XML 23 R5.htm IDEA: XBRL DOCUMENT
v3.20.1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands | Total | Series C Convertible Preferred Stock [Member] | Convertible Preferred Stock [Member] | Convertible Preferred Stock [Member] Series B And C Convertible Preferred Stock | Convertible Preferred Stock [Member] Series B Convertible Preferred Stock [Member] | Convertible Preferred Stock [Member] Series C Convertible Preferred Stock [Member] | Common Stock [Member] | Common Stock [Member] Series B And C Convertible Preferred Stock | Common Stock [Member] Series B Convertible Preferred Stock [Member] | Common Stock [Member] Series C Convertible Preferred Stock [Member] | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member] Series C Convertible Preferred Stock [Member] | Accumulated Other Comprehensive Income [Member] | Accumulated Deficit [Member]
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Balance at Dec. 31, 2017 | $ 13,000 |  |  |  |  |  |  |  |  |  | $ 413,362 |  | $ 1,387 | $ (401,749)
Balance (in shares) at Dec. 31, 2017 |  |  | 2,431 |  |  |  | 115,651 |  |  |  |  |  |  |
Share-based compensation | 355 |  |  |  |  |  |  |  |  |  | 355 |  |  |
Sale/Issuance of common stock | 1,624 | $ 3,041 |  |  |  |  |  |  |  |  | 1,624 | $ 3,041 |  |
Sale/Issuance of common stock (in shares) |  |  |  |  |  | 6,723 | 92,169 |  |  |  |  |  |  |
Conversion of Convertible Preferred Stock into common stock |  | 8 |  |  |  |  |  |  |  |  |  | 8 |  |
Conversion of Convertible Preferred Stock into common stock (share) |  |  |  |  | (1,320) | (3,228) |  |  | 7,921 | 80,868 |  |  |  |
Beneficial conversion feature related to Series C Convertible Preferred Stock |  | 2,487 |  |  |  |  |  |  |  |  |  | 2,487 |  |
Accretion of beneficial conversion feature related to Series C Convertible Preferred Stock |  | (2,487) |  |  |  |  |  |  |  |  |  | (2,487) |  |
Foreign currency translation adjustment and accumulated other comprehensive income | (169) |  |  |  |  |  |  |  |  |  |  |  | (169) |
Net loss | (12,634) |  |  |  |  |  |  |  |  |  |  |  |  | (12,634)
Balance at Dec. 31, 2018 | $ 5,225 |  |  |  |  |  |  |  |  |  | 418,390 |  | 1,218 | (414,383)
Balance (in shares) at Dec. 31, 2018 | 296,609 |  | 4,606 |  |  |  | 296,609 |  |  |  |  |  |  |
Share-based compensation | $ 127 |  |  |  |  |  |  |  |  |  | 127 |  |  |
Sale of common stock and pre-funded warrants, net of offering costs | 4,421 |  |  |  |  |  | $ 4 |  |  |  | 4,417 |  |  |
Sale of common stock and pre-funded warrants, net of offering costs (in shares) |  |  |  |  |  |  | 3,000,000 |  |  |  |  |  |  |
Sale/Issuance of common stock | 2,208 |  |  |  |  |  |  |  |  |  | 2,208 |  |  |
Sale/Issuance of common stock (in shares) |  |  |  |  |  |  | 184,666 |  |  |  |  |  |  |
Conversion of Convertible Preferred Stock into common stock (share) |  |  |  | (2,647) |  |  |  | 334,199 |  |  |  |  |  |
Exercise of warrants | 490 |  |  |  |  |  |  |  |  |  | 490 |  |  |
Exercise of warrants (in shares) |  |  |  |  |  |  | 65,114 |  |  |  |  |  |  |
Warrant derivative liability reclasssifiedto equity due to exercise of warrants | 794 |  |  |  |  |  |  |  |  |  | 794 |  |  |
Beneficial conversion feature related to Series C Convertible Preferred Stock |  | 554 |  |  |  |  |  |  |  |  |  | 554 |  |
Accretion of beneficial conversion feature related to Series C Convertible Preferred Stock |  | $ (554) |  |  |  |  |  |  |  |  |  | $ (554) |  |
Foreign currency translation adjustment and accumulated other comprehensive income | (1,218) |  |  |  |  |  |  |  |  |  |  |  | $ (1,218) |
Net loss | (10,887) |  |  |  |  |  |  |  |  |  |  |  |  | (10,887)
Balance at Dec. 31, 2019 | $ 1,160 |  |  |  |  |  | $ 4 |  |  |  | $ 426,426 |  |  | $ (425,270)
Balance (in shares) at Dec. 31, 2019 | 3,880,588 |  | 1,959 |  |  |  | 3,880,588 |  |  |  |  |  |  |

X
- Definition Represents the information pertains to accretion of value due to beneficial conversion feature. + References No definition available. + Details
Name: | pstv_AccretionOfBeneficialConversionFeatureValueConvertibleInstruments
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Beneficial conversion feature related to preferred stock. + References No definition available. + Details
Name: | pstv_BeneficialConversionFeatureRelatedToPreferredStock
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Foreign currency translation adjustment and accumulated other comprehensive income loss. + References No definition available. + Details
Name: | pstv_ForeignCurrencyTranslationAdjustmentAndAccumulatedOtherComprehensiveIncomeLoss
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Prefunded stock issued during period shares sale net common. + References No definition available. + Details
Name: | pstv_PrefundedStockIssuedDuringPeriodSharesSaleNetCommon
Namespace Prefix: | pstv_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Prefunded stock warrants issued during period value sale net common. + References No definition available. + Details
Name: | pstv_PrefundedStockWarrantsIssuedDuringPeriodValueSaleNetCommon
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reclassification of warrants from derivative liabilities to additional paid in capital. + References No definition available. + Details
Name: | pstv_ReclassificationOfWarrantsFromDerivativeLiabilitiesToAdditionalPaidInCapital
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Stock issued during period shares warrants exercise. + References No definition available. + Details
Name: | pstv_StockIssuedDuringPeriodSharesWarrantsExercise
Namespace Prefix: | pstv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Stock issued during period shares warrants exercise(shares). + References No definition available. + Details
Name: | pstv_StockIssuedDuringPeriodSharesWarrantsExerciseShares
Namespace Prefix: | pstv_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 20 -Section 55 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=118258462&loc=d3e11149-113907 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 20 -Section 55 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=118258462&loc=d3e11178-113907 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116855982&loc=d3e4534-113899 + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of shares issued during the period as a result of the conversion of convertible securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-30) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The gross value of stock issued during the period upon the conversion of convertible securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(31)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(30)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockholdersEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant