PDC-1421 · program

PDC-1421 for Major depressive disorder

Phase 2CompletedABVC BioPharma, Inc. (ABVC)

Indications for PDC-1421: Major depressive disorder · Phase 2 Attention-deficit/hyperactivity disorder · Phase 2

PDC-1421 (ABV-1504), an oral botanical Radix Polygalae extract described by its sponsor as a norepinephrine reuptake inhibitor, for major depressive disorder. A Phase 1 single-dose escalation study in 30 healthy volunteers in Taiwan (2012-2013) found doses up to 3,800 mg safe. The FDA cleared the Phase 2 IND in March 2014. The Phase 2 study (NCT02395978, BLI-1005-002; Stanford and four Taiwanese sites) randomized 60 adults with moderate-to-severe MDD to 380 mg or 760 mg three times daily or placebo for 6 weeks, after a 12-patient open-label Part I. ABVC reported in 2019 that the high dose met the pre-specified primary endpoint, a 13.2-point MADRS reduction vs 9.2 on placebo. However, the primary analysis posted on ClinicalTrials.gov, a three-arm Kruskal-Wallis test, gives p=0.393, and the low dose did not separate from placebo. ABVC lists the program as Phase II completed and says it will use the high dose in Phase III, which it intends to out-license rather than run itself. No Phase 3 trial has been registered. A related Phase I/II study in depression among cancer patients (ABV-1601, NCT03833206, Cedars-Sinai) is registered but not yet recruiting.

Data current as of

Development timeline

Phase 2Apr 2015 – Feb 2028
  1. UpcomingClinicalTrials.gov estimated primary completion of the Phase I/II PDC-1421 (ABV-1601) study in depression in cancer patients: February 2028
  2. Licensing dealABVC and BioLite license MDD and ADHD rights for PDC-1421 to AiBtl BioPharma↗
  3. mixedPhase 2 PDC-1421 (ABV-1504) in MDD: sponsor reports the high dose met its primary endpoint (MADRS -13.2 vs -9.2 placebo, ITT); the registry-posted Week-6 primary analysis is p=0.393↗
  4. Phase 2 MDD study completed (CT.gov study completion date). The sponsor announced results on 2019-05-23, claiming the high dose met its primary endpoint; the registry-posted primary analysis is p=0.393. The 10-Q gives 2019-10-31 as the Phase II completion date.
  5. Trial (portion) completedPhase 2 study of PDC-1421 in major depressive disorder completed
  6. Phase 2 MDD study NCT02395978 (BLI-1005-002) started, after US FDA Phase 2 IND clearance in March 2014 and Taiwan FDA clearance in June 2014.
Phase 1Nov 2012
  1. First subject visit in the Phase 1 single-dose escalation study in healthy volunteers at Taipei Veterans General Hospital (NCT01774045); 30 enrolled, last visit 2013-07-05.↗

Readouts

  • February 2028AnticipatedRegistry resultsNCT03833206

    ClinicalTrials.gov estimated primary completion of the Phase I/II PDC-1421 (ABV-1601) study in depression in cancer patients: February 2028

  • 2019-05-23ReportedFull resultsmixedNCT02395978

    Phase 2 PDC-1421 (ABV-1504) in MDD: sponsor reports the high dose met its primary endpoint (MADRS -13.2 vs -9.2 placebo, ITT); the registry-posted Week-6 primary analysis is p=0.393 ↗

Clinical trials in Major depressive disorder

NCT03833206ABV-1601-001Phase 1/2Recruitingn=12

A Phase I/II Study of PDC-1421 for Treating Depression in Cancer Patients: Part I Dose Escalation

Started Jan 2027· Primary completion Feb 2028· 📍 1 site across 1 country (United States)

NCT02395978BLI-1005-002Phase 2Completedn=72

A Phase II Study of PDC-1421 Capsule to Evaluate the Safety and Efficacy in Patients With Major Depressive Disorder

