Warren Chow, MD
Hematology & Oncology · Orange, CANPI 1093822017
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $7,329 of the $8,991 with a category attached, or 81.5%. GSK accounts for 88.8% of it on its own, with 7 other manufacturers making up the rest. Reporting peaked in 2019 at $8,002 and has fallen 93.4% since, to $531 in 2025.
Across 25 payments — averaging $359.62 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- GSK$8K
- Boston Scientific$282
- Inari Medical, Inc.$233
- W. L. Gore & Associates, Inc.$229
- Balt USA, LLC$209
- Shockwave Medical, Inc$19
- plus $33 from 2 others
Across 77 payments — averaging $16,385 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- E.r. Squibb & Sons, L.L.C.$625K
- GSK$222K
- Hexal AG$171K
- AstraZeneca$90K
- Amgen$78K
- Epizyme, Inc.$40K
- plus $36K from 3 others
What the payments were for
- Consulting fees$7,32982%
- Travel & lodging$2222%
- Food & beverage$1,44016%
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| GSK | 7 | $7,984 |
| Boston Scientific | 10 | $282 |
| Inari Medical, Inc. | 1 | $233 |
| W. L. Gore & Associates, Inc. | 2 | $229 |
| Balt USA, LLC | 2 | $209 |
| Shockwave Medical, Inc | 1 | $19 |
| Amgen | 1 | $18 |
| Abbott | 1 | $15 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
How this compares
$8,991 in reported general payments places this provider in the 65th percentile of 1,363 hematology & oncology providers in California.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| BraftoviEncorafenib | 19 | $296,904 |
| MektoviBinimetinib | 19 | $224,676 |
| MekinistTrametinib Dimethyl Sulfoxide | 12 | $167,853 |
| TafinlarDabrafenib Mesylate | 12 | $154,599 |
| Imatinib Mesylate | 30 | $2,600 |
| Levothyroxine Sodium | 22 | $277 |
| Prochlorperazine Maleate | 12 | $122 |
| Olanzapine | 19 | $88 |
| Dexamethasone | 18 | $73 |
| Ondansetron OdtOndansetron | 11 | $72 |
| Ondansetron Hcl | 12 | $63 |
| Prednisone | 16 | $23 |
Paid to pharmacies, not to this prescriber.
Other hematology & oncology in Orange
- Catherine CoombsOrange$786K
- Arash Rezazadeh KalebastyOrange$516K
- Misako NagasakaOrange$507K
- Elizabeth BremOrange$335K
- May ChoOrange$334K
- Angela FleischmanOrange$255K
- Dennis SlamonLos Angeles$3.1M
- Sandra HorningStanford$2.5M
- Mohammadbagher ZiariCorona$2.5M
- George YaghmourLos Angeles$1.9M
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.