recurrence, particularly in APROP cases. 6

Dosing Regimens

Standard Intravitreal Dosing

• Wet AMD: 0.5 mg intravitreal every 4 weeks for initial 6 months, then transition to PRN (pro re nata) regimen. 3
• RVO: PRN dosing with median of 3 injections (range 1-5) over treatment course. 4, 5
• ROP: 0.25 mg/0.025 ml intravitreal as monotherapy, with retreatment for recurrent neovascularization. 6

Treatment Duration Considerations

• Majority of patients (74.8% in AMD, 79.21% in RVO) are treatment-naïve at initiation. 2, 5
• PRN regimens require monthly monitoring until complete retinal vascularization achieved. 6
• If incomplete vascularization without recurrence, supplement with laser photocoagulation to residual avascular retina. 6

Safety Profile

Ocular Adverse Events

• Most common ocular AE is increased intraocular pressure (4 events per 126 patients, 3.2%). 3
• IOP changes are minimal and non-significant across all indications (baseline 14.92 ± 3.2 mmHg vs week 48 14.50 ± 2.1 mmHg, P = 0.9068). 2
• No serious ocular adverse events reported in prospective studies. 3

Systemic Adverse Events

• Most common non-ocular AE is pyrexia (5 events per 126 patients, 4.0%). 3
• 78.9% of all adverse events are mild in severity. 3
• One death occurred unrelated to study drug. 3
• No discontinuations due to adverse events in clinical studies. 3

Immunogenicity

• Anti-ranibizumab antibodies present in 7.9% pre-treatment and 7.1% post-treatment, with no clinically significant immunogenicity-related adverse events. 3

Critical Monitoring Parameters

Visual Acuity Assessment

• Measure BCVA using Snellen's or logMAR chart at weeks 4,8,12,16,20,24,30,36, and 48. 2, 5
• Success defined as losing fewer than 15 letters from baseline. 3

Anatomic Outcomes

• Monitor central subfield thickness or central retinal thickness via OCT at each visit. 2, 3
• Assess for presence/resolution of intraretinal fluid and subretinal fluid. 2, 4
• Track proportions: IRF decreases from 70.63% to 30% by week 12 in RVO; SRF decreases from 65.63% to 24.38%. 4

Intraocular Pressure

• Check IOP at each visit, though significant changes are rare. 2, 3

Contraindications and Precautions

From FDA Label (IV Formulation)

• Gastrointestinal perforations and fistulae risk. 1
• Surgery and wound healing complications—discontinue at least 28 days before elective surgery. 1
• Hemorrhage, arterial thromboembolic events, and venous thromboembolic events. 1
• Hypertension and posterior reversible encephalopathy syndrome. 1
• Renal injury and proteinuria. 1
• Embryo-fetal toxicity—avoid in pregnancy. 1

Ophthalmologic-Specific Precautions

• Monitor for endophthalmitis following intravitreal injection (standard sterile technique mandatory). 3
• Assess for retinal detachment or increased IOP immediately post-injection. 3

Patient Selection Algorithm

For Wet AMD

1. Age ≥50 years with BCVA between 20/40 and 20/320. 3
2. Confirmed choroidal neovascularization on OCT/angiography. 3
3. Initiate with monthly 0.5 mg injections for 6 months. 3
4. Transition to PRN based on disease activity (fluid on OCT, vision decline). 2

For RVO (Branch or Central)

1. Confirm RVO diagnosis with macular edema on OCT. 4, 5
2. Initiate PRN regimen with minimum 3 loading doses. 4
3. Re-inject based on persistent/recurrent macular edema or vision decline. 5
4. Continue monthly monitoring until CMT normalizes and fluid resolves. 5

For ROP

1. Stage 3+ disease in zone 1 or zone 2 posterior, or APROP. 6
2. Single 0.25 mg/0.025 ml intravitreal injection. 6
3. Mandatory re-evaluation at 7 weeks for recurrence (highest risk period). 6
4. Retreat with razumab if recurrent neovascularization; add laser if incomplete vascularization without recurrence. 6

Common Pitfalls to Avoid

• Do not confuse Razumab (biosimilar ranibizumab for ophthalmology) with bevacizumab (oncology anti-VEGF). 1, 2
• Do not delay retreatment in ROP beyond 7 weeks if recurrence occurs—this is the peak recurrence window. 6
• Do not use fixed monthly dosing indefinitely in RVO—transition to PRN after loading phase to minimize injection burden. 4, 5
• Do not skip OCT monitoring—anatomic response (CSFT, IRF, SRF) guides retreatment decisions more reliably than vision alone. 2, 3
• Do not assume immunogenicity is clinically significant—antibody presence does not correlate with adverse events or reduced efficacy. 3