Started Apr 2015· Primary completion Mar 2019· 📍 5 sites across 2 countries (Taiwan, United States)

mixedprimaryChange in MADRS total score from baseline to Week 6 vs placebo (Part II) — ITT (n=21/19/20): high dose (2 capsules TID) -13.19 (SD 9.68), low dose (1 capsule + 1 placebo TID) -9.21 (SD 8.32), placebo -9.2 (SD 7.98). Per-protocol (n=15/15/14): -13.4, -10.4, -8.6. (p=0.393 (Kruskal-Wallis across all three arms, as posted on ClinicalTrials.gov))

Mixed. The sponsor states the high dose met the pre-specified primary endpoint, a 13.2-point MADRS reduction vs 9.2 on placebo (ITT, averaged over the 6-week treatment period). The statistical analysis posted to ClinicalTrials.gov for the Week-6 primary measure is a three-arm Kruskal-Wallis test with p=0.393, and the low dose did not separate from placebo. Small study: 60 randomized in Part II, plus 12 in an open-label Part I. No serious adverse events were reported by the sponsor.

NCT01774045Phase 1Completedn=30

A Dose Escalation Phase I Study of PDC-1421 Capsule to Evaluate the Safety in Healthy Volunteers

Started Nov 2012· Primary completion Jul 2013· 📍 1 site across 1 country (Taiwan)

metprimaryDose-limiting toxicities (physical exam, ECG, vital signs, laboratory values, C-SSRS) after single oral doses of 1, 3, 6 or 10 capsules (380-3,800 mg) — 0 dose-limiting toxicities in PDC-1421 and placebo groups on every registered primary measure

Single doses up to 3,800 mg were safe and well tolerated in 30 healthy volunteers in Taiwan, with no dose-limiting toxicities and no suicidal ideation or behavior reported.

Formulations

FormulationRouteRegimenPharmacokinetics
PDC-1421 oral capsule (380 mg Radix Polygalae extract)
Capsule containing 380 mg PDC-1421 extract. Phase 1: single doses of 1, 3, 6 or 10 capsules (380-3,800 mg) after a meal. Phase 2 MDD and ADHD studies: 1 capsule (low dose, 380 mg) or 2 capsules (high dose, 760 mg) three times daily after meals; 28-day (Part I) to 42-day (MDD Part II) or 56-day (ADHD Part II) treatment periods. Placebo capsules contained corn starch.
OralThree times daily—

Mechanism of action (compound-wide)

Mechanism as described by the sponsor: a botanical norepinephrine reuptake inhibitor. In radioligand-binding assays run in 2007, the extract inhibited the norepinephrine transporter with an IC50 of 2.102 micrograms/mL, with weaker activity at the dopamine and serotonin transporters. Because the test article is a multi-component plant extract, this is not a molecular binding constant, and no single active constituent or independent peer-reviewed confirmation of the mechanism was found.

TargetActionAffinity
NETprimarySLC6A2Reuptake inhibitor—ⓘ

← Full PDC-1421 compound page (identity, identifiers, all indications)

Sources

  1. ABVC BioPharma, Inc. Form 10-K for fiscal year 2025 (filed 2026-03-03) — U.S. Securities and Exchange Commission (EDGAR)
  2. ABVC BioPharma, Inc. Form 10-Q for the quarter ended 2026-06-30 (filed 2026-08-12) — U.S. Securities and Exchange Commission (EDGAR)
  3. NCT01774045 - A Dose Escalation Phase I Study of PDC-1421 Capsule to Evaluate the Safety in Healthy Volunteers (results posted) — ClinicalTrials.gov (U.S. National Library of Medicine)
  4. NCT02395978 (BLI-1005-002) - A Phase II Study of PDC-1421 Capsule to Evaluate the Safety and Efficacy in Patients With Major Depressive Disorder (results posted) — ClinicalTrials.gov (U.S. National Library of Medicine)
  5. NCT03833206 (ABV-1601-001) - A Phase I/II Study of PDC-1421 for Treating Depression in Cancer Patients: Part I Dose Escalation — ClinicalTrials.gov (U.S. National Library of Medicine)